Flat 8 - is it possible
Flat 8 - is it possible
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Discussion

rev-erend

Original Poster:

21,587 posts

301 months

Wednesday 27th December 2006
quotequote all

Just thinking what the new Porsche 911 engine configuration
might be..

V8 has been suggested - but is a flat 8 possible.

It would seem to make sence from a packaging perspective..
they could mid mount with the engine at the rear .. and maybe
even squeeze in a few rear seats..rolleyes

davidy

4,489 posts

301 months

Wednesday 27th December 2006
quotequote all

Of course a Flat 8 is possible, Ferrari used Flat 12's in F1 cars for years (most of the 70's)

davidy

Marki

15,763 posts

287 months

Wednesday 27th December 2006
quotequote all

Porker 917 was a flat 12

rich 36

13,739 posts

283 months

Wednesday 27th December 2006
quotequote all

At one point a Flat 16 was planned in the Le Man era

odyssey2200

18,650 posts

226 months

Wednesday 27th December 2006
quotequote all

I think that in the 60s or 70s, rootes group had a flat 8 diesel.

he had one as a bench test engine at college, but there was also something else weird about it.
It had a rocker arm arrangement from one central crank so that the pistons moved towards each other and created a combustion chamber in the middle and was a 2 stroke.

The problem with a flat 8 porsche 911 is that you are making the engine longer and therefore increasing the rear overhang.

Thats the last thing you should be doing with a car which is already a triumph of engineering over physics.

best to just make it mid mounted like the Caymen, boxter and the other big V10 thingy

rev-erend

Original Poster:

21,587 posts

301 months

Wednesday 27th December 2006
quotequote all
Think you missed that I suggested mid-mounting it like the Porsche boxter..

Yes - I know Fiat .. sorry Ferrari have flat 12's but that is 12 not 8..

I presume that it matters not how many cylinders you have because the crank would be horizontally opposed - so the cranked is a 180 degees flat plane affair anyway.

odyssey2200

18,650 posts

226 months

Wednesday 27th December 2006
quotequote all

The crank shape does not matter.
We have in line 5 cyls. norrow V5s with one cylinder head etc.

Flat 8 would be effectively 2 flat 4s one behind the other




Edited by odyssey2200 on Wednesday 27th December 17:05

odyssey2200

18,650 posts

226 months

Wednesday 27th December 2006
quotequote all

It has already been done by porsche!


http://en.wikipedia.org/wiki/Porsche_

Have fun!!

cymtriks

4,561 posts

262 months

Wednesday 27th December 2006
quotequote all

The crank is going to be very wiggly if the cylinders "box". There will be eight throws, remember that a V12 has only six throws.

If the cylinders do not "box" then the engine will be no smoother than a four cylinder turned onto its side.

The remaining possibility of non "boxing" cyinders and a cross plane crank would be very hard to balance properly, in fact some compromise involving firing order and balancing shafts may be required.

Difficult.

Pigeon

18,535 posts

263 months

Thursday 28th December 2006
quotequote all
odyssey2200 said:
I think that in the 60s or 70s, rootes group had a flat 8 diesel.

he had one as a bench test engine at college, but there was also something else weird about it.
It had a rocker arm arrangement from one central crank so that the pistons moved towards each other and created a combustion chamber in the middle and was a 2 stroke.

You're thinking of the Commer TS3 engine, which had three cylinders and six pistons.

odyssey2200

18,650 posts

226 months

Thursday 28th December 2006
quotequote all
Pigeon said:
odyssey2200 said:
I think that in the 60s or 70s, rootes group had a flat 8 diesel.

he had one as a bench test engine at college, but there was also something else weird about it.
It had a rocker arm arrangement from one central crank so that the pistons moved towards each other and created a combustion chamber in the middle and was a 2 stroke.

You're thinking of the Commer TS3 engine, which had three cylinders and six pistons.



hhmmm age clouding the memory again!

jellison

12,803 posts

294 months

Thursday 28th December 2006
quotequote all

Exact - Eh 908!

bmgm3

10,480 posts

260 months

Saturday 30th December 2006
quotequote all
Porsche built a flat 16 with nearly 2000 bhp for a 917. Car was tested but never raced. Wikipedia says Coventry Climax built a proto flat 16.

jellison

12,803 posts

294 months

Monday 1st January 2007
quotequote all
bmgm3 said:
Porsche built a flat 16 with nearly 2000 bhp for a 917. Car was tested but never raced. Wikipedia says Coventry Climax built a proto flat 16.
I have pictures of this somewhere!

coetzeeh

2,830 posts

253 months

Monday 1st January 2007
quotequote all
Lycoming have been building flat 8 engines for aeroplanes for decades - used mostly in crop sprayers & Piper Commanche 400 built in the 60's.

Andrew Noakes

914 posts

257 months

Monday 1st January 2007
quotequote all
bmgm3 said:
Coventry Climax built a proto flat 16.


The FWMW - all 1.5-litres of it!

BRM's H16 was effectively two stacked flat-8s with their crankshafts geared together.

jellison

12,803 posts

294 months

Monday 1st January 2007
quotequote all
The Can am'er 16 was no where near 2000 bhp. was around 8litres and NA, would have made more power than the then 8.8 Big Mac lumps but no where near the flat 12's blown power of around 1100bhp in the races (5.4 litres) and 1500 odd in the Special Run that Mark Donohue at Talladega in 75 at an "Average!" of 221mph.

16 was too big and heavy and no where near the power of the Turbo 12. It weighed 850kg!!

odyssey2200

18,650 posts

226 months

Monday 1st January 2007
quotequote all
So in answer to the original question.


YES!

Mr Whippy

31,449 posts

258 months

Wednesday 3rd January 2007
quotequote all
Wonder why they ever have to change?!

The new GT3 is damn powerfull, and if you want torque you add a very low pressure VNT turbo thing...

V8 in a 911 would honestly be really boring, they'd probably share it with some Audi too rolleyes

Dave