Front Engine'd Porsche's at Le Mans ( 1981 )

[Buchanan Automotive]

In June 1981, Le Mans 24 hour car racing event ( France ), Porsche entered a prototype 944Turbo ( 924 GTP ) , it was the 2.5L 944 all alloy engine ( half a 928 engine in many ways ) , but with a prototype Twin Cam 16V cylinder head & was the first Porsche to race with the very new /experimental for 1981 , Bosch full electronic ( motronic ) fuel injection system with digital ignition ( mapped )  , this was used to make the best possible power & fuel economy in this prestigious 24 hour event & with better fuel economy results in less pit stops & over 24 hours this all adds up , in fact this Porsche ( 924GTP / 944/ 71 engine ) was the first car ( ever ) to race at the Le Mans event with full electronic fuel injection & mapped programmed ignition system 

 

Note } The Porsche 944 model ( NA ) had not yet been released to the public yet , but would be within a few weeks of the running of the 1981 Le Mans event & as Porsche's top executive at the time ( Ernst Fuhrmann) summed up his marketing strategy by saying " Racing is good for every car " , very much like the saying we had in Australia or the USA , meaning " race on Sunday & sell on Monday ", and if you're car does well at the track , it often results in more sales 

 

Note 2 }  This special pre production 944 Turbo engine with its 16V twin cam cylinder head ( engine code number 944/71 ) was designed by Hans Metzger even though the Porsche 944 alusil engine crankcase & crankshaft & balance shafts were all standard production ( 944 ) items for the upcoming 944 model range , the special twin cam head / cams etc was unique to this engine and Porsche made very few of them 

 

Engine 1 = Development engine , at times had a twin cam head & 352 HP

 

Engine 2 = New engine 16V head

 

Engine 3 = Tested at Paul Ricard circuit & after test engine was scrapped

 

Engine 4  = New engine , some parts from engine 3 , used for long distance testing at Paul Ricard circuit

 

Engines 1-2-4 ran in both 2 valve head & 4 valve head configurations , some of the engines that had 4 valve heads were rebuilt & also tested with 2 valve heads 

 

Engine 5 = Like engine 4 

 

Engine 6 = This engine was also tested in one of the race cars

 

Engine's 7 , 8 , 9 = Information lost 

 

Engine 10  = was used to race ( 924 GTP Le Mans car )

 

Engine  12 = For practice at Le Mans (Bosch motronic electronic injection ) and Kugelfischer mechanical injection at the Norisring

 

Engine 13 = no information if this engine was even made ? 

 

Engine 14 = Engine went to Australia ( Alan Hamilton ) , I was even luck to get a photo of this engine at Porsche cars Australia back in 1983 while I was participating at a Porsche training course & at the time I / we had no idea how rare this engine was 

 

These Metzger designed 944 Turbo ( 944 / 71 ) engines had a unique twin cam ( cam cover ) with the cast word on the Top section of the the cover the word Porsche , and on the lower section the cast words " Le Mans " 

 

  Note 3 } at the same 1981 Le Mans 24 hour race , Porsche had other cars competing as well }

 

Going for an outright win ,Jules sponsored  Porsche 936/81 "Group 6 "Space-frame open top Spyder , this Non Road car based proper race car driven by Derek Bell & Jacky Ickx , took out the outright win 

 

Going for a class win was ( Car no 01 ) 924 GTP ( 944 / 71 engine ) driven by Walter Rohrl & Jurgen Barth , starting 43rd on the starting grid & finished with a class win and an astonishing 7th place outright in a road car based vehicle .

 

In the book " The Porsche 924 Carrera" written by Roy Smith , Walter Rohrl comments on co driving this prototype 944 Turbo ( 924 GTP ) at Le Mans }

 

  In the number 01Porsche 924 GTP everything was going smoothly - well almost , it was something very special because we were racing the 944 engine for the first time , it had bad turbo lag and only had power between 5,300 RPM & 5,700 RPM ,( was designed to have power from 3,000RPM ) it was incredible , so difficult & I remember sometimes you had the feeling on one lap it had no power & then on the next lap the car felt like it was a bit better , the good thing was it always kept running , we never had a problem during the race ( part from the strange turbo lag issue ) , we drove for 24 hours just filling with fuel , changing tyres once or twice and I think brake pads once , We got a special prize for the car with the shortest standing time in the pits and 1st in the GTP 3+ Litre class ( GTP over 3 litre class is for NA engines over 3,466cc )

 

In the number 36 Porsche 924GTR driven by Schurti / Rouse , they came 1st in the IMSA GTO class and a fantastic 11th outright , not a bad effort for the little Audi based engine that started 48 th on the starting grid

 

Note 4 }  The 924 GTR is based on the 924 Turbo / 924 GT / 924 GTS , meaning 2.0L cast iron block and a single cam , 2 valve alloy cylinder head and of course Turbo Charged with a front mount intercooler , but with mechanical fuel injection .

 

Note 5 } The 2.0L 924 GTR ( for the 1981 24h Le Mans race ) was geared to do 330 Kmh 

 

Regards

Bruce Buchanan

Buchanan Automotive 

 

 

[OzJustin]

Interesting read Bruce. It wasn't a typo in the below sentence? A 400rpm powerband would be ridiculously difficult to drive around, even at Le Mans with high revs on the long straights!

" it had bad turbo lag and only had power between 5,300 RPM & 5,700 RPM ,( was designed to have power from 3,000RPM ) "

[Buchanan Automotive]

No it was not a typo , that was the problem they discovered on race day , Walter Rohrl didn't go intro the exact details in the book , so it must of happened early on in the race & it was not easily solved in the pits during the 24 hour race & they must of decided to just put up with it and carry on regardless