924 Carrera GTR 16V head
02-19-2010, 04:26 PM
#46
Addict
Rennlist Member
Rennlist
Small Business Partner
Rennlist Member
Rennlist
Small Business Partner
Yep, and color scheme is right on. Loved that car. Of course the '88 was the one to get with the 'lotus' suspension, lol. And if you were a die-hard the 88 formula. But the non-GT/SE style front never did appeal to me, much like the 944NA front (yuk).
I still remember dreams of swapping in the DOHC 3.4. That was absolutely the motor that should have came in the car, and the Quad-4 as the 4-cylinder version instead of the lame 2.5 Iron Duke.
I still remember dreams of swapping in the DOHC 3.4. That was absolutely the motor that should have came in the car, and the Quad-4 as the 4-cylinder version instead of the lame 2.5 Iron Duke.
02-19-2010, 04:33 PM
#47
Formula One Spin Doctor
Rennlist Member
Rennlist Member
Maybe for the street guys and non-pro... But was the GTP car really that far behind? F1 of the late 70's:
"2.61-litre 4-cylinder Offys in 1978 were producing over 800hp on methanol with an 8.1:1 compression ratio on boost levels of up to 45psi without intercooling" (Forced Induction Performance Tuning).
Nearly three times the boost of the GTP car, and (a lot) more compression, and a few years earlier to boot!
Hell the 1940's P-38 Lightning had a CR of 6.65:1.
Seems sad if the 6.8:1 CR is/was true.
"2.61-litre 4-cylinder Offys in 1978 were producing over 800hp on methanol with an 8.1:1 compression ratio on boost levels of up to 45psi without intercooling" (Forced Induction Performance Tuning).
Nearly three times the boost of the GTP car, and (a lot) more compression, and a few years earlier to boot!
Hell the 1940's P-38 Lightning had a CR of 6.65:1.
Seems sad if the 6.8:1 CR is/was true.
First off - Offys were mainly Indy car engines...
Second - they had no head gaskets – the head was integral to the block. Very handy for running high cylinder pressures and temps.
Third - They were also, as you pointed out, methanol fueled – that’s a completely different ball game. I believe that methanol was not legal in most endurance racing back then…
Fourth – the 924/944 entered were a street based vehicle, not a formula/GTP car…
BTW – everybody should read up on the old offy’s – amazing engines with decades of winning performances.
Second - they had no head gaskets – the head was integral to the block. Very handy for running high cylinder pressures and temps.
Third - They were also, as you pointed out, methanol fueled – that’s a completely different ball game. I believe that methanol was not legal in most endurance racing back then…
Fourth – the 924/944 entered were a street based vehicle, not a formula/GTP car…
BTW – everybody should read up on the old offy’s – amazing engines with decades of winning performances.
Sorry Duke and Chris.. you're both wrong. (EDIT: correct for the 70s as Rogue stated.) High horsepower formula 1 days were run on a crazy fuel called Toluene. 70psi type stuff.. crazy.
I just looked it up on Wikepedia to support my statement.. here's a quote.
"Toluene can be used as an octane booster in gasoline fuels used in internal combustion engines. Toluene at 86% by volume fueled all the turbo Formula 1 teams in the 1980s, first pioneered by the Honda team. The remaining 14% was a "filler" of n-heptane, to reduce the octane to meet Formula 1 fuel restrictions. Toluene at 100% can be used as a fuel for both two-stroke and four-stroke engines; however, due to the density of the fuel and other factors, the fuel does not vaporize easily unless preheated to 70 degrees Celsius (Honda accomplished this in their Formula 1 cars by routing the fuel lines through the muffler system to heat the fuel). Toluene also poses similar problems as alcohol fuels, as it eats through standard rubber fuel lines and has no lubricating properties as standard gasoline does, which can break down fuel pumps and cause upper cylinder bore wear."
I guess Im off by quoting a fuel from the 80's and you were stating 70's. But isnt the motor in question from the 80's?
And yes.. Chris is right.. I guess you're all young? I didn't think you guys were. 7:1 compression was the norm. I was a kid all through the 80's, but I loved me sum racing. IMSA was my favorite back then.
