www.the351cforum.com

So some schmuck today on facebook is claiming an iron cleveland head can not flow more than 290 cfm no matter what you do to it. He says everyone who claims they flow more is using a bogus correction factor simply to get big numbers because his custom built flow bench says so. He claims he has done cylinder heads for pro stock cars in Australia, and was on the design team for the original SVO head project. Funny though that no one has heard of him.
And I will give him credit for one thing, it takes some big balls to basically call Jon Kaase a liar. LOL

Another reason to love Farcebook or the internet in general.

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Chris - Merkel, TX
http://raceabilene.com/kelly/hotrod
"Owner built, owner abused."

Well good for him.

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Brent Lykins, Lykins Motorsports
www.lykinsmotorsports.com
brent@lykinsmotorsports.com

This in a nut shell is one of the big problems with using flow numbers from multiple sources when comparing cylinder heads in that they are almost totally meaningless and useless. My little Superflow bench is calibrated using the PTS plates and doing so results in a correction factor of about 8%. On my bench on a 4.030 bore a 4V Cleveland head with a clay radius and no porting, a fresh valve job and a new SI stainless steel valve with no back cut will flow right at 300cfm at .700 lift. I bet it won't on his bench but if his bench was used to compare several heads to one another it would give valid comparative results and that's all a flow bench can typically do are my results correct or are his results? Who knows. Either way it doesn't really matter.

Same here, Dave. Superflow bench. 312 cfm with a 50° seat. No porting. Just good valves and a good valve job.

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Brent Lykins, Lykins Motorsports
www.lykinsmotorsports.com
brent@lykinsmotorsports.com

Trying to remember the name of the bench we used when I flowed the 4V stuffed heads and the 2Vs I ported. Mfg is out of business but the bench is quality and has/had a set of calibration plates. Raw flow numbers are kinda bench racing - in some respects - anyway. Just one part of the equation. I'd like to see published velocity numbers or curves at a fixed depression and the standard lift increments.

I also have a custom flow bench - built from plans published in Car Craft back in the 80s. It's in the shed, maybe I should put it back together and make up some numbers. I wonder if the vacuum motors still work....

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Chris - Merkel, TX
http://raceabilene.com/kelly/hotrod
"Owner built, owner abused."

KV Typical guy with his mouth being the fastest thing he owns. Flow benches are relative tuning aids . They are not reality and never will be until actual engine operation is incorporated to obtain flow numbers. They are a representation of a "point in time" measured at a constant time with a constant flow of air that doesn't vary. Someone WAAAAY smarter than me needs to explain to me how that is reality. Helpful , YES ultimate , HELL NO.
Randy

I understand a bench is only good to compare heads/ports on the same bench, but when some idiot comes out and says everyone who says a head can flow "x" amount of air is a liar, I'm gonna call bullshit. There are a couple thousand people in this country who get pretty similar results on a wide range of benches, and when someone posts "my worked heads flow 350 on the intake...." and this assclown comes out and says "no factory iron head can flow that much no matter what is done to it, the most you can get is 290 cfm", I'm gonna call a spade a spade and call out his bullshit. Gavin's high dollar flow bench is wrong, period.
You can all dance around the PC camp fire all you want, but fuck that, I'm not playing that game.

It seems to me though that if Gavin's bench is wrong by that much that he should be able to figure it out by other means. "Man that velocity seems really high for the amount of CFM for this amount of port area" or "this thing really makes some big numbers and runs very well for having heads that only flow X amount"....

In my own personal experience I find that my flow bench numbers tend to correlate pretty well with numbers from my dyno when I use a program which deals with this sort of thing like Pipe Max. Randy makes some very valid points about a flow bench and how it really only shows you what might be happening inside of the port at one instant during the induction or exhaust cycle. I agree with that and I think its one of the reasons why people who only look at flow numbers from the flow bench and nothing else are missing out on a lot of data that the bench could provide. One of the main things it allows you to do is measure the velocity in different areas of the port and that information is useful when determining weather or not a particular port will work well with other stuff to create an effective combination. One aspect of using the flow bench that I find to be incredibly difficult is how to use it to determine what area needs to be modified to improve the port. I'm just not good enough at porting to be able to say, do this, do that and it'll be better for sure...

That's how I used my home brew in the way back. It only used manometers to measure flow and pressure drop and there was a thin copper pipe with a manometer for checking "velocity". You could run some base numbers at a certain pressure drop, then grind a little, put the head back on and compare manometer readings. Not a Super Flow lol but the concept was sound IMHO.

Seems to me, as a tech guy, that we have the technology to put a head on a device that would cycle the air in the port as it might on an engine and use sensors to collect data at a high enough rate to study activity in the port in real time.

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Chris - Merkel, TX
http://raceabilene.com/kelly/hotrod
"Owner built, owner abused."