27 replies to this topic

[hydra]

http://www.bmwm5.com...ssrelease2.html

Alright, its not an F1 engine, but I still thought you guys might enjoy this at least as much as I did, plenty of sexy aluminum castings to go around ;)

What I don't get is how the **** did they get this thing to weigh 240kgs?? (says that in the first page, http://www.bmwm5.com...essrelease.html )

Just for the sake of reference the McLaren F1's engine, which was a 6.1L-V12 weighed 230-240kgs, and the Enzo V-12 weighs in at 220kgs... What the hell's going on here?

[Todd]

Originally posted by hydra
http://www.bmwm5.com...ssrelease2.html

Alright, its not an F1 engine, but I still thought you guys might enjoy this at least as much as I did, plenty of sexy aluminum castings to go around ;)

What I don't get is how the **** did they get this thing to weigh 240kgs?? (says that in the first page, http://www.bmwm5.com...essrelease.html )

Just for the sake of reference the McLaren F1's engine, which was a 6.1L-V12 weighed 230-240kgs, and the Enzo V-12 weighs in at 220kgs... What the hell's going on here?

Nice looking engine. Shame about the car it comes in. Oh well. Hopefully, there will be tuners swapping them into E46s and other pre-hideous BMWs.

As for weighing more than the two exotic car engines, that is no surprise. The BMW engine in the McLaren road car, which incidentally was the only part of the car that met, let alone exceeded, design objectives, was a cost no object exercise. The materials used were fairly exotic, and many components were fabricated where they would be cast for a normal production car. I read that the exhaust headers for the F1 cost more than an entire 850CSi engine. Another consideration is durability. An M5 is a real car, even if the new one will be a really ugly car. Its engine must meet normal BMW durability requirements, where as the engines in an F1 or an Enzo can expect meticulous maintenance, minimal mileage, and a rebuild at 50k miles. The M5 engine, on the other hand, can look forward to oil every 12 to 15k and a set of spark plugs at 90K. It needs to be much more substantial. I also notice that it has quick light cold start cats on the exhaust manifolds. Theres a quick source of massive weight that the F1 almost certainly didn't have and the Enzo probably doesn't have.

[Slumberer]

Simple: A bigger capacity engine has bigger (or more) cylinders therefore bigger (or more) "holes" in it doesn't it?;)

[jpf]

Originally posted by Todd


Nice looking engine. Shame about the car it comes in. Oh well. Hopefully, there will be tuners swapping them into E46s and other pre-hideous BMWs.

It's German for "The Bangle, The."

Nice engine pics. Weird though, that there seem to be throttle butterflies in the intakes, as this is a valvetronic engine. Redundant for safety?

[Ursus]

Originally posted by jpf


Nice engine pics. Weird though, that there seem to be throttle butterflies in the intakes, as this is a valvetronic engine. Redundant for safety?

I dont belive it's a valvetronic engine. Afterall the press release mentions individual throtle butterflies. It's got double VANOS though.

[jpf]

I guess maybe I should have read the release ... didn't see those links at the bottom of the page. I saw this and thought I recognized it as the valvetronic actuator: http://www.bmwm5.com...motor/9-800.jpg

[Engineguy]

Engine weights have always notorious for not stating what's included... unfairly comparing engines in different states of dress is common since so often you don't have all the facts. But lets give it a go.

Assuming (perhaps incorrectly) that the weights quoted are fully dressed in "drop-in" installation ready form as the official photographs show them, let's to compare the BMW S70/2 6.1L V12 (Mclaren F1) to the BMW S65 5L V10 (M5).

Assuming exhaust back to the first disconnect joint: The V12 has extremely thin wall (0.8mm) inconel headers (quote... "the McLaren sports car's exhaust system alone would cost as much as a small family car")... estimating pipe lengths and diameters from photos, I calculate 4kg differance there (not as much as you would think, but the primaries on the V12 are much longer than those on the V10). Then there are the integrated cats... 4kg each?

