Tractorsport Flowbench Forum Archive

Posted: **Fri May 29, 2009 7:10 pm**

Here are some links to help understand what you would see in wet testing. Lots of good stuff.

This is linked to the E-fluids site. Everything that has to do with wet or dry flow. You spend days here. Be sure to check out animations and pics also.
Here is a direct link to the galleries.

A whole bunch more here, fluid dynamics. Check out the table of contents.

Here is a site from gas laws, to airspeeds and nozzle flows. Science stuff for even the exhaust.

Maybe I should have put this in the links section.

Chris.

Posted: **Fri May 29, 2009 8:19 pm**

I'll pin this post so it stays on top

Posted: **Sat May 30, 2009 4:38 am**

Top Fuel Interesting Tid Bits

* At full throttle, a Top Fuel dragster consumes 11.5 gallons of Nitromethane per run; a fully loaded 747 consumes jet fuel at the same rate but produces 25% less energy.

Edited By larrycavan on 1243673225

Posted: **Sat May 30, 2009 12:33 pm**

[color=#000000]Larry, These figures are really

Posted: **Sat May 30, 2009 5:51 pm**

Interesting Doug...Thanks for the correction.

The point of the post was in the regard of wet flow considerations. I once saw a T/F video of fuel being delivered into the cylinder. Un-freaking-believable is the best I could describe that....

Not sure if TF head designers wet flow test. However, considering the enormous amout of fuel being consumed, the extreme swings the other way as compared to gasoline engines.

On a 1.7:1 a/f ratio, "wet" is an appropriate word, regardless of aircraft related comparison inaccuracy.....

Here's little video to get the point home

Another

How would one proceed to accurately wet test for such considerations..... A garden hose and a flowbench seem like unlikely test combo....

Edited By larrycavan on 1243735862

Posted: **Fri Jul 24, 2009 3:13 am**

While working for John Medlen I did the cylinder head flow testing for John Force Racing. John Force had a bench built specifically for the heads and shipped it to John Medlen's shop. At Medlen's shop we also designed and built our own line of Alcohol cylinder heads, nearly identical to the fuel heads. We did all testing at 68 inches of water, but we didn't do any wet testing.

Posted: **Sat Aug 01, 2009 10:41 pm**

Posted: **Sun Aug 02, 2009 9:18 pm**

Quote: "How did you guys arrive at 68" as being the number?"

68" of Water = 5 Inches of Mercury.

The Ford Flow Bench used in the early 1960s for the Ford Racing Programs: Lemans, NASCAR, Trans-Am, etc tested heads at 5 Inches of mercury.

It was one of the most powerful Flow benches at the time. A sketch of the bench is shown in one of the following SAE papers from the time. I have attached the SAE numbers.

# 670066 Modified High-Performance 427 Cu In. Engine Is Used in Ford Mark Ii-Gt Sports-Racing Car

# 670067 High Efficiency Air Induction System for 427 Cu In. Engine Used in Ford Mark Ii-Gt Sports-Racing Car

I could not find a "Free" web site that actually had copies of the papers. Maybe others can find a link.

Testing at very high depressions helps you to find issues that you would not see at 10" or 28" test pressure. Ford documents every head tested at the following test pressures so that we can discuss info with a variety of testers:

10", 20.4", 25", 28" and sometimes other test pressures up to and including the 68" test pressure.

Tom Vaught

Posted: **Mon Aug 03, 2009 9:55 pm**

Could it be that they are 'dry testing' at 68" to simulate a 'wet test' condition in the absence of a wet bench big enough to keep up with the heads?

Posted: **Tue Aug 04, 2009 9:42 am**

I feel once you throw water into the mix at that high of a depression that it can turn even more "messy" in the whole tract. At those speeds, who knows how the liquid will react. That is where the mixture becomes very important. If it separates or "binds together" somewhere in the tract, then it may not follow the port. But on the other hand, in a running motor the depression drop is so fast, substantial and high, that the liquid would further vaporize into the air. It all comes together thinking of how one part of the cycle can effect so many others. Then we try to get a good carb and tune to compensate for something else not doing it's job. That depression "amount" would be hard to calculate on how it vaporizes the liquid so by testing different amounts is the only way that I know of to arrive at a "close enough" conclusion.

Posted: **Fri Aug 14, 2009 9:40 pm**

Here is a link to another article about Dart's ideas with wet testing. They go a little more in depth with what they are looking for.

Posted: **Sat Aug 15, 2009 7:53 pm**

Wow, it's very easy to see, having watched that video, why these things are so tough to keep lit' as they say, wow. I have read though, that the top fuelers consume between 12-13 gallons on one pass...... not sure if that is correct, i can't prove that.........

Tractorsport Flowbench Forum Archive

good links for wet testing