generator fan replacement

[tom martella]

Any ideas on a replacement fan for a '65 C? I've been told that a Volkswagen will work, but which one specifically? Seems that there are two types of fans: one with a "dog house" on it, and one without? Has something to do with the thickness of the fan. It appears that new fans are no longer available/ being made. Any help or suggestions would be appreciated.

[Alex Mestas]

Tom:
I’m not sure about a Volkswagen compatible replacement Fan BUT when I was in Sedona for the WCH, and saw firsthand what can happen when a fan fails and the destruction it causes to not only the fan, but to your oil cooler and potentially the top of your crankcase. In this case the guy was very lucky that he was at idle when he heard it go and had enough sense to immediately turn the car off. From what I’ve learned is that the fan rotates twice the speed as the rpm’s, so when one of the fins breaks loose it’s like a domino effect. Small shreds of fan blades are projected destroying everything they hit. Not a pretty sight. How often do they fail? These cars are 45 years old or older, so they are now recommending that you replace your fan with a welded and balanced fan next time you drop your engine for any reason.

I went ahead and found a used Porsche fan. I bought a used one from a fellow forum member and I then shipped it to RIMCO (Riddle Machine) 520 E Dryer Road, Santa Ana, CA 92707-3737, www.rimcovw.com. They tig weld the rivets and balance the fan. Hope that helps and I’ve attached pictures for your reference of what the fan looks like before and after they weld the rivets.

[Dirk Heinrich]

"dog house" refers to the shroud (newer style on VW engines) - shouldn't concern you.

There are 2 different fans: 16 and 28 blades (like Alex' fan). You had 28 on your C before and want to stay with it for better cooling.
I just recently went through a swap and, like Alex, had the blades welded. Some think it is not necessary and they are highly unlikely to come off unless you race. Well, someone had a bad incident like that just recently in Sedona at the WCH.

One thing, you might want to pay attention to is the offset as indicated in blue in the picture here. The bigger offset - 16mm - will a) cause trouble putting the fan on, and b) cut it pretty close with the clearance to the shroud. I managed with it though.



... if for some twisted reason you decide to go with a 16 blade one, hey, I have one for you

[Dick Weiss]

Any fan should be checked for looseness at the stakings which can be re-staked (w/a backup on the opposite side) carefully w/o needing any welding and re-balancing costs.
The early 16-blade fan is sufficient for the more-open early oil cooler, but the 28-blade fan is needed to get proper air flow thru the later hi-meshed oil coolers and the fan housing should have the volute ring (no screen) on its entry.
Also, you must keep the later coolers clean from any oil-misting picking up any dust over the years which tends to clog the bottom 3rd of the cooler's entry-face and "works its way up"; I just did a rebuild on a C which had its cooler almost clogged completely--you could barely see thru it! Even the engine was covered w/oil-grunge from 25 yrs. or more--the worst one I've had to clean so tools would fit the hardware--time consuming!

Dick

[Mark Pribanic]

I have a 1968 small diameter 12V generator that I had for sale at our annual Florida Owners Group "Gathering of the Faithful". One of our member only wanted the 28 blade fan for an engine build be was working on. When I got home, I found another 28 blade fan in my parts bin and shipped it to him. He tried it on 2 engines and it rubbed both times. The fan was a mystery fan I had, not knowing if it was a 356/912 or VW fan. I removed the fan from the small diameter 12V Bosch unit that came with a spare engine. I am going to ship this to him to swap out the first one sent.

My question is? how do I know this one will work? Apparently there are minute differences between fans, but none I've seen are stamped marking them as such.(VW,356 or 912) Any advice on the differences or how to tell if it will work for him? Here's some shots I took a few minutes ago

[Jack Staggs]

Let me try to clear this up. Porsche NEVER made a fan for 356/912. They all are VW units, designed for the stresses of those slow revving, low rpm power plants. Granted, VW fan ratios are higher than Porsche, but are rarely subject to the types of extreme service that a 356/912 is called to deliver.
BTW, I was the guy that had welded fans at Sedona. I brought two, and both were needed.

[Alex Mestas]

When Jack Staggs carries welded and balanced fans in case of emergencies people should heed the advice.

I came home from Sedona and it was the first thing I did. "Just in case". I saw the destruction an exploding fan can create and it was not a pretty sight. Simple preventive maintenance.

[John Clarke]

Hi All

Fabricated out of all those individual sections it's an accident waiting to happen!
It's a Worry!
A shame No One has Remanufactured the 356/912 fan in Polycarbonate or Carbon Fibre or Similar.
I don't suppose with the relatively small numbers of our Cars that it would be economically Viable. Don't want to go " Off Topic" but what are the 911 and the Corvair fans made of?

Cheers

Jay

[Mark Pribanic]

Let me try to clear this up. Porsche NEVER made a fan for 356/912. They all are VW units, designed for the stresses of those slow revving, low rpm power plants. Granted, VW fan ratios are higher than Porsche, but are rarely subject to the types of extreme service that a 356/912 is called to deliver.
BTW, I was the guy that had welded fans at Sedona. I brought two, and both were needed.

So a 28 blade fan, is a 28 blade fan, is a 28 blade fan? So the one I sent him would be the same, as the one I am about to send him? I was told the fan was rubbing on the shroud. I can only assume the fan may be out of round or bent?

Jack, you've welded some fans for him in the past. You'll probably end up with this fan as well.

[Erwin James]

Hi,
I am quite happy with the 28 blade fan and working without any complaint.
Jack could you fix another fan? PM me for help....
auto repair minneapolis

[Thomas Sottile]

I just went thru the change on my SC motor, you have two choices, one have your fan welded, there are venders who can do it. Two, you can purchase a 28 blade V.W fan and with a little spacer changes works fine in fact the newer fan is about 1/4 deeper this should allow for better cooling. make sure you put a new fiber gasket on between the shroud and the generator; you may need two. Tom

[Roy Lock]

A shame No One has Remanufactured the 356/912 fan in Polycarbonate or Carbon Fibre or Similar.
Jay

The idea of a carbon fiber is a great marketing gimmick, but in reality, you do not want a fan made from that material unless you can assure yourself that it will not sustain impact damage from anything.

When any foreign object hits carbon fiber, it will sustain damage that you can not see. When it fails, there will be no warning, it will come apart. This is the same for fiberglass, which carbon fiber is in a similar class to.

It will be very expensive because of manufacturing costs to lay up the individual plies and assemble. If you use a RTM process with chopped carbon, you will not get the strength of laid plies. Kinda self defeatig.

You can buy a new VW cooling fan balanced and welded for about $59 from a SAMBA dealer.

[Jack Staggs]

Mark: 28 blade fans can have variations to the center area, but all can be made to work.

Roy: I have seen the ad on the samba, but the only fans seem to be the wider late VW that won't work on 356/912. They aren't black oxide coated either.

[Juha Vane]

Could not find anything about the impeller lateral runout?
How critical is this? Mine has now 0,50mm lateral runout.

There are several? different versions of VW 28 blade impellers,
would someone know a VW number for the right impeller.

[Doug McDonnell]

I have a fan I took off the Outlaw C I sold. It has a spacer tack welded to the fan and I replaced it. Found when I took it apart due to noise. Which was caused by loose fan due to pulley side nut being used on fan side. But I like everything correct so replaced this fan with a correct one my old hippy VW mechanic had. Will give away for price of shipping.