36hp vs 40hp cooling fan

[panicman]

I have the fan from my 40hp and a 36hp fan sitting side by side.

They are identical in appearance except that the slotted holes are obviously larger on the 40hp one (the 36 fan was sand blasted)

I weighed them and found that the 40hp is one ounce heavier, but again, it has some grime on it, while the 36hp fan was sand blasted.

Is there any difference that would prevent me from using either when I reassemble my 36hp?

[EVfun]

Interesting, I looked up information about the fan in Progressive Refinements and came up with the following:

6 Aug 1959 VIN 2,528,890 - Fan bore increased to 28mm, formerly 20mm

1 Aug 1960 VIN 3,192,507 - 34 bhp engine introduced, formerly 30 bhp

8 Nov 1960 VIN 3,432,861 - Now 28 blades 20mm bore, formerly 16 blades 28mm bore

I'm not sure what the 20mm bore and 28mm bore are referring too, the change was made at the same time the generator went from 160 watts to 180 watts. There was about 3 months of 40 horse engines with the lower blade count fan used on the 36 horse engines.

I was considering putting a 36 horse fan, and fan shroud, on my 1600 engine because the buggy engine tends to run cold. I'd have to replace the oil cooler to do it as I have a doghouse style fake 36 horse fan shroud on it how. I would install a power pulley, like on my last buggy, but I like my early EMPI fan guard that fits between the pulleys.

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[Heiferman]

Gonna bump this and offer an answer if anyone runs across this thread and then ask a question.

A 30mm fan will work in any of the fan shrouds but if you are running a doghouse it will not pull as much air as the 36 and there will be a gap that disallows it from properly pulling air in. It will likely result in overheating. If you are running a doghouse, run a 36mm fan only. I suspect a 36mm fan would rub on a non-doghouse shroud (I may be wrong about that.)

Now my question: Did all fans have a double D mounting hole? I just pulled this and suspect it is worn out.

Years ago I had one that cracked the center out and spun on the shaft while under load. It took me a little while to figure out what the screeching was!
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- 1973 Thing, 1970 Ghia, some LandCruisers and an old Ambulance