boredsoIstrokedit

What performance gains are seen. Unfortunately, the motor has to be 9.0, so I can't benifit from the additional compression w/o detonation. GKull, you had swain do em right?

gkull

http://www.swaintech.com/autolc.html

Yes, I also told Monty who had his done that my pistons still have a nice coating at @ 20K miles of 10.84 compression on one bad day of detonation. I'm going to redo the heads completely because I took a horizontal wire brush grinder and cleaned the cambers. I plan on doing the exhaust ports and exhaust valves.

I don't know I could verify any performance gain. Read their sites Info. also i found some place in Texas that had good prices.

I don't understand has to be 9.0?

boredsoIstrokedit

"has to be 9.0" = the compression rule at the track is maximum whistled compression of 9.0 to 1. The rules don't necessarly mention a lot of other things :D, but this one is stringent, and tested at least 2 times per season it seems like. :cheers:

Twin_Turbo

how are they gonna test the compression? the cranking pressure is related to the dynamic compression, so the choice of cam and the intake has a large effect on it. There's no sure way to tell compression but to verify the components inside the engine

boredsoIstrokedit

They use a machine called the "Whistler" We have found a way to get a little more "legal" compression, but it has nothing to do with the cam. It blows air into the plug hole, then the piston is moved to TDC, and it measures compression volume. I assume that it calculates the volume of the air blown in, and the pressure, since pressure times volume= moles of gas times a constant times the temp. Basically, volume equals temp divided by pressure. Machine is not that accurate, and temp fluctuations result in HUGE discrepencies in readings, but that is the best equipment they can afford. and the rules say "whistler results are final". :cheers:

Chuck Harmon

I would think you could easily fool the whistler method by overtightening the valve lash.

Chuck


[Modified by Chuck Harmon, 3:30 PM 3/27/2003]

Twin_Turbo

They would have to accuratly find BDC after the intake stroke and then TDC after comprssion. There's a problem though since at BDC the intake valve is still open at BDC. If they would rotate further to after BDC where the valve is closed their volume ratio method would not be accurate. Also, the longer the duration is (or the larger the ICL) the longer the valve will be open after TDC and the more it would leak and the more inaccurate it would be. That system sounds like a totally trivial system to me. It's got as little to do with compression as a cranking pressure test. It does not matter if you blow in the air via the spark plug or let the engine inhale it via the intake and a wide open throttle. The compression ratio of the volume going into the cylinder will be the same. The only benefit of this device is that you can taylor the amount going in and have a marginally degree of accuracy if there is no or little leakage. Just my opinion.

79Bluestreak

boredsoIstrokedit, I have a shop in Edgewater, We are applying ceramic coaltings to exhaust system as well as the internal parts. I would like to talk to you some more about what you had done to your engine. I have a 79 that I am currently coating all the internals, as well as using the coating as a decroative application. :chevy :chevy

boredsoIstrokedit

Oops. Forgot to mention one thing. We take the rocker arms off, or at least free them and turn them off to the side. Sorry for the confusion, because you guys are absolutely right. :rolleyes:

boredsoIstrokedit

I just moved to FL, where is edgewater at. I would LOVE to check out your vette, and shop. I just moved down here March for a couple of years, and I am away from my vette. :sad: :sad: Email me.