I'm new to the forum. Hope to get some good Info from everyone! I was wondering what kind of numbers I will be looking at with this setup:
383 lt1 block 6 inch rods
compression is 12:2:1
crank internally balanced
-5cc flattop pistons
le2 heads (lt4 heads)
1.6 comp pro mag rockers
55cc with flow numbers at 297 intake and 202 exhaust (not sure at what lift)
234/242 with .612 lift 111lsa +4
milled to 58mm lt4 intake
58mm TB
k&n cold air intake
30# injectors (soon to be 42lb injectors)
MSD ignition
There is more but all I can think of off the top of my head. Just looking for a good idea on how much power I'm looking at.
Everyone give it a go and tell me what u think!

 

Excellent setup should make 420 - 480 rwhp depending on trans and tuning, definately get rid of the 30# injectors, the 42#'s are a good choice.

 

I think the CR is too high for pump gas. You are going to have to run it rich and without much advance to avoid detonation. If you plan to run it at the track, you should consider two different tunes, one for race gas to use at the track. With a safe tune for pump gas, I expect you will be dissapointed and not see anywhere near what is posted above. Please post results once you have it tuned/dynoed and good luck.

How did you decide on 12.2:1?

Rich

 

Hey Rich do you think a water/meth kit could help him stave off detonation?

 

Well my engine has the same compression ratio, same pistons, LT1 heads by LLoyd and ran 10.82@127mph on straight 93 octane so I'd say yes it will run on pumpgas fine. I also run 34degrees of timing so you don't have much to worry about. Now maybe when it's 100+degrees outside and you lug the engine there could be some detonation but I have only had mine running for a few months and it's been nice weather. You should easily make 400+ rwhp. Goodluck Clint

 

Agree with TA LT1 I'm running about the same compression in my 355 on premium pump gas in Lousiana heat without detonation .


Mike

 

Its not strictly static compression ratio. You have to look at dynamic CR and the effects of the cam overlap.

 

My sig has my DCR and SCR in it with a similar setup. I run on pump gas and road race the car consistently. You will have a DCR over 9 but as long as you take care of the engine and tune properly, you should be fine. However, quench is something to consider in engine design.

Saying all this, I would have preferred a lower DCR but taking off the heads after my season of only road racing the engine showed the combustion chamber was perfect. Granted, I do run an AFR of 12.2 to make sure I don't have problems and my timing is 35 degrees max.

 

Thanks for the replies. Lloyd Elliot is the one who sent me in that direction with the compression. From the people I have talk to, the compression will be fine on pump gas. We have 93 octane here in louisiana. It def will have a good tune on it once I get it all put together. My uncle has built many of engines and thinks will be fine so I think I should be fine. I will definently post the dyno numbers when I get it tuned. I was hoping to be in the 420 range give or take a little.