Getting started on a 917K

[Fran Hall RCR]

Falconer V12 is a Chevy with 4 more cylinders...

A liquid cooled Flat 6 engine would fit but the packaging would probably all be behind the driver..even if the sponsons were used to house a heat exchanger or two...

 

[John Milmont]

holy quick reply!

anyway, is is weight the only problem with putting everything behind the driver?

 

[Fran Hall RCR]

Polar moment is obviously a factor.....But it will be your car and you can certainly build it your way...so long as its a Flat engine it wont be too big of an issue....

The original carried all its mass/weight in the tail.....with only an oil cooler up front...so it may well be a non-issue....the overall full up weight will be higher though..

 

[Russ Noble]

Aero these days has a major influence on the way cars handle but if you go back a few years to the F5000's, the leading Lola T300/400's and the McRaes all had very little weight up the front giving a lower polar moment and making them more responsive, or twitchy, if you like.

No one could call them nimble with a heavy chebby stuffed in the back of them but that low polar set up was a faster package than any other F5000 configuration in it's day. They looked to handle quite well, but as with all cars, the good pedallers can alter their driving technique and choose racing lines to optimise the vagaries of what they are driving.....

I agree with Fran, I think within reason weight distribution is a non issue. Personally I would rather have extra weight in the back than in the front.

Cheers

 

[Richard]

I agree with Fran, I think within reason weight distribution is a non issue. Personally I would rather have extra weight in the back than in the front.

Cheers

Ditto - well designed & sorted rear suspension + superwide rear tyres. All that's left to do is light 'em up and have some fun...

 

[John Milmont]

how much did the original engine and trans combo weigh? That engine looks anything but light...

how about one of these in their? Small light weight V8



an lower cost alternative to the porsche 6cyl might be a Subaru 6. Iv heard about some pretty impressive numbers coming from a turbo'ed EZ30r something like 400+ hp at the wheels. With the cost of a rebuild for a porsche engine, you could probably get 2 or so Subaru engines.
A viable alternative?

 

[colin artus]

Regarding engine length, Porsche at one stage developed a flat 16 for the 917 before opting for the turbo route. I believe they built 3 of these engines, one of which they gave to a collector in Japan.

 

[Chris Kouba]

I always wondered about putting a radiator up in front, looks like its not possible. Seems like a liquid cooled engine is going to be difficult... Well, didn't they put a [SIZE=-1]falconer v12 in a 962? Wasn't that a air cooled car? Wonder how the cooling went with that! [/SIZE]

John,

I stand to be corrected but the FIA and IMSA had different requirements. If I remember correctly, IMSA required the motors to be air cooled for GTP but Gp C allowed water cooling- and the heads were. The rads were in the side pods adjacent to the doors, with the oil coolers and intercoolers.

As for the extra size, it shouldn't be too hard to squeeze a longer motor into a 962/956. Have you ever seen their bellhousings? They're about 15" long. It's the gold colored thing in this photo:

More pics HERE.

I SO want one to go with my 40!

 

[Fran Hall RCR]

Cool pic Chris,

A 917 is no 962....huge size difference in the engine bay.

 

[Chris Kouba]

Thx Fran, but I certainly can't take credit for the pic. You did catch the link to the others, right?

I've seen the openness of the 962/956 engine bay but can't confess to having seen that of a 917. I'd imagine it's a bit tighter around all the tubes...

 

[John Milmont]

 

[John Milmont]

The top pic is of one of the CAN-AM cars...

 

[Brian Hamilton]

Yeah,
Can Am Porsche 917's were the only ones that were turbocharged. None of the Le Mans cars were.
Now that being said I have another alternative to the engine situation. We all want the sound right? That really rough idle, kinda whiny, high revving engine? Have you ever heard of a 4 rotor Wankel rotary engine?
Pineapple Racing builds them to order. They have about a 2.6L displacement and can be over 500HP in N/A form. Imagine a twin turbocharged version? Can you say 1,000HP+?
I mean it's not a Porsche engine, it's not a large engine. It is light, reliable, high revving, and POWERFUL though! But, then again it's all up to the builder. But IMHO that would solve quite a bit of the weight issues and all that. Now as far as cooling, that would be another issue altogether.
Maybe a heat exchanger located on the actual deck-lid with a fan on it sucking air through it so it resembles the original Porsche fan? Maybe located on the top of the engine itself doing the same thing? Hell, you could make the rotary look like a flat 12 if you really wanted to. Haha! It looks like a large crankcase with no cylinders protruding from it.
Oh well, that's just me tossing out weird ideas, but I think it'd be a feasible option. The engines run about $6k for N/A and about $8k for forced induction if I remember right. Check them out though...
Pineapple Racing

Laters,

Brian

 

[Steve26]

rockonsmileI can honestly say I would be perfectly content driving one of Frans 917's around with a stock 911 engine! These cars look like their going 150MPH when they're sitting in your driveway and would be more than fun on a Saturday afternoon chasing your friend around in his GT40 (or being chased!) Let's see, a Gulf GT40 on one side of the garage and a Gulf 917 on the other... I will have good dreams tonight.

