TI Cooling system test, Week one in review

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Fri Jan 23, 2004 9:33 pm

What a week...

We burned over 30 gallons of fuel, snapped a driveshaft, and put about 15 solid hours of run time on the test engine. I logged a 90 hour week and we are still here.

I will attempt to share what I learned in this testing that was mostly centered around the TI DTM, and compared to the VW GOL system, and the stock TI doghouse system. The DTM received the most amount of test time, while the GOL has just started its testing. The TI stock system was basically used to get a baseline and a target to beat with the TI DTM.

TI DTM:

It needs more work.....

I don't know exactly where Joe left off with his design, and testing, but I sure wish that I did. A very nice fellow sent me one that he had bought from Joe just before he died. He let me use it to base my vanes and etc from, so thats what I did. I copied it vane for vane perfectly.

When we first started testing we had temps between 100-175 degrees more than the coolest cylinder on the hottest cylinder. Today we were able to knock that down to 75 degrees, but never got it any better than that. Brent and I tried for 5 solid days to overcome a situation of an extremely cool #1 cylinder, and 25 degree hotter #2 cylinder.

Joe only had one pair of vanes in his shroud design on the left bank, and they were very short and simple. We thought for sure that more vanes would makethe system work much better but when we addedthem it COOLED #1 AND#2 even better! Obviously it increased restriction on the left bank and increased pressure to the right bank. We removed them and then started to restrict the flow going to #1 and #2 severely. No matter what we did we could not heat up #1 very much at all. Finally we almost restricted it 100% and it still ran super cool..... At this point we installed a stock system to rule out a problem with the engine and the temps were BETTER all around and #1 warmed up to 310 degrees instead of 265!! Magically the temps on number 4, which was previously the hottest with the DTM dropped by 40 degrees, and the number 3 cylinder ran hotter by just a few degrees.

We removed the stock shroud and made more vane changes. We still have the same issues, and when we post the graphs you'll see that very clearly. Only on one test did the DTM beat the stock system, and now we are going back to the drawing board with it. I have a VERY strong feeling that the problem lies in the shape of the vanes more than anything else. I have noticed that air direction means more than anything else, I found that out with the TIV DTM. The TIV system has basically the same vanes, but the system cools so much better its amazing! Heck we only made ONE change to it, to make it perfect. I made almost 60 changes to this shroud in 5 days and while some of them showed benefit, none of it was drastic enough to be able to capitalize on.. The things we thought would make huge changes, did nothing.

I tried restricting the oil cooler cavity, restricting the #1-2 cylinders, adding vanes, removing vanes, reshaping vanes, adding deflectors, removing deflectors, add ing differnt cylinder tins, and even cutting holes in the shroud just like we did to the 911 TIV shroud that made such a difference. The only thing that made any significant changes was when I added an extension to one lower vane- it cooled us off 50 degrees.

Is more air the answer?- NOPE!! We tried Joes hybrid fan, also tried using a Porsche 356 upper pulley, as well as slowing the fans down... The temps barely budged when they were slowed down, and all we did with more air is cool #1 BETTER! More air is not the answer, atleast until we get the direction straight it isn't... Then I'll try it again, but I bet it hurts it just like it did on the TIV DTM.

I believe that with changing the vanes to a shape that has a broader radius on the leading edge, and as the vane directs it gets more narrow will hep tremendously. This shape would be almost like a modified airplane wing, but just shaped to direct the airflow. The stock TI vanes are like this, but I feel with the DTM design that it will work even better than stock. It is so amazing that no matter what we did as soon as the TI DTM went back on we had a freezing cld #1 cylinder and hot entire left bank. The test engine is providing us with repeatable results within 2-3 % all the time, so testing is super accurate.... If not I'd have shot myself already.

At this point I cannot spend any more time on the TI system. Everyone that is on the mailing list, we won't be offering them as soon as I thought. This set back may very well require months of work to overcome. In the mean time we are going ahead and testing the other systems and that has already began. I promise not to give up on this. I want to make it happen as a tribute to Joe and to get an alternative out there that works better than anything else.. I have a friend who has 3 degrees in aerodynamics, etc and he is going to try and help me get it straight and ready for some more testing. He has designed stator vanes for Turbine engines, so I think he will be a huge help. Just after a phone call he thought it was vane shape and position related as well.

I stil feel confident, because I have a consistant 30 degrees cooler temperatures on #1-2 than the stock system......

