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Buchanan Automotive

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

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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 

 

 

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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 ) "

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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

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