where to start with a BMW 4.4 V8
Discussion
Pondering the tuning possiblities available with the BMW V8 fitted to my Series I Aero 8.
Easy fix is a chip from various places that will liberate another 15-20 horses which along with sports 'zorst will = 310-320 bhp.
However, I'd be looking to keep the car in line with the later cars that are now putting out anything up to 375bhp using the newer verison of the BMW 4.4lV8.
Anyone got any suggestion on where to start? Can you buy 'off the shelf' camshafts, forged pistons etc, or get the cylinders bored out etc? Just trying to get an idea of what it might cost...
Easy fix is a chip from various places that will liberate another 15-20 horses which along with sports 'zorst will = 310-320 bhp.
However, I'd be looking to keep the car in line with the later cars that are now putting out anything up to 375bhp using the newer verison of the BMW 4.4lV8.
Anyone got any suggestion on where to start? Can you buy 'off the shelf' camshafts, forged pistons etc, or get the cylinders bored out etc? Just trying to get an idea of what it might cost...
The M62 4.4 litre engine uses a 92mm bore and an 82.7mm stroke. The engine is in a relatively low state of tune, and if memory serves it produces about 286 Bhp. It has 98mm bore centres so there's some scope to bore out, but uses a "parent metal" bore- so would probably need iron liners.
Forged pistons can be custom made by Accralite, JE, Wiseco in the US and even Wossner over here but it's not cheap.
The cylinder head flows reasonably well, but no where near as well as say the BMW M50 straight six, the 318iS 16 valve or , of course the S50 "M" engines.Still the cyl head flows well enough to take advantage of a wilder cam shaft. I think Schrick do a performance set of cams for the engine- but I would have to check my catalogue at home. It could get expensive however as there are 4 cams to think about.
I believe the engine has hydraulic tappets but they're of a different design to the M5 S62 engine so you would have to check if these become a limiting factor in terms of revs.
Even the S62 M5 engine doesn't rev high as standard (only to about 7000 rpm).
The stock engine produces peak power at 5400 rpm with peak torque at 3600 rpm- the cams have a max lift of 9mm which certainly re-affirms a state of tune more for big heavy saloons. The later engines have VANOS (1998 onwards- does yours?) (Earlier engines were Motronic 5.2 and later ones were Motronic 7.2).
The crankshaft is a forged steel one piece 5 counter weight affair but is quite robust.
I would forget about "performance chips"- on a naturally aspirated standard engine they don't offer much unless the original design was so handicapped (which it isn't). The claims are bullshyte. All they usually do is offer agressive fueling on transients. The compression ratio as standard is lowish anyway (10:1), so "chipping" (going for more agressive ignition) and running on higher octane fuel is unlikely to yield much if anything.
If the engine hardware is modified then it is definately worth custom mapping the engine or going for a bespoke mappable engine management system and giving it to someone who knows what they're doing- preferably an engineer, rather than a glib talking-"know-it-all" technician/mechanic.
None of these mods will come cheap- so it may be worth investigating installing the physically similar M5 5 litre V8 engine?
Forged pistons can be custom made by Accralite, JE, Wiseco in the US and even Wossner over here but it's not cheap.
The cylinder head flows reasonably well, but no where near as well as say the BMW M50 straight six, the 318iS 16 valve or , of course the S50 "M" engines.Still the cyl head flows well enough to take advantage of a wilder cam shaft. I think Schrick do a performance set of cams for the engine- but I would have to check my catalogue at home. It could get expensive however as there are 4 cams to think about.
I believe the engine has hydraulic tappets but they're of a different design to the M5 S62 engine so you would have to check if these become a limiting factor in terms of revs.
Even the S62 M5 engine doesn't rev high as standard (only to about 7000 rpm).
The stock engine produces peak power at 5400 rpm with peak torque at 3600 rpm- the cams have a max lift of 9mm which certainly re-affirms a state of tune more for big heavy saloons. The later engines have VANOS (1998 onwards- does yours?) (Earlier engines were Motronic 5.2 and later ones were Motronic 7.2).
The crankshaft is a forged steel one piece 5 counter weight affair but is quite robust.
I would forget about "performance chips"- on a naturally aspirated standard engine they don't offer much unless the original design was so handicapped (which it isn't). The claims are bullshyte. All they usually do is offer agressive fueling on transients. The compression ratio as standard is lowish anyway (10:1), so "chipping" (going for more agressive ignition) and running on higher octane fuel is unlikely to yield much if anything.
