30 replies to this topic

[Henri Greuter]

I hope this question isn't too specific for the answer: "Buy a book about them..."

Because I have a book on BRM and also a few which have some on F1 engines.

 

 

While doing some research on racing fuels used over the years I ran into some interesting blends and staggering consumption rates for a few engines. But for one engine of wich I expect truly horrendous figures, I haven't found anything better yet than a statement that it was not known but estimated at 2-3 miles gallon.

That is said about the BRM V16.

well, 2-3 mph is a rather vague value with quite a variable.

So I would like to ask if anyone can, but also, wants to tell me (ant other readers!) what (s)he knows about the fuel consumption figures for the BRM V16.

Thanks in advance,

 

Henri

[Charlieman]

Which fuel mix?

 

If the fuel consumption of the BRM V16 had been exceptional (compared to an Alfa Romeo, for example), we'd expect to read about it in historical descriptions of the team's preparations. Going to the start grid carrying 20% more fuel would have been a significant factor at the beginning of a race -- assuming that the BRM was expected to last for long.

 

For later multi cylinder engines (e.g. V12 Matra and Ferrari), valve area and gas flow rates were significant design factors. The engines were designed with the expectation that they would put more fuel into the combustion chamber than a Cosworth V8, with the fuel weight cost offset by max power. The Ferrari 180 degree V12 didn't deliver many more revs than a Cosworth V8 but it worked for them.

 

1950s analyses (mostly Pomeroy based) suggest that the BRM V16 was designed for high piston speed (i.e. high revs), high supercharging pressures, high BMEP. On a high speed circuit, the high everything means high efficiency and "normal" fuel consumption for a supercharged GP engine. Pomeroy had an obsession about piston speed -- it was a limiting factor in the early days of racing. Post WWII and the lessons from aero engine design, it was a lesser factor, especially with non-supercharged engines.

[Ray Bell]

Betweem the Mays/Roberts book on BRM and the Design and Behaviour book with input from Pomeroy, we could probably find some kind of figures...

I agree that '2-3 mpg' is a huge variation, but it might have catered for different circuits too.

[Charlieman]

Betweem the Mays/Roberts book on BRM and the Design and Behaviour book with input from Pomeroy, we could probably find some kind of figures...

The BRM V16 never raced flat out continuously over a series of long races. If it had done so, we could use information about fuel tank size and distance.

[Henri Greuter]

Which fuel mix?

 

 

 

I did find a fuel formula of 80% Methanol, 10% acetone and 10% Benzol used from 1953 on. It was kmnown as Shell racing fuel nr 1.

Difficulty is that the name benzol is used for two liquids: First an a oldfashioned name for what nowadays is called benzene (cyclic C6H6) ut also us used as name for a oil product consisitng of benzene and Toluene. Os was the toluene contaminated benzene used or was it pure benzene ?

 

 

Henri

[Charlieman]

I did find a fuel formula of 80% Methanol, 10% acetone and 10% Benzol used from 1953 on. It was kmnown as Shell racing fuel nr 1.

Difficulty is that the name benzol is used for two liquids...

Search around Benzole and you find a Shell connection. And BRM used Shell fuel for a few years.

 

https://en.wikipedia...ational_Benzole

[Tim Murray]

In B.R.M. Volume 1 (p117) DCN quoted Tony Rudd on the refuelling strategy for the BRMs in the 1951 British GP:

The race was over 260 miles. The cars held about 75 usable gallons and did about 2½ mpg on the 1951 fuel which was a 70 per cent alcohol mix. If we got it right, we might - just about - get away with one refuelling stop.

[f1steveuk]

That fuel mix' sounds like one of Rod Banks', who was at one time a consultant to Shell. Better known for his fuel expertise with aircraft engines, he did have a habit of including Tetra-Ethyl lead, as an anti knock agent.

 

For example, his sprint "cocktail" for the Schneider Trophy Rolls-Royce R Type engine was 30% Benzol, 60% Methanol, 10% Acetone and 4.2 cc of tetra-ethyl lead per gallon. In 1931 the Supermarine S6b was using 14 gallons a minute!! (6 pints/horsepower/hour, as well as 14 gallons of pure castor oil per hour). 

