How To Torque Cylinder Head Bolts

Summary

In this video, Eric demonstrates the proper method for torquing a cylinder head on a BMW e30 M20 B25 engine. He emphasizes the importance of following a specific sequence: first to 30 Newton meters or 22 pounds, then 90 degrees twice. A special tool, resembling a protractor for a torque wrench, is used to ensure the correct angle of torque. The video also covers the preparation of the engine, including cleaning and oiling the bolts, and using a precise torque wrench for accuracy. Eric shares his experience with past issues of blown head gaskets and hopes this method will prevent future problems.

Takeaways

• 🔧 The video demonstrates the correct method to torque a cylinder head, specifically for a BMW e30 M20 B25 engine.
• 🛠️ A special tool, resembling a protractor for a torque wrench, is used to ensure the proper angle of torque is applied to the head bolts.
• 💡 The process involves tightening the head bolts in a sequence of stages, with specific degrees of rotation rather than just torque values.
• 📚 The BMW manual specifies a particular order and method for tightening the head bolts, including initial torque and subsequent 90-degree turns.
• 🧰 The engine has been recently rebuilt, and all components such as the head bolts and the head gasket are cleaned and prepared for assembly.
• 🔩 The head bolts are Torx type, requiring a specific tool for tightening, and are initially tightened to 22 pounds or 30 Newton meters.
• 🔄 A cross-pattern is used for tightening the bolts to ensure even distribution of torque across the entire cylinder head.
• 🛒 The video mentions a recommended torque wrench and provides an Amazon link for purchasing the special tool used, with a disclosure about affiliate compensation.
• ⚙️ The tool is used to mark the torque wrench at 0 and 90 degrees to facilitate the correct angle of rotation for the bolts.
• 📹 The video includes a demonstration of the entire process, from preparing the engine to the final tightening of the head bolts.

Q & A

What is the engine being discussed in the script?

The engine being discussed is a BMW M20 B25, a 2.5-liter inline-six engine from a BMW E30.

Why is a special tool used for torquing the cylinder head?

A special tool is used to ensure the correct angle of torque is applied to the head bolts, which is crucial for avoiding issues like blown head gaskets that have occurred in the past with this particular engine.

What is the purpose of torquing the head bolts in a specific sequence?

Torking the head bolts in a specific sequence, including turning them to a certain number of degrees, ensures even distribution of torque across all bolts, which is essential for the proper sealing and longevity of the engine.

What is the first step in torquing the head bolts according to the BMW manual?

The first step is to tighten the head bolts to 30 Newton meters or 22 foot-pounds.

How does the special tool function as a 'protractor' for the torque wrench?

The tool helps to measure the angle of torque applied to the bolts, ensuring that each bolt is tightened to the correct angle as specified by the manufacturer.

Why is it important to clean and oil the head bolts before installation?

Cleaning and oiling the head bolts ensures they go in smoothly and reduces the risk of cross-threading or damaging the threads, which is critical for proper assembly and function of the engine.

What is the significance of using a high-quality torque wrench for engine work?

A high-quality torque wrench provides more accurate measurements, which is essential for engine work where precise torque values are critical to ensure the engine's integrity and performance.

What is the recommended pattern for tightening the head bolts on the BMW E30 engine?

The recommended pattern is a cross pattern, starting from the center and working outwards, which helps to distribute the torque evenly across the entire head.

What is the second step in the torquing process after the initial 30 Newton meters?

After the initial torque of 30 Newton meters, the bolts are then turned an additional 90 degrees, and this process is repeated once more for a total of two 90-degree turns.

Why is it beneficial for the presenter to provide a link to the tools used in the video?

Providing a link to the tools used allows viewers to easily purchase the same equipment, which can be helpful for those attempting a similar project, and the presenter may also receive a small compensation for the referral.

