are 911 fans all the same

willyw · 05-04-2003, 04:34 PM

Help, I need info asap . I have a chance to buy an 11 blade fan to upgrade my 1976 2.7. Are these fans universal as far as fit ? I don't know what year or size motor the one for sale is off of. Thanks----Bill

masraum · 05-04-2003, 04:36 PM

Nope, the outer diameter and the pulley size changed from time to time, of course the shroud size also changed to match the fan size.

Sonic dB · Sonic dB's Garage

I'd say we all have similar traits: The desire to go fast... the love for the classic 911 lines, the way our ears perk up at the sound of the finely tuned air-cooled engine...

Yeah...most 911 fans are pretty much the same..

willyw · 05-04-2003, 04:43 PM

Thanks, Steve, for the prompt reply. This forum has been very helpful to a novice like me.---Bill

willyw · 05-04-2003, 04:48 PM

This is the fan I would buy, I don't like fooling around bidding and like the buy it now feature. Also the price is right. Take a look and tell me if it looks like it would fit my 2.7

willyw · 05-04-2003, 04:48 PM

Sorry, forgot to post the link

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2414021378&category=33600

masraum · 05-04-2003, 04:55 PM

Personally I would stay away from that one since it has a couple of chunks missing out of the fan blades (the blades just to the left and right of the top-most blade). Those missing pieces make the normally balanced fan, unbalanced. Having an unbalanced fan can cause vibration that can kill your alternator.

Besides, all of the fans look pretty much the same, so I don't think there is anyway to tell what size fan it is without a part number or measurements. If you bought the fan and then needed a matching shroud it could get expensive because the shroud is the expensive part. I just replaced my fan and shroud with new parts as the old were cracked, the fan was about $250 from Pelican, and I paid $400 for the shroud from the dealer (damn, why didn't I have my $100 rebate coupon then...)

willyw · 05-04-2003, 05:21 PM

Thanks again, good advice as usual---Bill

911pcars · 05-04-2003, 05:41 PM

You should be able to id the fan by it's OD, number of blades and the blade shape. There were basically 5-blade and 11-blade fans with various diameter fan and crank pulleys to determine the fan speed and air flow volume. I suppose you have a 5-bladed version in your '76 2.7.

I agree with Masraum. Take a pass on this one which may require add'l funds to balance. B. Anderson's book shows the various fan blades available through the "early" years and shroud differences.

Sherwood Lee
http://members.rennlist.org/911pcars

willyw · 05-04-2003, 06:12 PM

Thanks, Sherwood

kcope · kcope's Garage

The part number is right on the top of the fan housing. my 71 uses #901 106 101 5R. I couldn't find a number on the fan itself.

willyw · 05-04-2003, 07:16 PM

Thanks Ken

jluetjen · jluetjen's Garage

Beware part numbers. Very often Porsche (or rather their suppliers) would cast a number onto a part. This is the casting number, not necessarily the part number. Very often the machining will be different for different applications or models even though the casting is the same. I'm pretty sure that most of the 2.2-2.7 heads all have the same casting number, but some of them (S's, 2.7's, etc) can be very different.

As far as I know, numbers which are scribed or punched onto Porsche parts (for example engine and transaxle serial and model numbers) are generally accurate unless they have been changed during a rebuild.

The best way to ID a fan is by the blade count and the OD of the fan (225 mm or 245 mm. Divide by 2.54 for inches) and pulley. Obviously the ID of the houseing needs to match the OD of the fan.

willyw · 05-08-2003, 06:57 AM

Thanks for the info, by the way if anybody has an 11 blade fan for my 1976 2.7 let me know----Thanks, Bill

911pcars · 05-08-2003, 12:52 PM

I think I saw a brand new, off-the-shelf fan on ebay recently.

Sherwood

Bill Verburg · Bill Verburg's Garage

I used a 245mm 11 bladed fan from an '84 Carrera on my '76 C3 which had the same oem fan and pulley as your '76 2.7. The Carrera fans have an additional benefit over earlier ones in that they have vents for the alternator. They also work fine w/ the stock pulley halves.

As an additional note, the only ones you cannot use are the 226mm '78/79 SC fans.

willyw · 05-08-2003, 01:08 PM

Thanks guys----Bill

Hetmann · 01:21 PM

If you do have to settle for a used fan with a chipped blade, you can balance it yourself. New ones are quite expensive.

You would make a simple jig and suspend the fan on a hard dowel between with two parallel level surfaces. The edge of two pieces of sheet metal would be ideal. Make it as friction free as possible. Spin the fan and see where it settles. The blade pointing down is the heavy side. You can remove material by drilling into the detents on the inside of the fan, little by little. You will see that this is how the fan was balanced originally, as some are more drilled out than others. Go slow and remove just a little material at a time. Repeat process until the fan does not always stop with the same blade pointing down.

Targa Dude · Targa Dude's Garage

Hi Willy, I have a Fan out of My 77, Red and Black powder coated about 14 months or so ago, Still looks great! Make me a reasonable offer plus shipping and it's yours.

Later, Jorge (Targa Dude)