Flywheel & Clutch: The V12 has a smaller (200mm) carbon-carbon clutch with aluminum pressure plate, on a very minimal aluminum flywheel. The V10 has a 250?mm clutch/pressure plate on a massive steel flywheel. Let's say 12kg difference.

Cam drive: On the V12 only the intake cams are variable timing, on the V10 intake and exhaust both are... 6kg for the extra mechanisms?

Other: I'll assume the A/C compressor and alternator are a little higher capacity for the luxury sedan; 3kg, and the CF airboxes lighter than the magneseum ones; 2kg.

After explaining away this "external" stuff you see roughly a core engine with 82% the displacement, 82% the number of cylinders, and 87% the weight of the engine purpose-designed from clean sheet for the "cost-is-no-object" McLaren F1. Not too shabby... not too flabby.

[mrman_3k]

It is amazing to see how much larger the road car V10 is compared to the Formula One V10 engines. Also look at the size of that clutch compared to F1, just amazing to see the differences!

[hydra]

Actually, the Mac F1 engine isn't very exotic at all, its just a poked and stroked 850CSi (S70) engine in fancy dress... No Titanium con-rods, just steel and aluminum alloy (with a CF airbox). And while I'm not 100% certain, but I'm pretty sure the S70/2 came with double VANOS, which makes sense as that would have facilitated the use of 2 E36 M3 head castings, and we all know those came with double VANOS... Lets forget about the Macca engine for a bit. 230 kilos is still a hell of a lot for a modern, all aluminum engine. Just to put things into perspective, an all-iron 5.0 small-block ford weighs 450lbs (205kg) FULLY DRESSED! Granted its only got 8cyl instead of 10, and 1 cam instead of 4, but its still an ALL-IRON motor (the aluminum manifold alone weighs 35lb!) and can still be punched out to 5.6L, whereas I would imagine the BMW V10 is pretty maxed out as it is... Needless to say, I'm not very impressed :

[Engineguy]

As far as I know, the S70 was a 24 valve, 380 BHP production engine. The Mac F1 engine was not the BMW production V12. It was specifically designed for the F1, according to Gordan Murray's own words...


On October 25, 1990, Gordon (Murray) visited Munich. The hopped-up production V12 would not do: "Too big and heavy. Definitely not for us. Then Paul (Rosche) asked, 'What do you really want?', so I told him: big displacement in the smallest possible package-size - absolutely no more than 600mm long - revving to around seven-five - 550-plus BHP - maximum weight 250kg - rigid enough to work as a load-bearing structural member - dry sump lubrication to minimize overall height and avoid surge in high-G cornering."

"And Paul simply said, 'We'll do a new engine'."

November 15... "I outlined the kind of car we intended, and laid it on the line that power-to-weight was the bottom line. I told them to consider it in everything they did. Never use a 10mm bolt when a 9mm will do, consider weight as driving the design..."

Rosche called Murray at one point to announce a feasible bore and stroke of 86mm by 87mm - 6,064cc; "Six point one litres Gordon, how does that sound?"

"...to accommodate large-capacity cylinder bores within minimum-sized block dimensions - no more than 3mm separating each from its neighbours." While this absolutely minimised overall package size, Motorsport actually employed well-proven and conservative core technology and materials.

Both the minimum-size new dedicated block and heads were cast in aluminum...

Variable valve timing was featured, with a hydraulically-actuated phasing mechanism retarding the inlet cam... (disassembled engine photos clearly show it's only the inlet cam)

I don't type very fast, so buy the book if you want more... but it's made very clear that the design of the engine specifically began after and for Murray's stated requirements.

By the way, I discovered since my previous post that Murray's goal was 250kg including cats and silencer. He allowed 30kg for the entire exhaust system in his estimates... BMW came back and said the exhaust system would weigh 100kg! Hence the Inconel headers. I don't know if the four cats had Inconel shells, but the massive silencer box was fabricated from stainless steel... and earned it's keep by doubling as the car's rear crash structure (since the engine/transaxle are the only structure aft of the cockpit). They missed his goal by 16kg, so the whole engine from airbox to exhaust silencer box was 266kg. The 627 BHP (versus his request for 550) easily made up for the 16kg.

