Scott_92RS

Ok, this idea just popped into my head for some reason, I guess being at work at 7AM messes up my head. Would it be possible to get 2 cheap MAF's and set them up to measure the airflow before and after going though a port, then you could take the difference and figure out the CFM somehow. No idea how to convert gm/sec to cubic ft/min though. Might have to break out the chemistry and determine the molar volume of the air flowing though the system to do the conversion. I dunno, just an idea, dont flame me if its the most retarded thing you've ever heard

MrDude_1

that would really depend on how accurate the GM sensors are....


but if they were accurate enough, and consistant between sensors, yea, i think that could be done.

ede

why not just make something to float a ball in a tube, like a flow meter? 7am, that'd be like going in at noon for me, got here this morning at 4:50 after a 90 mile drive.

Scott_92RS

Doesnt really need to be a GM MAF, I guess just whatever is available, and whatever is cheap. Even if both MAF's were way off (by the same amount), wouldnt taking the difference of the 2 readings negate an inconsistancies? Even if both MAF's read high or both read lower than actual, the difference would be the same.

Scott_92RS

Damn, I think I'd be looking for something else, although I dont know how much they're payin ya to make the drive

Scott

bnoon

Excelent idea!!! I'm on my way to steal the K&N display from the local parts store!!! LOL!

As long as you measured a few sets of heads that had been flowed on an actual bench, you could make marks on the clear tube for at least some sort of reference. Perhaps use an installed height micrometer for valve lift measurements...

Scott_92RS

Come on guys, you KNOW it'd be cooler with an LCD readout Probably a crapload harder to make though, lol.

ede

i'm paid pretty damn well, and i get to surf from work

MrDude_1

me too.



but i only drive 3 miles to work, and can leave as late as 10 mins before i should be here







they would have to be consistant between meters..

but the ball in tube idea would probly work better. perhaps not as cool looking, but cheap and accurate.

1bad91Z

iTrader: (1)

Scott, you're a tard.

If you want a REAL flow bench, I can probably get you one cheap.

It might only be a 25 in. water bench, but it's a real flow bench.

Tom comes across equipment deals ALL the time and I know of a place or two where you can buy a used flow bench.

The 25 in. water benches are ALOT less expensive than the 28 inch benches.

Just have to do a calculation to get the 28 inch / water flow numbers.

1bad91Z

iTrader: (1)

Or, you can be a ghetto Mcguiver and build one like this guy:

http://www.4cycle.com/karting/html/flow_bench.html

1bad91Z

iTrader: (1)

More info on building a nicer bench:

http://victorylibrary.com/mopar/bench.htm

Scott_92RS

I dont need a flow bench (although it'd be pretty cool), I'm just saying that maybe one could be made using MAF sensors. The ball-in-tube idea sounds like it would probably work too. Come to think of it, I guess only 1 maf sensor would be needed to read the amount of air coming through the port, attached to a vacuum. There would need to be some way to accurately regulate the amount of vacuum though. Again...just ideas here....

Scott

1bad91Z

iTrader: (1)

You can build the bench in the second link for $800.00

It will measure CFM in 28 inches of water. It's a nice bench. No computer read-outs though. You'll have to do the pen and paper for results.

Scott_92RS

$800 isnt exactly what I'd call a DIY "budget" flow bench. The Ball-In-Tube bench would be cheaper than a ****, as would the MAF bench (if possible).

1bad91Z

iTrader: (1)

There would be no way to accurately measure anything with your idea. You might be able to see a gain or a loss, but it wouldn't be in any accurate data format like you would need if you are porting anything that requires the ports to be identicle or as close to as possible.

Plus, you need at least a 4 inch bore to mate with the combustion chamber of the head. The MAF is 3 inches MAX, I believe.

Time is money, where's my fiddy?

Scott_92RS

Why dont ya read the article you posted, bunghole. The guy used sections of 3" pipe in his design..... And how can you be so sure that there wouldnt be a way to accurately measure? A MAF is there to accurately measure airflow, the amount of fuel injected depends on that sensor to function correctly.

Where's MY fiddy....

1bad91Z

iTrader: (1)

In my head, I was picturing the MAF mated to the combustion chamber which would be too small for the cc.

I still dont think your idea would be worth the time or effort.

Remember your hover craft idea?

They make pills for ADD ya know!

Scott's mind = :lala:



Just giving ya crap. If you want to spend $100 plus bucks on a MAF, I have all the tools to fab anything you want to try to build.

Scott_92RS

Hey, that remote controlled hover craft would have worked if we would have used more than 1 fan, or a more substantial motor. Its not my fault man, 3 months of doing absoulutely NOTHING (layoffs shortly after...) at work and thats what happens. Hell, I was being paid to make that thing

1bad91Z

iTrader: (1)

lol, you need

bnoon

Actually, now that I've thought about it a little more... a MAF bench isn't a half bad idea... 5V source, a voltage readout on the ECU lead... flow several known head combinations at different lift levels and write down the MAF output voltage.... hummmmmmmmmmm

Scott_92RS

Exactly Ya never know, it could work..... I'm looking for a cheap MAF, I'll let you guys know if this contraption ends up giving some kind of useful data.

bnoon

I just picked up an Escort MAF... yes, I know it's a F... O... R... D, but the small engine MAF was really cheap and will flow sufficient air for testing one port at a time. If you do get a MAF, get one from a really small engine like I did, or you will have to modify it to increase the sample rate due to only flowing one port at a time. You'd have to increase the sample tube size I would imagine... Anyway, I'm off to the mecca of hot rod parts, Home Depot, to see if they have any clear tubing to float a ping pong ball in... I'm going to try both methods, either at once or both at the same time. We'll see!!!

crnsuperduty

Check out Dwyer.com I'm a test engineer of Pneumatic valves/regulators/filters. One of the things I do is flow test. you can get a Dwyer pretty cheap, it would be considerable more accurate. As long at the downstream side is open to atmosphere 1 meter will read SCFM. Feel free to contact me with flow test questions.

onebinky

iTrader: (1)

The vortex style MAF meters that they use on alot of the Mitsu's are supposed to be extremely accurate. I believe it's still a 5v reference as well.

I can try and dig up some info on it if your interested, I have it in my school notes somewhere

Matt Parsons

Yes that works, and I've seen it done. The one I saw just had a powerful motor that pulled air through the head, then blew it through a Ford MAF and used a manometer. The operator reads the output in volts. If you're trying to build a bench to compare before/after projects, it works fine. The resolution is nowhere near as accurate as a commercial machine though and comparing the two is meaningless.

Matt Parsons

What kind of money are you talking about, and what bench? I've often toyed with buying one. I know of a Saenz bench, which appears to be identical to a Superflow S900 with the two manometers. It's in great shape, was used by a fanatic nhra Jr. Dragster builder who also made billet rods, jugs, carbs, pistons, head strap kits, cranks... all in a shop in his back yard. They had a dyno and a practice track out back.

Anyway I can buy the bench for $1,200