12 blade 964 fan question
 

Hi Guys

I bought a 12 blade 911 964 fan housing and alternator, i also have a type 1 engine, i already have the 11 blade fan, but found this is a little bigger

i´ve seen other 12 blade fans but i think they are aftermarket "Style" fan , smaller than this .

i would like to know if has any of you installed a 12 blade fan on a type one engine , if so what is the kit ( Shroud ) will fit ?

http://images.thesamba.com/vw/gallery/pix/763504.jpg
http://images.thesamba.com/vw/gallery/pix/763503.jpg

lol i did the same still not sure if i can use it, looks like no one knows
cheers mark

How much clearance does it have with the engine lid closed. I wonder if the shroud assembly cold be moved a little further back from the engine in order to get more air over the nr. 2 cylinder.

I know that there's a small and a large diameter kit available from the guys that supply CSP:http://kaefer.motor-sport-service.de...asehauben.html

They're 260mm diam.-I don't know how big the outer diam.of a 964 12-blade is.

Regards,Arnoud

finally we ended up machininig the fan so it can fit an earlier 911 housing
so we had to machine the alternator mounting , since the fan is wider , and decrease the fan´s diameter , also the hub had to be modified so it will accept the old key.
the good thing is that we can switch between fans on the same housing since all of them will fit

in the future we will dyno the 5 blade vs the 11 blade vs the 12 blade fans !! and we will post the results

https://lh4.googleusercontent.com/_Y...0/DSC07408.JPG

https://lh4.googleusercontent.com/_Y...0/DSC07406.JPG

https://lh5.googleusercontent.com/_Y...0/DSC07405.JPG

https://lh6.googleusercontent.com/_Y...0/DSC07407.JPG

https://lh3.googleusercontent.com/_Y...0/DSC07404.JPG

Pulley ratio
 

https://lh3.googleusercontent.com/_Y...0/DSC07404.JPG[/QUOTE]

Hello, nice how you have over come the 12 issue. From what I have read, the 11 blade and it outter ring is bias to the 1&2 cylinder. Since you ommited the otter ring, you might have an even greater over shock of 1&2 cooling. I believe Wally did some work on the 11 blade and 12 blade. I don't know the in's and out's but try and ask him.

Lastly, I see your pullies, you may be loosing allot of why you are using the 12 blade setup, using the larger OD Alt pulley. Will the car be in cold climate? That fan needs to turn, even more at idle after coming to a stop in traffic and you engine has been working hard.

Just my 2 cents.

Pricing on a 12 blade
 

How much did your 12 blade set you back? I have a shroud for a type IV. The person I bought it from, did testing on both the 11 blade and 12 blade. He said, because of the veins on the 12 blade housing, directing air flow was much better using the 12 blade. My setup is ready, but if the 12 blade is not to crazy in price, I may use the 11 blade on a second engine. I had a set of cylinder made and I really must address cooling.
http://i86.photobucket.com/albums/k9...2.jpg~original

Thanks for your reply

We bought it on Ebay USA for $290,00 USD
the problem with the housing is that it is a lot bigger, and we think there should be a poor amount of air to cilynders 2 and 4 ,we also doubt the deck lid will fully close, keep in mind our tests were done with a type 1 engine case , type 4 cases are very hard to find in Argentina.


As for the pulley, we can machine it to decrease the diameter, or we can put a bigger crank pulley . our crank pulley is a 5 inch diameter,just like the original Porsche diameter, we also have the option of a Scat Dry Sump power pulley or the usual 6 inch power pulley , we will measure the 4 cilynder cht and oil temps.

Never seen a wally test, other than the Richert kit.
Sandeep´s tests provides great information.

A nice feature that i read about the curved 12 blade fan, is that it takes fewer hp, compared with the other fans

question, did you remove the fan center hub and chrome plated it ? , is that a custom center hub ?
it looks really nice, how did you bolt it again to the fan ?

regards

Fan Hub
 

Hi, the fan hub is custom due to I wanted to use a serpentine belt. I had my machinist create new holes and the hub bolts to the fan; it will have acorn nuts facing outward.
http://i86.photobucket.com/albums/k9...8.jpg~original
http://i86.photobucket.com/albums/k9...2.jpg~original
http://i86.photobucket.com/albums/k9...4.jpg~original
Please understand nothing is together as yet, I will start building in the next few months.
With my type IV setup I am not sure if the 11 blade is the better way. Walter did some test before he went horizontal. Where did you see the data about the number 2&4 having cooling issues on a 11 blade/ type one or IV?