I Sherlock'd My Dead Big Block Chevy and Found Out Why It Broke!

Summary

The video details the process of diagnosing issues with a 632 cubic inch big block Chevy drag boat engine that failed during racing. After tearing down the engine and inspecting the parts, evidence of metal-to-metal contact between the exhaust valves and pistons is discovered, likely causing bearing failure. Measurements confirm lack of proper piston to valve clearance. The engine issues stem from a rushed rebuild prior to competition where clearances were not properly checked. The rebuild compromised power, reliability and ultimately caused catastrophic failure. While rebuilding again is possible, a different engine will likely go into the boat for the next race season.

Takeaways

• 😟 The 632 cubic inch big block Chevy engine broke at a drag boat race event last year, so Cleetus is finally tearing it down to diagnose the failure
• 😞 There were ongoing valve train issues with the heads that were never fully resolved, likely causing component failures
• 🤔 The crank, rods, and pistons were replaced when converting the engine for nitrous, but clearances seem to be incorrect
• 😟 Bearing damage indicates debris circulated through the engine, wearing down components prematurely
• 😟 Evidence suggests exhaust valves were contacting the pistons, damaging both
• 😔 All of the exhaust valves are bent from contact with pistons and guides are damaged
• ☹️ The lightweight NA parts were never meant for the rigors of nitrous and are now compromised
• 😕 Proper clearances are critical, the installed parts had insufficient piston to valve clearance
• 😐 The engine builder is talented but time pressures led to overlooked measurements
• 🙂 Despite engine issues, Cleetus still had fun racing with friends and learned a lot diagnosing failures

Q & A

What type of engine is being worked on in the video?

A 632 cubic inch big block Chevy engine.

What happened to the engine that caused it to break at the drag boat race?

The engine dropped a valve which caused it to lock up and break.

What mods were done to the engine to prepare it for nitrous?

It got a new crank, rods, and pistons.

What issue was discovered when disassembling the engine?

There was evidence of the exhaust valves contacting the pistons due to insufficient piston to valve clearance.

How did the lack of piston to valve clearance manifest itself?

There were circular wear marks on the pistons that matched marks on the exhaust valves.

What other issues were found with the engine?

The crankshaft bearings showed uneven wear indicating a possible issue with the crank flexing or taper in the journals.

What will need to be replaced to fix the engine?

The valves, pistons, and possibly the crank will need replacement. The cylinder heads may also need work.

Why did the engine builder miss the clearance issue originally?

He was in a hurry and didn't have time to check all the clearances before assembly.

What was done to measure the existing piston to valve clearance?

The engine was reassembled with lightweight checking springs and the clearances were measured with a dial indicator.

What engine will go in the boat next instead of rebuilding this one?

A proven reliable engine built by Sonny already sitting in the boat will likely be used next.

Outlines

00:00

😀 Preliminary inspection of the broken engine

The video host inspects the disassembled 632 cubic inch big block Chevy drag boat engine that broke at a race last year. He expresses excitement to rebuild it, noting the corrosion damage from water exposure at the race track.

05:01

🌊 The engine's racing history and previous issues

The host outlines the engine's past - originally built by Jim Guthy, raced successfully by Joola Camp to a championship win, then sold to the current owner. It has had recurring issues like broken valves and leaking cylinder heads that have been repaired multiple times.

10:02

🔧 Preparing to disassemble and inspect the engine

To diagnose the recurring issues, the host begins disassembling the engine by removing accessories like the tunnel ram intake manifold. He points out grounding issues with the nitrous system wiring and improper head bolt torque procedures.

15:03

🤔 Assessing damage from the last failure

With the heads removed, the host finds significant damage from the last failure including bent valves, damaged guides, debris in the cylinders. He suspects incorrectly reassembled rocker arms caused valvetrain issues.

20:05

🔬 Inspecting the bottom end parts

The host removes the oil pan, crankshaft, pistons and connecting rods to inspect the bottom end components. He finds some detonation damage and improperly gapped piston rings among other issues.

25:06

🚣 Measuring crankshaft journals to check for taper

Using a micrometer, the host carefully measures the crankshaft main and rod journals at different points to check for taper. Finding none, he rules out the crank flexing as the cause of the bearing damage.

30:09

💡 Discovering evidence of piston-to-valve contact

Noticing odd wear marks on the pistons matching those on the valves, the host determines that inadequate piston-to-valve clearance led to contact between the exhaust valves and pistons.

35:10

🤯 Explaining the piston skirt dents

The host further discovers multiple pistons have dented skirts from hitting the crank counterweights during assembly. This caused even tighter clearances and more valvetrain issues.

40:25

🔍 Investigating piston deck height

They measure how far the piston is protruding from the cylinder bore and use check springs to manually activate the valves and physically check piston-to-valve clearances.

45:27

😔 Bent valves confirm the diagnosis

Putting the valves in a lathe, the host finds they are significantly bent, confirming intermittent contact with the pistons led to the failures. Major repairs are required before the engine can race again.

Keywords

💡engine

The main theme of the video is diagnosing and repairing an engine for a jet boat. The engine is a 632 cubic inch big block Chevy that was built for racing. It broke at a drag boat competition so the narrator is taking it apart to figure out why it failed.

💡bearings

Engine bearings are parts that allow smooth rotation between moving engine components. The video shows that the bearings in the engine's crankshaft are badly worn, indicating a problem.

💡detonation

Detonation refers to abnormal combustion in an engine, which can cause damage. The narrator and mechanics suspect detonation may have caused the engine's bearings to fail, but find no evidence of it.

💡pistons

Pistons are engine components that move up and down to transfer force from combustion to the crankshaft. The video finds that the new pistons installed in the engine were hitting the crankshaft.

💡valves

Valves control airflow into the engine's cylinders. The narrator discovers exhaust valves repeatedly hit the pistons, damaging both components.

💡clearance

Clearance refers to the gap between moving engine components. Insufficient piston-to-valve clearance caused parts to hit each other and fail in this engine.

💡rebuild

To rebuild an engine means to disassemble, inspect, replace damaged parts, and reassemble it. The video shows the narrator beginning the rebuild process to diagnose and fix the broken engine.

💡crankshaft

The crankshaft is a key engine component that converts piston motion into rotational motion. The video investigates whether crankshaft issues could have caused bearing wear.

💡damage

Physical damage to engine parts from contact and overstressing is shown throughout the video. Identifying and understanding this damage is key to diagnosing the failure.

💡diagnosis

The overall process of systematically testing components and deducing root causes of failure is engine diagnosis. The video illustrates this through the disassembly and inspection of the damaged engine.

