Advanced Engineering Tech - Higher Compression




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C5natie
05-07-2009, 11:17 PM
Hey guys, hope you can help. I have a stock bottom end LS1 with 60cc TFS heads and a stock 0.052 gasket. I will be doing some r&r on the car and was wondering if going to a 0.040 gasket is worth it? Im not too sure but the c/r calculator shows a change from 10.9-11:1 with the 0.052 gasket to 11.4-5:1 with the 0.040 gasket. Will half a compression point make a difference? Maybe a little more responsive on the throttle or a few ponies? Thnx for the answers ahead of time. BTW i dont mind using higher octane or race fuel to prevent detonation.


1 FMF
05-07-2009, 11:36 PM
well going off the basic principle of mean effective pressure, how an engine actually makes power by taking advantage of compression and the expanding force of the gas created when the air-fuel mixture burns, higher compression ratio is your friend, you want all that is possible. The limiting factor is usually the fuel and how much it can be compressed before it detonates without the spark, but you say you don't mind race fuel so as long as the compression doesn't exceed the detonation capabilities of the fuel you're good. After the fuel, the other limiting factors i suppose are clearances- piston to valve and piston to head, and then after that it would be material strengths.

And the higher the compression ratio, the more efficient the engine. Also, it has been found that the tighter the piston to head clearance, called quench, the less likely detonation will happen for a given compression ratio fuel octane combination.

C5natie
05-07-2009, 11:42 PM
^^
Well Im running the 215 TFS heads with a 13.5 degree valve angle. I called Vengeance Racing where I bought them and the guy said that the 0.040 gasket should clear no problem. I wonder if anyone here is running those heads at 60cc with a 0.040 gasket. Plus I dont have a huge cam, 228/234 112lsa so its only on the mild side. Hope theyre right.


SlickVert
05-08-2009, 03:19 PM
The big difference will be that with the .040 gasket you will have a tighter quench. That will reduce the detonation tendency while increasing compression. Win Win!
Most head and cam set-up use the .040 gasket.

C5natie
05-08-2009, 09:11 PM
^^
Well, mostly guys with aftermarket pistons. Most heads with 60 and under cc's might have clearance issues with the valves. Since I have a stock bottom end I went with TFS heads with the 13.5 degree valve angle.

JUNK
05-09-2009, 11:24 PM
The plain fact is that it will be less likely to detonate w/ the .040 gasket, as u would have perfect quench assuming piston is .006-.008 out the hole. As said b4, win win, do it.

C5natie
05-10-2009, 02:00 AM
Thnx guys. Parts are on the way.