The Basics

[Blocker]

Hey guys.
I'm real new to this flow bench stuff so dont crucify my ass. Please.
Iv never phisicly looked at a flow bench in action but I am looking into porting multi vavle heads for street car use but I need to be able to produce nice balanced ports that are even. So here are some questions that are basic I have searched. you link me if you cant be bothered to anwser I no how painful noobs are.

1. When testing exhaust ports on a flow bench does the flow bench blow rather than draw for better real world testing?
i.e inlet ports draw air ex ports port air out of the head.

2. The bore on the engine is 86mm do I need to get air drawing threw a 86mm cylinder on the flow bench with the head on top
drawing threw the inlet ports? i.e most home made jobs seam to have a 5-6" hole in the bench.

3. How do you measure Velocity on a flow bench? A air speed indicator?


I have loads more simple questions I am not a math guru either so simple stuff is mint,.

[SSR]

Well you're definitely from the UK, whereabouts?

You need to re-create as closely as possible real world situations so yes, an identical bore size is needed and you would suck or blow through all your ports just the way it would be doing on a working engine.
The item you need to make, source or study (search on here) is called a 'Bore adaptor'.

Yes velocity is measured with an airspeed device. As you may be aware Bruce (site owner) sells all the parts and plans for the DIYer to build his own bench, if you are serious I would recommend buying them, for the price, quality, knowledge, patience and pure helpfulness (of Bruce and the guys on here) you won't find better anywhere else. Part of his 'kit' comes with a velocity probe which you can put into various parts of the port to check velocity as it differs greatly in different areas.
Some guys make their own probes so do a search on here and on the old forum (this one moved a year or two ago, but the old one still exists I think) on how to make them.

[Blocker]

Haha ya got me all wrong. I'm a Kiwi. (hang sh*t here)

Certinly Bruce's bench looks like a good thing. I'm still to new to this to be able to understand what I'm looking at.
But i'm working on it. I'v Ported heads for years but iv only ever user MPH to work out if things are working or not. Or iv taken the head to a local "pro" with a old bench that im not even sure is that trustworthy. The numbers he gives me look to good to be true.

A lot of the stuff I work with is turbo. It's not well understood how important a good head is. If things are not going so well making numbers the simple thing is just to smash more boost in.
The whole idea I look at with the heads is that after work the car should make more power with less timing and ramp boost faster.

I digress.

I will have a bit more of a poke around and talk soon Thanks SSR

[SSR]

'Lol' (sic) I would have laid good money on you being a Brit, where did you learn to spell so badly and use adjectives like 'Mint'? !!

I guess there are a few ways of learning, I chose 'buy the best equipment you can afford, then learn how to use it', probably a bit backwards, but it works for me.

"The whole idea I look at with the heads is that after work the car should make more power with less timing and ramp boost faster."
Yep, or same power with less boost also.

Hope you enjoy having a root around.

[jfholm]

Neat thing about this forum is that there are people from all over the world. Neater yet is we all get a long with each other. I hope the world leaders drop in here to see what it takes for people to like each other.

John
USA>UTAH>MIDVALE

[Blocker]

If I gave a ass about spelling I would have found a forum for it.
But being that I sit here in my 1/2 inebriated state it's the last I worry about.

OK so what flow bench do you have?? SF600 seam to be the balls as far as a top shelf bench goes. I got NFI what they are worth either. big $$ I bet.
What sort of work are you doing with it? V8? 4 banger ? space shuttle?

As I understand it 28" of depression is the common ground for testing on car heads. Would you use 28" for say a bike or a go kart of is that over kill?

I no of a guy down south TK is his name making a flow bench from a 8/71 scavange blower from a old detroit. men't to pull like 40" @ 600 cfm. That has nothing to do with anything but It's cool.
anyway what i'm getting at is what is the part on a bench that makes the water rise to the 28" line? Is the water forced up the tube by air pressure pushing on a bladder?

What is the difference between the vertical water scale and the horizontal? iv seen a bench with 2 vertical scales. Is vertical for depression and the horizontal flow threw the head when testing?

Thanks in advance chief.

[Tony]

Hello Blocker, welcome to the Forum.
I am in Melbourne, a bit closer than some of the other guys here.

What is the difference between the vertical water scale and the horizontal? iv seen a bench with 2 vertical scales. Is vertical for depression and the horizontal flow threw the head when testing?

Ah!
Grasshopper, you are asking about "the meaning of life".
You have definitely come to the right place.
Check out this thread, all will be revealed.
http://www.flowbenchtech.com/forum/view ... hp?f=3&t=5

[Blocker]

Very good very helpful. Thanks Tony.. wait Tony?!

Are you indeed TK the genuine article?

[Tony]

Not sure who TK is, but I am not he.

[Blocker]

Not sure who TK is, but I am not he.

it's cool. He is a well respected over on the performance forum he runs a race shop down you way and is
generous with info on port work and heads.

So what sort of stuff are you doing with heads??
Or are you just keen on the topic? In which case I still respect what you have to say.