Stock system
The stock system still has yet to have comprehensive tests done with it. We simply took some numbers with it to see how good we were doing with the DTM.. Basically the stock system is not bad at all.... Hell so far it has overall beat everything else. Monday I will be testing stock systems all day long. Thats including the stock doghouse and non doghouse systems.

The engineers at VW were not stupid. I'm sure they saw the same thing we did with the #1 cylinder and its extreme cool temps. That explains why they created a duct just ver it to force feed the oil cooler on the doghouse models. So far the average temps on the stock system have been much better than we would have ever imagined! The only cylinder that has issues is #3, and we plan on adding a vane to see if we can cure that while we are at this point....... There is much more to do with the stock system, stay tuned.

VW GOL cooling system

Over on the speed and drag racing forum this system has been the rave, so I bought one to test. 3 words explain it- IT DON"T WORK. On the first test the system had a cooler #1 cylinder, (imagine that...) but it was still hotter than the other two systems we had tested. The entire engine was hotter. With the stock TI system the engine would not get over 378 degrees on the hottest cylinder, and the hottest we got with the DTM in the worst run was 425 degrees... The GOL system saw temps over 500 degrees just in 10 minutes of run time. It was so hot that we had to shut it down before we had a failure! I'm going to try and make some changes to it, but when you have a 200 degrees difference from one side to the other, its not very promising....I'll add vanes, and speed the fan up, and we'll see what happens tomorrow...

I think the GOL system is suffering because it is normally found in a front mounted application and gains ram air from the forward movemet of the car... in our application this is not so...

In closing I will say that this is VERY hard work, very taxing on the mind and makes for bad dreams at night. It is so confusing and all standards must be kept all the time..This is probably the toughest project I have ever embarked upon- but we'llfind out the truth when we are done. I can only spend 4 days next week on this, as the dyno is getting backed up severely already. If I have to stop I'll remove the test engine and not touch it till we are ready to test again....

Nest week I plan on testing all the stock stuff on Monday- Tuesday and then swapping to Chrome junk on Tuesday... Including a test with chrome valve covers and 36 HP shroud. I even have a trapezoid center mounted fan to try!

Wednesday will be 911 test day, and If I had to bet I'd say that the stock system has a good chance of beating the 911 system!!! Now THAT would be funny!

Looks like the TI DTM lost this battle, but we'll be back and conquer the winner..I don't give up!!! This one is for Joe!

I appreciate all the suport yiou guys have given, I'm just glad to have the opportunity to do the work. It is the most intesresting work Brent and I have ever done- Also the most aggrevating!

Pics and graphs to follow..........

vwfye · Post by **vwfye** » Fri Jan 23, 2004 11:37 pm

wow, you are a busy guy! can i ask if you used the GOL with or without its little oil cooler?

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Sat Jan 24, 2004 12:34 am

Used the GOL with the stock provided cooler today, will remove it tomorrow to see what happens..

The heads baked with that shroud.

Post by **sparkmaster1** » Sat Jan 24, 2004 7:34 am

Great, informative report. I can't wait to hear how the Chrome stuff does. Did you borrow it from OS? LOL Tim

NO_H2O · Post by **NO_H2O** » Sat Jan 24, 2004 7:58 am

I can testify to the intense testing and frustration going on at Jakes. I only saw the joy 2 times while I was there. Once when test 11 of the DTM was equal to the stock system and when the drive-shaft came apart at 6500 rpm on test 12. Anyone who finds joy in scatering something at 6500 rpm is hard core in my book. I think he likes loud bangs and flying parts, as long as it is not on a customers product.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Sat Jan 24, 2004 9:24 am

No H20,

You are right, I have an obsession with scattered pieces....

I also have an obsession with this damn shroud now, had 3 different dreams about it last night...maybe Joe is sending me a message.

NO_H2O · Post by **NO_H2O** » Sat Jan 24, 2004 9:52 am

I think the airfoil shaped vanes are the answer. Did you dream about those

bugnut68 · Post by **bugnut68** » Sat Jan 24, 2004 11:15 am

Jake, I, as well as many other enthusiasts I'm sure, appreciate the testing you're doing as well as the fact that you're sharing all this info with us. Without people dedicated to ensuring the air-cooled VW (and Porsche) live on I"m sure the industry would eventually just disappear. I'm greatly looking forward, in particular, to seeing the results of all the "chrome aftermarket junk" testing. I've always wanted to know how that stuff would fare in hardcore testing, even though some of the parts are obviously inefficient just looking at them. Have you ever tested the results of placing the oil cooler behind the shroud? I know it's a horrible idea and just about the worst thing you can do, but here in Oregon there's a couple of guys that do this on their race cars and in some of the older (mid 80s) mags there were a number of cars that were set up like that...Again, I know that's a dumb thing to do, but I'd be interested in seeing some numbers on that too. Good work so far!

