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View Full Version : BBC open chamber and closed chamber confusion


fatjodycat
04-27-2009, 06:23 AM
Can you run open chamber heads on a motor that has closed chamber heads on it? I notice that ads for BBC heads never state whether they are open or closed chamber. I also looked at pistons in the Doug Herbert catalog and they have open chamber, closed chamber, and then saw open/closed chamber. Would a motor with GM closed chamber heads accept lets say the GM "990" open chamber heads? Thanks in advance. Eddie

ARUSSELL
04-27-2009, 10:23 AM
You can put a set of open chamber heads on a closed engine and have no issues other then less compression.

fatjodycat
04-27-2009, 03:12 PM
Thanks.

oldandtired
04-28-2009, 02:47 AM
The closed chamber heads have valve shrouding problems, effecting their flow. It's just a design thing. If you run closed chamber pistons with closed chamber heads, at least the dome assist in the breathing.
Dave

fatjodycat
04-28-2009, 05:00 AM
Thanks Dave. That gives me more ammo for when I decide what to do for some more hp. I have a .30 427 with oval port closed chamber on it. It is a strong motor but I know there's more potential in it. Eddie