|08-20-2007 08:47 PM|
.025" might work on a Mopar, but on a Chevy, you're just begging the pistons to hit the heads.
GM makes .026" shim gaskets for less than $10 each, and .028" composition gaskets for a little more. I'd be more comfortable with one of those.
|08-19-2007 10:33 PM|
So that's what I smelled when I sat down here?
|08-19-2007 10:05 PM|
|08-19-2007 07:32 PM|
|timothy9972||The heads are already bolted down and I sat the engine in the car yesterday. This is my first real build. Watched and helped many times but this is my first time to do it and even then I had a friend that is familiar with Mopars help out. SO it is all new to me.|
|08-19-2007 03:31 PM|
|techinspector1||With the piston 0.010" in the hole and a 0.015" gasket, the piston to head clearance is only 0.025". GOOD LUCK.|
|08-19-2007 02:04 PM|
.010 in the hole at TDC
we did check the valve to piston clearance with some clay and there is plenty of clearance
|08-19-2007 01:15 PM|
Well, actually, the narrower the squish is, the more resistant the motor is to detonation. But there is a mechanical limit to how narrow you can go. That's why I was saying I don't see how you can build a 11.72 motor with 59 cc heads and flat-top pistons.
Timothy, how far down in the bore is the piston at top dead center?
|08-19-2007 08:04 AM|
|Greg T||The squish or quench area is the gap between the piston flat and the head flat @ TDC, which allows the flame to accelerate and cool during ignition. The wider the quench area the more resistance you have to detonation. Also, the quench is a safety net so that your piston doesnt make contact with the head. You cant just deck blocks, shave heads and throw in some domed slugs. Life is not that easy.|
|08-19-2007 07:47 AM|
|timothy9972||What is squish?|
|08-19-2007 12:41 AM|
|techinspector1||So, what does the squish measure?|
|08-18-2007 11:14 PM|
|timothy9972||metal shim gasket with a compressed thickness of .015, and the block has been milled|
|08-18-2007 10:31 PM|
|Greg T||With that much static you have more than plug gap to be concerned with. I would immediately change the cam to the comp 292 to bleed off some of that cranking pressure.|
|08-18-2007 09:08 PM|
Using 0.039" compressed for the gasket, zero deck, 5 cc's in the piston eyebrows I get 11.08:1 static c.r. I don't see how you could get to 11.72 with flat-tops in a 350. Even at 11.08, the cam's too short.
Anyway, with that much compression, start with a gap of 0.035". Widen it a little at a time to experiment, depending on your ignition system and the coil you're using.
|08-18-2007 08:38 PM|
Anyone have a guide on how to gap spark plugs on custom engine?
Chevy 350 .040 over/ "double hump" 2.02 heads (been shaved with 59 cc chambers now), forged flat top pistons, compression ratio 11.72:1, XE274H cam (Lift .487/ .490), HEI, Edlebrock 650 CFM carb
any other info I need to provide?
ps using accel header plugs