Recipe For A Hot, Low Budget 318 Mopar

Summary

In this video, the creator gives an in-depth overview of their modified 318 Mopar engine build, highlighting the key components and modifications. Starting from the oil pan up, they explain modifications like piston reorientation, a Hughes Whiplash cam, and stock heads with porting work. The engine features a Holley Street Dominator intake, a 750 CFM carburetor, and a simple fuel system. The video also covers the ignition system, exhaust setup, and cooling system, all aimed at achieving a low-compression, reliable street engine with potential for future upgrades. Viewers can follow the build and see it in action at the track in upcoming videos.

Takeaways

• 😀 The engine is a 318 Mopar with minimal modifications, focusing on a street-strip build.
• 😀 The stock oil pan, pump, and bearings were reused, with only minor tweaks to the short block, including swapping the pistons side-to-side.
• 😀 The camshaft used is the Hughes Whiplash cam, known for its performance in other engine setups, and it’s installed straight-up.
• 😀 Stock push rods, rockers, and lifters are used, with a lifter motor to match the camshaft's profile.
• 😀 Cylinder heads are stock 318 closed-chamber heads from 1967-73, with some bowl porting and a welded heat crossover to ensure better manifold compatibility.
• 😀 The intake manifold is a Holley Street Dominator single-plane, gasket-matched to the intake ports for improved flow.
• 😀 A 750 CFM Holley carburetor is used with stock jetting, which performs well for this engine combo, with no immediate changes planned.
• 😀 Ignition is managed by a Mallory dual-point distributor, running on one set of points for now, with the second set to be activated when nitrous is added.
• 😀 The fuel system features a Holley Street pump, with a regulator added for future upgrades to a larger pump.
• 😀 The exhaust system includes mismatched headers (Hooker on one side and unknown on the other) and simple Purple Hornies mufflers for straightforward performance.
• 😀 A stock fan clutch is used in the cooling system, intentionally set loose to improve cooling, allowing manual control over the fan blades while the engine runs.
• 😀 A nitrous system is in place but not yet active; it will be added in the near future for additional power.
• 😀 This 318 Mopar build is designed to be budget-friendly and simple, with a focus on tuning and minor performance tweaks rather than extensive modifications.

Q & A

What modifications were made to the engine's short block?

The only modifications made to the short block were rotating the pistons side-to-side in their bores, which reverses the piston offset and improves the rod's angularity during the early power stroke.

Why does the engine use loose bearings?

The builder prefers a loose motor for better performance. Even when having cranks cut, they go for extra thousandths over to ensure a loose motor, which they believe contributes to better engine morale and performance.

What type of camshaft was used in the build?

A Hughes whiplash camshaft was used. The builder had used this cam in a previous engine and was impressed with its performance, so they decided to use it in this build as well.

What work was done on the cylinder heads?

The cylinder heads are stock 1967-1973 318 closed-chamber heads. They were ported, with significant work done on the intake and exhaust bowls, though the porting is not aesthetically neat. The heat crossover was welded shut in the heads rather than the intake manifold for easier manifold swaps in the future.

What modifications were made to the intake manifold?

The intake manifold is a Holley Street Dominator, a single-plane intake. It was gasket-matched to the intake ports and had sharp edges smoothed out, but otherwise, it was kept stock.

How was the carburetor modified?

The carburetor is an old 750 Holley unit. It was not modified in terms of jetting, as the out-of-the-box jetting was found to be ideal for the engine setup. The only modification was grinding off the choke tower for better hood clearance.

What is the purpose of the spacer between the carburetor and intake manifold?

The spacer adds a total of two inches of height between the carburetor and intake manifold. This helps with hood clearance and future adjustments, though the spacer doesn't currently serve any specific performance purpose other than providing enough clearance for the engine components.

What type of ignition system is used in the engine?

The engine uses a Mallory dual-point distributor, but it is only running on one set of points at the moment. The second set of points is kept as a backup for future nitrous use.

How is the fuel system configured?

The fuel system consists of a Holley street pump with an added regulator. The system is designed to accommodate future upgrades, such as a larger fuel pump, though it works well with the current setup.

What type of headers and exhaust system does the engine have?

The engine has mismatched headers, with hooker headers on one side and an unknown brand on the other. Both sets feature 1 5/8-inch primaries with 3-inch collectors. The exhaust system includes a pair of old purple headers, making it a basic and simple exhaust setup.