Custom Cmbustion Chambers

[Frederic Breitwieser]

>I was kind of under the impression flatter chambers (in the head) with dished
>pistons made for the most efficient chambers. With the plug in the middle of
>the chamber, the mix is ignited and burns radially outward. Assuming a multi
>valve head, this seems to be the best geometery. No?

A friend of mine was doing some experiments on a Chevy 350, and found what
you had described to be very efficient.

The valves were not entirely round, as both the intake and the exhaust
valve had a "notch" cut into the circular area where the spark plug went
in.  The valves were slanted away from each other.  The inside of the head
was very flat, and the valve disks were parallel to the piston head, with
the valve stem at an angle.  I'm not sure how he kept the valves from
rotating, which would be disasterous, but he did get the thing onto the
dyno.  Unfortunately, the engine broke down on the bottom end and he hasn't
pursued it.  The pistons were like you described, dish style.  Money and
time killed his project.


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 HMMWV
2000 Buick-Powered Mid-Engined Sports Car