Outlines

00:00

🔧 Torquing BMW E30 Cylinder Head

The video script explains the process of correctly torquing a cylinder head, specifically for a BMW e30 with an M20 B25 engine. The narrator emphasizes the importance of following a specific sequence of torque values and angles, rather than just reaching a certain torque value. A special tool from Amazon, described as a protractor for a torque wrench, is introduced to ensure the correct angle of torque is achieved. The script details the preparation of the engine, including cleaning the block deck and oiling the new head bolts. It also mentions past issues with the engine, such as blown head gaskets, and the hope that using this tool will prevent future problems. The BMW manual's instructions for torquing the head bolts in a specific order are referenced, and the script outlines the first step of torquing to 30 Newton meters or 22 pounds, followed by two 90-degree turns. The narrator also discusses the importance of using an accurate torque wrench for engine work and provides a link to purchase the special tool used in the video.

05:01

🛠️ Demonstrating Torque Tool Usage on BMW E30

In the second paragraph, the video script continues with a demonstration of how to use the torque tool on the BMW e30's cylinder head. The narrator shows how to set up the tool by clamping it onto an exhaust stud and ensuring it doesn't move during the torquing process. The tool is used to turn the bolts from one piece of tape to another, marking 90-degree increments. The script describes the process of torquing the bolts in a cross-pattern, starting from the center and moving outward, to evenly distribute the torque across the head. The narrator also addresses a minor issue with the tool's clip moving slightly and the need to apply more force to hold it in place for the second round of 90-degree turns. The video concludes with the successful completion of torquing the head and a brief introduction of the narrator, Eric, who invites viewers to subscribe for more tool and car-related videos.

Keywords

💡Torque

Torque, in the context of the video, refers to the force applied to a bolt or nut to tighten or loosen it. It is a crucial concept in automotive mechanics, especially when assembling engines. The video emphasizes the importance of applying the correct torque to cylinder head bolts to ensure a secure and even fit, which is vital for the proper functioning of the engine. Incorrect torque can lead to engine failure, as mentioned in the script where they've 'blown a couple of heads' due to improper torque application.

💡Cylinder Head

The cylinder head is a critical component of an internal combustion engine, housing the valves and camshaft. In the video, the process of correctly torquing the cylinder head is discussed. It is essential for sealing the combustion chamber and ensuring the engine runs efficiently. The video script describes a specific method for torquing the head of a BMW e30 M20 B25 engine, highlighting the need for precision in this process.

💡BMW e30

The BMW e30 refers to a specific model of the BMW 3 Series, produced from 1982 to 1994. In the video, the engine being worked on is from a BMW e30, and the script provides detailed instructions for torquing the cylinder head of this particular model. The e30 is a classic car among enthusiasts, and the video's focus on this model speaks to the audience's interest in maintaining and repairing such vehicles.

💡M20 B25

The M20 B25 is a specific engine type used in the BMW e30, an inline-six engine with a 2.5-liter displacement. The video script discusses the unique torquing sequence required for this engine's cylinder head. Understanding the specifications of this engine type is essential for the viewer to follow the instructions accurately and ensure the engine is assembled correctly.

💡Torque Wrench

A torque wrench is a tool used to apply a specific amount of torque to a fastener, such as a bolt or nut. In the video, a torque wrench is used to ensure that the cylinder head bolts are tightened to the correct specification. The script mentions the importance of using an accurate torque wrench, as opposed to a cheaper alternative, for engine work to avoid over- or under-tightening, which can lead to engine damage.

💡Tightening Sequence

The tightening sequence refers to the order in which bolts are tightened, and the amount of torque applied at each step. The video script outlines a specific sequence for the BMW e30 M20 B25 engine, which involves initial tightening to a certain torque, followed by additional turns to a specific angle. This sequence is crucial for achieving even pressure across the cylinder head and preventing warping or leaks.

💡Head Gasket

A head gasket is a seal that sits between the engine block and the cylinder head, preventing fluids from leaking between the two. In the video, the script describes the process of installing the head gasket before torquing the cylinder head. Proper installation of the head gasket is essential for the engine's performance and longevity, as a failed gasket can lead to coolant or oil leaks.

💡Amazon

The video script mentions purchasing a specific tool from Amazon, which is a popular online marketplace. The tool, described as a 'little protractor for your torque wrench,' is used to ensure the correct angle of torque is applied to the cylinder head bolts. The mention of Amazon serves as a practical resource for viewers looking to acquire the necessary tools for their projects.