Highlights

The motor locked up at the drag racing finals last year, so it's finally being torn down to diagnose the failure

The crank, rods, and pistons were recently changed to run nitrous, but it ended up slower and unreliable

Found evidence of the exhaust valves repeatedly hitting the pistons, causing damage

Swirl marks on the pistons match machine marks on the exhaust valves

The exhaust valve guides are damaged from the valves bending when hitting pistons

Going to measure the actual piston to valve clearance to understand what's enough

Putting in lightweight "checker" valve springs so the valves can be manually operated

At 10 degrees before TDC, the exhaust valve is still closing as the piston comes up

Measured only 0.125" piston to exhaust valve clearance, seems tight given the damage

The intake valves likely were also hitting pistons, based on marks in those areas

Took the valves out and put them in a lathe - confirmed they are bent from hitting pistons

The valve train may have lacked control, letting valves bounce into pistons at high RPM

Will be repairing with increased piston to valve clearances to prevent future failure

For now, will run a spare motor instead of rebuilding this one due to the extensive repairs needed

Hope the engine builder doesn't get upset, this is meant as an educational breakdown of what went wrong

Transcripts

it took two days of measuring parts for

this 632 cubic inch big block Chevy but

I finally know why this thing broke at

the World Finals of dragboat racing last

year and right about now this big block

Chevy is making the Hemi and that b air

looked damn nice and

reliable that still runs this uh not so

much and I don't know if I'm fixing it

anytime soon watch

[Applause]

this

[Applause]

[Music]

