Why wet test?

[86rocco1]

I just got a response to my query, the vendor doesn't know, it was a surplus item they picked up from somewhere and they don't have any technical information on the flashlight.

[Flash]

Not to change the subject to much but what about Smoke...Dye?

Chry uses a smoke machine that add smoke to your fuel tank(test for evaporate aka fuel vapor leaks)
This "smoke" leaves traces behind that can be seen with a Black Light.

Has any one tried this? Mite be worth a try on a port that is stumping yeah.............wouldn't be wet, so could be us with Bruce's flow bench/plans. ???

[bruce]

I have a smoke generator I have used in the past, it will fill the shop up real fast with smoke!

I might have to play with it on my new bench, I only used it a few times on my old pitot bench.

[blaktopr]

I have and will be answering all those questions in my testing. Also spoke to Bruce about AF ratios and air mass to be used in testing with the computer. Fuel injector calibration fluid has the same SG as fuel. Maybe Tom V. can get me some. Before you guys get too far with the details. Just try black water on white chamber. Enough to make your head spin.

Chris.

[blaktopr]

Maybe I can find a computer programer, and make a program that models wet flow. I think it can be done.???

[jsa]

[blaktopr]

I have found wet testing gave me answers to many questions. Things become more clear when you get to the why.

Flow patterns would probably be different when using smoke because it has less mass.

I have found separation problems that would have been left not adressed if not using these means. I confirmed this talking to other head porters who do this for a living (nobody high end)

You get to understand pressure differentials inside the port and chamber.

You start to understand how the pressure recovery in the cylinder can effect airflow through the port.

You can see the trend of why there are complete or incomplete burn in the chamber.

You can see the effects of different valve seat angles.

You can study the effects a "heavier" mixture has at higher velocities. Whether or not the port can still handle it.

You can see where puddleing can occur in the port or chamber.

Why a particular combo needed more or less spark advance. Was it chamber shape or port shape that made the difference.

What a sharper/ thinner/ wider valve margin causes.

Carb spacer design and its effects on signal and pressure recovery.

Booster design, and how it meters fuel

There are some off the top of my head. There was an article in Drag Racer (?) talking about Dart's bench. My friend read it to me over the phone. He was stunned by two things.

1. That a wet test system can be built at home for cheap compared to the Dart bench.
2. That everything I told him I found through my testing and speculations I made were stated in the article. By Dart and used in PS racing to find gains.

They are developing heads using this medium. Now I was thinking about what are we gonna do with it. Once I finish the attachment and motor box, my testing will be in full swing again. Just as John was mentioning, I will be looking into measuring and flow testing not just with cfm, but the converted necessary LBS of air and fuel for the target HP level the head is intended for. Once I get some kind of working prototypes together and see if there is info to be found, I am going to work with Bruce and others on this site to try to develop a way for the flow computer to also read and control the liquid medium and work it to LBS for mass readouts. So you would get readouts of cfm, lbs/min, AF in relation to the bench's air/fuel reading, in relationship to the HP target you are testing.

Once static is higher than 28" on my bench, the whole test will be documented usid fluid and air through the whole test for the numbers. Then visual tests to see what other issues to be addressed.

I'm not letting Dart have all the fun.

Chris.

[blaktopr]

[jsa]

[slracer]

Ed, In case you missed the "LED lights..." thread, check this out for wavelength!



Now, if we only knew the color! -- Doug

[86rocco1]

[blaktopr]

[86rocco1]

[larrycavan]

Wet testing is one of those things I have not been totally sold on. Not because I don't believe it won't show you anything. On the contrary, I have a tendancy to believe it can show you misleading things. Things that may cause you to chase your tail....so to speak.

It's John's evaluation of the actual amount of fuel [that is the type & quantity of fuel most of us deal with] actually being consumed during a cycle that I consider a key factor in the whole process.

Add to that the affects of the flow pattern changes introduced by every component attached upstream of the port.

This points to the method being used during the wetflow testing and the possibility of chasing your tail.

As long as the tests are conducted with the entire intake tract installed and with the actual amount of liquid that will duplicate the amount of fuel the live running engine will receive, then the possibility of observing something useful should rise considerably.......So logic would dictate anyway...

Conversely, to just start spraying unmeasured amounts of fuel into an intake port while vacuum is applied, then observe the pattern of distribution in the port runner and chamber would, IMO, quite possibly be very misleading.


Witness the results of the wet tests conducted by another forum member with his ever progressing Studebaker project.

Now I'm not knocking wetflow testing. I am simply pondering the possible ways it may or may not be of value. The real value seemingly lies in the method.

Another obstacle is the fact that you don't get to visualize the affect of the squeeze with a wet flow rig. As such you have to make assumptions [assumptions are nothing new to us in this game :;): ]


Any cylinderhead that comes to me that has not been cleaned up prior, gets a close inspection of the valves, ports & chambers before any carbide touches metal. The residue left behind from the combustion process is one of the best examples of what takes place inside that running motor. Some problems are quite easy to spot.

After having drawn a conclusion from that inspection, a properly conducted wet flow test could be use to affirm or deny your initial assesment....JMO

I look forward to more of Chris's results.



Edited By larrycavan on 1243141563

[86rocco1]

That just makes wet flow testing like everything else in engine development, an imperfect tool whose result require interpretation and as such are also open to misinterpretation.