💡Cross Pattern

A cross pattern is a method of tightening bolts in a crisscross fashion, starting from the center and working outwards. The video script describes using a cross pattern when torquing the cylinder head bolts. This method helps to distribute the clamping force evenly across the joint, reducing the risk of distortion or leaks.

💡Newton Meters

Newton meters (Nm) is a unit of measurement for torque. In the video, the script specifies the torque values in Newton meters, such as 30 Nm for the initial tightening of the cylinder head bolts. Understanding the concept of Newton meters is important for accurately applying the correct torque, as different units of measurement can lead to improper tightening.

💡Engine Rebuild

An engine rebuild refers to the process of disassembling, inspecting, and reassembling an engine to restore or improve its performance. The video script implies that the BMW e30 engine has been recently rebuilt, which is the context for the need to correctly torque the cylinder head. The term 'rebuild' is significant as it sets the stage for the detailed instructions provided in the video on how to properly assemble the engine components.

Highlights

Demonstrating the correct way to torque a cylinder head, specifically for a BMW e30 M20 B25 engine.

The importance of torquing in a specific sequence to avoid issues like blown head gaskets.

Introduction of a special tool from Amazon that assists in torquing at the correct angle.

Previous problems encountered with the engine due to improper torquing methods.

The use of a protractor-like tool to ensure the correct angle of torque is applied.

Preparation steps including cleaning the engine block deck and oiling the head bolts.

The necessity of using a high-precision torque wrench for engine work.

Instructions on how to use the torque tool with painters tape for ease of use.

The specific torque sequence for the BMW e30 engine: 30 Newton meters, then 90 degrees, and another 90 degrees.

The importance of applying torque in a cross-pattern to distribute it evenly.

The use of a torque wrench with one-click precision for accuracy.

The process of applying the first round of 90-degree turns to the head bolts.

Adjusting the torque tool for the second round of 90-degree turns.

Challenges faced while torquing due to the engine stand's mobility.

Final steps in torquing the BMW e30 head and the engine's specifications.

Eric's invitation to subscribe for more tool and engine-related videos.

