Looking at the motor in my 31 tudor and I'd like to play with porting the heads. I've gasket matched, pocket ported before but want to play a little deeper on the 31 motor. Always wanted to build a flow bench and been reading up on it and my biggest question is on the manometer. Anyone build an inclined one? If so how long did you make it? I see some homemade ones that as long as 36 but as short as 16". I understand inclined they are more sensitive and I also see calibrating them and setting them up they say they are calibrated at 28 inch of water. How do you scale 28" if the scale is only 16"? Anyway I've finally decided to build one and hoping on here have done the same and have some good advice for me!!
Wouldn't it be easier, and maybe cheaper to just buy one of the kits ? I know there was just a short time back a coupla kits available. All you had to do was provide the actual "bench/table" and the vacuum and the manual labor for assembly. I was going to build one, a couple of years back. I just decided to spend the money and have my work tested on a Superflow 600 that's checked every year for accuracy. Actually, to me, "accuracy" is much secondary to "repeatability". This is my main reason for the Superflow payout. I'm betting that a professional machine is much more repeatable than a hardware store vacuum, regulated or not. Plus...it takes up MUCH less room in the garage ! Mike
kits are about 1000 bucks. I don't really want to spend that much when I can build one for atleast half that price. If I were going to do this to make money then I'd look at something better but for just playing around with my stuff and a couple friends I can't see any reason to tie up a bunch of money into it. Besides I thought it would be cool to play with different things like carbs, etc.
Having worked in a race engine shop on 4 cylinder scca and svra motors years back and spending many hours with a die grinder in my hands I would say the scale is not important but like said above repeatability is what you are looking for so you can see if you are helping or hurting You just want to compare apples to apples If you were working with a lot of different engine makes then the actual number may mean more especially to the customer Wish you luck keep us posted
There is some outstanding information on how to setup your own DIY flowbench (and how to calibrate it using a home-made Helgesen plate) in David Vizard's How to Port and Flow Test Cylinder Heads (ISBN 978-1-934709-64-1). The porting guidance in the book is awesome. Well worth buying the book before having your first crack at a set of heads. Cheers, Harv
One of the car mags had a nice series of articles about building your own. I think it was Hot Rod. I'll see if I can find my copy. Will reposting it violate copyright laws?
Probably not, as long as you aren't reselling the information, claiming to be the owner of the information, or offering it on a commercial, "for profit" website.
I remember the Hot rod or Car Craft magazine that had templates printed on the pages that you could cut out and glue them on some card stock..... I think it was for the then new "Slant Plug Turbo heads" that chevy came out with in '76-'77....
The Jalopy Journal
