m60 cam timing improvement

[BenzoNI]

What is that guy saying in the quoted material at the end? That he isn't happy because now he has too much power for his level of traction???



If so, it's not something you usually see people being unhappy about.

No it's because the power delivery is different.

He has lost mid range torque.

[Tjabo]

What is that guy saying in the quoted material at the end? That he isn't happy because now he has too much power for his level of traction???

If so, it's not something you usually see people being unhappy about.

[BenzoNI]

This may be of interest, guy using M62B44 engine, M60 cams with S62 ITB.

Shows some combinations of timing and inlet track length and what is does to actual HP figures back to back on the Dyno.

Right after some serious messing about with cam timing, inlet trumpet length and 3 sessions on the dyno (over 15 hrs in total) I have some interesting results....

First dyno session she only managed 291hp@6900rpm not great and 275lb/ft@5200rpm still not great, this was with cams set to 109deg peak on both and inlet track length from the head of 200mm....

So back in the garage she went, did some research on M60 cams and the general school of thought is that there is to much valve overlap, so redial the cams...

Second dyno session power was up, good..??? Not really, 321hp@7100rpm, but torque very not good...!!! 255lb/ft@4900rpm, now I should point out at this point that nobody recommends revving the M62 past 6800rpm so this really did concern me and it characteristics of an BMW M3 six I wasn't happy...!!! Also the power was still climbing at 7100 and I chickened out..
The cams where set to 115deg peak on both and same inlet track....

Right so now what...??? I almost give up and pulled the motor.. But I'm no quitter, so back in the garage changed cam timing to 112deg inlet and 110deg exhaust, I also did some research on the inlet track length, the S62 M5 motor sufferers really badly from fitting really short inlet trumpets, so I had already had a set of the BMW original trumpets... So bugger it I fitted the aswell.... This took the inlet track total length from 200mm to 375mm approx...

Third dyno session, happier...?? Yes, sort of.. 357hp@6400rpm and 324lb/ft@5000rpm....

So now I should be happy, right...?? Well it's not the same to drive, it's very cammy, before if you put your foot down it would pull from no revs at all and pull to 6k, now it pulls from low down, not like it did, but if you where used to an M3 you'd be very happy, but in third gear as it goes past 5k (about 80mph) it starts to struggle for grip, even in the dry weather and that's with 245 tyres on it, its very unsettling to drive....😞😞

[MonkeyMadness]

So at the end he says its "almost" identical to the M62b44TU timing.
When did bmw adopt Alpina's timing and bring it in house?
Only asking cause I'm running an M62b44 Non-tu out of a 98.
would this benefit me or hinder me?

[Jon_A]

Is this identical on the B30 as well?

[zogs]

can someone explain this to me
M60B40 modified cam timing

NOW IO/IC 0 BTDC / 66 ABDC
NOW EO/EC 54 BBDC / 8 ATDC

what does io/ic eo ec means, I know that inlet and exhaust, but what does o/c

And which is the best timing for m60b40?
How it is possible to set them in right degrees without spec blocks?

[Jonsku]

Maybe Jonsku will weigh-in since I think he does this to his swap cars, as to what the differences feel like, real world...

I'm using the "Alpina timing", which is the same as in M60's in first E38's. Unfortunately I don't have any specific info on degrees etc so I don't know how it relates to the timing mentioned in the first post.


What comes to "rough idle", I don't agree with that at all. My M60 idles and revs very, very smoothly (you can put a coin standing on the engine and it stays upright all the way to the redline). My engine has original DME that's slightly adjusted in dyno (power gains were slightly under 10%).


I do agree that cam timing in M60's is quite "neutral", and there might well be quite a lot of improvements available "for free". Also more aggressive cams would benefit the otherwise so "mild" engine, similarly to lightweight flywheel (which, of course, doesn't increase power / torque but translates the engine into much more "sportier" direction).


Guess we need a brave soul with M60B44, dyno / mapping shop available and a free day to try out various things :)

Well, it turns out the guy who did the cam timing change claimed 297 bhp, not 297whp. He actually dyno'd 273whp. I don't know why people use estimated bhp numbers when discussing modded cars, especially when you have a legit whp number to use. And 297bhp from 273whp is like an 8% drivetrain loss, I'm don't think e30's are that efficient. It would be more like 330bhp.

Yap, 15% for drivetrain losses would be closer to truth..

[iamsam]

Yeah read about that as well, but I don't want to try that just yet.. We should dyno our different swaps..

1.m60b40
2.m62 with b40 heads
3.above with the timing upgrades

yes for the love of all that is holy someone please dyno their M60B44 already!

[JGood]

Well, it turns out the guy who did the cam timing change claimed 297 bhp, not 297whp. He actually dyno'd 273whp. I don't know why people use estimated bhp numbers when discussing modded cars, especially when you have a legit whp number to use. And 297bhp from 273whp is like an 8% drivetrain loss, I'm don't think e30's are that efficient. It would be more like 330bhp.

[Jean]

Yeah read about that as well, but I don't want to try that just yet.. We should dyno our different swaps..

1.m60b40
2.m62 with b40 heads
3.above with the timing upgrades

[senorcarey]

well B44 pistons have flat tops, while B40 pistons have valve reliefs, so would valve clearance become an issue then?

And my original question more specifically is, if this M60B44 hybrid build bumps you up to ~330 bhp, what would you gain on top of that with the aggressive cam timing?

Flycut the piston tips for valve relief.

Win-win.

[iamsam]

I thought it was mentioned that the gains are past 4k rpm and not in the mid range?

[bmwmech1]

Bruce and I had talked about this thread a year or so ago and bounced around the ideas in it. That was all we ever did though, was just talk about it. From what we had discussed, it seems as though the changes would be better suited for a street car rather than a full-on race car, since most of the gains were in the low-mid ranges. Maybe Jonsku will weigh-in since I think he does this to his swap cars, as to what the differences feel like, real world...

Garey

[iamsam]

Unless the pistons are stroking higher in the B44 block, there is no reason why it would not work. I would expect it to have the same impact on the running motor,mbut that I can't speak to.

well B44 pistons have flat tops, while B40 pistons have valve reliefs, so would valve clearance become an issue then?

And my original question more specifically is, if this M60B44 hybrid build bumps you up to ~330 bhp, what would you gain on top of that with the aggressive cam timing?

[nrubenstein]

If this really works, then the next logical question is: Can you do this to an M60B44 hybrid, and how much power might it end up with, providing the factory ecu can be tuned accordingly?

Unless the pistons are stroking higher in the B44 block, there is no reason why it would not work. I would expect it to have the same impact on the running motor,mbut that I can't speak to.