 

I know he advised Coventry Climax at one stage as well, so fuel economy wasn't high of his priorities! 

Edited by f1steveuk, 30 August 2017 - 15:34.

[Michael Ferner]

In B.R.M. Volume 1 (p117) DCN quoted Tony Rudd on the refuelling strategy for the BRMs in the 1951 British GP:

That sentence doesn't make sense. 150 gallons times 2.5 mpg makes 375 miles, more than enough to last to the finish in a 260 mile race. If the quoted race distance and tankage are correct, then the consumption would be more like 1 and 3 quarters of a mile per gallon.

[kayemod]

In B.R.M. Volume 1 (p117) DCN quoted Tony Rudd on the refuelling strategy for the BRMs in the 1951 British GP:

The race was over 260 miles. The cars held about 75 usable gallons and did about 2½ mpg on the 1951 fuel which was a 70 per cent alcohol mix. If we got it right, we might - just about - get away with one refuelling stop.
 

 

Impressive figures, or maybe that should be unimpressive figures, but didn't the Alfa 159s have similarly prodigious thirsts, and would their fuel have been a comparable mix?

[Roger Clark]

Tim's Tony Rudd quote seems strange: 75 gallons at 2.5mpg should give a little over 180 miles. I know they wouldn't let it run that low but it should give a useful margin with one stop in a 260 mile race.  He did also say that they had had problems transferring fuel from the rear to the front tanks which restricted capacity.  They did have a solution but hadn't been able to test it.

[Michael Ferner]

Impressive figures, or maybe that should be unimpressive figures, but didn't the Alfa 159s have similarly prodigious thirsts, and would their fuel have been a comparable mix?

I think I remember reading about 1.6 mpg for the Alfettas!!

[Charlieman]

I think I remember reading about 1.6 mpg for the Alfettas!!

I believe that is what I suggested for the BRMs...

[kayemod]

I think I remember reading about 1.6 mpg for the Alfettas!!

 

Yes, that's roughly the figure that I half remembered, who would ever have thought that the BRM V16 would be a more economical choice, but then again, maybe it wasn't. Since Tony Rudd's figures don't seem to make much sense, Perhaps the true BRM consumption figure was close ro the Alfa's as Charlieman suggests, would the Alfas have been burning a similar fuel mix?

[Tim Murray]

As Roger says, Tony Rudd was very concerned about the problems in filling the front tank at pit stops due to an air lock in the system. He reckoned that when this occurred, the front fuel tank 'refused to fill above one-third full, i.e. only some 20 gallons...'.

Thus there was a good chance that perhaps up to 40 gallons would not be taken on board at the pit stop. Driver-operated valves were fitted to solve the problem, but the drivers had to remember to open them before refuelling commenced. At their first pit stops during the race Parnell and Walker both forgot, so that the two cars between them took on less than 50 gallons of fuel, instead of the planned 60 gallons each. Thus both cars required a second fuel stop.

[bradbury west]

Talking of V16 fuel consumption reminds me of the story of Graham Hill when BRM took a V16 for demo laps at the South African GP. He enjoyed the prodigious power so much, giving it real stick around the circuit, that he used the entire fuel supply in either one or two demos, which was not the plan. But the noise and spectacle, and no doubt appreciation of the crowd, was fantastic.
OT the Alfettas thirst came back to bite them at Spa, ISTR, when an unblown Talbot proved to be their nemesis, running without time sapping refuelling stops.
Roger Lund

[Henri Greuter]

Yes, that's roughly the figure that I half remembered, who would ever have thought that the BRM V16 would be a more economical choice, but then again, maybe it wasn't. Since Tony Rudd's figures don't seem to make much sense, Perhaps the true BRM consumption figure was close ro the Alfa's as Charlieman suggests, would the Alfas have been burning a similar fuel mix?

 

 

Well, to prove that I'm not listening/reading only to what is told but that I can share info too:  The 1951 blend used by the Alfa is reprted to have been 97.5% methanol, 1.5% water and 1% ricinus oil. Consumption was about 1.6 mpg but the atrocious consumption was also because of the engine almost drowning in fuel. An overdose of fuel was used to assist as cooling aid within the combustion chamber. There was even some overlap in which both valves were open simutaneously in order to pump the mixture through the combustion chamber for cooling purposes.

