Why wet test?

[blaktopr]

I am happy to bring info to the people here. I know what wet testing does for me, thats why I keep pushing toward the answers to everyone's question. I don't want to sound like I am on the soapbox. Something like this may have to be seen in person.

My addiction now is to build a bench that will rival Dart's and maybe do more at pennies on the dollar. What I am offering is info and the possibility of a plan to allow others to embark on the same journey. It's all part of why this forum was started. I am hoping that I will see the results sooner than later in my car. A wet test developed 60's cast iron head.

A/F ratios, correct SG of liquid, air flow and mass will be investigated. I want to try to see if airflow testing with a proportional amount of liquid can give different results with cfm. The effects of liquid under higher depressions may be different. Plus a way to have the liquid turns into a gas or if it can with a drop in pressure through higher airspeeds.

There are others out there that benefit from this testing and I know it. Thats why I keep pushing on. And even little me is getting into the wet flow circle.

Chris

[86rocco1]

Chris,
It's nice to see someone taking the bull by the horns. It sort of dovetails with with my previous comment, we don't know enough about this tool to properly use it and interpret the results, we need someone to investigate this to determine when and how it came best be used.

[larrycavan]

Chris,

Are you working strictly with plenum manifolds are have you also tested with I/R setups?

Larry C

[200cfm]

Chris, I read some in Barnhouse today and he discussed briefly the A/F combo of the port in a light that I had never thought of before (at least visually). I was familiar with different fps and pressures that can occur in our ports, but Mr. Barnhouse pointed out that the port itself is experiencing areas where there is rich and lean mixtures. And that rich and lean areas will vary around the valve discharge cone areas. That the air might be turning on the SSR but that not much fuel will be carried along with it, hence lean in that area, and the rich fuel might be exiting the valve somewhere else and that chamber turbulences could kick the fuel back into the air. Made me think how wet flow testing could be in evaluating the port and valve discharge for rich/lean areas of interest. (tom c)

[jfholm]

Below is a link to the internal video of a running engine. I wonder if this is "really" an honest to goodness running engine? Looks like a lot more fuel than I calculated and the burn is way different than I expected. If it is an actual video it should give some really good insight. You will notice some of the cycle is missing. Why? Anyway it is very interesting and adds to this discussion.



John

[86rocco1]

Have you ever run a fuel injector outside of an engine? The visual impact that the tiny amounts of fuel can create is pretty startling so that aspect of the video doesn't surprise me, I'm wondering what kind of camera/engine set-up is needed to make that type of video.

[jfholm]

Ed,
Your right about the injectors and I forgot totally about that. But going back to Tom's comments about lean and rich spots in intake tract. I know that we need 12.5 to 1 to get the burn correct for acceleration. (give or take) But maybe we need to introduce a lot more fuel to get that ratio? Depends on the efficiency of the engine I guess. Are we wasting the fuel and not burning it?

The camera is installed like a pressure transducer. It must have some thick glass between the chamber and the lens???

John

[jfholm]

I also thought about that video. Things we DO NOT know:
What kind of fuel?
Induction system?
Naturally aspirated or blown?

I does appear to be a Hemi and it may be a dual plug and the camera is screwed into the second plug hole.

John

[Flash]

[jfholm]

Well DUH! Did you guys notice that there are 2 exhaust valves? I just noticed that.

One thing about this video it sures shows the need for wet flowing. There seems to be a ton of fuel going in.

John

[Flash]

[jsa]

[color=#000000]Things I see....
4 valve pentroof chamber
crank angle

[larrycavan]

[Flash]

[blaktopr]

Really quick before I get to sleep and get back to this. Larry, All plenum setups, but also just a radius. I feel no different from what you work on. I have a friend's YFZ 450 that needs work. Maybe I will get a chance to try it out.

Watching frame by frame helps. I noticed a bunch of things....

1.We can't see the SSR, but the prominent flow path shows the A/F riding across the EX valve down and back up toward the IN. The high pressure front at the bottom gets drawn back up to the roof. A vortex in the direction of the camera circle. That is understood through wet testing and weather.

2. Fuel begins at the far side of the IN valve closest to the camera. Can't really tell what it's doing over there, but you see a slower burn there.

3. Watch the face if the intake valve. Notice the CCW swirl. (Seen in wet testing) Notice the swirl continues during compression and power. Watch the fire ring it causes below it. That fire ring/funnel must be still from rotations due to the pressure diffs in there. Happening at about .54 and 1:13.

I'll come back later after some sleep. Been working overnights.
Chris.