Quench area?????? Dumb question.

art leong · 12-27-2007, 04:39 PM

I'm new to this quench area stuff. In the past everything I've built(really gotten into) has had a hemi or a dished piston. So the idea of quench didn't come up.. My head has a rectangular area (combustion chamber) the rest is flat. The piston has a dome in the center. with flats on either side.
With no head gasket the flat area of the piston hits the flat area of the head. The flat area of the piston is 0.010 above the deck. I'm running an aluminum rod that the manufacturer says to have at least 0.050 piston to head.
By using a 0.074 head gasket. I should have 0.064 piston to head. Correct so far?
Now where does the quench area theory.come in If I use a thinner gasket I'm afraid of collisions.
I think the basic idea of the quench area is to keep the force(after combustion) on the piston, not on cylinder walls etc. Is this right
The next gasket increment I can go to is .120 thick. Thats from cometic.
I've had somewhat of a breakdown in communications (he wanted me to just put it together and not worry, 16+ to 1 comp, and 0.020 piston to valve) with the guy the did the machine work and supplied the pieces. So I get no help there. I realize that the OHC motors are different. But I can't see them that different.

Bill Harris · 12-27-2007, 08:37 PM

I'm no engine guy so I'll tell you more than I know. I was under the impression that the quench area promoted turbulence in the cylinder on the compression stroke and the turbulence was beneficial to the combustion process... i.e., more complete burn and more resistance to detonation. I have read a couple of articles on how close the piston has to come to the head for the quench concept to be effective, but I seem to recall that the spacing should be less than 0.040" or so. I think you can order custom thickness gaskets from Cometic, but I would wonder if going from 0.064" to 0.050" would be worth the trouble.

Good luck

Adger Smith · 12-27-2007, 08:56 PM

Art,
Check you PM

12-27-2007, 04:39 PM	#1
art leong VIP Member Join Date: Dec 2001 Location: Richmond Hill, Georgia Posts: 2,003 Likes: 0 Liked 1 Time in 1 Post	Quench area?????? Dumb question. I'm new to this quench area stuff. In the past everything I've built(really gotten into) has had a hemi or a dished piston. So the idea of quench didn't come up.. My head has a rectangular area (combustion chamber) the rest is flat. The piston has a dome in the center. with flats on either side. With no head gasket the flat area of the piston hits the flat area of the head. The flat area of the piston is 0.010 above the deck. I'm running an aluminum rod that the manufacturer says to have at least 0.050 piston to head. By using a 0.074 head gasket. I should have 0.064 piston to head. Correct so far? Now where does the quench area theory.come in If I use a thinner gasket I'm afraid of collisions. I think the basic idea of the quench area is to keep the force(after combustion) on the piston, not on cylinder walls etc. Is this right The next gasket increment I can go to is .120 thick. Thats from cometic. I've had somewhat of a breakdown in communications (he wanted me to just put it together and not worry, 16+ to 1 comp, and 0.020 piston to valve) with the guy the did the machine work and supplied the pieces. So I get no help there. I realize that the OHC motors are different. But I can't see them that different. __________________ Art Leong 2095 SS

12-27-2007, 08:37 PM	#2
Bill Harris Member Join Date: Mar 2002 Location: Ooltewah, TN Posts: 421 Likes: 13 Liked 26 Times in 13 Posts	Re: Quench area?????? Dumb question. I'm no engine guy so I'll tell you more than I know. I was under the impression that the quench area promoted turbulence in the cylinder on the compression stroke and the turbulence was beneficial to the combustion process... i.e., more complete burn and more resistance to detonation. I have read a couple of articles on how close the piston has to come to the head for the quench concept to be effective, but I seem to recall that the spacing should be less than 0.040" or so. I think you can order custom thickness gaskets from Cometic, but I would wonder if going from 0.064" to 0.050" would be worth the trouble. Good luck __________________ Bill Harris ex 2172 STK ex 2272 S/S

12-27-2007, 08:56 PM	#3
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Quench area?????? Dumb question. Art, Check you PM __________________ Adger Smith (Former SS)