Theoretical engine combo - need input!
04-13-2005, 08:16 PM
#16
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What I would want to end up with is:
16V head for better power and low end torque
951 pistons for correct compression
turbo for obvious reasons
Intake would have to be fabbed, no big deal - I work in a machine shop. The independant cam adjust ment would be way cool, as well as getting rid of that stupid piggyback chain BS that factory chose to go with.
16V head for better power and low end torque
951 pistons for correct compression
turbo for obvious reasons
Intake would have to be fabbed, no big deal - I work in a machine shop. The independant cam adjust ment would be way cool, as well as getting rid of that stupid piggyback chain BS that factory chose to go with.
04-13-2005, 08:19 PM
#17
As I understand it, the 8v would be better for the midrange response while the 16v would flow more at higher rpms for more top end power; all things being equal otherwise.
What happened to Powerhaus? This was their specialty.....
What happened to Powerhaus? This was their specialty.....
Last edited by streckfu's951; 04-13-2005 at 08:35 PM.
04-13-2005, 09:39 PM
#18
Burning Brakes
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There have been threads on this in the Turbo forum. Those guys have beat this subject to death and I think they decided it wasn't worth it money wise.
Powerhaus advertises in Excellence to turbo 16v and 968 with numbers over 500hp.
Turbo 944 engine with a 16v head finished Lemans 7th overall in 83 or 84. It won the award for efficiency and staying on the track the most during the race with only about 50 minutes in the pits. The head was not a prototype for the S and S2 head but it was 16 valves. It put out 375 to 400 hp, detuned for reliability.
A 944GTR engine is in my avatar but with carb induction.
Powerhaus advertises in Excellence to turbo 16v and 968 with numbers over 500hp.
Turbo 944 engine with a 16v head finished Lemans 7th overall in 83 or 84. It won the award for efficiency and staying on the track the most during the race with only about 50 minutes in the pits. The head was not a prototype for the S and S2 head but it was 16 valves. It put out 375 to 400 hp, detuned for reliability.
A 944GTR engine is in my avatar but with carb induction.
They really aren't thay expensive.
04-13-2005, 10:26 PM
#22
The 924/944 GTP was the introduction of what would become the 944 motor. It was a 2.5L aluminum alloy block with 16V head, turbo and balance shafts. It was actually raced at Le Man 1981 with balance shafts. The motor has a really neat valve cover with "Le Man" cast right into it. It but out between 420bhp (as raced) and 500bhp (tested).
The 924 Carerra GT, IIRC, was built for homologation purposes for the earlier Le Man efforts. It had the 2.0L iron block with 8V head and turbo and cranked out 210bhp. The other iteration of the theme where the GTS (245bhp) and GTR which cranked out quite a bit more horses (>275bhp?). The GTR, still a 2.0L iron block and 8V head, was raced at Le Man in 1980.
The 924 Carerra GT, IIRC, was built for homologation purposes for the earlier Le Man efforts. It had the 2.0L iron block with 8V head and turbo and cranked out 210bhp. The other iteration of the theme where the GTS (245bhp) and GTR which cranked out quite a bit more horses (>275bhp?). The GTR, still a 2.0L iron block and 8V head, was raced at Le Man in 1980.
04-14-2005, 02:19 AM
#26
Hitsquad Ninja
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custom pistons run $700. of course sleeving or nikasil coating would be needed. and it really isn't THAT expensive. it's a very attainable goal with patience and time.
04-14-2005, 03:44 AM
#27
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Originally Posted by jonnybgood
924GTR was 1981 and had 375 hp
944GTR was 1986 and had the 944 engine block.
944GTR was 1986 and had the 944 engine block.
They ran a 924 Carrera GTP 944 in Le Mans in '81, it had a 944 engine and had 16 valves. It made 420HP, and eventually placed 7th driven by Juergen Barth and Walter Rohrl. This engine was capable of making 500HP @ 1.5bar, but raced at 1.1bar. This car was a white one with "BOSS" all over it, it was one of two at Le Mans in '81 the other being a works 924 Carrera GTR. There was never a 944 GTR as raced or designated by the factory.
Interesting direct quote for all you racers:
Originally Posted by Chapter 5: 924 and 944 in Competition pg. 108
At one stage, Metzger persuaded Prof Bott to let him test the engine without the balancer shafts as a means of saving 5HP. 'They came back to me a few days later,' Prof Bott recalls with satisfaction. 'They said we must have the balancer shafts because without them the vibrations are so bad that everything is breaking . . . the engine will only last a few hours.'
04-14-2005, 07:26 AM
#28
Race Director
"There was never a 944 GTR as raced or designated by the factory."
This is correct... This was an IMSA GTO car made by Fabspeed. I've actually seen some parts from this car, an unused undrilled, unfinished head. It was actually a special part custom-made by Porsche with 951 part#. But it differed from the normal 951 part in that it had HUGE ports and HUGE valves and the valves were close to vertical. Also used 14mm head-studs torqued down to around 150 lb*ft....
This is correct... This was an IMSA GTO car made by Fabspeed. I've actually seen some parts from this car, an unused undrilled, unfinished head. It was actually a special part custom-made by Porsche with 951 part#. But it differed from the normal 951 part in that it had HUGE ports and HUGE valves and the valves were close to vertical. Also used 14mm head-studs torqued down to around 150 lb*ft....
04-14-2005, 11:36 AM
#29
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There is some confusion on the 944 Lemans car. Paragraph 3.10 Production and Import Figures in the 924/944/FAQ lists the 1981 car as 944 GTP/R Le Mans. Micheal Cotton makes the mistake of calling this car a 924 Carrera. All 924s had the earlier engine block. The 944 Lemans car had the 944 engine block. In the ads by Porsche from 1986 with this car next to the 944 Turbo Porsche's ad refers to it as the 944 GTP
944 GTR
I didn't know that this 1986 car was not campaigned by the factory.
944 GTR
I didn't know that this 1986 car was not campaigned by the factory.
04-14-2005, 11:40 AM
#30
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AND I believe the S pistons are cast, not forged. Also you have to consider that the construction of the "S" 16V head is not designed for turbocharging. Yes it would probably flow a lot better than a comparable 951 8V head, but not as well as if it were designed for that application (i.e. the 968 turbo). I'd strongly recommend going with the sodium valves and seeing if there's a way to get ceramic liners cast into the head also - both were standard on the 951 heads, not sure about the 968 turbos.