I've also seen a story that there was an S70/1 engine (48 valve, 550 BHP) that was designed for a cancelled 1990 BMW M8 (of which only one crude prototype was built)... that might explain why they had McLaren's engine on the dyno 10 months after they claim to have started designing it. I was always amazed that BMW would do such a low volume engine from scratch, even for a project as prestigious as the McLaren F1. Perhaps the truth is that it was an engine looking for a car... Paul calls his old pal Gordon, Gordan sits down in that airport lounge when their flight is delayed with Ron, Creighton, and Mansour and, when talk turns to the big picture of what businesses McLaren should expand into beyond Formula One... hmm?

Back on topic... I can look at the pictures of the M5 V10 parts and not see much fat... it is a state-of-the-art production engine design... and 4 valve DOHC heads are always heavy. A V10 is not the most weight-efficient way to build a high-performance 5L engine; a 100mm by 80mm V8 would make more sense IMHO, but then if you have to help justify millions invested in F1 by associating one of your production cars to it, you might think otherwise. Also, in a two-ton sedan the weight penalty almost disappears as it is such a small percentage of the vehicle weight, so marketing considerations might overcome all else. Speaking of marketing, if the E36 M3 engine carried the McLaren F1 cylinder head, wouldn't BMW's marketing department make sure everybody on earth knew it?

[Greg Locock]

"230 kilos is still a hell of a lot for a modern, all aluminum engine. Just to put things into perspective, an all-iron 5.0 small-block ford weighs 450lbs (205kg) FULLY DRESSED! Granted its only got 8cyl instead of 10, and 1 cam instead of 4, but its still an ALL-IRON motor (the aluminum manifold alone weighs 35lb!)"


so far as the weight of steel vs aluminium blocks, by the time you have made them stiff enough (you did know that blocks and heads are stiffness limited?) there is nothing much to choose between them as materials. You do usually get a bit of an advantage with aluminium, but it is not night and day.

so, we'd give it what, 10% weight increase for the extra cylinders? 2 kg per extra cam and associated gubbins? how much for a 4 valve head?

[Powersteer]

Those exaust extractors changes shape for compactness is amazing. Clutch housing looks large and heavy, I believe BMW can reduce it but won't for good reasons and one of them happens to be cost plus this is still a saloon car. Chain/gear driven camshafts. The extra metal area to cover it adds weight to other solutions.Why isn't the gap between the cylinders not as close as those on thier production 5 liter V12? Individual throttle body for the ultimate throttle responce, this car is going to be nice and fugly.

I wonder what if the block were made of magnesium. I remember an old american mag (front cover, Jaguar XJR-15 next to a red Diablo) I had which had a lot of moded Corvettes, Motor Trend I think. Anyway, there was one tuning firm which made a magnesium block for the ZR1's engine (L98?) identical to the standard engine and the firm claim 100ib weight saving to the iron block and 23ib to the aluminium alloy. Has there ever been an all magnesium engine? If it were a V-10 or V-12, this might seem an interesting option. By the way, how heavy is the V-10 on the Porsche Carrera GT?

[Wuzak]

Wasn't the block on the '94 or '95 Ferrari F1 V12 cast steel?

Did they ever do one in cast titanium as well?

[BRIAN GLOVER]

The XJR 15 is the most beeootiful car ever made. That and the 220 put Jag out of bussiness. Both cars started out with a V12. The 220 ended up with a V6.
The ZR1 engine was cast aluminum(LT5) The L98 GenII Chevy engine was cast iron with later versions having aluminum heads and the all aluminum LS1 is 100lb lighter than this engine. The F50's V12 has a cast iron block and if my aunt had balls she would be my uncle..

Originally posted by Powersteer
I wonder what if the block were made of magnesium. I remember an old american mag (front cover, Jaguar XJR-15 next to a red Diablo) I had which had a lot of moded Corvettes, Motor Trend I think. Anyway, there was one tuning firm which made a magnesium block for the ZR1's engine (L98?) identical to the standard engine and the firm claim 100ib weight saving to the iron block and 23ib to the aluminium alloy. Has there ever been an all magnesium engine? If it were a V-10 or V-12, this might seem an interesting option. By the way, how heavy is the V-10 on the Porsche Carrera GT?


