Closed / Open Chamber Heads

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Closed chamber is a sort of heart shaped raised area around the valves, about half the chamber, as opposed to the complete bowl shaped relief/chamber. This reduces chamber area, increases CID a bit. Search 302 heads for pics of closed chambers.
 
Closed chamber is going to raise your compression versus an open chamber head. If running closed, you need to make sure your pistons sit low enough so the valves don't slap the top of the piston
 
pauly said:
Closed chamber is going to raise your compression versus an open chamber head. If running closed, you need to make sure your pistons sit low enough so the valves don't slap the top of the piston
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Thanks Guys for the info.Ron
 
I don't think a closed chamber head casting effects piston/valve clearance but we do want to check everything when mixing parts. cheers
 
Closed chamber

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the close chamber head is designed for squish, which is that part of the chamber which causes the fuel-air mixture to head to the valve side at supersonic speeds at tdc to produce a better flame front and combustion for more horsepower.
 
bOb shingler said:
the close chamber head is designed for squish, which is that part of the chamber which causes the fuel-air mixture to head to the valve side at supersonic speeds at tdc to produce a better flame front and combustion for more horsepower.
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piston to head clearance is fairly critical w/ the closed chamber-quench type heads .
 
... and mill all the chambers to the same depth as the deepest one of the 8. Or don't waste the time. Quench and open chamber are oil and water. If you don't do a lot to address the issues using them and trying to get the parts close together safely you get oil floating on water...
 
moper said:
... and mill all the chambers to the same depth as the deepest one of the 8. Or don't waste the time. Quench and open chamber are oil and water. If you don't do a lot to address the issues using them and trying to get the parts close together safely you get oil floating on water...
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I should have mentioned the part about equalizing chamber volume and depth, but I ASSumed anyone spending the effort to get quench with the OC head would reconcile that. I've done it so many times it's basically simple repetition for me.

You can bet everything that anyone running Stock and Super Stock has been doing it for years.
 
That's the thing - most are using open chamber heads to avoid spending on closed, and don't spend on blueprinting either. That's why I always say if you're going open chamber factory - ignore quench. There are pistons billed as good for that - but none of them work with any real effect without spending on blueprinting the shortblock and heads.
 
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