Help Please--917 Engine Fan Info

[George Manont]

Hi,

From HEMMINGS, it says , " ... The center takeoff gear also powered the top-mounted fiberglass cooling fan via a bevel gear. The fan required as much as 17 hp to run at 90 percent engine speed and could move up to 5,100 cubic feet of air per minute..."

Read further... here

Genesis of a Champion - Porsche 917 | Hemmings Motor News

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[Cliff Beer]

One minor snippet on this one...

I read in a porsche racing history book I have that the fan had to be horizontally mounted rather than vertical (as on all other porsche engines) due to the length of the flat 12...those cylinders farthest away would not receive adequate cooling.

On a somewhat unrelated note, I replaced the six blade fan on an old 911 I had with the more common 11 blade fan and it made a heck of an improvement in keeping the engine temps down.

 

[Les]

You guys have done yeoman's service in bringing me every so much more information than I thought was even possible to obtain!

Thank you, everyone, very much, for all these invaluable nuggets of knowledge!

Les

 

[Jac Mac]

Les, just in case you feel the need to fabricate a fan drive with bevel gears, find an old AP auto trans out of any British Leyland or BMC Austin/Morris Mini/1100/1300/Allegro etc. These things have a couple of spiral bevel gearsets that would be ideal size wise for making a drive setup for that fan.

 

[Chris Huck]

If you go to my album, mid way down there are some pictures of the cut-away engine in the Porsche museum, shows you how it was done. Picture is worth a thousand words!! https://www.flickr.com/photos/47153142@N03/sets/72157624323634826/

 

[Gabriel Von Wahl]

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[Graham T]

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That was really a very informative reply Gabriel ................................ ?

 

[Pierre-Louis]

If you love 917, here are some pics of the incredible car that had just stopped behind me, as I'was working on a fuel leak on my friend's GT40 in the pits of Le Castellet track, last sunday.

Put off the wrenches, to have a look at this "thing" ! 1300hp (I was said ! ), and it seemed to be almost undriveable, as its driver had sometimes some issues to stay on the track ! And what a sound !

Got some close pics of the engine (and fan !) Sorry, taken with my phone...

 

[Thierry B]

Thanks for the pictures.
it's a 917/10, but it's strange there is no rear wing...

this engine is normally aspirated, it's 630bhp (maximum)

(1300bhp it's for 917/30 turbocharged motor)

 

[Gabriel Von Wahl]

That was really a very informative reply Gabriel ................................ ?

Thanks for noticing the error lol.

I had replied too early about why the fan located under the engine would be problematic but I went on to see someone had responded with rationale so I edited my post. I don't have permission to delete the post, and didn't want to come across as a d*ck for restating a previous post.

Hope all is well and you are enjoying the 917!