I don't know why I'm so excited to see a

motor that I know is broken I know why

cuz I was at Ace Racing Engines two days

ago measuring bearing clearances on an

LS motor and I forgot how much fun it

was to build Motors we're going to work

on this one

ourselves if my skills with a drill are

any indication yeah you're you turn

wrenches and not not building a

house shout out to Andy RS at RS

precision machine for cading up the 632

big block Chevy we broke World Finals

after uh I believe I said it was five

passes it broke I think it was six well

this will be interesting because I

bought the boat complete and the motor

was fresh when I bought it but I didn't

know exactly what parts were in it I had

the motor rebuilt these are the parts

that came out of it so now we get to

find out you know what was in it to

begin with these parts were all set up

for this motor to be naturally aspirated

so they're lighter stuff yeah look how

corroded everything is from being in

Firebird which is the equivalent of

saltwater Wild Horse Pass that track

used to be called Firebird so we all

still call it firebird and it just

corrodes everything anything that gets

wet Firebird again though oh yeah they

changed the name again didn't they yep

back to Firebird back to

firebird and this is the original tunnel

ram off that motor that engine loved

this tunnel ram with these long Runners

and it did not like this tunnel ram with

these shorter Runners and I'm sure there

was a way to tune around that but this

thing was down like 500 RPM at wide open

throttle all that changed were piston

rods and crank same displacement little

less compression it was down over 100

horsepower so something was unhappy

about

it like brand new not even not even

scuffed let's see if we can figure out

what kind of Crank out of this thing

4750 racing crank the rest of it's gone

that's the stroke you can see where it

had a lot of malerie shoved into it to

balance it so whoevers it was gone I

wonder if it's a Bryant it's had a ton

of work to it look how thin the

counterweights are and look how long

they are because of how big the stroke

is this is the 632 combo is an

interesting combo it's 4 and 3/4 stroke

and I believe it's 4600 bore and I don't

know I'm not a huge fan of that

particular combo however when this was

actually aspirated that boat ran really

well all right we don't know what it is

but it's a damn nice looking crank

that's a beautiful crank and I believe

this stuff should be CP pistons and

cillo connecting rocks I'm almost

positive Brian Morland designed these

way back in the day for DOA camp and

this is what was put in this

motor and I think what we're going to

see if these are them is short

compression

height wrist pin up in the oil ring like

real thin Pro Stock looking oh yeah look

at that look how short this piston is

wow look at that the oil ring it's got a

support rail cuz it's the wrist pin is

up into the oil ring look how small the

wrist pin is I was just going to say

that is a small wrist pin this is one of

the reasons we couldn't put nitrous to

this thing first off there's not much

meat between the top of the Piston

especially in the valve relief area so

there's the exhaust valve relief this is

the intake valve relief there's not much

material between the top ring and that

so that's no good for nitrous then the

wrist pin is really small and light if

you threw nitrous at this it's going to

flex these rods are also really light

like if you look at how deep this

channel is yeah that channel there that

channel there the meat of that Rod is

probably a/ inch wide this is

lightweight naturally aspirated Go Fast

Pro Stock looking stuff so that means if

that thing didn't get honed where it had

a ton of piss in the wall clearance with

this this could go back together na it

would be a drag deal it used to make

like allegedly 1250 horsepower Na and uh

and it ran good when it wasn't breaking

valve springs that's the other thing is

I would love to know why did it have so

many valve train

problems so then the next thing to do is

uh pull the intake and the carbs off

pull the heads off and find out did it

screw up a piston that'll be an

interesting thing because it ran crappy

all weekend it was not fast right but

the night before it broke when I was in

the pits we checked the valve springs we

checked the valve lash the push rods

were all in one piece it wasn't broken

it just didn't run good and then I made

a hit sounded fine just wasn't fast

drove it off the lake put it on the

trailer drove it into the pits and we

started doing a compression check

and that's when the motor locked up and

so it had no compression we were about

to pull the valve cover and I hit the

button a few more times and then the

motor locked up so the push rod broke

somewhere driving it to the ramp I guess

and then the valve broke when we were

rolling it over so maybe we get lucky

the one thing that tells me we might we

might not get lucky is I've had another

motor it was actually blast me we had

something on top of the piston in the

cylinder just hit the start button and

it went went up there and pinched it and

it was enough to Dent the Piston Dent

the valve seat basically the head had to

come off and get welded it's possible

that piston and that head and you work

but I don't know we'll take it apart and

find out this is what happens in a

working garage with you know leaves

blowing in when the doors open and so

now we got that off the floor we'll blow

it out then we'll take motor carburetor

off these are gen 3 Holly dominators

that have had a good bit of work done to

them by John Morland at C&J engineering

that's why they're not for sale cuz John

is in my opinion one of the best carb

guys on the planet I hope he never

retires it do it down don't wor it

didn't go inside coming apart but I'd

still like to not not drop things in the

M possible unfortunately these are

stainless washers I can't use a magnet

to get them off I got to lift it and

hopefully not drop them peek down you

can see the plenum

bars yeah that's the second stage of

nitrous that we never hit never used it

thank God I think we would have been in

a lot more trouble

yeah yeah the first stage didn't work

great the second stage would have

probably not made it better no we can uh

disconnect Nitrous system and fuel

regulators and then unbolt the tunnel

ram and get the tunnel ram off we're

taking off the manifold bolts which are

a really nice ARP stainless 12 point um

and we're taking note of how the bolts

are now this bolt really tight this one

that had the ground wires going to the

nitrous solenoids snug but not tight and

one of the things I don't like I was

talking about I don't like it when

people ground nitrenoids or ignition

coils to bolts in the intake manifold or

the valve cover because that bolt goes

into the valley right that bolt has

thread sealant on it because it's going

into the valley it's not a blind bolt so

now you're just relying on the ring

terminal up against the washer and the

flange of the intake for a ground Source

well that flange of that intake is on a

gasket so how good is your ground path

really I say it sucks and so uh when the

boat goes back together I don't know if

it'll have nitrous on it or not but it

damn sure won't be grounded to the

intake manifold like that not into it

yeah see there's the bolt that just came

out of there with stuff all over the

threads the other thing I want you guys

to pay attention to is you can see how

oblong the ring terminal

is it's going to fail at some point

because what happens is the washer the

bolt head or you know maybe maybe prior

to this install it didn't have a washer

on it but the bolt head grabs it tries

to spin the ring terminal and then

Oblongs it and you do that enough times

and eventually the ring terminal fails

this is sketchy cuz it's such a thin

plate I don't I don't want to bend it

you

know almost like it's hitting a wall in

there definitely got all the bullets

right

yes

okay there we go just shifted Beauty yay

intake is off let's give the complete

history of this motor as I understand it

guy named Jim guthy built this motor it

was raced by joola Camp successfully as

far as I understand he won a

championship with it I'm not exactly

sure what happened but it broke at some

point dropped a valve I think when I

bought it it was fresh that's what it

was advertised as and I didn't know it

had been wounded I just heard it was

Fresh So after the fact I found out it

had broke and one of the heads had to

get fixed I think by Joey gross of gross

Racing Engines who's fantastic engine

builder so we get it it's fresh go to

the first race it's just got problems