Transcripts

I'm gonna show you how to torque a

cylinder head the correct way and what's

interesting is that this particular

engine this is from a BMW e30 it's an M

20 B 25

you've got to torque it a specific way

and that means the last time that you

tighten up the head bolts you got to

turn it a certain number of degrees as

opposed to bringing it to a certain

torque value to do it properly there's a

special tool that I got from Amazon it's

pretty inexpensive I'm gonna put a link

to it down below we've torqued up the

head before and maybe not with the best

results we've blown a couple of heads we

could blown a couple of head gaskets on

this car before so hopefully this is

gonna work properly

everybody's we're gonna show you how

we're gonna do it so we've had some

problems blowing up this particular

motor before it's probably because we

didn't work down the head properly we

didn't have even torque across all of

the bolts so hopefully with this tool

it's like a little protractor for your

torque wrench it's gonna help us get the

correct angle of the torque and

hopefully avoid this problem in the

future so let's show you how we're gonna

do it to prepare everything we've

cleaned up the entire deck of the block

and this engine has actually been

rebuilt recently we've got all the head

bolts here and we just oiled them up so

they go in nice and clean and we've also

cleaned up the head it's brand new

surfaced head so everything is nice and

clean and we're gonna have to tighten up

the head bolt and we're going to use

this tool over here which is basically a

protractor and what I've done is I've

put a marking some painters tape on the

zero and then ninety degree mark and I'm

gonna show you how to use it in just a

second and basically that's all that we

that's all that we're gonna do is just

we need to get these bolts to 90 let's

go over to the BMW manual here so

there's a there's an order specifically

to tighten up the the head bolts and

then on this particular BMW which is an

e30 what you got to do is tighten up the

first time you do stage one to 30 Newton

meters or 22 pounds and then you do 90

degrees and then 90 degrees again so

it's kind of an odd sequence of things

to do but that's how it works in this

BMW so let's show you first and we're

gonna do is put the head gasket on and

because everything is so nice and clean

it's a little bit slippery so if we just

put it on it actually slides ha

by itself so one of us is going to hold

the gasket in place the other one is

gonna go get the head put it on and then

one of us is going to put the bolts in

so what's gonna happen is I'm gonna hold

the gasket in place and I'm gonna put in

a couple of bolts what we're gonna do is

just put them in finger tight right now

these are Torx head bolts they look

they've got this weird torques gonna

head and you need a special need a tool

like this so I'm going to put everything

on a link in my amazon link down below

and I get a little bit of money if you

purchase this stuff off Amazon it's

certainly not a lot but I will get

compensated a little tiny bit for it so

you're gonna use these would appreciate

it if you click on my link it doesn't

cost you any more so in this particular

head it requires twenty-two pounds like

I said over in the book over there to

begin with 30 Newton meters I think it

is so we've got this nice torque wrench

this is AC CE di this is a pretty nice

one when you're doing some engine work

you definitely want to have something a

little bit more accurate I don't think

you're Harbor Freight torque wrench for

$26 what you're gonna use on your wheels

is really what you want to use when

you're torquing an engine together so

you want something a little bit more

accurate this is a mid priced option

there's some higher priced ones to take

your pick but if you're doing engine

work probably want to do it more

accurately we're going to do a cross

pattern here basically where we start in

the middle yeah we're gonna start in the

middle and then we go out and then we

move in so basically we keep the torque

we kind of distribute the torque as

we're doing it across the entire head

first round is 22 so we're gonna start

with number one there's that one and

we're gonna take those two 22 pounds

which is not very much and we'll click

and that's it only one click I know some

people in the comments of my other

torque wrench of video we're talking

about two clicks no no no one click only

never two clicks I don't care what your

grandpa said I don't know what character

next door neighbor said it's a one click

look it up on any torque wrench website

one click guys one click alright number

two is gonna be right

yeah they're alright okay so for the

next round we're gonna use this tool

here like I already showed you but I put

some tape at the zero and then 90 to

make it really easy for us it's probably

you can't probably can't see it that

well on camera but basically what we

gonna do is we're gonna put this our end

here like that and then the wrench on

this side that's it so we're gonna have

somebody aka me hold this as we go

through it so number one is gonna be

that one I believe that's what this is

the clamp onto something that's

stationary on the motor so that this

doesn't move to the pivot oh yeah

all right oh yes so let's let's put it

like two there okay so we're just

putting out on an exhaust stud yeah

pretty that's pretty good we're just

gonna turn it from one piece of tape to

the up next and that's it and one

continuous motion I don't think we

weren't that accurately for so we're

trying to do it in one continuous motion

all right so you can see how we set it

up basically so we set this soups it's

loose right now you can move it around

so we're basically gonna set it to the

zero mark pressure get set up and then

I'm gonna move the camera out of the way

here for a second here we go we're gonna

go to 90

alright I'll show what that looks like

see that's 90 that looks pretty good to

me point seven five ninety point seven

five yeah we're off a little bit so we

just did the first round of 90s and now

we're gonna do it again second round

this gonna be the last time are you

ready for this excitement because yes we

are this is gonna be harder to do this

time because this whole engine stand of

course is on wheels and so I've been

holding it and it wasn't too hard last

time but now another 90 degrees is

actually a significant amount of torque

so one of the issues we've been having

is this little clip thing here to kind

of hold the gauge in place it's moved

slightly so we're gonna try to clip it

on a little bit better and I'm gonna

have to use a little more grunt to hold

this in place go now this is the second

ninety and this one's gonna be hard

harder all right I'm ready all right

so that's how you torque a BMW e30 head

for the record this is an M 20 b25

engine that's a two and a half litre

inline-six that comes out of a BMW e30

in 1989 my name is Eric if you want to

subscribe it's gonna be right over here

I've got a whole bunch of videos on the

Toyota Supra and I love you guys love

that we have a few more tool videos

coming up as well see you in the next

one

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