[/B]

[Engineguy]

Aluminum blocks do save some serious weight. Take the traditional 4" bore small block Chevy V8... since in its cast iron form it is a mature product that has been refined for material reduction/strength increases for decades. The cast iron production blocks and the Goodwrench ("limited racing") blocks were 142 lbs.

The cast iron Bowtie blocks ("maximum effort racing," i.e. NASCAR) were 182 lbs.

The GM aluminum Bowtie 4.125" bore blocks ("maximum effort racing," same power levels, same strength as cast iron Bowtie) were 90 lbs., a 92 lb. savings.

(All these weights include grey iron, nodular iron, or 8620 steel maincaps and in the case of the aluminum blocks, ductile iron dry cylinder liners.)

Other aluminum versions by aftermarket firms range from 75 to 100 lbs., though to get down to the 75-80 lb. range they use aluminum or titanium maincaps and a lot of surfaces that are normally left as-cast are machined to remove material.

The Jones Engineering magnesium blocks (they were tested by Chevrolet in a pair of Corvettes for 150,000 miles each in the late 1980's) are currently being tested in sprint cars and dirt track modifieds... they weigh 51 lbs.

Speaking of magnesium, let's not forget the millions of VW Beetles and several years of Porsche 911's that had magnesium crankcases (and BMW motorcycles?).

[Engineguy]

Originally posted by Greg Locock
...

How much for a 4 valve head?

I buy car and motorcycle cylinder heads to bandsaw 'em up and study them for best design tricks and practices... here are some formulas that come from my empirical observations...

Including aluminum casting, cams, cam sprockets, followers, valves, springs, and aluminum cover:

At a 78mm bore size, typical superbke production DOHC head... 4 lbs + (7 lbs x number of cylinders)... the best designed ones, and substituting magnesium cover... 3 lbs. + (5.5 lbs x number of cylinders).

At a 92mm bore size, typical automotive production DOHC head... 6 lbs + (12 lbs x number of cylinders)... the better designed ones, and substituting magnesium cover... 5 lbs. + (10 lbs x number of cylinders).

At a 102mm bore size, typical automotive production DOHC head... 7 lbs + (16 lbs x number of cylinders)... the better designed ones, and substituting magnesium cover... 6 lbs. + (13.5 lbs x number of cylinders).

At a 106mm bore size, typical automotive production DOHC head... 8 lbs + (18 lbs x number of cylinders)... the better designed ones, and substituting magnesium cover... 7 lbs. + (15 lbs x number of cylinders).

An aluminum small block Chevy 2-valve head, with its valves, springs, rockers, pushrods, valve cover, lifters, half a cam, and half a cam sprocket weighs in at about 31 lbs. (51 lbs. if cast iron). From the above, a 2-valve DOHC head for the same engine would be 60 to 80 lbs. Lets call it 70 lbs., a gain of 29 lbs. We multiply it by two (two heads) and add a few lbs. for longer timing chain, the tensioners and guides and the much larger chain cover to enclose it all. We've added 70 lbs (32kg) in our conversion from 2-valve to 4-valve. Like I said... 4-valve DOHC heads are heavy.

[hydra]

Wow... Mind-blowing info EngineGuy! Major props for that... As an aside, and I don't really expect you to know this, but do you know of any engines with a main journal diameter of 48-50mm, with a width of 16-20mm? Any combination(s) will do...

Greg, to go back to your post on Aluminum vs. Cast Iron, the substitution of iron heads for aluminum on any small block is good for a 45-50lb savings, and as EngineGuy pointed out, another 50-80lbs for the block. Back to the SBF... You could probably get one down to 320lbs (145kgs) or so if you made it all-aluminum, made your own IR-style manifold, in addition to a couple other tweaks here and there... That's pretty close to the weight of an S2000 engine, in addition to being good for a comfortable 600bhp NA!

