M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: Leo_328i on October 24, 2010, 05:59:05 AM
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Hey guys,
After doing a lot of trawling through bimmerforums, a common mod for M50NV engines is to get a spare intake cam and replace the exhaust cam with it.
Apparently its a good performance mod despite the fact that the cam specs are the same for both intake and exhaust - perhaps the specs are wrong?
Does anyone know if this is possible or has been done before on an M42?
Would be pretty awesome if this was a cheap cam upgrade mod for M42s!
Cheers.
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i looked into this as well, but abandoned the idea when someone reported to me that the specs were the same.
if you feel like it, you could get a regrind for the intake side and then let us know if swapping it over to the exhaust made any further difference... but you'd have to do it in 2 parts for the results to be meaningful.
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The thing is that the cam specs for both intake and exhaust are the same for M50NV too yet there seems to be some sort of benefit in doing it.
Wouldn't be up to getting my intake cam reground - I had a mate put cat-cams on and it didn't ran really shit with his stock chip. It obviously needs a retune but the costs just add up too much and its not worth it for me as the 318iS is my DD and an E36 328i is my weekender!
If I could get an M42 intake cam for cheap somewhere and give it a go, that would certainly be worth a try! :)
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another thing i never thought to look into when i was researching this the first time-
the e30 and e36 versions of the M42 intake cam have different part numbers.
e30 part: 11311727137
e36 part: 11311734118
(i also used realoem to check euro vs US, because the euro m20b25 cam is "sportier" than the one we got here in the states... however, for the m42 they are the same on both sides of the pond.)
unfortunately, without having someone sitting down and manually degree all 4 available cams (intake and exhaust side for e30 & e36 versions), it's pretty much a shot in the dark as to which would have the most aggressive profile- the e36 version could be "improved", or it could just as easily be a "torquier" grind spec'd for the heavier car. and yeah, just because the internet says the cams are the same specs doesn't make it necessarily so... this applies to both M50 and M42.
swapping the intake cam over to the exhaust side works on some VW and Nissan engines as well, which is why i started wondering if it'd work on the m42.
& yeah, you'd definitely want a chip remap to go with a regrind, if you were to go that route. i've got a 91-oct MarkD chip, as well as the dbilas ITB setup, and i've got a 4-1 header coming soon, so it could be worth it for me to try a regrind on the intake side...
i'm guessing you're in the UK? you could try asking around e30zone to see if anyone has/knows of a spare m42, or has upgraded their cams already... would love to hear results if you try it.
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This site show the M50NV cams to be different In vs. Ex. Don't know if it is accurate.
http://www.usautoparts.net/bmw/engines/m50.htm (http://www.usautoparts.net/bmw/engines/m50.htm)
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wish that site had a similar page for the M4X engines...
http://www.esatclear.ie/~bpurcell/318isengine.html#techinfo_engine
reports inlet 252 exhaust 252 Lift: inlet 10.2 exhaust 10.2
http://www.jannousiainen.net/hobbies/bmw/e36_318is/year_2006.htm
reports "242 degree / 9,2 mm lift" for his e36
all i've been able to find, but from above it looks like i guessed right... e36s have both more conservative cam grinds and the DISA system to haul around the heavier chassis.
also found this with a google search, which contradicts the above...
http://m42club.com/forums/showthread.php?t=5652
apparently Boyracer found lift to be identical, and couldn't tell a naked-eye difference on duration. i was hoping we'd dig up something i hadn't discovered before, but it really doesn't look like there are any gains to be had playing with stock camshaft combinations.
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I "think" the information below is factory literature. The M42 240 deg / 9.7 data is the same as the M50 NV intake cam which makes sense since the engines are so simular.
http://www.motortraders.net/groups/group.asp?group=1&menu=89 (http://www.motortraders.net/groups/group.asp?group=1&menu=89)
The camshafts rotate in five bearing journals and are lubricated from internal cylinder head oil passages. The relatively short opening duration of 2400 combined with high valve lift (9.7mm) ensure good torque characteristics. The camshafts are of a hollow cast design for weight reduction.
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I found them to be the same specs. I dont have any later cams . But the 91 cams are the same to each other. The VW 16 cams are not the same.
MM
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Cool research guys,
I found this on M50NVs which claims that its a load of BS:
http://forums.bimmerforums.com/forum/showthread.php?t=1116523&page=9
Apparently the cams cant actually be swapped in an M50NV? Maybe it will apply to M42s too seeing that the engines are basically from the same family.
