Hi Everyone.. I'm a long time lurker on this site but this is my first post.

I have been able to get so much information from reading past threads and posts that I felt I wanted to thank everyone who takes the time to share their trials and tribulations and help others when they can.

I have already purchased a short block from an engine builder, all forged 355cu 4bolt JE pistons, 6" I beams and 3.48 crank. Got an excellent deal on these parts that were intended for a circle track build, so I jumped.

This engine will be for a 1991 6sp. I want to go with a single plane efi intake much like rklessdrivers setup, only I want to use a 4150 style TB.

I need to decide what heads and cam.. and I will continue to work with my builder on that.. but really what im most curious about here is the single plane set up to replace tpi.. the builder does not have much experience on this swap and we wonder what hidden problems we will encounter as we move forward.

Any of you who have single plane setups, do you have any words of advice on the single plane set up?

 

Fuel lines.... the best way is to buy the accel metric o-ring to 6AN adapters and build new AN fuel lines from the fuel filter to the fuel rails/engine.

The Eldebrock Victor E EFI intake is a decent manifold and Eldebrock makes rails that bolt right on. Air cleaner clearance will be tight with a 4bbl style TB.

Lots of options for heads and cam. That intake will support a nice TQ curve and make good power from 3000 to 7000rpm on a 355, so alot depends on how radical of a cam your willing to deal with and how much $$$ you want to spend.

 

Thanks for the reply Dude. Much Appreciated.

I was thinking of calling the techs down at Jegs, or even Comp Cams and running the set up by them and see what they recommend. I have a bit of a set back in the fact that the pistons are 9:1, so that will be a limitation unless I can find a way to bump that up a bit.

But I'm feeling positive about it if you say the biggest hurdle with the intake is the fuel lines.

 

What is the PN of the pistons you have?

If you don't know the PN - how big is the dish in them?

Compression ratio varies with the combustion chamber, block deck height and head gasket so you maybe could easily get enough compression to build something worthwile with them.

Jegs and the Comp Cams tech line is not where I would recomend you find info on this. I would be glad to help you.
Will

 

The P/N is JEP-181916.. they are +5.00cc.. with a compression distance of 1.250 in. The block is standard deck height..

That's what I was thinking, as far as there being a few ways to get the compression up. I just want to avoid milling the heads if I can. Im warming up to Brodix IK180 or 200s in a 64cc chamber.

I really do appreciate the help Will. My engine builder is a race guy and keeps recommending that I go 18* and full roller.. etc etc. He has like 25 years track experience.. Its been hard to get a less extreme perspective and I pretty much have had to come up with the combination on my own bc hes kinda difficult to deal with.. So here I am.

 

Ok that is a flat top 2 valve relief piston.

With a 64cc chamber you would be about 10.5 compression ratio depending on deck clearance and head gasket... Thats really close to where you want to be for something like this.

The IK 180 is going to give you a good power to about 5800-6000 RPM on a 355.

The IK 200 is going to extend that to 6500-6800RPM.

They are decent heads for the money. With hyd roller cam springs (w/1.470 springs they are like $1299.99 at the online retailers)

I will say it's only $300 or so more for a set of CNC ported AFR 195's....

Camshaft wise I see no reason to spend $450 on a custom ground stick. I would recomend a camshaft something along the lines of these (2) Howards Hyd rollers.

280/286 @ .006
227/233 @ .050
.560/.560 w/1.5
112 LSA

or

284/288 @ .006
231/235 @ .050
.510/.530 w/1.5 (I would run 1.65/1.60 rockers on this cam .561/.565)
112 LSA

The actual PN would depend on if you needed a factory style hyd roller or a retro hyd roller.... that depends on if you are using the factory L98 block or an older 2pc rear seal block.
Will

 

This is really good info. I do have a question regarding 6500-6800 RPM range.. I hear and read that 6300 is about the max rpm for hyd roller using rev kit and girdles.. Is that not accurate?

I would LOVE to be able to go 7k rpm, but dont want to have to go solid lifters and do lash adjusting.. and worry about idling and street driving etc.

Also, are there any issues supporting that rpm range with SD/MAP computer for 90 - 91 yr models?

 

Turning hyd rollers beyond 6500 depends on how stable the valve train is.

My personal 92 has turned 7400RPM under power on occasion and will live at 7,000 all day long. It has Morel lifters, Trend 3/8 pushrods, T&D shaft mount rockers... PSI valve springs, Ti retainers ect.... A lot of $$$ tied up in it.

Alot of that has to do with the how aggressive the lobe profiles, rocker ratio, spring pressure are and how big of a base circle the cam is ground on. There is alot to it and I can't give that knowlege away.

The second cam with my recomended 1.65/1.6 rocker combination is going to crap out about 6800RPM with your typical stud mount rockers, 140lbs/400lbs valve spring pressure and 5/16 pushrods.....

Now you could do some work with more valve spring pressure, 3/8 pushrods, Morel Lifters and shaft mount rockers to get it Past 7000 pretty easily but honestly IMO its a tad small on duration to make power beyond 6800 RPM. Really it is a best case scenario as far as where it makes power compared to how stable I think it will be....

A very similar custom grind from Mike Jones Cam Designs I did for a member here (which has a slightly more aggressive lobe) worked out very close in reguard to RPM stability.

The first cam which is actually a larger lobe with smaller duration would be more stable at the valve but only because of the lower rocker arm ratio... however the smaller cam just dosen't have the duration needed to make power to 7000RPM.... IMO its just gonna striaght run out of power about 6500rpm.

I am not familiar with the PE tables in the 91's computer so I can't tell you if 7000rpm or beyond would be a problem or not. On my 92 the PE tables stop just before 7000RPM but if you operat the engine beyond that RPM it just goes off the last known table.

Will

 

Dude. You have no idea how much help this is. Thanks alot for the time and expertise.

This weekend our engine guy is going to be installing an engine he built in my brothers camaro. We are all really excited to see how that goes..

Half filled 505cu Big Block with Brodix BB2+ heads.. We literally cannot wait. But the point is I will be able to run alot of this new info past him and see what he says..