Car and goals: 1994 Camaro Z28, full interior, A4, 3.43 Stock Rear End, no suspension upgrades. Looking for 400 or more rwhp. Budget is roughly $2500.

Well im still juggling ideas for my build. I wanted to ask a few more questions, as im considering more now keeping the car n/a and spraying some n20. Heres the questions:

What would the difference be between using 6" rods, and 5.75" rods? so far ive seen that you can use either in any ci build, but i dont understand the pros and cons between the two.

A 383 consists of a 4.030 Bore, 3.75" Stroke, ?.??" Rods?

What compression would be best to have in a 383 build?

What is the main power difference between a n/a 355 and a n/a 383 with the same heads/cam/bolt ons?

Thanks alot

 

The A4's came with either a 2.73 or a 3.23 rear axle ratio. They never left the factory with a "3.43" (or a 3.42).

A larger displacement engine needs better flowing heads to make more power. Put the same heads on a 355 and on a 383, and they will probably both make the same HP, just more on the bottom end with the 383, and a lower peak HP rpm. The 383 will run a lot smoother on the low end than the 355, with the same cam. I larger displacement generally can tolerate a larger cam.

Unless you are building a NASCAR engine, or trying to squeeze the last possible HP out of a one-off engine for the Engine Masters competition, do not obsess with rod/stroke ratio, and rod lenght. I've found that with a large hit of nitrous on a 383, a 5.85" rod allows you to run a thicker piston crown and drop the ring pack down to keep it away from the intense heat of the nitrous combustion, and provide stronger ring lands. You will need ring rails for the oil ring with a 5.85" rod. A 5.75 rod would probably not require the rails, but you end up with a fairly heavy piston.

If all you are spraying is a small shot, a set of forged pistons on the stock PM rods (resized) may be the most economical setup. $2,500 isn't going to go very far toward building a 400+rwHP engine, PLUS nitrous. You need a lot of drivetrain work and a lot of suspension work to put that kind of power to the ground.

 

+400rwhp from $2500? 300shot and throw any left overs into the suspension. prolly wont last too long tho..

 

Wow.... i had my 2500 budget spent out with like 300 left on the 355 turbo build.... thats crazy. what about just an n/a 383 with heads/cam with around 400 hp... would i be able to hit that with the 2500 budget.

 

LE2 set up, Youll need alot to support that if your stock though.

 

Considering a good h/c package will cost you $2500 and you have no supporting modifications, not to mention no factored cost on the intangibles, $2500 won't get you far.

You'll need at the very LEAST headers, a full exhaust system, valvetrain components (not included in the h/c package, things like rockers, pushrods, lifters), etc.

IMO, for you starting from stock you will need at least $4000 with using the stock bottom end. Even then you'll need a GOOD tuner, so tack on an extra few hundred bucks for that alone.

 

i removed the mods from my sig because i was doing a rebuild. i have all the bolt ons, supporting true duals exhaust with pacesetter lt headers. so i do have supposrting mods. 58mm tb, ported intake manifold.

 

The pro's and con's of different rods seem to have its ups and downs, but like injuneer said, I would not worry about rod lenght "that much". The rod MUST match the piston. So see what rod the piston you want needs.

Compression is up to you Nitrous does not mind compression so no specific ratio for nitrous.
Just dont over do the compression or else you will need to use race gas.

Power difference between would be minimal, that 383 needs more air from the heads.

 

sorry about the original post injuneer, got my numbers mixed up with the ratio, they are 3.23s. but at this point im looking into a LE1 head/cam package with all the forged rods, forged pistons, and a new crank. the 383/355 decision is still at hand and isnt that big of a difference price wise, since im paying to get my stock crank polished and ground, the difference is only 70 so im still debating on that. thanks tho for everyones help