m42 Cam Timing Revisited

[Fraser]

Alright, I can't for the life of me find solid answers regarding adjusting the cam timing on the m42, short of Stu's old article which is not exactly the most involved. I am looking to play around with the timing on the intake cam a bit to hopefully get rid of a little of the "falling on it's face" feeling above 6k. (which may have a bit to do with the stupid "trick" manifold on this thing...e36, unfortunately the e30 IM won't clear the hood.)
Does anyone know the proper procedure for adjusting the cams? I assume you could loosen the bolts on the cam gear and just back up the crank until it's where you want it, but that seems way too simple. What am I missing?

Thanks!

[Stu]

Re: m42 Cam Timing Revisited

Alright, I can't for the life of me find solid answers regarding adjusting the cam timing on the m42, short of Stu's old article which is not exactly the most involved. I am looking to play around with the timing on the intake cam a bit to hopefully get rid of a little of the "falling on it's face" feeling above 6k. (which may have a bit to do with the stupid "trick" manifold on this thing...e36, unfortunately the e30 IM won't clear the hood.)
Does anyone know the proper procedure for adjusting the cams? I assume you could loosen the bolts on the cam gear and just back up the crank until it's where you want it, but that seems way too simple. What am I missing?

Thanks!

The falling on its face is definately because of the manifold. Have you personally tried to fit the early manifold?

Call my father for instructions on adjusting the timing. Pete McHenry is his name, and his shop # is (336) 761-0643.

[Fraser]

Thanks Stu!
No, I haven't personally tried to fit the e30 mani., I've just heard that it doesn't fit from second-hand internet hearsay. If I could find an early IM for the right price, I would certainly try to fit it though.
Were you running advanced timing on your m42 before it went away? Worthwhile, or no? I've got a 3.73 on the car (w/1:1 5th it's pretty short), and I'm not incredibly worried about torque loss.

I had to run an auto-x this weekend with LONG straights, and the acceleration from 6200 to rev limit (where I spent most of my time) is tepid. Now I'm looking for solutions.

[Stu]

Thanks Stu!
No, I haven't personally tried to fit the e30 mani., I've just heard that it doesn't fit from second-hand internet hearsay. If I could find an early IM for the right price, I would certainly try to fit it though.
Were you running advanced timing on your m42 before it went away? Worthwhile, or no? I've got a 3.73 on the car (w/1:1 5th it's pretty short), and I'm not incredibly worried about torque loss.

I had to run an auto-x this weekend with LONG straights, and the acceleration from 6200 to rev limit (where I spent most of my time) is tepid. Now I'm looking for solutions.

Do you have a 3.73 out of an E30? If so, was it a direct fit, no problems at the input shaft or subframe top mounts?

I didn't do it to my M42, though I probably should have. A freidn of mind that works at the local BMW dealer has a '92 318is. He tried all sorts of settings with his cam timing, and he got it to pull pretty hard up top, though he lost a lot of low end....and he had to advance the intake cam a LOT.

s

[Fraser]

Do you have a 3.73 out of an E30? If so, was it a direct fit, no problems at the input shaft or subframe top mounts?

I didn't do it to my M42, though I probably should have. A freidn of mind that works at the local BMW dealer has a '92 318is. He tried all sorts of settings with his cam timing, and he got it to pull pretty hard up top, though he lost a lot of low end....and he had to advance the intake cam a LOT.

s

:? hmmm...I really would like gain a little up top, but I don't know if a significant loss of mid-range is worth it- especially with the heavy-ish chassis. I am tempted to play around with it nonetheless. You don't have bits from your m42 still laying around, do you Stu? :P (I'm curious about the manifold now...)

Yep, the 3.73 is from a 325is- input shaft bolted right up, as did the subframe mounts. Used e30 half-shafts, though I don't see why you couldn't just swap the flanges and use the stock axles. If you don't use an M Coupe diff cover, the oil vent has to be tweaked just a bit to clear some sheet metal. It's a very tight fit compared to the small case that comes in the car.

Thanks for the info!