If the engine hardware is modified then it is definately worth custom mapping the engine or going for a bespoke mappable engine management system and giving it to someone who knows what they're doing- preferably an engineer, rather than a glib talking-"know-it-all" technician/mechanic.
None of these mods will come cheap- so it may be worth investigating installing the physically similar M5 5 litre V8 engine?
Cheers guys.
Sounds like the engine as others have said is a strong unit, capable of producing a darn sight more power.
As Mr Rex says though, it might end up being cheaper to source a s.h M5 engine and drop that in the front instead. Guess I'll ahve to look into the cost of aquiring such an engine, and whether it could be wedged into place in the very tight engine bay.
Sounds like the engine as others have said is a strong unit, capable of producing a darn sight more power.
As Mr Rex says though, it might end up being cheaper to source a s.h M5 engine and drop that in the front instead. Guess I'll ahve to look into the cost of aquiring such an engine, and whether it could be wedged into place in the very tight engine bay.
Edited by mr_tony on Wednesday 13th September 14:12
Don't know what exhaust manifolds the aero8 uses but the standard BMW V8 ones are really terribly restricting, they are real block huggers, double skinned and its impossible to get even a little finger down the ports. They really strangle the engine. If possible change them and go for tuned length exhaust manifolds
I stuck this engine into an AK Cobra and even with homemade manifolds, although I also decatting it, the engine revs very much more freely.
I'm told that taking the cats off it should release an extra 30 bhp or so, and the car did feel and sound so much better/ faster once the SVA ( and hence the cats) were out of the way.
Best of luck,
Tony
I stuck this engine into an AK Cobra and even with homemade manifolds, although I also decatting it, the engine revs very much more freely.
I'm told that taking the cats off it should release an extra 30 bhp or so, and the car did feel and sound so much better/ faster once the SVA ( and hence the cats) were out of the way.
Best of luck,
Tony
mustard said:
PS Mr Tony did you get my recent mail?
checked my mailbox and got nothing - send via my profile should work as I'm gettingmails from others on the Mog forums. Thanks for the extra advice guys. Agree with you Tony that the standard manifolds are restrictive, though with the factory sports exhaust it's shown a big improvement in throttle response / drivablity. However I guess I don't know whether the replacement of the exhaust itself included newer less restrictive manifolds (I'm not so technical if you can tell!!!)
the idea of the Alpina B10 engine is certainly an interesting idea!
Tony427 said:
Don't know what exhaust manifolds the aero8 uses but the standard BMW V8 ones are really terribly restricting, they are real block huggers, double skinned and its impossible to get even a little finger down the ports. They really strangle the engine. If possible change them and go for tuned length exhaust manifolds
I stuck this engine into an AK Cobra and even with homemade manifolds, although I also decatting it, the engine revs very much more freely.
I'm told that taking the cats off it should release an extra 30 bhp or so, and the car did feel and sound so much better/ faster once the SVA ( and hence the cats) were out of the way.
Best of luck,
Tony
I stuck this engine into an AK Cobra and even with homemade manifolds, although I also decatting it, the engine revs very much more freely.
I'm told that taking the cats off it should release an extra 30 bhp or so, and the car did feel and sound so much better/ faster once the SVA ( and hence the cats) were out of the way.
Best of luck,
Tony
The tuned length exhaust manifolds is an excellent point. On a VANOS engine making full use of low speed cam advance/more overlap at low speeds- this will predominatly bolster up low speed torque- due to increased charge efficiency from scavenging.
De-cating is unlikely to gain quite that much power these days.
I've seen double the back pressure on a certain 3 litre V6 only make a difference of 7-8 Bhp at top end. Strangely enough- the back pressure in this case effected peak torque MORE that peak power- and I put this down to variable cam timing and there being more overlap at mid engine speeds- which inhibited efficient scavenging. Again if full use of VANOS is being used-this is likely to be the case again.
if its anything like the M5 V8 its a crap engine in my opinion......I was previously a design engineer for Mountune - we did the engine conversion for Ascari road cars, and the twin turbo V8 600bhp motor for the Le-mans race cars.......in short the problem is with the aluminium cylinder block from Mahle - the bores are not nikasil coated they are some special aluminium from mahle which is just finish machined - its OK for the standard engine and standard pistons - but as soon as you start fitting different pistons and pushing the power up - the bores scuff in no time........the solution was to nikasil coat the bores which cost several thousand pounds........I design engines for a living and believe me - the BMW V8's are nothing special - although the block is ali - the angine is heavy - not a good basis for a tuned engine on the bores alone - I would use something with steel liners or a cast Iron block
knightly said:
if its anything like the M5 V8 its a crap engine in my opinion.......in short the problem is with the aluminium cylinder block from Mahle - the bores are not nikasil coated they are some special aluminium from mahle which is just finish machined - its OK for the standard engine and standard pistons - but as soon as you start fitting different pistons and pushing the power up - the bores scuff in no time
Actually it's not a special process, it's Alusil or or aluminium alloyed with silicon and hardened to the hypereutectic region.