from sitting around you know wiring is

not happy the data system's not happy

there's a bunch of corroded stuff hoses

were junk and it broke some valve

springs and it Milkshake the oil the

very first race I ever went to and so

after that it went back to the engine

builder Mike Miller it was not the

original engine builder but he was he he

had he had refreshed this thing and it

was at that point he was like when I

refreshed it I never changed the Val

Springs cuz they were new so when I took

it back to him it got new valve springs

so seemingly our valve train issues

should have been solved except they

weren't after that we had problems with

it's still milkshaking it's self which

ultimately we figured out at one of the

races it was a paracity problem in the

cylinder head over over there we had a

rocker arm just break had an adjuster to

shove right through the back of the

rocker arm and well when we started

diagnosing why that happened it was

because the rocker stand was loose like

all right well that's weird so we check

them all tighten them all up fig that

problem's gone and then after that it

was just stupid stuff you know we we

decided to go to World Finals and we

decided we didn't have enough in the bag

to be competitive in any of the classes

at World Finals not the 6C bracket class

not the heads up Eight Mile class none

of them so you know we said to Mike can

we go through this thing and put pistons

in it and Rings cuz we know we're not

going to be able to spray any nitrous

into this motor it's got lightweight

Parts in it and he says yeah and it this

was like in August World Finals were in

November and right before World Finals

when he goes to put it together he

realizes that the new Pistons the skirt

hit the counterweights of the crank and

it was like oh crap at that point it

became a mad thrash to hurry up and find

a crank for this because you can't get

Pistons quickly so he finds a crank gets

it balanced a lot of people helped with

transporting it and machining it and all

this stuff it goes together and then it

goes on the dyno at West Tech

performance and I get a phone call from

Steve brle who's running the dyno and

he's frantic he's like the motor's

running hot and The Rocker stands keep

coming coming loose like one by one

they're coming loose the end results of

the dyno test was the motor was down on

power but everybody agreed it was

probably fine let's go race it and we

went and raced it and it lasted like six

passes I think I think at the time I

thought five but it was six basically it

didn't make any power it didn't go fast

and it dropped a valve but now today

we're ripping it apart to figure out why

the motor the entire time I've owned it

has always had something wrong with it

and so I would love to either just fix

it and sell it or fix it and be sure

nothing's wrong with it and we'll put it

in something I just don't know what I

don't know if it's going to go back into

the boat I I'll be honest with you this

motor took the fun out of drag booat

racing real fast for me in the beginning

it was very fun I I let the problems go

I was like whatever it is the boat sat

around fine whatever I'm here with my

friends we're having fun the first few

races were really fun and we won a

couple of races in this boat we kicked

butt which was fun while having problems

with this motor we were winning and in

the end we you know Joe and I were

really looking forward to going to World

Finals we hadn't been in like 15 or 20

years we were fired up about it and that

deal was fun because of who we were with

and where we were at the

racing you know by the time we left we

went you know what we're just going to

take matters in our own hands we're not

going to show up anymore hope things are

right according to I think Mike Miller

it got new valves because I think before

before I got it you know before I bought

it m and the reason the motor was out of

the boat was I think it had dropped a

valve and hurt the head so I believe the

head got repaired and the valves got

replaced but the old Springs got put

back on because they only had a couple

Laps on them and those were the springs

that we were breaking when I bought the

boat so these valves were new but now

that I found out that on the dyno all

the Rockers came loose and The Rocker

stands came loose dude there's no way

I'm going to run these valves again cuz

look what look what just happened you

know we broke one now is the lifter

you're stuck no that's good news so this

is the side that we had a problem

with and this is the side that basically

push rod tip broke off it happened

somewhere between pretty much the launch

ramp and the pit cuz I drove the boat in

and it sounded just fine I made I made

my pass it wasn't fast I drove the boat

put it on the trailer everything was

fine went to the pits started looking at

the data and we're like it's just slow

it's unbelievably slow and I started

questioning the motor and so we go to do

a compression check and we get to number

three and it has zero compression pull

the valve cover off that's when we see

the push rods broke in half go to roll

the motor over and it locks up and

because the head of the valve broke off

so if you look through the number three

exhaust port and I'll give you some

light here Joe so you can show them that

if you look in

here the head of the

valve is sideways it should not be there

you should see the back side of the

valve you shouldn't be seeing the face

of the valve maximum air flow right

there yes and if you look at the guide

there's a chunk of the guide missing

right yeah well if you come over here

this one's doing the same there's a

chunk of that guide missing let's go

look at the other

ones um that one seems okay how about

that one that one looks all right let's

go to the other side because I'm

starting to

wonder did it Bend valves when it was on

the dyo looks all right looks all right

all right so at a minimum we've got one

over there where the guide is broke so

look at this right here right see the

chunk out of the side of this yeah this

is probably one one of the ones that

came loose on the dyno it beat the snot

out of the rocker arm it broke the guide

the valves probably bent and that's why

this thing wasn't making the power it

should have made on the dyno I think I

think the motor was wounded before we

ever ran it at uh World Finals which

sucks but what do you you going to do

well let's take it all apart that's

racing is it

really it I don't know I don't know but

we're going to make the best of we're

going to fix this we're going to make it

right I don't know I feel like we should

fix it and make it better than it was

and put it back in the boat and run it

if that becomes not fun this is a great

motor if we can get rid of the valve

train issues yeah it really is maybe

Pete can get rid of the valve train

issues the big thing for me is do these

heads even go back on because they need

rockers they need valves I don't know

we've had nothing but problems with this

valve train do we even put these back on

good news is it didn't didn't stick the

lifter in the bushing so that's great

news the thing I wonder about is this is

the one that failed how many other bent

valves do we have from when those rocker

stands came loose on the dyno that's

kind of what I want to find out today

and for those of you are at home that

know the history of this motor there's

the part where the head got welded by

Andy RWS after I bought it it was

leaking we tried to fix it with what we

use JB Weld in fact the JB Weld top

secer JB Weld topset JB Weld got us

through two races that we won and then

finally it just started leaking again so

Mike Miller pulled the head off Andy

rolls welded it put it back in service

hasn't leaked since in fact the oil

looks great next thing to do is we will

we can't roll the motor over so have to

be careful when we do this but we'll

take all the Rockers off take all the

push rods out put them in that organizer

and then we'll pull the heads off and

see how screwed up this head is from

where the valve broke off cuz I'm pretty

sure the chamber is going to be beat up

the seat might be broke and then I want

to disassemble both heads to see do we

have any other bent Valves and if we do

we'll go see Pete and then I don't know

does it go back in the boat the Sunny's

motor is already sitting in the boat you

know it just needs headers it just needs

headers and and new computer system or

just a carburetor true like if you put

EFI on it yeah that's a big process but

if you just throw a dominator on it it

has a front drive distributor like this

motor it's sitting in a box we could run

it na that might be the quickest way

back on the water cuz who knows how long

