6 replies to this topic

[RobMk2a]

I understand that for the 1954 Season cars were allowed either 750cc Supercharged or 2,500cc N/A engines. As far as I can see no 750cc Surpercharged cars ran, the only possible eligible car would be an earlier AFM (is that correct).

I've come across an interesting snippet (from TAG Allison in Harts of Coppull) that Oliver Hart (speedway rider) made a tender bid in Summer 1952 for a BRM V16 (not sure if it was for an engine or car) with the view of creating a straight eight 750cc engine (I assume to enter the new GP formula) Whilst I'm not sure if this was practical, Oliver knew Reg Parnell and other members of the motor racing fraternity. The idea was not pursued as The Owen Organisation won the tender (is this the correct time frame).

Has anyone (Doug?) come across Oliver's offer letter or is this just a 'pipe dream'.

Thank you for your help.

Rob Pennington

[Allan Lupton]

The structure of the V16 would not lend itself to the construction of a straight eight, but it is conceivable that one could imagine deriving a V-eight from that.

Pipe dream is the best summary either way, I'd say.

[ensign14]

I understand that for the 1954 Season cars were allowed either 750cc Supercharged or 2,500cc N/A engines. As far as I can see no 750cc Surpercharged cars ran, the only possible eligible car would be an earlier AFM (is that correct).
 

 

DB and Giaur both took advantage to enter non-title races with blown 750cc engines.  They were bog-slow.
 

[uechtel]

In 1948 to 1950 there was a 'midget' class in Germany allowing 'home-built' cars with supercharged engines up to 750 cc, for which the AFM had been built. So in theory there would have been a number of 'eligible' cars, but of course they were never intended for Formula 1 and would have been absolutely uncompetitive and outdated.

[DCapps]

Keep in mind that the regulations for the International Racing Formula One (which were related to technical parameters of the cars) were separate and distinct from those of the CSI's World Championship for Drivers and both of which were also affected by other stipulations laid down in the CSI's Sporting Code. While this might be unnecessary to point out to more than a few here, there might be others who may not realize this distinction. Not until the 1961 season did the CSI mandate that events held as part of it's World Championship for Drivers use cars that conformed to the International Racing Formula One, although the regulations for the two remained separate and distinct from one another.

 

It was not until the the FIASCO War and and the FIA's terminating the World Championship for Drivers effective the end of the 1980 season, that the FIA and its FISA merged the two formerly separate sets of regulations, technical and sporting, into one, thereby creating a new championship.

 

The regulations for the 1954-1957 International Racing Formula One and its extension with changes for the 1958-1960 seasons were actually very simple, covering relatively few pages and the same for those pertaining to the World Championship for Drivers. Most of the contemporary discussion regarding the inclusion of the supercharged 750cc tend to suggest that it was something of a sop, not taken very seriously by those teams seriously considering participating in events being held to the formula.

[Ray Bell]

Of interest are a couple of quotes from books:

From Design and Behaviour of the Racing Car
On the basis of 1952 knowledge it was reasonable to expect that an atmospheric engine could be built to give 115bhp/litre at 8,000rpm, which would be the equivalent of 290bhp at this speed with 2.5-litres swept volume.

To equal this the 750cc supercharged engine would have to have a boost pressure of 50psi and a brake mean effective pressure of 520psi to give 400bhp/litre. But these figures could only be met if the compressor were separately driven, and with say 100bhp added to drive it one would be looking at 700psi at 8,000rpm as against a mere 193psi on the supercharged engine.

In addition, at say 6,000rpm the torque of the supercharged engine would be about 15% below that of the unblown type and the fuel consumption would, at around 1.5lb/bhp/hour, be more than twice the unblown calculated at 0.65lb/hp/hour. P129

These were the figures which Mercedes-Benz came up with. Getting back to the BRM question, then, these factors would still have been valid, as would the fact that the 3:1 ratio of unsupercharged engine to supercharged grew to a slightly less favourable figure of 3.33:1

That being the case, it's pertinent to mention that the change to a 2:1 ratio came along before anyone seriously considered forced induction again.

But there was more on the BRM planners' minds according to Raymond Mays in his book with Peter Roberts:

From BRM - Mays and Roberts

The problems of providing and maintaining suitable superchargers to give the very high boost needed were such that we considered the 2½-litre unsupercharged engine to be quicker and cheaper to develop. We had learned the hard way that it is the speed at which you can develop and improve that counts - hence the choice of a simple four-cylinder unblown engine.

I think this answers most questions.

[Lee Nicolle]

They were just 60 years ahead of them selves.Modern Bike engines with forced aspiration would make bigger numbers than the then 2.5 litre of the day, or even a production based n/a engine of today. Torque comparison would be interesting as well.