0.040 Gasket or mill?
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0.040 Gasket or mill? Bits and pieces of this question have probably been answered a thousand times, but I'm still unsure of the answer so here we go. I'm planning to do H/C/I on my 2000 LS1 with 853 heads stock. I'm swapping them for Livernois Stage II heads with a custom cam. My question is: I was planning to use an 0.040 cometic to get to approximately 11:1 (by my calculations), but I'm not sure what quench that leaves. I have read that 0.035 is the recommended minimum. I could wait to pull the old heads and measure the deck height, and that may be what is recommended. I could have the heads milled 0.010 and use an 0.045 gasket, which would put my quench at 0.037 minimum (0.008 out of the hole is the most I've read on this forum, could be wrong). Should I wait and put a dial indicator on it, or should I have the heads milled? Probably six of one, half a dozen of the other but my thinking was I have a bit less total volume if I used the thinner gasket as opposed to milling and a slightly thicker gasket. Any advice is greatly appreciated.
Quench is the distance from the top of the piston to the flat surface of the head, so milling won't affect the quench, it will affect the chamber size and compression ratio. Only the gasket thickness will affect the quench unless you want to start working with the short block since the piston out of the hole distance is whatever you have on the motor now.
I would wait until you get the heads and then measure the out of the hole distance before ordering gaskets. This also makes sense since the cylinder head chamber width may determine the required gasket bore and not the cylinder diameter. Bottom line, make all the measurements and then order gaskets.
I would wait until you get the heads and then measure the out of the hole distance before ordering gaskets. This also makes sense since the cylinder head chamber width may determine the required gasket bore and not the cylinder diameter. Bottom line, make all the measurements and then order gaskets.
What your looking for is a minimum of .040" piston to cylinder head deck clearance #.
If your piston is out of the hole(above deck you would run that # +.040")
.009"-.011" out of hole + GM o.e. .051" thickness
If it's flush or in the hole .040"s are fine
you need this clearance for when the piston starts to get loose and rock a little so you don't kiss the cylinder head.
You should be mocking up all clearances or making sure your builder is.
If your piston is out of the hole(above deck you would run that # +.040")
.009"-.011" out of hole + GM o.e. .051" thickness
If it's flush or in the hole .040"s are fine
you need this clearance for when the piston starts to get loose and rock a little so you don't kiss the cylinder head.
You should be mocking up all clearances or making sure your builder is.
I measured mine including piston rock. Also running a .040" without issues. The beauty is that quench which is as tight as I'd ever go allows higher CR and/or mire timing than you normally would be able to.
I'm at about .033" Quench without issue and about 1000 miles and many pulls to 7k.
I'm at about .033" Quench without issue and about 1000 miles and many pulls to 7k.
Bits and pieces of this question have probably been answered a thousand times, but I'm still unsure of the answer so here we go. I'm planning to do H/C/I on my 2000 LS1 with 853 heads stock. I'm swapping them for Livernois Stage II heads with a custom cam. My question is: I was planning to use an 0.040 cometic to get to approximately 11:1 (by my calculations), but I'm not sure what quench that leaves. I have read that 0.035 is the recommended minimum. I could wait to pull the old heads and measure the deck height, and that may be what is recommended. I could have the heads milled 0.010 and use an 0.045 gasket, which would put my quench at 0.037 minimum (0.008 out of the hole is the most I've read on this forum, could be wrong). Should I wait and put a dial indicator on it, or should I have the heads milled? Probably six of one, half a dozen of the other but my thinking was I have a bit less total volume if I used the thinner gasket as opposed to milling and a slightly thicker gasket. Any advice is greatly appreciated.
