Tom, I made a "can" to check the flow of a alpine cyl head I was porting.
I followed the set up described in the book "practical gas flow". I used an
old Fosters lager can (the tin version) as it is the same diameter as the
alpine
cylinder. It had to be cut to a length determined by a formula in the book.
then a conical piece attached to that and connected to a shop vac with a
variable port in the vac hose and a vac guage made from 1" clear hose
filled with water. I was able to check as I went along the porting process
for how much improvement was being made. I checked them with the valves
installed, one closed and the other held open at its maximum lift. The can is
sealed to the head
with some modelers clay. I was able to improve mine from 11" of water down to
7".
The scale is not exact but it was a significant improvement.
Brent Edinger
Tom Hill wrote:
>
> I visited the machine shop today to inquire about the progress of the flow
> bench testing of my bonafide Holbay head vs. the stock head. In order to
> perform the test, they must fabricate a "can" that is similar in dimension
> to the engine cylinder. They are in progress and advised me to check again
> next week.
>
> It seems that if it isn't an American V8, you better not be in a hurry.
The
> last oddball engine I had built took a year. I will be lucky if this one
> doesn't take longer.
>
> Tom Hill
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