Brabham-BMW BT52 (1983)
Within four years all the front runners had turbo power – but the explosively powerful engines often failed to last the distance.
Qualification was based on a single lap. Teams used every trick to unleash maximum power from the engines for that circuit – even if it meant they detonated on the way back to the pits.
Brabham used petrol that was 84 per cent Toluene – a highly powerful and dangerous chemical. In qualifying the car was reputedly capable of an eye-watering 1,400hp.
It won driver Nelson Piquet the world championship.
I just looked it up on Wikepedia to support my statement.. here's a quote.
"Toluene can be used as an octane booster in gasoline fuels used in internal combustion engines. Toluene at 86% by volume fueled all the turbo Formula 1 teams in the 1980s, first pioneered by the Honda team. The remaining 14% was a "filler" of n-heptane, to reduce the octane to meet Formula 1 fuel restrictions. Toluene at 100% can be used as a fuel for both two-stroke and four-stroke engines; however, due to the density of the fuel and other factors, the fuel does not vaporize easily unless preheated to 70 degrees Celsius (Honda accomplished this in their Formula 1 cars by routing the fuel lines through the muffler system to heat the fuel). Toluene also poses similar problems as alcohol fuels, as it eats through standard rubber fuel lines and has no lubricating properties as standard gasoline does, which can break down fuel pumps and cause upper cylinder bore wear."
I guess Im off by quoting a fuel from the 80's and you were stating 70's. But isnt the motor in question from the 80's?
And yes.. Chris is right.. I guess you're all young? I didn't think you guys were. 7:1 compression was the norm. I was a kid all through the 80's, but I loved me sum racing. IMSA was my favorite back then.
Brabham-BMW BT52 (1983)
Within four years all the front runners had turbo power – but the explosively powerful engines often failed to last the distance.
Qualification was based on a single lap. Teams used every trick to unleash maximum power from the engines for that circuit – even if it meant they detonated on the way back to the pits.
Brabham used petrol that was 84 per cent Toluene – a highly powerful and dangerous chemical. In qualifying the car was reputedly capable of an eye-watering 1,400hp.
It won driver Nelson Piquet the world championship.
Sorry – you are wrong in calling out ‘wrong’!! Duke and I are right in what we said. 
The Offy was an Indy car engine that ran on Methanol – the poster mentioned the Offy so that is what we were talking about.
You are right about the F1 turbo period, they did use ‘rocket fuel’ as they called it – but that never made it to Indy car racing and the Offys….
The Offy was an Indy car engine that ran on Methanol – the poster mentioned the Offy so that is what we were talking about.
You are right about the F1 turbo period, they did use ‘rocket fuel’ as they called it – but that never made it to Indy car racing and the Offys….
PS: The disadvantage of running Low CR on a turbo engine running on gasoline is not power , it's throttle response and fuel consumption . TR can be over come with an anti-lag strategy , you will not overcome the consumption.
The picture posted of the BMW f1 engine , notice where the TB is ! that was there anti-lag strategy of the time , TB in front of Turbo ...
Last edited by A.Wayne; 02-19-2010 at 05:00 PM.
02-19-2010, 06:15 PM
#48
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
For what it's worth (not much) I bet $ I might be first guy on here with a turbo car. 1963 my first car was a '62 Corvair Spyder. GM knew nothing , and I mean nothing about how to set a turbo up. Lag was so bad didn't have any until spooled up in the second gear floored it in. Side draft single carb, no intercooler and do not even remember a BOV or Waste gate. Seem to remember it had a spring loaded extermal "pop off" valve in case of a back fire, which it did at times.
“what car was the first production car with an air-cooled rear mounted turbo engine?”….GM of course! – Covair!
BTW – the turbo corsair did not have any boost control other than a restrictive exhaust. No BOV either….
02-19-2010, 06:18 PM
#49
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
The Offenhausers had an integral head/block – all one casting. To do a valve job you had to start at the bottom of the engine and reach the valve seats from inside the cylinders…
02-19-2010, 06:51 PM
#50
Instructor
Greetings from Aruba!
