What else did BMW do with the MacF1 engine?

[FunkyNige]

I don't know that much about the development of the McLaren F1, but on a show I saw a few years back theymentioned GM went to BMW asking for an engine to a certain spec. I find it hard to believe that BMW would develop a high spec engine then only sell 100(?) to put in the F1s then give up on it.

So what else happened to it? Was it in development before Gordon Murray asked for an engine?

[jmcc500]

I believe they developed it for an in-house project that got canned (M8?). Perhaps someone can confirm?

[andygtt]

it was basically a development of the V12 unit in the 850csi (S70), they put the heads from the M3 on it along with new internals etc.

The engine costs £150k from Mclaren I'm told so there wasn't really anything else to put it in I guess as it was too expensive.

[omi]

Apparently they put one in an X5...

http://video.google.com/videoplay?doc

[omi]

Sorry, my bad...

Someone said:

It's not the Macca F1 engine.. An impressive study demonstrates the sheer size of the technical potential the X5 actually has on tap under extreme conditions: The X5 Le Mans is propelled by the V12 engine carried over from the Le Mans winning car, with unparalleled performance at a corresponding level. This means that the engine of the X5 Le Mans experimental vehicle performs a power unit developing 700 bhp (514 kW) and has a torque of 720 Nm (531 lb-ft) at 5000 rpm, which accelerates this experimental car from a stand-still to 100 km/h in 4.7 seconds. Top speed is 278 km/h (173 mph). The idea behind the X5 Le Mans experimental vehicle originates primarily from a technical ambition: BMW's engineers wanted to explore and demonstrate the X5's real absolute limits in practice. As a kind of welcome side effect, their efforts produced a compelling showpiece whose powerful looks reflect its impressive inner values. Racing-car technology The most striking change to the exterior is the bonnet scoop for the air from the radiator. Further exterior modifications were made at the front and rear bumper covers, the wing skirts and sill covers, the exterior mirrors and wheels. The chassis with 20-inch wheels was lowered by 30 millimetres (1.18 inches). Depending on the type of duty this car is applied to, 315/35 or 275/40 tyres are mounted on its front wheels, while its rear wheels are generally fitted with 315/35 tyres. Axle load distribution is almost ideal, at 51:49% front/rear. Exterior dimensions are basically the same as on the standard X5. The interior, on the other hand, looks quite different, with a definite high-tech touch. The more comfortable standard seats were replaced by four bucket seats with a particular emphasis on sportiness, and aluminium stands out as a predominating element throughout. Award-winning power unit: BMW engine sets racing-sports standards BMW's six-litre V12 engine is the perfect engine to meet the challenge of sports-car competitions. In 1995 this engine celebrated its first great triumph as the winner of the 24 Hours of Le Mans - powering the closed McLaren BMW sports car. BMW's greatest success with this power unit was the BMW V12 LMR's final win in the legendary 24-hour race in 1999. For racing use, the engine's output was derated to approx. 580 bhp (426 kW) by installing air supply limiters. The X5 Le Mans is a one-of-a-kind vehicle and it is not for sale. There are no plans to produce it in small batches or on a larger scale.

[slinky]

Talking of the F1 Engine... Has anyone got any higher res images (1024+) of the lump?
I'd really like a blueprint style cross section of it for my study... any ideas on that one as well?

Cheers,

slinky

[Frik]

There's a good version in Driving Ambition.

HTH.

[slinky]

Frik said:

There's a good version in Driving Ambition. HTH.

Stupid me.. I'll have a look in my copy downstairs!

slinky

[eliot]

omi said:

Apparently they put one in an X5... http://video.google.com/videoplay?doc

I saw that car at Goodwood a couple of years ago. If you think it sounds loud in the video, you ought of been in the paddock when they fired it up; All the F1 boys turned round complaining how loud it was!. It was very fast.

[r988]

andygtt said:

it was basically a development of the V12 unit in the 850csi (S70), they put the heads from the M3 on it along with new internals etc. The engine costs £150k from Mclaren I'm told so there wasn't really anything else to put it in I guess as it was too expensive.

