Flow testing a modded intake....

If you were to flow test an intake manifold, would you have to blow through it, or suck trough it, or does it make a difference???

I have a spare intake manifold I am experimenting with, and I am thinking of making some kind of redneck flowbench.

I am thinking of conencting the return plenum to it, and blow trough the plenum with a shopvac. Then, using some ABS plastic, or perhaps some pvc pipe; make header looking contraptions to mount to the intake; then some kind of air flow sensor off ebay to measure each runner to check for equal flow...

I would think I could use some modeling clay and/or ATV to seal it back up and possibly thru trial and error, come up with an intake that will have more volume and flow equally to all cylinders...

I ran it by the guy at the machine shop and he gave me a bit of weird look, but did say thats basically what they do there.

Would a shop vac flow enough air for this purpose??? I got a decent 4.25 HP craftsman shop vac...

Anyone think it would work

If you want to measure it, you need a flow bench. But if you just want to watch it, you could use something to pull air through and then use smoke, watching how the smoke flows through the ports looking for places where the air needs to be re-directed.

Randy did a bunch of his own flow tests on the intake mods he has done. Maybe he'll pipe up. If not, send him a PM and see if he has some hints.

I really dont think it would be easy to flow it seeing as how there aren't any runners in the intake manifold.

I don't care to measure, I just want sme more volume.

The makeshift flowbench would be to ensure even flow...

It would look like a set of headers comming off the intake manifold.

Soeone ele I spoke with says there is a mothod where you put a ball in a cylinder and see how high the ball goes. Woudl require some tweaking of course, but I am curious to bolt such a contraption to a stock manifold, and see how it does first....