02-19-2010, 07:28 PM
#51
Formula One Spin Doctor
Rennlist Member
Rennlist Member
02-19-2010, 09:43 PM
#53
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
02-20-2010, 12:12 AM
#54
Team Owner
Chris, I've looked for any data on that system but can't find it. Everything is from my memory and I was like 15 when I got that car. The way to hot rod at that time was wrap the exhaust in asbestos and foil insulation (right, boy what we didn't know!) to retain heat and add a 2 bl down draft carb. The little car was fast for its time. Took awhile but for sure had turbo pull. Friends with small block Chevy and early Ford V8s were amazed. Added a rear camber compensator since had swing axles (you just think a 911 can get nasty) and viola: 911 before there was one. My dad wrecked it twice and I got hit a couple of times. Mom and Dad decided it was "dangerous" (duh) so got me a new '65 GTO. Amazing huh?
02-20-2010, 12:19 AM
#55
Team Owner
Thinking about the all in one block and head used to fly and think that most the air cooled Continental and Lycoming flat 4 & 6 engines are that way; head and cylinder all in one. Gasket is at the base to crankcase halves. Blowing a head gasket at 10,000 feet in a light single would be a very bad idea. Also twin ignition and plugs (twin mags) and until few years ago no additives or multi weight oils least get carbon deposits in the cyls, or so was the theory.
02-20-2010, 08:55 AM
#56
Addict
Rennlist Member
Rennlist Small
Business Sponsor
Rennlist Member
Rennlist Small
Business Sponsor
Thinking about the all in one block and head used to fly and think that most the air cooled Continental and Lycoming flat 4 & 6 engines are that way; head and cylinder all in one. Gasket is at the base to crankcase halves. Blowing a head gasket at 10,000 feet in a light single would be a very bad idea. Also twin ignition and plugs (twin mags) and until few years ago no additives or multi weight oils least get carbon deposits in the cyls, or so was the theory.
02-20-2010, 11:17 AM
#57
Team Owner
Most basic was the Piper Turbo Arrow. A "fixed" waste gate, no IC and as you probably noticed none seem to have ( or used to) a "timer" for shut down oil flow. Used to fly with friends P Barron a lot. On landing started a 3 minute timer, don't hit the throttles or jazz it after roll out. Lot of times sit there on the tarmac while line boy kept signaling to shut it down but still had to cool the turbos. At least it did have altitude compensating waste gates. I bet you could fix one a lot better.........except for that pesky FAA log dealie.
02-20-2010, 12:28 PM
#58
Racer
Join Date: Jan 2005
Location: Central CA
Posts: 451
Likes: 0
Received 0 Likes
on
0 Posts
The biggest reason why the Factory run such a low compression was simply because the lack of development time. The time frame was less the six months to develop and prepare the engine for Le Mans 1981.The Joint between block and head was( and probably still is) the main problem. It couldn't keep the cylinder pressures in check, and after couple of hours of running the higher boost, it would brake. The engineers blame this on the small sealing surface avaliable on top of the cylinder bore. So the Factory decided to revive the 936s and go for out right victory and the 949 to a seconds, and is mission was change to just a class winner.
regards,
AL
regards,
AL
02-20-2010, 01:03 PM
#59
Formula One Spin Doctor
Rennlist Member
Rennlist Member
Most basic was the Piper Turbo Arrow. A "fixed" waste gate, no IC and as you probably noticed none seem to have ( or used to) a "timer" for shut down oil flow. Used to fly with friends P Barron a lot. On landing started a 3 minute timer, don't hit the throttles or jazz it after roll out. Lot of times sit there on the tarmac while line boy kept signaling to shut it down but still had to cool the turbos. At least it did have altitude compensating waste gates. I bet you could fix one a lot better.........except for that pesky FAA log dealie.
02-22-2010, 11:00 AM
#60
Drive-by provocation guy
Rennlist Member
Rennlist Member
Thread Starter
Join Date: Apr 2002
Location: NAS PAX River, by way of Orlando
Posts: 10,439
Likes: 0
Received 0 Likes
on
0 Posts
I've always wondered how the 1/4 guys run a turbo on a carb engine with no a/f control or data log etc. ????