it'll take to fix this thing if you're

ever wondering whether your lifters are

on the base circle of the cam which is

when you want to check for valve lash

when you want to test your Springs if

you have the intake off it's super easy

you can see it so like this one is open

cuz it's up this one is closed cuz it's

down these ones obviously aren't on

anything right now but you can see

that's the base circle of the cam if you

look over here here we'll come to this

one this one is on the base circle of

the cam cuz it's down this one is on the

lobe cuz it's up and if you come up to

the cylinder head side so that's open

the valve you look here The Rocker is

down the valve is open you look at this

one it has lash you can lift it up and

down and if you come down and follow it

that's down it's on the base circle of

the cam and if you look that's the base

circle of the camam there there the one

next to it that I said was open you can

see it's it's on a lobe the lobe is up

and if the intake is on the easiest way

to do this is you just look at the

rocker arms and you can tell whether

it's open or closed um I like to use the

EO I meth method which is if the exhaust

is opening like as soon as it starts to

open then you know the intake is on the

base circle like a big block Chevy and

you can check that one and then IC

intake closing intake opens all the way

up it's closing once you get about

halfway the intake is closing the

exhaust will be on the base Circle

you'll feel lash in it you can check

that one time to pull the head bolts and

then the heads on uh aftermarket big

block

Chevys a lot of

them will have bosses in the valley that

you can put another set of head bolts in

these D big Chiefs have the provisions

for these so instead of the bolt going

into the block this comes up from the

Block into the head this side's

threaded and I don't remember off top of

my head what the torque spec is for

these but these were not amazingly tight

I just grabbed it with my allen wrench

and undid it pretty

easily I I don't remember if it's a 38

or a 7/16 bolt I to look it up when we

put it back together what it's supposed

to

be but long story short you got to get

these four

out then pull the head bolts off then

the heads come

off that one there yeah and then uh and

I don't know why but we have different

Hardware over here this is a socket head

Allen and

then this

is what's

that I don't know what that is a smaller

socket head I don't know why we got two

different sets of Hardware in here it's

weird crap out of that piston not as bad

as I thought it was going to be though

bad not

what is that what's on that one is that

a ding too kind of looks like it looks

like something went in there it's too

bad we didn't have a spare piston for

this motor so far it looks

like the cylinder's okay but yeah it

looks like something hit that one too

it's got a couple of little dents right

there yeah and something right there

it's possible a piece from that one W up

over there went back through the intake

but unlikely but Poss

there's this chunk a little bit of

shrapnel floating around in the lifter

Valley there let's go look at the head

see the head got

[Music]

trashed oh yeah yeah valve seats junk

it's into the heads probably going have

to be welded too that's a bomber those

are big intakes yeah those look like

2450s or maybe even bigger going to go

have to see Pete probably take both

heads and all the valves fix these and

either put it back together or fix these

and sell these and try something

different what are you thinking I don't

know edel Brock has symmetrical Port

deal that supposedly avoids some of the

issues you have with a spread Port deal

offset cup lifters and rocker arms and

right you know you have like when you

put one of these together you end up

with if you look at some of these intake

ports

you end up with some of the hardware

going into the intake PS see right there

that's where that's where a headbolt

breaks into the intake Port you have to

seal the headbolt when you install it

and I believe some of these

issues aren't present with a symetrical

port head but I don't know I've never

used one before the spread Port stuff

flows good it's just it's older

technology like this is all based on Pro

Stock stuff from 30 years ago that's

been changed you know valve angles have

changed

it's a nice set of heads these are dark

big chees allegedly poured by Curtis

bugs they they made great power but we

have not had the reliability with them

so horsepower is awesome but not if it's

temporary yeah they've been a major pain

in our butt yep I don't believe this is

related at all to the cylinder head I

think this was somebody blew it series

of events The Rocker st came loose and

then the push rods fatigued and next

thing you know you have that you know

the question is if we repair this and

make sure the rocker stands are tight

and get the valve Springs right do we

make great power and it lasts or do we

just keep finding new problems there's

the cutter marks where it swiped across

the deck and decked it and that's one of

the roughest decks I've ever seen for an

MLs gasket and maybe that's why the

coating is sprayed on it is maybe that's

the only way to get it to seal but I

don't know most Motors I've ever seen

use an MLs gaset the deck is very very

smooth this is weird and it's worse on

this end than that is this end this end

is much smoother this the first Rod cap

we took out I don't see any signs of

detonation I see you know some trash

went through the coating that's the

streaks but there's no pits there's no

the bearing doesn't look deformed for as

much as we struggled spraying nitrous on

this thing and not going fast we didn't

rattle at least this first piston did

not get rattled that's good

news and it felt like it felt like the

Rings sprung

apart all right so again I don't have

any paperwork on the motor and so I

don't know what the ring gaps were like

originally but if you look the top Ring

The Gap is much smaller than the second

one it doesn't feel like it has a ton of

tension it's possible these are low

tension Rings or it's possible this one

got hot I don't know we'll pull the rest

of them out and see what they look like

and then we can always put the ring in

the boore and measure the gap of what it

is when it's in the boore this side of

the bearing that's interesting

I think the bearings recoded but if you

look it looks like it's starting

something scratched it something went

through it into the next layer of metal

I don't know what the second layer of

metal is in there but see how it's like

kind of a gold color yeah that's

interesting okay looks okay though let's

look at the next one there yeah same

thing this bearing if you look at the

very edge of the bearing yeah you can

see a little bit of the

gold

yeah check the clear is for

sure how's that look same thing it's

down into I don't know if that's copper

or what it is but it's down into that as

far as our ring gaps there's the top one

second one ought to be on the opposite

side and it is the second one's much

bigger now there are there are engine

builders that run the second ring bigger

than the top ring as far as the Gap

again I don't any paperwork I don't know

what this was set to we could call Mike

and ask him cuz I don't know

that bearing stayed in the

rod oh that's

interesting so this is the one we had a

problem with right there's the dent the

top ring Gap is right there the number

two ring in gap should be about 180°

away from it yeah it's right there the

reason you separate them by 180° is so

whatever gases get through this Gap

don't just easily find their way through

the second one so did that one somehow

rotate that one looks okay about the

same so this one's way over here yeah so

there's the top ring 180° out is the

second ring these are scuffed pretty

good for a a brand new motor but maybe

that's I mean it's a tall deck block but

maybe that's indicative of a giant

stroke side loading the 632s they they

they do complain about the side loadad

into the cylinder wall got to be it

right I don't know it's my first one

that's what we'll tell everybody it's my

story I'm sticking to it man you don't

even know you don't know about SI 454

guys you don't even know what's up I

know you can have your chop how's your

side load

yeah got chop I got side load I'll be

wearing out piston skirts every three

seasons yeah

that they don't have that on the edge

one of them didn't but I'm just sitting

here wondering these journals all got

tapered in them or without the nitrous

this thing was down 500

RPM from where oh wow that doesn't want

to come out is it rocked in there

[Music]