Haha mate, I'm actually from Australia, not England. Spent 6 months in the USA earlier this year and I'm yearning to go back ASAP. Loved Cali!
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I "think" the information below is factory literature. The M42 240 deg / 9.7 data is the same as the M50 NV intake cam which makes sense since the engines are so simular.
http://www.motortraders.net/groups/group.asp?group=1&menu=89 (http://www.motortraders.net/groups/group.asp?group=1&menu=89)
The camshafts rotate in five bearing journals and are lubricated from internal cylinder head oil passages. The relatively short opening duration of 2400 combined with high valve lift (9.7mm) ensure good torque characteristics. The camshafts are of a hollow cast design for weight reduction.
I think this is definitely the most credible piece of literature out there on the M42 cams.
Funny that when the M50NV became the M50TU (VANOS) in 1993 they switched from the 240 / 9.7mm cam to a 228 / 9.0 cam as the VANOS could compensate for the loss in duration and the engine was able to produce the same peak power and have a fatter torque curve.
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Curious if anyone has tried this...
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While this does not actually answer the question, I had some discussions with catcams about swapping inlet and exhaust cams. The specific issue I was chasing, assuming a start point of a 290/275° setup, it is possible to later buy a 298° inlet cam and move the 290° from inlet to exhaust.
Catcams advised that the only difference is the angular position of the cam lobes. This means that the factory tool cannot be used during the installation. If you time the camshafts using a dial gauge / lift at TDC, the swap should be no problem.
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Catcams advised that the only difference is the angular position of the cam lobes. This means that the factory tool cannot be used during the installation. If you time the camshafts using a dial gauge / lift at TDC, the swap should be no problem.
I can confirm that factory tool or similar method is no good with non-original cams... I had shrick copies (256/10.2mm) timed just like originals and car did not run very well on low revs, it stalled a lot while reversing etc.
I think reason was because there was too much overlap, works a treat on high revs but kills bottom end power. So anything else than originals and you should time the cams with dial gauge etc.
I have measured E30/E36 M42 intake/exhaust cams and lifts are identical on all and I suspect so are cam profiles.
(http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs634.snc4/59454_430326788462_589403462_5043109_7780036_n.jpg)
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Any chance of you setting all the cams up in an engine with a degree wheel on the crank and measuring them boyracer? That is the only true way to determine whether any / all the cams are the same.
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Call around to local machine shops and find one with a gadget called a Cam-Doctor. Way faster than using a head. Last time I had a cam checked it was like 25 bucks.
Lift and duration are not everything, ramp time and lobe shape matter too.
Dave
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Topic revival blast from the past:
I have just had both inlet and exhaust cams measured from a ~95 M42 using a cmm machine here at work.
They are identical.
No quick and crafty inlet to exhaust swap to be done there.
Will post part numbers later for reference
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I'll chime in as well, I just sent my late intake to delta cams for a re-grind. They said it was 200deg at .050". From what I read on Catcams site it should be 207deg. So I swapped Both late cams into my early running M42 and noticed a significant difference in torque and a minor loss in top end. I attribute this to two possibilities. 1: I may have changed the cam timing enough to make a big difference. Now, I've played with cam timing before on other engines and haven't felt anything this significant and I was pretty careful when changing them out. 2: the other possibility is that the late cams are milder. (different part numbers I suspect designed around a different intake manifold but that's pure conjecture). The early intake is at delta now and they will tell me the orig specs before grinding to either confirm or dispel this which is why I have hesitated so far to post about my change in drive ability. IF there are any differences I think it would be more likely on the exh side. I suppose I'll blow the dust off my degree wheel and see if there is a difference. I will post Delta's findings as well. It will be interesting to see the results.
Edit: early cam at Delta
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Delta cam is regrinding your cams!!!! I sent mine to them 2 months ago after asking them 3 times if they could grind them and them telling me yes. Only for them to get my cams and tell me they couldn't then wait 3 weeks before they sent them back! I hope your experience is better than mine. Let me know how they turn out. I really wanted mine reground but all of the other shops were 3-4 times more than delta. Good luck.
Ronan
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Ronan,
I called Delta not too long ago as well. They won't touch the M42 cam!! They had issues with them braking, like snapping!
Benz-tech....You'd better call them again and tell them you have M42 cams and see what they say ::)
Cheers,
~Ralph
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My experience with them is not going well. It's been months. They will not weld but will re-grind which is limited obviously and since I'm not going for anything too big it will be fine. ANYTHING at all would be nice at this point since this is holding up the entire project.
I had good dealings with Isky in the past. I'm kinda wishing I had called them instead.