TC just posted this in another one of his threads....I have seen a lot of 917's in books, in person, under restoration and on the track. I have NEVER seen one with a side exhaust. Interesting picture...

I just came across this eBay auction of a Hot Wheels Porsche 917 with a couple of pics
here you can see it too - on both sides

configured for LeMans/1969...........

maybe today is a lottery day...
(heck I can't drool over women any more, so this will do...)

Yep, my original 917 hotwheels is like that too...never seen that first picture though!

I'd love to make some cookie-cutter megaphone tips for my sport muffler.

Those are called "anti-reversionary cones".

The Cap'n

The early 917s had the front six cylinders exhaust in front of the rear wheels. The rear six cylinders exited out the back of the car. I don't remember the reason, but I do remember that there was some technical reason for it.

They later changed so that all of the exhaust went to the rear of the car, and found that it worked better.

--DD

The Very Early 917's front 6 Bank Exhaust exited out the side. Those cars pumped out so much air it might have disrupted the air around the rear tire

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In this Guy's Case, the side exhausts might be Venting Out the Couch Farts

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The exhaust change was part of the changes made in between the 1969 and 1970 racing seasons, which tamed the handling of the 917 and produced the 917K. Ludvigsen says that the side-exit pipes dumped too much heat into the engine bay and the fuel system, so they were revised to join up with the pipes from the rear set of cylinders and exit out the rear of the car.

--DD

Gustl, Hot Wheels re-released the 917 around Christmas and I picked up 5-6 of them. Pretty good replica of the short tail version of the prototype body. So far, one is painted white to look just like the 25 prototypes, and I plan on making a longtail for one.

Just a guess, but I know drag racers are always big on equal length exhaust runners for headers - something about improving scavenging. The side exit was probably to try and get all the runners close to equal. Then they figured out that the bad outweighed the good and dumped it.

Here is a Pic Paul put up of a Ferrari (close to the same year of the 917). Go to something like the Equal Length

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