somehow you got I'm going to tap it tap

this side over here you got the ring out

on one side not the other okay you

catching it

yep

okay's coming with it okay got it oh

this one's more unhappy than the other

ones it's really copper looking here and

then it looks kind of like Heat going

that direction or it's wearing this way

where is our ring gaps on this one I

didn't look did you see them 180 wow so

so far it's this

one that one looks better except for

this monster scratch right there I

thought it was like a hair but it's not

catch your fingernail on that oh that is

weird weird it's like a it's a scratch

going this direction and you can catch

your fingernail on it huh what is

that these were coated bearings you can

see it at the Pary line but it took the

coating off of these things that didn't

last very

long second one is

there top one is

here far enough not 180 this looks like

a DLC coated wrist

pin two more

see it's darker here and it gets lighter

lighter lighter it didn't get into the

copper but we should measure these

journals feel like they're tapered for

that all that coating to be gone already

it's like a bunch of trash went through

the motor like it was something was

wearing or it was dirty when it went

together one or the

other number seven all right second ring

is here top ring

is here like 45° part that's weird all

right second ring

there top ring

wow it's

weird this is like 45° apart on this

one but

like this so were like almost 180 this

one's about 180 which is where I would

do it this one's

180 this one's like 45

45

45 this was less than 45 now timing

cover needs to come off Main Cap's off

crank out at that point we're done all

right cam shaft coming out I have no

idea what cam this is but it's got to

have a ton of duration and lift to

support you know 11 1200 is naturally

aspirated horsepower hopefully there's

some numbers on it that we can decipher

and call someone to find out cuz I'm

going to guess this has probably

295 270 degrees of duration um but as

far as how much valve lift it's a NY all

right they make good cams and we have

all the numbers we need off of this yeah

we can call isy give them all these

numbers they can tell us what we have

for a cam all right now that the Cam's

out uh we can pull the main caps off

pull the crank out and then we can start

comparing the old parts to the new

parts all right Joe broke loose all the

nut nuts for the main caps and now we're

looking at the main bearings definitely

had trash go through it yeah nothing too

severe but it's definitely had some

trash this is all brand new so yeah

these have I don't know whatever half

hour of dinno time and six laps on them

you can see the scratches in it there's

a pretty good one right there but this

is from debris going through the oil

system and most new engines after you

build them you'll have debris in the oil

system from parts betting in or if you

just didn't do a good job of cleaning

the parts or having a clean environment

when you build the engine it's part of

the reason we swept this place out is

any dirt that ends up inside the engine

goes into the oil and then gets sent

through the oil system and you got to

remember the gap between that bearing

and that

journal let's just say most Racing

Engines like a big block Chevy that

people build it's somewhere around 3,000

of an inch so you're

talking Micron siiz particles Scrat

scratching the coating off the bearing

this wasn't going to fail or anything

it's just you know like you said you can

see that trash went through it I didn't

see any signs of detonation on that

though so that's good news I didn't see

any if nothing else we didn't go fast

but we didn't detonate the motor either

right that's good news it's wild this

engine turned the exact same RPM with

nitrous that it turned when it was

naturally aspirated before personally I

think you know we had a

really really

really fat nitrous tuneup

could be why it was shooting ducks yeah

the the other thing that's interesting

is is I was talking to Josh Patridge

who's good friends with the original

engine builder of this engine and the

guy that used to own the boat Joe the

camp and he told me that uh this thing

was turning 73 7400 RPM and the boat was

running 560s 550s yeah before I got it

never ran that close we've never turned

more than 7,000 when it was naturally

aspirated so it was definitely down on

power like when I bought it from where

it was according to Josh I just talks to

him that's not the cam that was in this

motor originally yeah and looking too

looks like one and two when I unwrap

these old rods the Pistons are marked

but the rods aren't marked like all the

other ones so I'm wondering if the rods

Rod get replaced yeah maybe those two

did did it break a rod or did it break

you know a lifter and or drop a valve

and it ended up I bet what happened what

I understand about this motor is it was

originally built made over, 1300

horsepower won a championship ran for a

season or two it dropped a valve which

is probably why a piston and Rod got

changed or two of them it's probably why

they're not marked and then when it got

refreshed I'm guessing the cam got

changed and it's never made the power it

made before since yeah so it might be

worth looking into if we can find it out

what were the old cam specs lamp ran

lamp ran this thing and won and I don't

I've never heard of him having the

problems we've been having with this

thing you know maybe we go back to some

of the old combination and it makes more

power and lives longer if we even use it

that Sunny's motor is already in the

boat I say we run it and at some point

this goes back together and then the

question is do we run it na a or do we

run it on the bottle if we could rebuild

it and make over 1300 na this thing

would run pretty hard you know even

without nitrous I mean it ran hard when

it was na when we erased it it ran hard

we ran 131 132 mph so we'll get this out

compared to the the old crank we have

the old Pistons we have the old rods we

have the old Crank that came out of this

motor which was not broken we can

eyeball those parts compare them to what

we have and maybe we replace the cam and

the valve train and just put the old

bottom end back in it and see what she

does so now this one looks like it's

been detonated see that right there it

smashed something as it was going

through it oh yeah and this one is

really unhappy Jesus it's down into the

other layer there it wiped the coating

out unevenly wow okay this thing's not

happy that looks like a good crank

though I don't know why it would be

flexing oh

Jesus and that one's really bad too wow

it's wiped this half of the bearing it's

got deep scratches in it wow either the

cranks flexing or there's taper in the

journal or tap taper in the lion hone or

the clearances weren't happy now I'm

really glad we're taking this apart if

we were at the track and we found a

valve and replaced it and just kept

going and spraying it that would have

been bad and the reason I say it would

be bad is cuz unlike a car in a jet boat

if something goes wrong and the motor

locks up you can't just push the clutch

in and pull to the side you can't just

step on the brakes you don't have any of

that in the boat if the motor locks up

the jet drive stops spinning all the

water that's coming into the jet drive

from under the boat has nowhere to go

and basically front of the boat comes

smashing down into the water and you get

thrown out of the boat and it's not good

what I would like to do is if you go

back to this is the number four for main

bearing I would like to measure the

journal on that left to right and see if

there's taper in it cuz if you look at

this that looks brand new right there

and it's all scratched over here that's

brand new that's brand new it's all worn

here and this is worn then this is the

same on this side this one's worn here

here so either the line hone is messed

up or the journal has taper in it or the

crank is really flexing which we're not

making tons of power I'd be surprised if

this crank was flexing like that we

weren't even spraying it hard oh the

journals are scratched up in this thing

wow yeah look at the difference between

these two cranks uh on your right this

is the crank that just came out of our

632 on your left is the crank that came

out of this motor last fall when it was

rebuilt for

nitrous and what I was told by the

engine builder was that the counter

weights on this crank were so large that

the Pistons and rods he ordered from CP

cillo wouldn't fit because the skirt of

the Piston was actually contacting the

counterweight of the crank so here's a

quick comparison of our old piston old

crank new piston new crank now if you

look they are wildly different parts

um this has the the new piston has a

longer skirt so you can see why that was

going to be an issue it has a thicker

area up here the compression height is

taller the Rod is beefier you can look

at this Rod it is very light compared to

this one thicker wall wrist pin larger

wrist pin everything about this says

nitrous you know beat the snot out of

this this is lightweight na horsepower

type Parts really lightweight stuff and

then when you come over to our cranks

I'm not sure but I think this is a sunny

Bryant crank shaft um you can't really

tell because it got balanced where the

name was I believe this one here is a

Callie's the thing that I'm bothered

about this Callie's crank is that it

looks like it never got polished if you

look at all these journals especially

the mains sure they trash went through

them for sure but if you look at the

journals on the old crank this crank has

been run for years we ran it for an

entire season and it's beautiful this I

I'm questioning whether once it was

sized all these journals did it ever get

polished I I don't even know but yeah

it's interesting but we definitely when

you move over here we definitely have a

problem with either the crank flexing

and trying to take out the number uh

three and four main bearings or there's

taper in these journals or the line hone

in the block is off I don't know when

when you start looking at this old crank

like I'm going to compare this one here

to this one that wear is pretty even

from here to here yeah it looks really

good to my eyeball whereas this wear

looks brand new on this side and wore

out on this side which is what you see

on the bearing the only thing we can do

here at my house in my garage is we can

grab a micrometer and measure these

journals in a couple places and see if

we can find taper there we could pull

the bearings out of the block and torque

the Caps back on and we could check the

line hone um at least journal to journal

I can do that with a dial board gauge

short of that there's not much I can do

here with my knowledge base remember I'm

not a professional engine builder nor am

I a machinist I don't have any tools to

repair this stuff so I'm I'm an engine

assembler I can do that I've done that

pretty successfully in the past we can

build this engine once the machine work

is you know happy and the parts are

happy so I think our next step will be

we'll put the crank up on the bench grab

the mics measure it and see if there's

taper in it um if there's not taper in

it I'll assume guessing that number one

exhaust valve has an issue since the

guide is busted those are probably the

last few things we do with this and then

at that you know it's just okay look at

all the parts we got some point we'll

put it all back

together just not today Satan not

today

all right everybody at home this is an

outside micrometer this is what I used

to measure the

crankshaft I've got it set up in a pair

of soft Jaws lightly clamped in my Vise

so as not to twist this thing as best I

can keep in mind I am not a machinist

but I learned a few things like how to

read this thing this is the thimble this

is the sleeve this line right here is

the line that we use to read the numbers

and we start down here with zero so if

we thread this all the way in to zero we

are lined up right there now as I open

the jaw and we move this one 2 3 four

