What compression on race motor with N.O.
Thread Starter
TECH Enthusiast
Joined: Feb 2004
Posts: 743
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From: Foley, Alabama-southern Alabama
What compression on race motor with N.O. I'm building a 408 iron block strictly for 1\8 dragracing rpmrange 4500-7500,what compression would you run and suggest a solid roller for this set-up 5000 stall,4.88 gears 2200 car weight,also how big of no shot could I run in a 2 stage system? 
Well there are 2 thoughts on nitrous and race motors:
1. Lower Compression and More Nitrous
2. Higher Compression and Less Nitrous
(I am going the Higher Compression route, I am running 12.1 and around 300 worth of bottle, to start with)
So you kinda need to decide what you want to do. The main problems with Ls1's is that they only have 4 bolts per cylinder. So keeping the heads down becomes the main problem when running alot of cylinder Pressure. I would recommend Head Studs, Oring the heads, and get a GOOD tune before you start spraying the **** out of it.
1. Lower Compression and More Nitrous
2. Higher Compression and Less Nitrous
(I am going the Higher Compression route, I am running 12.1 and around 300 worth of bottle, to start with)
So you kinda need to decide what you want to do. The main problems with Ls1's is that they only have 4 bolts per cylinder. So keeping the heads down becomes the main problem when running alot of cylinder Pressure. I would recommend Head Studs, Oring the heads, and get a GOOD tune before you start spraying the **** out of it.
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Joined: Nov 2002
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Originally Posted by FASTONE
I'm building a 408 iron block strictly for 1\8 dragracing rpmrange 4500-7500,what compression would you run and suggest a solid roller for this set-up 5000 stall,4.88 gears 2200 car weight,also how big of no shot could I run in a 2 stage system?
The Bull
Joined: Jun 2002
Posts: 3,578
Likes: 2
From: Grand Rapids, MI
Nitrous loves compression!!! It's what makes it work. If you are building an all out race motor definitely look for serious gains at 13:1 and above. 13:1 is very dooable on these motors and with some proper setup getting to 15:1 is possible.
TECH Junkie
Joined: Aug 2002
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From: Fort Collins, CO
Not being able to use 93 Octane is definatley not something I'm worried about.
As far as servicing the motor, do you think putting new rings/bearings would be the only necessities, or would I be looking at new pistons and things of that nature?
As far as servicing the motor, do you think putting new rings/bearings would be the only necessities, or would I be looking at new pistons and things of that nature?