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Sat Jan 24, 2004 11:29 am

I might try that oil cooler test..

speedy57tub · Post by **speedy57tub** » Sat Jan 24, 2004 1:34 pm

Jake,
After our talk, I must say some of your frustration made its way to my head! I actually placed a great deal of thought and sketched and did a little equation crunching and now I know we are in the right direction. Your idea of taking air away from #1 should work. But first we have to baseline and maximize the current configuration so we can determine how much we need to reallocate to the hotter area. This has to be done in such a way that we minimize the pressure differentials within the shroud. We also need to study the air allotments expelled by the fan by determining how much air is being directed to each individual quadrant and how it is being directed. By sticking to our game plan per last night, I can analyze the hell of the shroud mathematically so we can predict what any change might induce. Hell I'll even do spreadsheets and write programs if needed! We can also introduce strategically located data acquisition points to determine what the shroud is doing with respect to any changes we make. Your testing will verify. Trial and error is still required but it can be minimize with this approach. You are definitely in the right track.

As far as employing airfoil type directional vanes, I think that will without help. It is important to have a smooth well-defined transitional curve from the area where it will first receive the expelled tangential air to where it introduces it to its intended location to be cooled. The curve has to be as long as possible to prevent a "scooping" affect, which can increase the undesirable pressures, which create the problems you are experiencing. Remember, an airfoil has lower pressure and slower air in the top and higher pressure and higher velocity air in the bottom. This is how VW controlled their Type 1 airflow and pressures to get the best result which was never 100% controlled. It was okay for "stockers" but we need better.

Once we baseline the best design then we can "rob peter (#1) to pay Paul (#3 and/or #$4).

Hey, Jake I still think the DTM can solve the deficiencies that VW failed to solve. They were only trying to cool a type 1 stock engine and that was sufficient. I know we can do better. I'm ready for the challenge, lets do it!!!!

speedy57tub · Post by **speedy57tub** » Sat Jan 24, 2004 1:36 pm

BTW, I waited last night but I didn't get your email and pics. I too got drawn in and now I am very curious and feel the challenge!

vwfye · Post by **vwfye** » Sat Jan 24, 2004 2:22 pm

jake, i am a 'prove to me your position' kind of guy, so if my questions come across the wrong way sometimes, that is not my meaning. i bought the GOL on the hope that it would be a cool factor that was also a cooling factor. i asked about the oil cooler in, because it's location sucks to me. Today, i did a low science test with my cool in and out on my engine stand with streamers and the mock up at 90 degrees. with the cooler in my streamer at the bottome of #3 barely moves, but with it out, the streamer stood straight out with 600 rpm of fan speed. it proves nothing, other than the fact that the oil cooler may be an impeedment. i am also interested in how the #1 was soo much cooler than the other cylinders. this intrigues me because in my shroud's vane system, #1 barely has access to the cooling air. i wonder if VW Brazil changed any of the shroud system when they swapped from crap gas to alky in 81. anyway, keep up the good work!

Joe vw · Post by **Joe vw** » Sat Jan 24, 2004 7:53 pm

Hi Jake, before you dismiss all the chrome shrouds as junk I think you should keep in mind that there are different brands and versions of the 36hp style,chrome,fresh air, or not. I have compared the Scat doghouse W/O fresh-air to a stock one and the internal veins are all there, although they should be reinforced W/adhesive silicone and welds inspected. They also are not drilled for flaps which I always install.
So, maybe you could test an as-is installed shroud and a Jake prepped version.
I know I don't have to tell you about the differences between the internal veins of a doghouse shroud and early (internal cooler) shroud. I have 2 shrouds hanging on a shop wall with the fronts cut off just to show people the difference. Many people use the early shroud with an external cooler (as you know big mistake). Maybe you could do a quick test just to show the temp. extreems.
I realize your not busy enough

, just thought to give you some more ideas.

Stroker 40 horse · Post by **Stroker 40 horse** » Sat Jan 24, 2004 8:14 pm

Why are you doing all your testing on a dyno?

spongeworthy · Post by **spongeworthy** » Sat Jan 24, 2004 10:25 pm

Hey Jake:

How about testing one of those old-school cast aluminum shrouds. I have had one on my Baja for several years and everyone keeps telling me I am going to cook the engine.

So far, the oil temps have always been in the safe range. I don't have a cylinder head temp gauge.

Charles