12 replies to this topic

[island]

Hi!
Jean-Pierre Jarier ran away with the
first race in 1973 at Mallory Park and went
on to win the Championship as he pleased.
Why was Paul Rosche`s four cylinder so
good? Did it have a better torque or more
top end speed than the Hart/Cosworth powerplants? Who watched a 1973 F2 race?

[Felix Muelas]

Island

Whilst looking for info on this subject, I found that probably the best idea would be for Paul Sheldon to answer some of your questions. So here it comes.

In 1972 the engine used by most competitors was the Ford BDA unit. In its stretched form it was far from reliable although this problem was solved towards the end of the season when the alloy block version was homologated. In 1973, the rules changed and, Instead of 1000 units of an engine, only 100 had to be produced. This allowed in the highly competitive and very powerful BMW M12 engine which was to be a mainstay of Formula 2 racing in one form or another for many years. In fact, the engine was in a class of its own and March Engineering backed a real winner when they secured its use solely in March produced cars. It almost Immediately became obvious that anyone else had a slim chance of success to say the least. This was especially unfortunate for all the other manufacturers who were hoping for Formula 2 success. For instance. Group Racing Developments (GRD) was a firm, along the lines of March who had already done well in Formula 3 racing with their star driver, Roger Williamson, who stayed with them to drive in Formula 2 races in 1973. Apart from March, all the other teams had to make use of the Ford BDA engine. Although successful in 1972, it was quite a different story in 1973.

:-)
Felix Muelas

[Nelson]

The BMW M12 was also the basis for their awesome F1 turbo engine wasn't it?

[Ray Bell]

More importantly, did it have the Apfelbeck head? This was an arrangement where the valves splayed out from the centre of the 'hemisphere' of the combustion chamber, so that it truly was a hemisphere, but required some fiddling to get the cams to work them. Did well in F2 earlier...

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Life and love are mixed with pain...

[David Beard]

Originally posted by Ray Bell
More importantly, did it have the Apfelbeck head? This was an arrangement where the valves splayed out from the centre of the 'hemisphere' of the combustion chamber, so that it truly was a hemisphere, but required some fiddling to get the cams to work them. Did well in F2 earlier...

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Life and love are mixed with pain...

Just how did that work? Was there any sort of rocker arrangement or did the cams act directly on the valves? ( I can't imagine how)

I've just been reading about Ferrai having something similar in a late 60s F1 engine.

Of course, if anyone gets round to electronic servo controlled valves in F1, with no camshafts, the valves can be at any old angle at all.

[LittleChris]

Originally posted by island
Hi!
Jean-Pierre Jarier ran away with the
first race in 1973 at Mallory Park and went
on to win the Championship as he pleased.
Why was Paul Rosche`s four cylinder so
good? Did it have a better torque or more
top end speed than the Hart/Cosworth powerplants? Who watched a 1973 F2 race?

I did, on Easter Monday 1973, at Thruxton and Henri Pescarolo won

[Roger Clark]

Originally posted by David Beard



Just how did that work? Was there any sort of rocker arrangement or did the cams act directly on the valves? ( I can't imagine how)

I've just been reading about Ferrai having something similar in a late 60s F1 engine.

Of course, if anyone gets round to electronic servo controlled valves in F1, with no camshafts, the valves can be at any old angle at all.

How were the 16 radial valves to be operated? Atop the end of te finger was a cup. Into this cup fitted the sperical end of the screw-adjustable tip of a roller-faced follower that swung from a pivot shaft below and inboard of each camshaft. The roller follower transmitted the cam's motion and the finger transmittted that motion into the plane of te valve.

Both the description and te drawing come from Karl Ludvigsen's "Classic Racing Engines"

[Frank de Jong]

BMW's 1973 F2 engine had an conventional, homologated 4-valve head. IIRC the apfelbeck head was replaced even earlier; the M10 apfelbeck engine was replaced during 1970 by the M12/1 with a conventional valve arrangement. The 1973 F2 engine was the M12/6.

[2F-001]

I recall an article in MotorSport ('70 - '71-ish) about BMW F2 motors from the years before the March tie-in. In part, I guess, used in their own Dornier-built cars. They seemed fairly adventurous; eg: multi-plug heads (a triple I think, even) and one which had the pairs of valves diagonally opposed across the pots, so that there were intake trumpets and outlets for all cylinders on both sides of the head. Or something like that. If anyone's interested, I'll try to find it.

I was at the Mallory F2 race, mentioned earlier. I think that must have been the meeting where Beltiose blew-up and it was claimed that a piece of piston, or other engine debris, went through the press-box window.

I remember too, the '72 Martini Trophy at Silverstone (Euro 2-litre sportscar series), when Quester dominated the first heat in a Chevron with what we understood to be some fancy works BMW motor that was set to blow the BD away... That was a larger capacity, of course, but I assumed there was some connection to the F2 programme that followed? Would that have been an M12 too?

[Frank de Jong]

Yes, Quester's Chevron used an M12 as well. Quester had a 1600 cc BMW engine for his March F2 in 1971 (unofficial, of course!) which was called M20 to the best of my knowledge. Doesn't make sense, really.

[JtP]

Originally posted by island
Hi!
Jean-Pierre Jarier ran away with the
first race in 1973 at Mallory Park and went
on to win the Championship as he pleased.
Why was Paul Rosche`s four cylinder so
good? Did it have a better torque or more
top end speed than the Hart/Cosworth powerplants? Who watched a 1973 F2 race?

The most impressive part of the race was Beltoise (?) blowing up his engine on the corner before the finish line and one of the conrods breaking the window in race control. He then climbed into his road car (Renault Alpine iirc) and setting off for home at some considerable speed. He was arrested on the slip road from the M1 to N circular which the police had blocked to stop him, having given up on active pursuit.

[Rainer Nyberg]

Slightly OT, but BMW power was also used in F3 during the same period, the pic below depicts the back of Freddy Kottulinsky's Lotus 59A with a 1600cc BMW engine. The picture is from 1971, the first year of the 1600cc Formula Three.

[David Beard]

Originally posted by Roger Clark






Both the description and te drawing come from Karl Ludvigsen's "Classic Racing Engines"

Thanks Roger.
Digging around in MotorSport I have found DSJs description of the Ferrari that first appeared at Monza in 67. I read that the latter motor had the valves radially disposed about the combustion chamber but less drastically so...those 'orrible rockers weren't required.