It doesn't become a "crap engine" if it achieves the goals it was originally designed for and fails when Monkeys who don't understand engines properly fail to modify the engine properly.
Did you acid etch the bores when you bored out so that the silicon stood proud and then subsequently hone? What coating did you specify on your custom made pistons? Did you ensure that the cylinder bore and piston skirts were a well matched tribological pair? You certainly don't type/talk like a "design engineer". You could have said that "you should be careful if boring the engine out" etc etc.
I've come across BMW V8 engines that have uneven bore wear in heavy load applications but it's not all that common. BMW also did a racing version of this engine (using the suffix "P" rather than "M" ) which was very successful in the USA.
The old Nicasil engine weighed about 210 kgs fully dressed- which is very competitive with other dual overhead cam engines of a similar capacity such as the Jag )although heavier than pushrod engine designs. However you then go on to say suggest an engine with a cast iron block. You won't find a cast iron block engine of similar capacity even approach the weight of this BMW V8- end of story. Even a Pushrod engine.
I think over sized iron liners inserts are best idea when boring the BMW V8 out.
Edited by Marquis_Rex on Wednesday 18th October 14:02
now why didnt I think of that at the time - acid etching the bores so the silicon stands proud - silly old me........get real - thats hardly common knowledge......and dont take my personal opinions so personally!......do you work for BMW, Mahle or Pierburg by any chance?........I agree with what you say - its OK what its designed for - hence my reccomendation to stick with the standard bores and pistons......but for a race engine - its not the best starting point.......sorry I dont sound like an engine designer to you - rest assured I am.......although I openly admit to not being an expert on the Mahle/Pierburg Alusil cylinder blocks - you have the edge on me there! - I do design engines for a living, I run my own company and am currently working for 3 major clients.......please check out my web site if you do not believe me........very simple and basic at the moment
www.knightecengineering.com
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www.knightecengineering.com
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knightly said:
now why didnt I think of that at the time - acid etching the bores so the silicon stands proud - silly old me........get real - thats hardly common knowledge......and dont take my personal opinions so personally!......do you work for BMW, Mahle or Pierburg by any chance?........I agree with what you say - its OK what its designed for - hence my reccomendation to stick with the standard bores and pistons......but for a race engine - its not the best starting point.......sorry I dont sound like an engine designer to you - rest assured I am.......although I openly admit to not being an expert on the Mahle/Pierburg Alusil cylinder blocks - you have the edge on me there! - I do design engines for a living, I run my own company and am currently working for 3 major clients.......please check out my web site if you do not believe me........very simple and basic at the moment
www.knightecengineering.com
.
www.knightecengineering.com
.
Good website (seriously) and you certainly have good credentials B(Eng)hons etc etc
No, perhaps it's not common knowledge, sure, but if you're a design engineer surely you're being paid for your expertise and knowledge on such matters?
If someone doesn't know something- that's fair enough, I guess when you proclaimed being a "expert" engine design (twice) and then de-nounced the BMW engine as "crap" it got my back up.
It is possible to stretch the engine and it certainly isn't the cheapest option to do so, but a Kraut motor rarely is. I still think that the hypereutectic/high silicon block isn't a bad one at all.
I don't work for Mahle, BMW or Pierburg or have anything to do with them, I just like to defend engines that I think are OK, and where alot of work has gone into them. I would have and have defended Aston, Jaguar and Chevrolet engines just as quickly. I was just trying to open the eyes of people outside the OEM engineering industry to the challenges faced.
I think the problem with the Alusil process is its only been used by BMW and also I think VW on their W16 engine.......I dare say Mahle-Pierburg hold many patents on the process which locks out any other companies wishing to use this process.
So back to the matter in hand......Vanos - we originally used this on the Ascari twin-turbo le-mans car and it was a waste of time - the problem was it was not quick enough to react and move the camshaft in time on a race engine - this was also a problem for the 1.7 ford Puma Vanos/VVC - as the whole BMW system weighed around 20Kg it was removed.
If I was tuning the 4.4 BMW I would concentrate on the following areas -
leave the pistons and bores standard!
