Ok in the quest that I am getting ready to build my motor, I am still stuck on wether I want to just do a 355 with about 12:1 or a 383 with the same compression. The only thing is when ever I read GM Hightech the featured cars or for a fact the recent LT1 vs LS1 shootout the 383s are JUNK!!! They run High to barley mid 11s NA with fully built 383s and A Great set of heads, where I am running a Home port head, with a Nitrous cam and run well into the 11s all day NA and 10s on spray.

I would love the extra cubes but what is with the LT1 and not working with the 383s? I see more junk ones then I do good ones. Can anyone help?

 

The reason in my opinion is they do not have enough cylinder head to feed a 383 properly, and or they are cammed wrong. Hard to get stock castings to flow over 280 REAL cfm, which in my opinion is the minimum need for a 383 to be healthy. Alot of 383's have the wrong combination of parts, folks think because it works good on a 355, it should be sooo much better on a 383, not always the case.


David

 

A high horsepower stroker LT1 can be built no problem. As with anything else, it's just the right combination of parts.

What are your goals? (rwhp/et/mph/driveability)

 

Basically I want to keep the stock appearene aka oil pan, so everyone says it can be done.

After finding that out I basically want a good nitrous motor with 12ish area for compression, get a good nitrous cam in there and have it creep low 10s or even a high 9. Right now I have done a best of a 10.60ish, and I figure if I did a good 383 and a fogger I should have no problems considering the over stock components that my engine consists of now.
I have no problem running race gas but I still want to be able to cruiz it when I want to.

 

Listen to FASTFATBOY. He's right.

 

So you are saying that even a fully ported (good) stock casting LT1 head, it is not feeding the 383 enough. Even if it is cammed right with a TRUE (steel billet) custom cam by a professional??

I would think that 450rwhp/tq is easily attainable with stock castings and a 38x??

And that, considering it is at the right time, should be plenty for a 10 sec N/A timeslip. I mean guys runnings heads/cam+100shot are in the tens with traction right?

Throw that direct port on there with a 200shot and you are in the low 10s high 9s, all considering traction.

 

If you are in the 10s with your home-ported 355, why spend money on another engine? Just tell everyone it's a 396 and that's why you blow off their sprayed motors.

I'm impressed with your 10 sec. Camaro. Post some pics and a few time slips. Don't be so shy.

 

Just a few examples.

I had a 383 with GTP ported LT1 castings, ported LT1 intake, 250 duration/.600 lift solid roller.

Made 452rwhp 416rwtq through full exhaust.

Larry, who I work with, has a 96Z, 383 RGR ported LT1 heads/intake, solid roller, turbo 400. Made 420+rwhp through a loose converter, runs 11.0 @122 on motor, and 9.80's at 137 on the hose.

I think those are some good running setups for the parts they have, and theres no reason that you couldn't build a stroker LT1 to have substantially more power if you stepped up to some aftermarket heads/intake etc.

 

12:1 is a lot of compression. You aren't planning to run that on California pump gas I hope.

 

my 383 has a 260/260 solid roller with 12.3:1 compression. I run pump gas because its my daily driver. But It loves the Leaded 114. With a peak HP at 7000 RPMs its a high RPM screamer. ITs no slouch.

 

I don't know much about California gas, but if the cam has enough duration, it will bleed off enough cylinder pressure to make 12:1 tolerable with pump gas. Static compression is only part of the equation.

 

Hey FATBOY what about my heads!!!!

 

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Note from moderator - knock it off.

 

why wouldnt an injected car dislike leaded anymore then a carb car setup for mostly unleaded?

we have a 87 Formula,runs low 9's@150+ and it runs on C16 at the track,pumpgas on the street. been doing so for a few years with various combo's and no problems.

 

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Play nice.