Hi. Can anyone help me? I'm looking for some Slant head flow numbers to compare with my own results that I gained from the head porting project I worked on during my Xmas holidays. I would just like to see if I'm heading in the right direction before I start playing with my next test head.
Here's where I'm up to, all numbers are at 28" and with a 1.72" Chev Intake / 1.5 Chev Exhaust.
Lift -----Int-------Exh
--.05----29.6------25.3
--.10----60.3------54.5
--.15----94.0------77.5
--.20---116.5-----96.8
--.25---140.0----112.0
--.30---163.2----124.0
--.35---179.9----134.5
--.40---186.8----142.4
--.45---190.6----145.4
--.50---185.6----147.4
--.55----N/A------151.4

Thanks Andrew

Welcome Andrew! I was hoping this info wasn t lost when the other site went down. Did you modify the combustion chamber in any way?

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

The only combustion chamber mod I've tried so far was this. I placed an old head gasket on the head and scribed near the intake valve. If you imagined the chamber as a clock face, the spark plug as the 12.00 o'clock position and intake valve on the left hand side, I blended from the scribe mark down to the valve seat between about the 7.30 to the 10.00 o'clock position. I felt it was worth the effort for the CFM gains made.

Andrew

P.S. I did make some exhaust templates but I've damaged my digital camera and I can't download the photo's it takes.

As a rule of thumb, I use 200 on the intakes and 150 on the exhaust side.
This is based on a well ported, big valve head at 27 inches.
I looks like you are pretty close to that.
DD

Thanks for the reply DD.
Those numbers will give me something to aim for.
I did get 202 CFM out of one practice intake port but I wasn't happy with the loss of low lift flow, now that I know 200 CFM is what you would expect I'll keep working on it. What lift were you getting your numbers at?
Have you noticed in the past a tendency for flow in the stock to mildly modified intake ports to quite suddenly stall in the .400" to .450" lift range?

Thanks Andrew

.500 to .525 lift is about the max.
To get good flow at those lifts you will loose some of the low end velocity.
DD

Thanks again DD
Any advice regarding combustion chamber mods other than what I have already listed above?

Thanks Andrew