No it was based off two M20 engines of the type used in the E30 325i (as an example). Paul Roche, the legend behind most BMW motorsport engines was developing an engine for the M8 model with DOHC per bank and 48 valves but that project was canned. Roche happened to be talking to Gordon Murray at some point and he mentioned he was working on the Mclaren Supercar and looking for a powerplant, Roche realised the M8 engine would fit the bill and was basically sitting around going to waste so used his influence bring back the engine and finish developing it with improvements and so it became the McLaren F1 engine.

I accept that the above may not be exactly how it happened as stories are vague and conflict slightly but that's more or less how I understand it happened. If anyone knows any better I'll stand corrected.

www.850csi.de/modelle_e.html#M8

[Marquis_Rex]

r988 said:

andygtt said: it was basically a development of the V12 unit in the 850csi (S70), they put the heads from the M3 on it along with new internals etc. The engine costs £150k from Mclaren I'm told so there wasn't really anything else to put it in I guess as it was too expensive. No it was based off two M20 engines of the type used in the E30 325i (as an example). Paul Roche, the legend behind most BMW motorsport engines was developing an engine for the M8 model with DOHC per bank and 48 valves but that project was canned. Roche happened to be talking to Gordon Murray at some point and he mentioned he was working on the Mclaren Supercar and looking for a powerplant, Roche realised the M8 engine would fit the bill and was basically sitting around going to waste so used his influence bring back the engine and finish developing it with improvements and so it became the McLaren F1 engine. I accept that the above may not be exactly how it happened as stories are vague and conflict slightly but that's more or less how I understand it happened. If anyone knows any better I'll stand corrected. www.850csi.de/modelle_e.html#M8

It's closer to the two S50s.
The original show BMW V12 of the early 80s was based on two M20s (and cast iron block to boot) but the final 2 valver in the 850i and the 5.6 litre in the 850 CSi (STILL a 2 valver) has a combustion chamber similar to the belt driven 318i M40 (an almost flat head by BMW standards with an offset bowl in piston-great for combustion efficiency but not as good at flow as an M20).
The Macca F1 is a 4 valver and it's combustion chamber and port layout are not dissimilar to the S50 "M" engines.
All the M40,S50,M50 and M20 and even V12 share the same bore centres.

[andygtt]

Gleamed from the research I have done on these V12 engines over the last few years the M70 (the 5.0L V12) is basically based on two M20 engines, the rods and heads and bores are almost identical even if the pistons and block are different.

The F1 apparently used the S70 V12 block which is the M devision version of the M70 and was used in the 850csi (5.6L) and apparently the alpina.

I always thought that the 4V heads used on the F1 were actually M3 (3.0L) ones as these also can be adapted to fit the V12 blocks.

[GavinPearson]

Suppose you find a BMW breaker who has V12s on the (relative cheap).

Is there a way to create a McLaren F1 engine replica that does the job almost as well as the real thing?

[andygtt]

Engine builder in the states does an engine that uses the same block bored to 6L with 4v heads for over 600bhp.... its cheaper than the Mac F1 engine as well at $85k

Ok I my be cheating by using twin turbos and the puristy will cry out loud, but I should be getting similar power from the V12 for well under £10k.

[Marquis_Rex]

I maintain it's NOT two M20s, the pistons, rods may be interchangeable, but they're interchangeable with the M40, M42s etc etc also anyway. The 2 valver M70 has a combustion chamber and port arrangement based on the M40 series of engines (even the pistons are similar with an offset bowl). The combustion chamber and port arrangement are what really defines an engine, along with it's intake manifold.Here again on the V12 the intake manifold is two straight logs, similar to BMWs later practice on their M50 ( 24 v 325i, 328i etc etc) engines and quite far away from the old M20, M30 etc arrangement of an "axial plenum".
A 24 valve version could be made using M3 bits but the biggest issue is the cam drive/chain drive.

[GavinPearson]

Marquis_Rex said:

I maintain it's NOT two M20s, the pistons, rods may be interchangeable, but they're interchangeable with the M40, M42s etc etc also anyway. The 2 valver M70 has a combustion chamber and port arrangement based on the M40 series of engines (even the pistons are similar with an offset bowl). The combustion chamber and port arrangement are what really defines an engine, along with it's intake manifold.Here again on the V12 the intake manifold is two straight logs, similar to BMWs later practice on their M50 ( 24 v 325i, 328i etc etc) engines and quite far away from the old M20, M30 etc arrangement of an "axial plenum". A 24 valve version could be made using M3 bits but the biggest issue is the cam drive/chain drive.