five 6 7 8 9 10 15

20 when I get back to zero I've exposed

the first line that's 25,000 of an inch

if I keep going we're at

45,000 zero again there's two lines

showing

50,000

75,000 100,000 then you're going to see

the number one appear right there so

essentially what's in the Jaws right now

is 100,000 of an inch thick now if you

keep going we'll just we'll just pick a

a random number over here a random thing

to measure this thing is is 200,000 of

an inch plus

2550 plus three we're not quite to four

so we're

253,000 not quite four so then we got to

move over here and what we do is we look

right here on the sleeve until we get a

line here that perfectly lines up over

here and in this case we're at

253,000

plus 4 so if you were to write that on

piece of paper it would be decimal

2534 and that's essentially how you read

this thing and this is the tool we used

to measure the main journals on our

crankshaft and figure out there was no

taper there that's not why our bearings

got taken out in our engine block it's

the next day I'm dressed differently

obviously today's going to be a good day

cuz we are about to learn a whole lot

together now if you recall yesterday

when we were tearing this motor apart we

didn't have a good reason why the

bearings look the way they did this is

what I'm talking about this is the

number four main bearing this is the

number three main bearing they are just

wiped out and oddly enough it's the

bottom half of the main right this is

the cap bolts onto the block this is the

bottom half this is where a lot of

pressure is present on the crankshaft

pushing down at all times cylinder

pressure but when you detonate something

you have even more and when you

physically have Parts hitting each other

pistons and valves you have even more I

think I'm pretty sure what we have going

on is metalo metal contact between the

exhaust valves and our pistons and I'm

going to show you why let's go through

the sequence of events race the boat

last November right before the race the

motor got rebuilt for nitrous it got a

new crank new rods new pistons on the

dyno which I wasn't there for I just

heard secondhand The Rocker stands were

coming loose on these cylinder heads the

dart big Chiefs and it was chocked up to

them needing Loctite which in hindsight

I've had spread Port style heads before

on engines I've owned I've never had to

locktite The Rocker stands to keep them

tight it's kind of odd yesterday we were

looking at all the bearings and I I

thought maybe the crank had taper and it

measured that the crank did not have

taper I didn't have a good reason for

why the bearings were wearing so I

started calling people I talked to Joey

gross who facilitated the crank getting

machined and ground and Polished he

verified that yeah it's all scratched up

cuz metal went through it but it was

polished I said okay I talked to Steve

Brule I talked to of West Tech

performance and bounc some ideas I had

off of him I talked to Mike Miller the

guy who built the motor Mike's opinion

was the bearings look like the motor had

detonated I thought to myself when we

were racing the whole weekend Mike

myself Joe everyone in our pit was

looking at the spark plugs constantly

because the boat just kept getting

slower at no point did I ever see any

sign on those spark plugs of the motor

detonating we would have seen aluminum

particles on the porcelain of the Piston

we didn't see see that we would have

seen peppering you know brown spots from

the fuel on the porcelain we weren't

seeing that nothing about this said this

thing's detonating and yet it was

getting slower almost every pass in

hindsight I wish we had cut the oil

filter open because we probably would

have realized the motor was eating

itself alive and we probably could have

stopped running it before the you know

exhaust valve on number three broke in

half but we didn't it's neither here nor

there so after talking to all these guys

yesterday I came back in the garage last

night and really started staring at the

combustion Chambers in the cylinder

heads and the Pistons I stopped looking

at bearings and started looking for a

cause for why the bearings looked the

way they looked and one of the things I

noticed was and this is the number one

piston out of this motor I started

seeing stuff on the Piston that didn't

make any sense to me on the Piston

there's swirl marks in the valve Rel Lea

for the exhaust valve and I thought to

myself okay that's weird cuz it doesn't

have it on the intake valve relief and

and I thought are those machine marks

well I don't know if it's machined in a

circular pattern there then this relief

would have it as well and it doesn't so

then I went to the cylinder head the

intake valve looks brand new you can see

the word manly written right on it and

there's no swirl mark But if you go to

the exhaust valve almost every one of

these there is a perfect machine Circle

in the middle of the exhaust valve that

matches the circle that's in the top of

the piston and the same circular swirl

marks now I got to call Manley real

quick but I'm pretty sure when I do if

they send me a picture of one of their

valves it's going to look a lot like the

intake valve it's going to look smooth

it's not going to look like it has swirl

marks and so once I noticed those two

things I started thinking you know these

valves rotate as they're going up and

down opening and closing I think the

exhaust valve is hitting the piston and

that's why you have the same mark on the

Piston that you do on the valve I took

it a step further

I called my buddy Brian uh at CP pistons

and said I need a picture of the Piston

before you know right after he got

machined before it was installed and

sure enough it looks a lot like it does

now except it doesn't have those swirl

marks in it and I said all right I'm on

to something so then I took bottles of

water and started filling the exhaust

ports and they're leaking the valves are

not seated anymore which tells me

they're probably bent and they're

probably bent because I think while the

engine was running those valves were

touching the Pistons over and over and

over again and they were spinning which

is what put the pattern in there and the

real Telltale here is if you put the

piston this is the number one piston

next to the number one chamber if you

put them next to each

other that pattern looks an awful lot

like that pattern right twinsies right

and I just so happen to have all the

Pistons out of this motor from when it

was naturally aspirated if you put it in

there this is the number one

piston you don't have that there's no

swirl pattern there's no circular mark

this does not match which tells me that

when the crank rods and pistons got

changed in this motor it didn't have

enough piston to valve clearance now

there's something else going on here

every one of these intake valve Pockets

has witness marks on them and the odds

of debris going through the motor and

landing in the intake valve pocket on

every piston and the exact in the exact

same spot is pretty slim so I'm thinking

we might also not have enough piston the

valve clearance on the intake valve I

don't think it's as bad as it was the

exhaust I mean clearly we broke an

exhaust valve in half the intake might

be an issue as well my synopsis here my

reason for why this motor ate itself

alive is that it was never happy after

it got rebuilt we had Pistons kissing

valves at 7,000 RPM but I am going to

learn something here what we're about to

do now is put the crank back in the

motor put the number one piston back in

put the head on with some lightweight

Springs and we're going to measure the

Piston the valve clearance and we're

going to find out with a steel rod and a

titanium valve in this motor how much is

enough cuz whatever we have here is not

enough piston valve clearance and once

we know that info then we know going

forward okay if we ever put this thing

back together we need deeper valve

reliefs in these Pistons or the Pistons

need to be moved down in the boore

something has to change about this

because if you if you just replace all

the same parts that are in it put it

back together it's going to die again

I'm actually surprised it lasted six

laps like this is wild to me what

started this whole thing is I had all

these Pistons sitting on my workbench

and I started staring at them and I'm

like I don't understand why these

bearings are getting wasted and I

noticed I think four or five of these

Pistons have a dent a chunk taken out of

the skirt where it's been hitting

something if you look right

here this surface and then boom right

there you can you can grab your finger

on on it the skirt is dented downwards

and you can catch your finger on it

because this hit something when the

motor got rebuilt for nitrous the plan

was just to put pistons and rods in it

we have a a really nice sunny Bryant

crank in this motor I guess when Mike

went to put it together the new piston

skirts wouldn't clear our crank so we

had to hurry up and overnight a brand

new crank and have it machined and have

it polished and have it sized and then

put it together well they're still

hitting so it adds a little bit of

insult to injury that I bought another

Crank That

you know ultimately didn't work it is

what it is we're going to have to

replace a lot of parts in this motor the

crank's not junk but every valve's got

to get replaced every piston hopefully

the rods are okay the wrist pins are

probably flexed from all the the

pounding they took the end result of all

of this is probably bent valves the

Pistons are compromised all the trash

from all the parts rubbing on each other

went into the oil system and scuffed the

cylinder walls scuffed the skirts of the

Pistons like the crank's going to be all

right the head needs to be repaired the

blocks fine you know the big parts are

going to be okay but but we're going to

have to replace a lot of stuff and I

don't know that I'm even going to do

that anytime soon because the Sunny's

motor which has proven itself to be

really reliable is sitting in side chick

I'm probably just going to make that run

figure this out later but for now we're

going to turn lemons and lemonade we're

going to find out how much piston of

valve clearance is enough for this motor

that was really long I'm

[Music]

sorry main caps are in we are about to

put the nuts and washers these are ARP

half in studs ARP is closed right now

because they're on the west coast and

it's in the morning on the East Coast so

I called Dart to find out what they

recommend for torque spec for this and

they have all their torque specs using

something called CMD number three not

ARP Ultra torque Fastener assembly Lube

but for our purposes we're not going to

run the motor we're just going to torque

the Caps down so the crank is in place

they said 105 we'll do 105 with this and

like I said we're not going to run the

motor it'll be fine so right now I'm

scraping all the silicone off of our

timing Cod cover

because

this needs to be a flat

surface again we're not running the

motor

but this is a jezel timing cover for a

belt

driven there is a spec and it's between

8 and 12,000 of an inch for the end play

or the thrust of the cam as it moves

forward and back in the block and so

there are shims in here that set that

you know ultimately when the motor goes

back together I don't want a bunch of

silicone stacked up when we install this

and since Joe's doing one thing and I'm

doing another I might as well just clean

it while I'm here and it'll be ready for

when we actually put this motor together

and run it at a later date for what

we're doing today just checking piston

the valve

clearance all right right now Joe is

cleaning the cam getting it ready to go

back in the motor I'm going to wipe off

the cam bearings make sure they're okay

and whoa they're not okay these things

are all chewed

up

hello oh yeah I got gouges deep enough

to catch your fingernail on them okay

these are getting changed too we'll Lube

them up it'll be enough for checking

piston about clearance be all

[Applause]

