saylorZ28

iTrader: (6)

ok i have a set up for 11;4;1 cr and i am wondering if that will be safe to run 93 + oct since lt1 is reverse flow can i get a away with that ratio ... plus it will have the squeeze.. 150 shot ... someone tech in

duh

iTrader: (16)

I don't see it being too bad, just make sure to run 92/93 whichever is higher in your area. Maybe look into the dynamic compression ratio calculator and see what that sits at. If your dynamic is much higher than 9.5:1 then you may want to double think your course of action.

ss.slp.ls1

iTrader: (36)

^^^Exactly, calculating your DCR is your best bet.
I think you should be fine on 93 octane though.

RamAir95TA

iTrader: (2)

You can go much higher than that (SCR considered). It's in the tune.

duh

iTrader: (16)

without cam specs and specifics for the engine you can't figure DCR and therefore can"t confirm what we all think, that he'll be fine.....

as for SCR I speced out a 414 with a SCR of 12.4:1 with a DCR of 9:1. With those numbers I could run 93 or even a boosted application (with some race gas) and really make some hp.....

94Z28rag

iTrader: (10)

Nitrous loves compression.

kinglt-1

iTrader: (26)

agreed with above post. The op should not have any problems with that compression on pump gas. Good tuning is key!

za355tx

iTrader: (108)

Honestly 11.4 is not that high. My setup before I parted was 12.4 scr and I didn't have issues. Lloyd Elliotts old car had a 13.1 scr so yeah you can get away with alot.

saylorZ28

iTrader: (6)

well i was goin to run an cc503 on this setup with ported heads and a 355 short block... but i've been thinkin bout the 383 and wonder how a 503 would act with it ...

RamAir95TA

iTrader: (2)

While it would be "fine" by most standards, you can get away with something much bigger. You need more duration and lift to fill the cylinders of a 383. I would look for something in the 23x+ range closing in on .600 lift.

LT1nitrouZ

Where can I find said dynamic compression ratio calculator? and what is the difference between the normal interpretation of compression ratio and dynamic compression ratio?

gregrob

iTrader: (8)

I'm tired. Google it

duh

iTrader: (16)

do a search here on tech and you should find one or two threads on it, just takes some looking.....BTW ^+1 I'm going to bed.....

saylorZ28

iTrader: (6)

i geuss i will stay with a 355..

NightTrain66

iTrader: (7)

here is a good DCR calculator.

http://www.wallaceracing.com/dynamic-cr.php

Just plug in the #'s listed and you will see how the IVC effects the DCR.

CC 503 is a descent cam for someone needing to pass emissions and a very mild gear/stall set up wanting a 6200 RPM shift point.

If you do not need to pass emissions, want to shift at a higher RPM and/or have some gear/stall, a larger cam would probably be more what you are after.

Lloyd

LT1nitrouZ

So with a good tune then 8.89:1 DCR would be fine to run on 93 octane judging by what has been said.

This topic is of particular interest due to the fact that the car I just bought has a 12:1 compression 396 and I need to get it to run safely on pump gas... horsepower doesnt matter on pumpgas, I can put a racegas tune in it at track. I just need to get from point a to point be safely on 93 octane.