Ideas for a 87 octane LS-1...
Thread Starter
Staging Lane
Joined: Dec 2005
Posts: 75
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Ideas for a 87 octane LS-1... Well since my piggy bank seems like it is going to be on life support for awhile...My dreams of building my turbo motor are going to be put on hold... 
That being the case and the fact that the best I have for fuel in my area is crappy 90 octane that I have yet to see work any better that our 87 octane, I have decided to see just how much power I can make on the 87 octane...
What I have so far is a stock bore/stroke LS1 short block with Lunati forged 12cc dished pistons and a set of their 6.125 Pro Mod rods swinging on a stock crank.
This will be a carbed engine using a Edelbrock Victor Jr. intake and the MSD adjustible ign. module.
What I am looking for are ideas/comments on what heads, combustion chamber size, compression ratio, cam profile, etc. would work best.
The car weight will about 2700# and I will most likely hit it with a 150 or more hit of N2O at the track.
That being the case and the fact that the best I have for fuel in my area is crappy 90 octane that I have yet to see work any better that our 87 octane, I have decided to see just how much power I can make on the 87 octane...
What I have so far is a stock bore/stroke LS1 short block with Lunati forged 12cc dished pistons and a set of their 6.125 Pro Mod rods swinging on a stock crank.
This will be a carbed engine using a Edelbrock Victor Jr. intake and the MSD adjustible ign. module.
What I am looking for are ideas/comments on what heads, combustion chamber size, compression ratio, cam profile, etc. would work best.
The car weight will about 2700# and I will most likely hit it with a 150 or more hit of N2O at the track.
Making power and 87 octane just don't mix. You wouldn't even be able to run the stock cr. I'd do the math to figure out where your cr would be with stock heads and the dished slugs, then go from there. I'd imagine you'd have to keep it at 9:1 at the most.
Ok, completing your build for the planned addition of a turbo is one thing. But optimizing your heads around N/A operation for the short term is probably not going to get you much. Save your maney for the turbo, and live with the lower output while you build up the funds to mave forward.
Also, why remove fuel injection from an engine you are planning to turbo/supercharge? Tuning that carb for either one is going to be much tougher. Tuning spark around boost without knock sensors is also going to be somewhat of a struggle.
Also, why remove fuel injection from an engine you are planning to turbo/supercharge? Tuning that carb for either one is going to be much tougher. Tuning spark around boost without knock sensors is also going to be somewhat of a struggle.
Well, technically, you want to run the lowest octane possible on your motor as lower octanes produce more power. However, you also have to fight with the fact that you need to lower the compression so much, that it's not usually a good trade off, especially not for a street motor. I'd stick with just dealing with the low output until you can get the turbos together. Always build for your future goal.
LS1TECH Sponsor
Joined: May 2005
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Compression with 66cc combustion chamber, .045 thick gasket, and 12cc dish pistons on 346 cubes= 9.3:1 compression. All pending on how far the piston is in or out of the hole, gasket thickness your gonna run, and valve sizes.
LS1TECH Sponsor
Joined: May 2005
Posts: 11
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Itll run on 87 octane just fine, but with not much compression and 87 octane, you will not be able to run as much timing and power output will be down quite a bit. If you plan on sprayin nitrous I would highly recommend some high octane fuel.
