Posted: Wed Jul 11, 2007 9:07 pmAs many know, I work for the Blue Oval guys.
I was having a discussion with an engineer the other day about
testing of intake manifolds and cylinder heads.
I have an old copy of Ken Speery's Flow Bench book he published in 1992 where described the GM Flow Bench lab and how they did their testing.
Their bench was based off of a GM Roots 6-71 Supercharger that
could flow 400 cfm and it used a variable speed controller. It used
a Laminar Flow Element as the flow measurement device.
The book gives some good information on how they combined computer testing, Engine testing, and Flow bench testing.
They felt intake testing was a three step process:
Flow the intake by itself and read the flow restrictions in the intake.
Flow the intake with a cylinder head at max valve lift and check
for swirl and tumble. He stated that the heads would mask a poor intake runner.
Test the intake and heads on a motoring dyno with the valves moving to determine transient flow.
I would like to know if anyone ever looked at flowing all of the runners at the same time with measurement devices at each runner like Smokey suggested years ago? Larry M?
Tom V.
ps The engineer I was talking to considered a manifold having
a 10% spread in balanced flow between runners acceptable and I thought that was a poor intake. I have always tried to be with-in 2% for all of the runners.
I was having a discussion with an engineer the other day about
testing of intake manifolds and cylinder heads.
I have an old copy of Ken Speery's Flow Bench book he published in 1992 where described the GM Flow Bench lab and how they did their testing.
Their bench was based off of a GM Roots 6-71 Supercharger that
could flow 400 cfm and it used a variable speed controller. It used
a Laminar Flow Element as the flow measurement device.
The book gives some good information on how they combined computer testing, Engine testing, and Flow bench testing.
They felt intake testing was a three step process:
Flow the intake by itself and read the flow restrictions in the intake.
Flow the intake with a cylinder head at max valve lift and check
for swirl and tumble. He stated that the heads would mask a poor intake runner.
Test the intake and heads on a motoring dyno with the valves moving to determine transient flow.
I would like to know if anyone ever looked at flowing all of the runners at the same time with measurement devices at each runner like Smokey suggested years ago? Larry M?
Tom V.
ps The engineer I was talking to considered a manifold having
a 10% spread in balanced flow between runners acceptable and I thought that was a poor intake. I have always tried to be with-in 2% for all of the runners.