 

Knowing the Alfetta 159 could come up with some 425 HP on a good day with such a fuel consumption figure, then I wonder how much the BRM  needed of its mixture to produce the reported reliable 585 hp at 11.000 rpm it is said to have been capable of.

Since I couldn't find the answers, that why I opened this thread.

 

Henri

[Allan Lupton]

When comparing the Alfa and the BRM I feel the different types of supercharger may be relevant. Alfa used roots blowers which are pretty inefficient, particularly so at high pressure differentials as there is no actual internal compression. That inefficiency is the result of them turning a lot of their driving horsepower into heat which is why the almost pure methanol fuel as coolant is needed, despite the low calorific value of meth..

The centrifugal superchargers of the BRM would have had far better efficiency at the well-known expense of a pressure ratio that increased as the cube of the speed of rotation. They would have needed the charge cooling effect of methanol but not as much as the Alfa so some benzol with its higer calorific value could be used. I'd have thought the 10% benzol was too low and something more like the 30% of the Rod Banks Schneider Trophy brew would be the thing.

 

In summary there is no reason to doubt that, if it was working as designed, the BRM could return a better fuel consumption than the Alfa and do so at a higher speed.

[D-Type]

To throw a small spanner:  I assume that we are talking Imperial gallons unless the discussion spreads to the Novi and other cars racing in the US

[Henri Greuter]

When comparing the Alfa and the BRM I feel the different types of supercharger may be relevant. Alfa used roots blowers which are pretty inefficient, particularly so at high pressure differentials as there is no actual internal compression. That inefficiency is the result of them turning a lot of their driving horsepower into heat which is why the almost pure methanol fuel as coolant is needed, despite the low calorific value of meth..

The centrifugal superchargers of the BRM would have had far better efficiency at the well-known expense of a pressure ratio that increased as the cube of the speed of rotation. They would have needed the charge cooling effect of methanol but not as much as the Alfa so some benzol with its higer calorific value could be used. I'd have thought the 10% benzol was too low and something more like the 30% of the Rod Banks Schneider Trophy brew would be the thing.

 

In summary there is no reason to doubt that, if it was working as designed, the BRM could return a better fuel consumption than the Alfa and do so at a higher speed.

 

 

Think that there is a lot to say for all this. On the other hand, the Alfetta was known for being a more driveable car with a larger useful rev range (lower in particular) then the BRM where no-one was home below 8000 rpm  and at the point that the doors of the stable went open to let all horses out you were overrun by them all in an all-out stampede so to speak.....

And that difference could be credited to the superchargers used on both engines. The BRM supposedly had more horses, the Alfa ones were more obedient......

 

 

Henri

Edited by Henri Greuter, 30 August 2017 - 19:19.

[Macca]

I believe that the Graham Hill demo was at Kyalami in 1968 ("It Was Fun") with its elevation of 5600 ft above sea level, Tony Rudd had the 4.5 inch restrictor plate removed and the R-R iris diaphragm throttle and variable geometry system (whatever that was) fitted to allow 50% more air through and it used 2/3 of a barrel of fuel in about 30 miles in the run.

It pulled 12,500rpm instead of the expected 11,000 and was later calculated to have been giving 780 bhp.......

Paul M

[Ray Bell]

Originally posted by Charlieman
The BRM V16 never raced flat out continuously over a series of long races. If it had done so, we could use information about fuel tank size and distance.

These books speak in fuel consumption per hour, from that maybe some significant calculations can be made?

Interesting the 780bhp comment. 585 was only a very rare reading on the dyno, then to read that Tony Rudd fitted different parts with a view to further test the power availability some 15 years after the cars became ineligible for WDC races shows he was a true racer at heart.

And I'll bet Graham knew all about what was going on!

[nmansellfan]

780 horses...! Graham must have been seriously moving at the end of Kyalami's straight if he kept his foot in all the way from Leeukop, possibly even faster than he and Jimmy were during the GP in their 49's.