Like said above I think a good starting point is to get a new exhaust manifold made - dont go too big on the primary OD otherwise you will have no back pressure and poor drivability out of corners - I would suggest no greater than 1-3/4" OD with 16 gauge wall thickness in stainless. use a foam (ITG) or cotton-gauze(K&N) air filter, use an aftermarket "piggyback" ECU that will allow you to hack into the standard BMW ignition and injector signals.
next steps would be ported heads, camshafts, a compression rise - but they are expensive modifications - but lets be honest the Aero-8 is an expensive car ;-)
So back to the matter in hand......Vanos - we originally used this on the Ascari twin-turbo le-mans car and it was a waste of time - the problem was it was not quick enough to react and move the camshaft in time on a race engine - this was also a problem for the 1.7 ford Puma Vanos/VVC - as the whole BMW system weighed around 20Kg it was removed.
If I was tuning the 4.4 BMW I would concentrate on the following areas -
leave the pistons and bores standard!
Like said above I think a good starting point is to get a new exhaust manifold made - dont go too big on the primary OD otherwise you will have no back pressure and poor drivability out of corners - I would suggest no greater than 1-3/4" OD with 16 gauge wall thickness in stainless. use a foam (ITG) or cotton-gauze(K&N) air filter, use an aftermarket "piggyback" ECU that will allow you to hack into the standard BMW ignition and injector signals.
next steps would be ported heads, camshafts, a compression rise - but they are expensive modifications - but lets be honest the Aero-8 is an expensive car ;-)
Marquis, I agree with your opinion on 'chipping' an NA engine like the BMW ones here.. However, surely this is not also true for remaps made via tuning it properly on a rolling road? I tend to be a great believer in these over the regular off the shelf generic chip offerings. Im sure there must be BMW specialists that can do this? Even if the engine isnt in a BMW car..
My thinking was that even if cams are pricey (because of there being 4), its still far less of a chore than a full strip down and rebore etc. So if cams, decent exhaust, plus maybe induction modifications added, then surely with the above mentioned custom remap ecu software this is going to give decent gains relative to cost. Right?
My tuning experience is not with BMW's however, and im more familiar with forced induction tuning. But still, much the same principles apply here too.
Cheers, P
My thinking was that even if cams are pricey (because of there being 4), its still far less of a chore than a full strip down and rebore etc. So if cams, decent exhaust, plus maybe induction modifications added, then surely with the above mentioned custom remap ecu software this is going to give decent gains relative to cost. Right?
My tuning experience is not with BMW's however, and im more familiar with forced induction tuning. But still, much the same principles apply here too.
Cheers, P
Why dont you look down the blower route, when i had my E39 540 manual there was a website that was quoting very good figures just by bolting on a supercharger.
www.540i6.com
www.540i6.com
numbnuts said:
Why dont you look down the blower route, when i had my E39 540 manual there was a website that was quoting very good figures just by bolting on a supercharger.
www.540i6.com
www.540i6.com
I guessing, but I would have thought you'll struggle for space on the Aero 8....... just doing an oil change is a big job! lol
PJR said:
Marquis, I agree with your opinion on 'chipping' an NA engine like the BMW ones here.. However, surely this is not also true for remaps made via tuning it properly on a rolling road? I tend to be a great believer in these over the regular off the shelf generic chip offerings. Im sure there must be BMW specialists that can do this? Even if the engine isnt in a BMW car..
My thinking was that even if cams are pricey (because of there being 4), its still far less of a chore than a full strip down and rebore etc. So if cams, decent exhaust, plus maybe induction modifications added, then surely with the above mentioned custom remap ecu software this is going to give decent gains relative to cost. Right?
My tuning experience is not with BMW's however, and im more familiar with forced induction tuning. But still, much the same principles apply here too.
Cheers, P
My thinking was that even if cams are pricey (because of there being 4), its still far less of a chore than a full strip down and rebore etc. So if cams, decent exhaust, plus maybe induction modifications added, then surely with the above mentioned custom remap ecu software this is going to give decent gains relative to cost. Right?
My tuning experience is not with BMW's however, and im more familiar with forced induction tuning. But still, much the same principles apply here too.
Cheers, P
Agreed ;
Marquis Rex said:
If the engine hardware is modified then it is definately worth custom mapping the engine or going for a bespoke mappable engine management system and giving it to someone who knows what they're doing- preferably an engineer, rather than a glib talking-"know-it-all" technician/mechanic.
If the engine hardware isn't modified, then custom mapping suited to your particular engine may still give a benefit, depending on the tolerances of your particular engine and how close or far it is from these. But don't expect miracles
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