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DudeAndHisBus wrote:Just a thought, but what would happen if you narrow the shroud on the 1/2 side, having a smaller percentage of it go over the #1 cylinder?

Wouldn't that increase the velocity of the air on the 1-2 side?

On the other hand, it may increase pressure on the 1-2 side and force more air to the 3-4 side.

I guess only testing will tell for sure.

Charles

Jake,
Per our conversation, I think reallocating air via the "transfer tube" might work provided we take the right amount of air and strategically reintroduce it at an area where it can produce a scavenging affect without raising pressure above the head (we already know what that would do). You should use a flat long scoop like VW did to direct air to the doghouse cooler. What areas in the 3-4 bank run the hottest? Email me, I have an idea!

I emailed you a zip file, did you get it? I want to send a shroud to you this week.

Jake,
I didn't get the file. Please send it again. Do you still have my address?
Thanks,
Tony
speedy57tub

Everyone seems to agree that the VW engineers who designed the cooling system were clever, bright, etc. Considering that the latest redesigns (like the FI venturi ring) were done in the early 70s, I am wondering where these designers are now. Since it's only 30 years ago, they could be still around somewhere, and flattered (and hopefully willing to contribute) that we're interested in their work. They could be in their sixties, or seventies, possibly some of the best years of life.

Jake,

I want to join those folks thanking you for doing this work and sharing it with us. There is no other way we could get the real scoop other than thru your applied research.

Thanks a bunch.

Hell they are probably dead from the stress....

I am convinced that the VW engineers had to undergo a lot of "trial and errors" to render their design which is not exactly 100% effective but adequate for their intended "stock" applications.

Jake, when you are testing the stock DH systems, have you tested the ones with and without the scoop that directs air to the oil cooler? All the 74 shrouds I've seen are without this scoop, but the earlier ones have it.

Will you also re-visit the T4 cooler in a T1 shroud again since you now have a repeatable baseline?

Have you tested the stock shroud with the T3 lower cool tins and with T1 deflectors?

The cylinder tin test is already completed...

The rest of the stuff is underway and already outlined for testing.

Jake,

remind me to buy you a beer at CYW this spring!!
Thanks again for all of your hardwork, time and money.

any new updates?


is today the stock non dog-house shroud test?

I have some new data, I just got one system done today- Mondays suck

This was the first test with the VW GOL cooling system.



Second test with the GOL system after a vane was added to the left side. I shut it down early before we damaged the engine



This one is a test with the center mounted style cooling fan with a stock drive ratio. Notice the cylinders run in temps as pairs, this trend follows all systems EXCEPT stock doghouse.



This is the first run with the TI DTM, just as Joe designed it. Stock drive ratio



This one is a Stock doghouse shroud with stock drive ratio. Notice the hotter #1 and #2 cylinders, but how even the cylinders run as pairs. this will not be seen with any other system, but its what our goal is. We WILL get overall temperatures down and keep them even!



This one is the best graph from the TI DTM before we saw that we needed to do some more design work. As you can see we have made some headway from the first run. I have some ideas that we are going to employ to get the overall temps down, then we'll try again.

Jake,
The 4th plot looks promising. In fact, the trends of some plots indicate that at least the cylinder temperatures within their respective banks are somewhat close and the disparity is really more between the banks. This is good since if something can be done to reallocate cooling air from one bank to the other per our conversation, maybe the problem can be solved.

What cooling configuration(s) are these plots for?