Carrera Fan shroud

A question to dman550 having looked at your file.I am interested in the photo's of the carrera fan shroud. Is this an original or a copy? I have been wanting to do this conversion for years and have been unable to locate a Fan assembly to to take a casting from. Any information would be well appreciated. Nigel

Two different individuals are buidling them now... Neither one will send me one for my direct testing against 14 different systems..

So Jake, are you saying "caveat emptor?"

~Joel

Are they up and running yet? I haven't actually heard if the two projects are complete?

There have been two items in my current engine build where I have deferred to builder and his recommendations...one in the area of exhaust and the other the fan shroud.
I want to approximate the 'look' of days gone by with my car and I thought it would be a snap to get a centered 'sebring-style' carrera exhaust thingie... "Yeah, it can be done but it don't compliment the engine's poer output..." Hmmm, why am I building a bigger engine? Oh yeah, power.

So cut to the fan shroud, afterall that's the big visual under the deck, right? Well guess what...Fans are another big thief in the power department. Unless you know what they're gonna suck out of your engine, you don't know if the trade-off, LOOKS v. PERFORMANCE, is worth it.

Check out the pictures that Dale posted of GB's new engine. As much dough as Georgie is spending, do you see a Carerra-style shroud or a 911 style shroud on his engine? Not yet anyway 'cuz it ain't been tested.

I think if I were building an engine component with thoughts of selling them to the public, I'd jump at the chance to get them evaluated. They may not measure up to some other styles but then again, they may be just fine in other build configurations, ie, sensible speedster owners who don't thrive on maximum go-fast or the spyder crowd as they are about 500 lbs lighter than the speedsters...

...and yes, that was a left-handed compliment to GB
ggrrrrrrrrr

Hi Jake who is the other maufacturer of this type of Fan shroud? Have you any contact details? Cheers Nigel

In my TI testing so far ..... NOTHING has beat the stock TI doghouse system!

Jake: Is that with or without the DTM monification?

Unfortunately that includes the DTM :-(

I'm on it... There are MANY challenges and issues that must be overcome... I have found that the engine its self is a problem!

Jake,
When the fan shroud is 100% ready to goto you for testing it will.....I have another month for a final fan to be balanced....I will be in touch


Dario

Your shroud is beautiful, Dario.

Im Guessing that, the T-1 problem Jake is refering to is the cylinder fin size restriction ,
Unless you could just stretch the block, crank,and head length . that's a barrier, that would cost more than a 911 rebuild, to over come, It would be touch.

Do the Nickie's help enough to get it as cool anywhere close to as good as a T-4

Oh yes! The early shroud would look perfect on eather a T-1 Or T-4 . But can it cool correctly. Thats another can worms. But if anyone can nail it. I think Jake's the best hope.

I've been following Jakes T1 shroud testing on Shoptalk, and the problem seems to be uneven cylinder cooling. Number 1 runs so much cooler than the other 3 cylinders.
Ron

Thank"s Ron ,But that's odd I would be very suspious of the fan placement, being to far back in the shroud .If I had to guess.

Im glad that's in Jake's care . It will be intersting to see how he corrects the flow.

It's also interesting to note that the guys at Gene Berg did much of the same T1 temperature testing over the past 20+ years that Jake is doing now and that they seemed to come to the very same conclusions.

The only Berg catalog I have came from the mid 90's and they devote about a page to their study, and have some tech sheets available, too (GB 801-cooling, GB 801-CR and GB 801-Heads) I have not read the tech sheets, but in light of Jake's testing, it might be interesting to see them. They make a lot of the balance between heads, compression ratio, carburetion, exhaust and cam to get the volumetric efficiency of the engine up to flow better and run cooler.

Berg doesn't (in this catalog) recommend anything other than stock, complete, GERMAN, 1971 or later cooling components (their opinion of other foreign aftermarket stuff was that it was junk) and that the fan have adequate air intake (usually more is needed with the later fan/shroud combination). Don't know if this info is available on their site, but it's in their (older) catalog.

I spent hours with them on the phone when I was initially building up my 2110 with stock VW gearing, and they convinced me that stock '71 or later cooling was the only way to go at that time (again, mid-90's). Still, I'm watching Jake's testing with great interest.