Back to my question, because I know you know what you're talking about (sorry to everybody else, but I know that Marquis_Rex has forgotten more than most "experts" have learnt) - if you wanted to make an F1 engine, what block and heads would you need?

The way I look at it, everything else isn't a problem, you can make an EN40B crank, a set of rods can easily be made, and the pistons need to be forged - whether or not there is an off the shelf M piston that works is another matter but nothing is insurmountable.

[Marquis_Rex]

GavinPearson said:

Marquis_Rex said: I maintain it's NOT two M20s, the pistons, rods may be interchangeable, but they're interchangeable with the M40, M42s etc etc also anyway. The 2 valver M70 has a combustion chamber and port arrangement based on the M40 series of engines (even the pistons are similar with an offset bowl). The combustion chamber and port arrangement are what really defines an engine, along with it's intake manifold.Here again on the V12 the intake manifold is two straight logs, similar to BMWs later practice on their M50 ( 24 v 325i, 328i etc etc) engines and quite far away from the old M20, M30 etc arrangement of an "axial plenum". A 24 valve version could be made using M3 bits but the biggest issue is the cam drive/chain drive. Back to my question, because I know you know what you're talking about (sorry to everybody else, but I know that Marquis_Rex has forgotten more than most "experts" have learnt) - if you wanted to make an F1 engine, what block and heads would you need? The way I look at it, everything else isn't a problem, you can make an EN40B crank, a set of rods can easily be made, and the pistons need to be forged - whether or not there is an off the shelf M piston that works is another matter but nothing is insurmountable.

Thanks gav.

OK, If I were doing it, I would use a V12 block (I believe the early 2 valver or 4 valver are the same, but I would probably check water ways just to make sure).
In the event they're not the same use the late 4 valve V12 block, use two M3 cylinder heads. I don't THINK the crank is too much of a problem, it's a 75 mm throw on the early ones and bigger for the 5.6 litre 380 Bhp S70. The cylinder heads have the same bore spacing. The only misgiving I have is this:

If you look at the M50 (standard 24 valve 325i,328i etc etc) engines, you CAN NOT directly use a Euro S50 (M power M3 engine) and put it on the block of an M50- the M power ALMOST matches up, but it has two big oil galleries each side of the head, the provision for which is not there on the stock M50. I'm looking into this- I don't know if the M50 block can be adapted to accomodate the S50 head.
Ok, Ok, by this time you're probably asking "What does this have to do with my original V12 question?". Well, if the stock M50 will needs adapting, you can bet the V12 most probably would. Anyway, I don't think this is too big an issue and some innovative thinking may be able to work this issue out.

If M3 pistons and rods were required to be used, the block height could be checked, if it comes too short , no big issue, a gasket/spacer could be used or custom forged pistons.

Anyway, as you correctly pointed out, pistons, rods and cranks can be custom made, the bigger issue would be to get to the bottom of the head/block mismatch, I know it ALMOST fits. The other potential issue is the chain cam drive- if you reverse the second cylinder head around for the other bank, it's chain drive is on the back. This could be potentially a bigger problem.

Then there's a length of the chain drive itself, and where the tesioner is, I know you could canibalise bits from the original V12 base and from donor M50s and S50s, but as someone like Wheeljack would probably agree, I think there's alot more to chain drive design and this would need to be thought out more carefully (numbers of chain links, numbers of teeth on sprocket, positioning of the tensioner etc etc)

[andygtt]

So if you were to modify the M70 would you use upgraded M50 valvetrain?
I plan to extend the rev range of my M70 engine to increase the revs to a 7500rpm redline and all I have gleamed is that I should use M3 springs and some custom cams..... I'd love to find a cost efective source of bigger valves etc to make it breath better.

[andygtt]

Regarding the chain drive, I know someone who is using the V12 in a similar project to me who has removed the chain drive completely on the M70 V12 and replaced it with a belt system so that cam timing is more easily adjustable.
I'd like to do this as I'm sure it would be beneficial for the setup of my unproven application, however I think this would be a step too far for me to attempt.

[GavinPearson]

Thanks for the clarification.