right W that's

close woo it's close and it's not so I'd

say the wristpin support the bottom of

the Piston where the wrist pin slides

through is got a solid eighth of an inch

between the counterweight and that and

when you rotate the Piston right at

bottom dead center you can see where the

skirt nicked a counterweight would have

been that one cuz that was the first

Crank that was in this motor cuz it

never makes you slide this in you start

rotating it it doesn't get around one

full res Revolution so how did the other

four get dented unless there's something

about this crank that's denting the

other ones like maybe number one got

dented with that crank during you know

the assembly process and then whoaa okay

order a new crank order this crank put

this crank in slide all of them in there

and the other ones got dented after the

fact on the second go round there's an

eighth of an inch because of the dent so

if the Dent's not there wait a minute

maybe they're still hitting it's because

of the dent we have the clearance that's

the tightest point right there see that

yeah oh they're hitting the so now find

the one for number five be right here

somewhere so it would be the Inside Edge

bottom dead center right so it would be

right in here so when this when this

rotates around we need to look at that

area let's look at another one got Nick

six not as bad as the others but well

that would explain I mean we're because

these two weights are almost identical

here you know what I mean number six got

it so let's see that' be on this side

this side and it would be valve relief

there number six got hit here which

should be here this counter weight this

one might be hard to see cuz it's a

really light just barely there was

another one that was pretty bad like the

first one yeah here you go number two is

number two is smacked hard you see that

you can feel it right there all right so

it would be on this side relief is there

it would be here so go it would be

somewhere right here so rotate it back

up I think that's it right

there so think got a big lip on it feel

that oh yeah catch your fingernail on it

I think it got it right there I mean we

can we call and ask Mike and be like all

right how many got dented during mockup

all right let's flip it over we'll find

top dead center we'll put the balancer

back on and the degree wheel because

it's aluminum block right now we're

going to figure out how far in or out of

the hole the Piston is in relation to

the deck surface uh we've already done

that once but we're going to double

check it anyway because this is domed we

can't put the dial indicator in the

middle of it so what we're going to do

is we're going to move it to the outside

Mark right here we'll zero it raise it

up a little bit so that it so that it

has some travel we will Zero it on the

deck surface and then we'll place it on

the Piston if you can hold it here I'll

try to find TDC in the hole and now it

is 21 in the hole if I rock it the other

way it is even with the deck surface so

if you cut 21 and a half it's about in

the hole about 10 th which is

interesting cuz earlier we measured it

and it was out of the hole let's go to

the other side here and see if that

works out I'll hold it and you rock it

tell me what you see you're at

zero okay that rocked up what's it now

about out yeah okay now push the other

side and go down 23 in the hole rock it

back the other way about a th out of the

hole so 22 so it's about 11 in the hole

10 or 11 when it's when it's not rocking

it's about 11,000 but this thing is

somewhere around 11 11 and half thousand

in the hole when it's level

now we're at TDC we can put our upper

gear on line up our dots and we haven't

changed anything so this should all go

back together exactly the way it came

off got it on we are on all right the

dots line up

perfect and uh we are at

TDC and we never broke these loose so

the cam timing is exactly the way it was

when we took the motor apart which

according to this was 2°

Advanced all right and that is your TDC

Mark all right now it's time for head

gasket and cylinder head now we're going

to clean the head gasket put the head

gasket on the motor and then we're going

to mock up the cylinder head with a

rocker arm and a push rod and before we

do that we're going to take out these

valve springs now these are the Val

Springs that are actually in the

cylinder head in the motor when it's

running they have a ton of Seat pressure

open pressure we're going to take these

out and put lightweight Springs in

they're called checking Springs that

will allow us to operate the valves

without all that seat pressure and open

pressure the cylinder heads are marked

so we know which side of the motor this

head was on that's number one number

three number five number seven so this

is the one will be working with we'll

show you two different ways you can take

these Springs off right

now we are now going to put the cylinder

heads on and measure our piston to valve

clearance which essentially is the gap

between the face of the intake into the

exhaust valve and the Piston where the

relief area is for each one of those at

various points essentially when the

engine's running and the Piston's coming

up and it starts to come back down the

intake valve is chasing it the closest

point between those two things are about

10° after top dead center the exhaust

Val valve the Piston is chasing it out

basically the valve opens and as the

Piston comes up the valve has to close

quick enough so the Piston doesn't run

into it and so the closest point between

those two things is about 10° before top

dead center now to test this we're going

to remove the springs that are on the

cylinder head these are these monster

pack racing springs they have a ton of

Seat pressure I think about 400 lbs they

have a lot of open pressure probably

about a th I don't have the specs on

them to make this easier to to measure

we're going to remove these real quick

and then we're going to replace them

with these soft Checker Springs and

there's a couple ways to do this I have

two different tools both of them are

from LSM this tool is an onad spring

compressor so essentially you can bolt

this to where the rocker stand used to

go put a wrench on it and compress the

spring I also have this one which is a

little easier to work with when the

cylinder heads are just lying about this

is another spring compressor that you

would operate just like this not bolting

into the head it's got a crank on this

end it's got a knurled part right here

that you can put a uh socket onto and

impact this end if you want same deal

compress the spring get the keeper out

pull the retainer off pull the spring

out replace the

spring okay there we go all right

where's the

magnet I'll just mag I'll just magnet

these off the

floor all right now gently release it

and because these were hitting the

Pistons they're probably bent which

means we can probably try to move the

valve move the valve a bit right now and

it's probably not going to want to do it

too well oh it did oh and it does not

want to come out so I'm not going to put

it in the lathe I'm going to let it go

the way it is all right so there's that

put a checking spring in there and this

we can compress by hand and reassemble

okay Old Spring is out we're getting to

ready to put our checking spring in uh

can you grab a flashlight real quick I

want to show the people at home so this

valve doesn't want to come out it gets

about that far and then I'm tugging on

it it really doesn't want to go you see

that right

there that valve guide used to stick

into the port about an inch and it

doesn't probably because the valve bent

in the guide because it was hitting the

Piston so I'm not going to try to get

that out any further we're just going to

put the spring in it and hopefully have

enough travel which I think we do to uh

measure our piston valve clearance

one down one to

go we

compressed there's the

keeper now we'll release the

handle okay stuck in our inner spring

here that's going to go

there compress it on here there we go

okay there's that

one dude you're the man you're holding

the camera you're holding the valve

all

right Bueno and now we're ready to put

our head back

on

go

this is the exhaust which should come

closest to the Piston at about 10°

before top dead center because basically

what's happening is the the Piston is

coming up pushing the exhaust out as the

valve is open and the valve doesn't

start closing until the Piston gets

pretty close right about 10° for top

dead center going to rotate this and if

you want to watch this in real time you

can look down the bottom and see what

the Piston's doing this valve is opening

so go ahead and for the people at home

call it out tell me what the Piston's

doing while I'm rotating this here the

exhaust valve has opened about 100 th000

uh and it's almost all the way down

200,000

300,000 pists all the way

4,000

500,000 600,000 you should start coming

back up

700,000 Piston's about a quarter the way

up

800,000 that is about Peak valve lift

and piston is on its way up it's the

exhaust valve is now starting to close

and we are about 80 degrees before we

get to top dead center and so if is

almost about 3/4 way up and should be

all the way up exhaust valve is still

shutting we are 10° for top dead center

and the exhaust valve is still closing

so picture that in your heads folks the

Piston is only 10° away in terms of

crankshaft rotation to being at top dead

center our exhaust valve is still

shutting so the Piston is chasing the

valve up this should be the closest

point that the exhaust valve and the

Piston are in terms terms of each one's

travel so now what we're going to do is

we're going to zero our dial indicator

here okay that's zero and we're just

going to activate the rocker arm by hand

and however much this travels is how

much piss the valve clearance we have

I've seen people run Motors as tight as

50,000 of an inch I've had

150 let's go a little

tight

100 35

135 let's try

7°

25 which is quite a

bit I would think that would be

plenty all right 125 thou that sounds

like that ought to be enough but clearly

it's not because everything's touching

we we'll

reverifying the spark plug hole piss the

valve clearance on paper seems okay we

have

125,000 p2v for the exhaust we have 100

on the intake and on paper I feel like

that would be a decent number except you

can't get around the fact that there's

witness marks on every piston in every

pocket for both intake and exhaust so

right now we're going to stick some

valves in the lathe and see are they

bent are there any witness marks on the

valves uh that'll pretty much confirm

what's going on and in the end it might

not be a piss in the valve clearance

necessarily it might be a lack of valve

control where the spring that's in there

installed height spring pressure

whatever might not be correct and the

valves are bouncing when they shut you

know so in the case of the exhaust as

the Piston's coming up and it's chasing

the valve and the valve closes and maybe

bounces off the seat and tags the Piston

I don't know let's see if these things

are bent or not I got a feeling they are

kind of looks like right there here put

them in the lath see if they're bent too

oh yeah we are bent valves hitting

Pistons the end of the story now the

question is oh there's my lovely bride

I'm not even going to tell her what I

spent to build it to go nitrous racing

and we're probably not going to talk

about rebuilding it because I'm not

doing that anytime soon here's the thing

I know that this video does not paint

the engine builder Mike Miller in the

best light but here's what you need to

know about this guy we are still friends

he is a really really great engine

builder he has built engines for record

setting Jet Boats the boat that I came

in second place to in my class this year

powered by one of his engines and he's

driven Jet Boats faster than I probably

ever will I think he had a bad couple of

days at work missed a couple of things

that just needed to get measured and

didn't because he was in a hurry the guy

works two jobs I get it uh we have

talked on the phone more than once he

handled me going behind him and

questioning his work and measuring it

better than most guys would have so I

give him a lot of credit for that uh and

my hope is that you know he and I come

to an agreement and work this out um I'm

sure we will I'm not not going to stress

over that and hopefully he doesn't watch

this YouTube video and you know get real

upset with me about it because I just

want to learn just want to know and I

like working on my own stuff I prefer it

actually the boat has been on the west

coast I lived in Georgia the only way

for me to race it was to leave it on the

west coast and put it in the trusted

hands of my friends and he busted his

butt on numerous occasions to get that

engine and that boat ready to go racing

just missed a few things it happens

anyway thanks for watching Fan's garage

hopefully this was educational I know I

learned a few things here today and uh

it's always good to get your hands dirty

in the garage this motor not going back

inside chick anytime soon Sunny Leonard

motor that's going inside chick and next

week back work on the

[Music]

Cadillac