[Engineguy]

Originally posted by hydra
... As an aside, and I don't really expect you to know this, but do you know of any engines with a main journal diameter of 48-50mm, with a width of 16-20mm? Any combination(s) will do...

At the large end of your range, the Honda F22, H22, and H23 blocks (i.e. the big 4 cylinder Hondas of the past decade or so... many of the 2.0L and 2.2L Accords and Preludes) are nominally 50mm x 20mm (uses 54mm main bores). The H-series are gaining on the B's in popularity for import drags, so extreme duty bearings may be available. Same size used in various other Honda blocks back to 1973 and up through at least 2001.

48mm x 20mm... 1993-1998 Toyota Corolla, Celica 1.8L 7AFE DOHC, 1995-2002 Toyota Tacoma 2.4L 2RZFE

48mm x 17mm.. ISUZU ENGINES: 1985-89 1.5L SOHC 4XC1, 1987-89 1.5L SOHC Turbo 4XC1-T, 1989 1.6L DOHC 4XE1

[hydra]

I guess I should have asked you earlier, but what about BMW's M70 V12? Again, I'm looking for the main bearing (inside) diameter and width...

Actually, I've got something that could be of interest to you... Check your PM.

[Greg Locock]

OK, Looks like race engines aren't stiffness limited. Production car engines are, and although the aluminium engine does end up lighter it is not much. Hmm, just having a think about where I know this from, it is very likely that with the use of appropriate technology you could pull quite a bit more weight out of an aluminium casting, with expensive tooling. I'll have a chat with our block designer, it would be nice to pull 30-50 kg out of the front of the car.

[rgsuspsa]

An utter mess, lacking well thought out and integrated concepts based upon first principles
of engineering. Nothing more than a camel, a would-be horse concieved by committee.

Ron Sparks

[Greg Locock]

Oh golly gosh, how many world beating race cars have you designed?

Me: One.

[rgsuspsa]

Hello Greg: If you wish to dispute my assertion, the only credible way is to address the facts
of the subject. Their abscense from your post speaks volumes.

Ron Sparks

[ZoRG]

I have a fiat uno turbo, desided to throw out the fiat motor and put in a honda vtec motor. The fiat is a 1.4L, with a Iron block. The honda, 1.6L with a aluminium block. I can honestly say the honda aluminium block is about the same weight maybe even slightly heavier than the fiat iron...

[Powersteer]

Why don't you prove your assetions first. Many of would like to know what they are. Could be educational and exciting or down right funny.

[Greg Locock]

I admit my reply was unfair, as it is basically an appeal to authority. However I put it to you that your comment is unanswerable in any rational objective fashion, and is pretty derogatory to the design engineers on that project.

[McGuire]

Originally posted by rgsuspsa
An utter mess, lacking well thought out and integrated concepts based upon first principles
of engineering. Nothing more than a camel, a would-be horse concieved by committee.

Ron Sparks

Personally, I have never understood that cliche. What's wrong with camels? If you want to go places and carry things a horse can't, a camel is a very useful beast. True, it's not a race horse, but then one would have to be rather ignorant to mistake it for one.

One could say a volume production engine is a camel by neccesity. It must be built to a myriad of compromises, from design to materials to production to vehicle packaging to emissions to fuel consumption to unit, tooling, manufacturing costs to serviceability, life cycle, and maintenance costs...just to scratch the surface. And since this is a V10, let's not forget marketing.

One person cannot possibly supervise and mediate all those complex and conflicting issues in the engine's design mission, so it must be designed by commitee. On the other hand, a racing engine is a race horse. It only has to do one thing well, and for that we are willing to put up with all the ridiculous needs and high maintenance of a thoroughbred.

I am curious to know what "first principles of engineering" you believe this engine violates.

[Lukin]

Ron Sparks,

Looking over your posts from the past you seem to heavily criticise people’s comments or the topic of discussion without actually having any valuable input. I’m assuming your pretty switched on in regard to the technical side so why don’t you actually say something worthwhile rather than what you seem to be doing and come off looking like someone’s grumpy grandfather. If you consider us beneath you technically then don’t post. This forum is good to learn so lets keep it that way.

Cheers
Lukin