porsche alt and fan

[zen]

i'm considering going with a FAT shroud. is there a particular porsche alternator and fan that must be used or any11 blade? yea, i realize i could call them and get the answer, but it is sunday and am curious. educate me please.

[Sandeep]

Zen,

I'm not sure what the dimensions need to be, but when I get the box (was shipped on Monday Nov 18th), it should be in the instructions.

I'll do a tech article on the install into my '74 standard during my break in December. Hoping to get the 44IDF's by then too. All I am missing is the header and exhaust, (STILL researching options ... ) :doh:

Sandeep

[kdanie]

Sandeep, I was poking around the BAS website a week ago. With the exchange rate the way it is, their headers are a good deal right now.
ken

[Massive Type IV]

All the Outside diameters of the Porsche fans are the same except the very new units. any 901 or 930 part numbered fan ring will fit.

There is a great deal of variation in the alternator/fan/housing interchange as the depth of the housing changed to accomodate larger alternators in the later years. There are 3 main alternator sizes, 35,55,75 and 90 amps and the each have thir own housings. The housings are not interchangeable, however I can machine the earlier rings to fit a later alternator. I suggest that you NEVER buy individual pieces, only 100% complete housings with a complete alternator and fan, all compatible. I have had to klearn this over the years, as well as other tricks. Even the drive ratio changes, as the later cars have a smaller top pulley than the earluier years, even with the 11 blade fan on both units.

It never ceases to amaze me how far people will go to make something look faster than it really is................It looks like a 245HP engine, but makes maybe 80 Horses after the fan pulls its share!!! I'll shut up now.

[Oliver Knuf]

*rofl*

[Wally]

Jake,
Great advise on the different types of the Porsche alternator/fans; should have know that earlier....

Although I know disagreeing with you is like cursing in church (Dutch proverb), I got your remark on the use of the Porsche cooling fans and don't agree with you on that one. I still believe by just looking at the set-up of the porsche fan and its intended use (6 cyl engines over 200 hp) compared with the type 1 cooling system that the former is superior. Even the fluid dynamics of former threads can't convince me and I think I have at least Oliver with me on this one (?) Since the hp drawback is less (although slightly) than with a type 1 cooling system, I really don't understand your disliking of the porsche system. And I haven't even mention looks (or costs/availibility) as you have noticed! I just want the best cooling system on my engine, period.
Don't get me wrong, I really like your work and dedication and Jake's thougths on all other subjects.
But than again, you still promised us a test a the subject some (judgment) day...
Walter

[Massive Type IV]

Wally, this is what I have came to the conclusion of.

People are going to *think* what they want, and preaching about something to those who have their mind already made up is worthless.

I have already done the testing you speak of, about 2 weeks ago, bt I'll keep the results for myself and will use it to build the best combo of engine/cooling system for my customers, as they never argue with me on what works, if they do I just won't build it.......

I'm not arguing points on cooling anymore, I will say this, I HAVE NEVER built an engine that the DTM shroud would not cool effectively, thats including the 11:1 test engine that I played with a few weeks ago.......If the engine is designed effeciently and effectively cooling problems won't exist at all for 99.9% of what I build........

Like I said no more arguments and no more technical posts from me on cooling systems at all, all it does is start a fight that no one can win because no one will listen....

[BergRace]

For those who read German:

There is some info on the Porsche systems on Gerd Weiser's pages. Click "Gebläsesystem"(SP?)

http://www.gwd-weiser.de/index2.htm

P.J.Berg.