Gordon

That Carrera Shroud is the one I would realy like work out, for both type engines. It looks so slick in the carrera and it's a radial fan not a axial like the T-1 .

I could care less what Berg has done, as I tend to believe that has been very little,( a whole lot of talk and chest pounding and little action) and not in a measured climate (Their dyno sits in the middle of the shop and not even in a controlled cell)Those guys don't impress me, and never have since I gained my own brain and threw out their blue book and catalog. That was 12 years ago.Their way of ultimate superiority is going to let them get passed up, heck they already have! If their testing was done with a 6. something :1 engine its all useless anyway because it runs so inefficient that it can barely sustain combustion! My test engine has 10:1 and makes 180 ponies!

The fact is that their testing has been done with just the TI system, and no comparative tests were done on the same engine, with the same load and constant speed, in the same environment. let alone it wasn't done with 14 different systems, 4 different drive ratios, 2 different fans and etc...

If they tested it, where is their results, weather plots, spreadsheets, etc.... If they have them they obviously don't care to share them or they would be on the net.

The problem with the aftermarket systems are all the same, and thats that the cylinders run in "pairs" with temperature and the splits between those temperatures are the issue. ALL THE AFTERMARKET shrouds so far OVERCOOL #1-2 and do not sufficiently cool #3-4 because of ZERO testing and crappy design work! The DTM has been the best aftermarket system so far, but thats not saying much. It took 15 consecutive runs with 50 shroud changes to make it work within 10% of the stock system- it has never beat it, only equalled it in close proximity anyway...

All the throies, all the misconceptions and guesswork are amazing. It seems taht everyone is an expert on the situation, but its odd how no one can make it better than VW did. I have 3 designs that we are going to try with the TI DTM and we are also going to incorporate so airspeed indicators with pitot tubes inside the shroud on each side to measure pressure differences as a base. Then we will start looking for the coolest portion of the heads, to find that area where the highest concentration of air is being sent and work to correct that.

This is going to be a long process. Joe did a great job of making the shroud- now we have to make it work. This has consumed me for 17 days. I'm determined to let this system teach me what I need to know to be ahead of the game on cooling the engines that I love.

Lead, follow, or get the hell out of MY WAY!

(before I'm forced to move you myself, and thats not fun most of the time :-)

Dario, as far as balancing your fan :
I have a CNC balancer and a mandrel that was made for a 547 fan, don't let the balanmce issue stop that shroud from making its way here. I want YOU to be here when I do the test work. If it has potential I'll find it, if It don't you'll know in the first 10 minutes of run time- thats all it takes! Ultra VW Magazine has agreed to publish all the systems and my findings, don't miss that opportnity!

Jake: Don't get me wrong....I'm not criticizing you in any way. In fact, I'm following your progress with as much interest as anybody (and there are a LOT of others just as interested). You ARE finding the same basic results as Berg, though, that the stock cooling was pretty damn good. That was my only point. Berg never was able to improve on it (or never tried) in any kind of scientific way.

When I was assembling my engine in the late 90's I didn't know you from Southern Yellow Pine, nor did I have this terrific forum to help me along. I researched as much as I could, and believed what made sense to my engineering mind. At the time, what Berg was saying made sense for me and I avoided all the after market cooling stuff, stayed stock and it looks like it was a good decision for then. Times change, better solutions are researched and found and better products come along and that's what progress is all about. Looks like it's your turn, now.

I (and many others) appreciate what you are doing - it is FAR, FAR beyond anything that we are capable of, and your analytical approach is to be admired (as are those posted graphs - beautiful!).

I sincerely hope that you find a breakthrough and provide these engines with the controlled cooling that they deserve. We'll all be watching for that article in Ultra-VW.

Gordon

Thanks Gordon.......

Aloha Jake,

Have you ever thought of doing a book like the guys from Pelican Parts for the T-1 & T-4 VW engines? You know a "101 Projects for your T-1, 4, etc." type of thing? I for one would be extremely interested.

I know you get sick of typing your engineering philosophy over and over on all these endless forums when you'd rather be building engines and having fun.

Anyway, just a suggestion.

Mahalo,
Joel

People approach me about a book all the time... I'm not an author.

If I ever did it, it would be atleast 10 more years down the road- I don't know enough yet.

Jake,

Understandable.

~Joel