Steve

 

[Brian Hamilton]

rockonsmileI can honestly say I would be perfectly content driving one of Frans 917's around with a stock 911 engine! These cars look like their going 150MPH when they're sitting in your driveway and would be more than fun on a Saturday afternoon chasing your friend around in his GT40 (or being chased!) Let's see, a Gulf GT40 on one side of the garage and a Gulf 917 on the other... I will have good dreams tonight.

Steve

Absolutely correct sir!!!

 

[John Milmont]

Yeah,
Can Am Porsche 917's were the only ones that were turbocharged. None of the Le Mans cars were.
Now that being said I have another alternative to the engine situation. We all want the sound right? That really rough idle, kinda whiny, high revving engine? Have you ever heard of a 4 rotor Wankel rotary engine?
Pineapple Racing builds them to order. They have about a 2.6L displacement and can be over 500HP in N/A form. Imagine a twin turbocharged version? Can you say 1,000HP+?
I mean it's not a Porsche engine, it's not a large engine. It is light, reliable, high revving, and POWERFUL though! But, then again it's all up to the builder. But IMHO that would solve quite a bit of the weight issues and all that. Now as far as cooling, that would be another issue altogether.
Maybe a heat exchanger located on the actual deck-lid with a fan on it sucking air through it so it resembles the original Porsche fan? Maybe located on the top of the engine itself doing the same thing? Hell, you could make the rotary look like a flat 12 if you really wanted to. Haha! It looks like a large crankcase with no cylinders protruding from it.
Oh well, that's just me tossing out weird ideas, but I think it'd be a feasible option. The engines run about $6k for N/A and about $8k for forced induction if I remember right. Check them out though...
Pineapple Racing

Laters,

Brian

Having an RX-7 I can say that a rotary did cross my mind. And a 4 rotor has quite an amazing sound. I was not aware of Pineapple building any 4 rotors, i glanced over their site and couldn't find anything on it. I would imagine that the cost of such an engine would be a little scary, but you say 6,000 to 8,000 for a custom motor? please send a link!
Again, cooling is in issue, rotaries are also known as being the hottest running engines out their (strange they have the coolest combustion temps) and need quite a bit of a cooling system. The x-ray pic of the 917 shows how cramped it is in side their, and i think their would be problems with mounting a heat exchange over the engine, let alone horizontally. This engine sounds like it would be a better fit for fran's superlite coupe.

 

[Brian Hamilton]

You are right about it being perfect for Fran's SLC. Pineapple used to advertise that they did offer 4 rotors and even had a custom engineered excentric shaft for it. You're gonna have to contact them for the up to date pricing. I was looking at doing this earlier this year for a Porsche 944. Don't ask, I'm into weird sh*t like that. haha I'll try to find the e-mail they sent me about the engine if I still have it.

 

[Thierry B]

If I remember, there was a rotary engine which won Le Mans in 1991 (Mazda 787B)

the sound was fantastic !!!

When they arrived for the pre test in march/april the quad rotor has no muffler....
you can imagine the sound in tertre rouge just before hunaudiere strait line.....the sound was like a Stuka attack !!!
ACO Marshall decided to add a muffler to this car for the race....

but the sound was still great....

you can ear the sound here
YouTube - Mazda 787B "The Legend" 4 rotor Le Mans car

 

[John Milmont]

Yeah, rotary engines are the loudest. This is because the exhaust port opens so quickly that it actually creates a sonic boom!

 

[Donnie Barnes]

To each his own, certainly. A three or four rotor would be neat, but I'll be fine with a 993 3.8 with big horns on it. A turbo four rotor in the SLC? Now that would be one sick ride. Maybe after Fran gets my 917 done...

From what I gathered talking to people you have to be VERY careful with that horizontal fan. It's not terribly hard to engineer one that will work, but it is hard to engineer one that will work for very long. Notice the talk on the UK website that was posted here that you need to have the block machined...for those of us in the US that means we really need to find someone here that can do it. There aren't any kits that I know of available with the parts you need (at least not yet...there are rumors of people working on that, but I'm not how hard it is being pursued). Original parts are pretty impossible to find, too.

Anyway, you can add me to the list of people that would love to have a horizontal fan. So if it comes down to having someone good figure it out, well, I'd share in the R&D costs. Now if we could only find a couple hundred more folks, it might be cost effective. *sigh*


--Donnie