Engine cooling fan

[kyhunting]

Are all of the engine cooling fans the same size. Will a 1987 3.2 fit a 1970 2.0?

Thanks

[Rot 911]

No

[SigmundF]

I think the cooling fans are the same size, but the pulleys are different...

1965-74/75 110 mm crank pulley - 95 mm fan pulley
1980-89 120 mm crank pulley - 80 mm? fan pulley

[Rot 911]

Sorry, I read your post to quickly and read it as fan housing and not just the fan.

If all you need is the fan, then here are the fan sizes:

all 930 are 245mm,
all 911 are also 245mm except the '78-79 911 which is 226mm.

[304065]

Originally Posted by Kurt V

Sorry, I read your post to quickly and read it as fan housing and not just the fan.

If all you need is the fan, then here are the fan sizes:

all 930 are 245mm,
all 911 are also 245mm except the '78-79 911 which is 226mm.

And except the SWB which are 250mm.

[relayswitcher]

Originally Posted by Rot 911

Sorry, I read your post to quickly and read it as fan housing and not just the fan.

If all you need is the fan, then here are the fan sizes:

all 930 are 245mm,
all 911 are also 245mm except the '78-79 911 which is 226mm.

But what about the difference in the number of holes in the hub. My '81 has more holes in the center hub than my fan on the '70....are they still 245mm? and from where exactly is this 245mm & 226mm measurement taken? apprec. the info. thx.

[Wil Ferch]

Fans are all different ( diameters, ratios, pulleys)

See this post--->
Engine Fan Drive Ratio

Wherein I say this--->

Guys:
There's still some misinformation floating around here ....
the small fan pulleys are 3.125", or 3.25" ( 80 vs 83 mm). Why such small change was ever made we'll never know. Notice that the pulleys are "pulley-halves". You can't simply change the upper fan pulley without also changing the mating fan ( which has the other "pulley-half" surface on it).

From my notes...and this is inconsistently shown in the various parts books, so don't hold me to it, it may be one model year "off":

1965-74/75.. 110 mm crank pulley..95 mm fan pulley
1976-77... 130 crank...83 fan ( may be 80?)
1978-79....130 crank... 80 fan ( or was that 83?)
1980-89.....120 crank....83 fan ( or was that 80?)

for fan sizes / blades / air flow:
1965-74/75....245 mm / 11 blade... 1.3:1 ratio..1390 liters air/sec
1975/76- 77.....245 / 5 blade.......1.8:1 ratio....1265 l/sec
1978-79...........226 / 11 blade ...1.8:1 ratio...1380 l /sec
1980-89.........245 mm / 11 blade...1.67:1 ratio...1500 l/ sec

Turbos used the 245/11/ 1500 set up.

Interestingly... the later curved fans for the 964 were quieter ( by being curved)...but resulted in lower flow:
-- 1.6:1 ratio..1010 l /sec (!).

fan belt sizes:
1965-75....9.5 x 710
1976-77.....9.5 x 725
1978-79....9.5 x 725
1980-on.... 9.5 x 710

There are "borderline" years where these specs don't quite match...and the goofy 80 vs 83 negligable fan size difference doesn't help to sort this out either. It won't make a difference in performance but watch out of you mismatch a 80 and 83 pulley half. BTW....aftermarket will sell 9.5/10x 710 as being "equal" to 9.5. Don't buy it. There have been reported problems with this. If possible, buy from dealer or Pelican and ask for the right size.

--Wil
__________________

[tomeric914]

Resurrecting a month old post...

Are all fan housings the same diameter or are the housings smaller to fit the slightly smaller fan of say a '78-'79 SC?

It also appears that only early fans are for sale out there. Is there any reason an early '70s 11 blade fan and housing couldn't be used on a later car?

I'm looking for an 11 blade fan and housing if anyone has one. I've got an alternator.

[tom1394racing]

Tom

The fan housing ring changed with the fan size and also with the alternator size

[Grady Clay]

Tomeric914,

You want the ’75 and later ‘Turbo’ fan and a fan housing appropriate for your alternator capacity.

The key is to turn the 11-blade, 245 mm fan at 1.82:1 of the crankshaft speed using the ’78-’79 134 mm crankshaft pulley. This cools the heads and cylinders, allowing the oil cooler(s) greater range running on the thermostat(s).

The ‘Turbo’ fan can be any 11-blade, 245 mm fan from ’80-’89 911 and ’75-> 930 Turbo. The important feature is the small (84 or 80 mm) pulley on the fan. It is possible to use the hub from the 226 mm fan or the 5-blade fan on an earlier (’65-’75) 11-blade fan.


The issue with the alternator is the fan housings changed the mounting depth for the alternator as the capacity of the alternator increased. What year is your alternator?

Best,
Grady

[tomeric914]

Thanks Grady and Tom.

Alternator is a Paris Rhone 75 amp 911 603 120 04. I assume that it's from a '79, but that's only based on the alternator coming with the '79 engine.

I've got the '79 crank and alternator pulleys. Now I just need to find the right fan and housing.

[RW964]

Hello I am in need of the main cooling fan for a 90 964 C2 mine seems to have a small crack starting and time for new parts. I just need the fan as far as I can see nothing else as all is working fine. But in the market for the main coil wires and not a complete set of spark wires.
New coils also later though. Where is a place to get the coil wires and fan please
Thanks Randy