[Roger Clark]

 Pomeroy had an obsession about piston speed -- it was a limiting factor in the early days of racing. Post WWII and the lessons from aero engine design, it was a lesser factor, especially with non-supercharged engines.

Pomeroy frequently explained that it was piston acceleration, not piston speed that was the limiting factor.  It was the mistaken belief that piston speed was the limiting factor that led to limited bore formulae and extreme long stroke engines of the pre-1914 cars.

[Roger Clark]

Well, to prove that I'm not listening/reading only to what is told but that I can share info too:  The 1951 blend used by the Alfa is reprted to have been 97.5% methanol, 1.5% water and 1% ricinus oil. Consumption was about 1.6 mpg but the atrocious consumption was also because of the engine almost drowning in fuel. An overdose of fuel was used to assist as cooling aid within the combustion chamber. There was even some overlap in which both valves were open simutaneously in order to pump the mixture through the combustion chamber for cooling purposes.

 

 

Henri

It was common to have both valves opened simultaneously. For example, the 1926 Delage opened its inlet valve 18degrees before top dead centre and closed its exhaust valve 12degrees after tdc

[Roger Clark]

I believe that the Graham Hill demo was at Kyalami in 1968 ("It Was Fun") with its elevation of 5600 ft above sea level, Tony Rudd had the 4.5 inch restrictor plate removed and the R-R iris diaphragm throttle and variable geometry system (whatever that was) fitted to allow 50% more air through and it used 2/3 of a barrel of fuel in about 30 miles in the run.

It pulled 12,500rpm instead of the expected 11,000 and was later calculated to have been giving 780 bhp.......

Paul M

Karl Ludvigsen, in his book on the V16 said:

 

"Geoff Wilde's team cautioned that a useful power curve could only be obtained if either the blower's inlet or its inter-stage section were automatically 'throttled' with a ring of variable-angle stator blades to help tailor the boost curve to the engine's requirements.  This was akin to a system used successfully during the war on Daimler-Benz and Junkers aero-engines.

 

"Though the Rolls men expressed a preference for inter-stage throttling, the system that they actually made for the BRM had variable-angle vanes at the blower's inlet, to be either boost- or speed-controlled.  One version of this had an iris-type throttle like the iris of a camera.  However, this system was destined never to be used during the engine's active racing life."

Edited by Roger Clark, 30 August 2017 - 23:38.

[barrykm]

Talking of V16 fuel consumption reminds me of the story of Graham Hill when BRM took a V16 for demo laps at the South African GP. He enjoyed the prodigious power so much, giving it real stick around the circuit, that he used the entire fuel supply in either one or two demos, which was not the plan. But the noise and spectacle, and no doubt appreciation of the crowd, was fantastic.
OT the Alfettas thirst came back to bite them at Spa, ISTR, when an unblown Talbot proved to be their nemesis, running without time sapping refuelling stops.
Roger Lund

 

...it certainly sounded like it...(I was there   )

[bradbury west]

A very lucky (young) man

RL

[Lee Nicolle]

This may sound silly, the sound of the engine on the few You Tube clips I have seen it sounded thirsty,, it took time to get on song then sounded super strong when it was there, and that sounded like a LOT of fuel.

Methanol reputedly varies as well. Different brands seem to do different things, that now in 2017. This according to the speedway blokes who generally use methanol.

Sprintcars are actually using less these days and making more power. And sound better as well.

[Charlieman]

What the books say...

 

"V16: The story of the BRM engine": Published by MRP. Nothing about fuel consumption but glorious illustrations.

 

"BRM V16" (Ludvigsen): On page 79, there is a potentially interesting graph showing boost but it is too blurred for much interpretation. BSFC (Brake Specific Fuel Consumption) is lowest at 8,000 rpm and is 15% higher at 11,500 rpm.

 

I'm off to read Pomeroy.

[Ray Bell]

Slack of me to take so long to look into this...

The Mays/Roberts book on page 215 gives a fuel consumption figure of 3mpg. This is not qualified regarding circuit or anything.

Of some interest, they quote 7mpg for the alcohol mixture used in the 2.5-litre cars, 10mpg on Avgas in '58 and '59 and 11mpg for the 100-octane fuel in 1960. The V8 is quoted at 12mpg.