M30 CAM Specs Quiz time...

[JoeS]

What is the duration, lift and overlap of the following stock cams from the M30:
B35
B34
B33

Oh... and what was the cam like in the M106?

[DaCan23]

I think the duration was 276, lift 11.2, and overlap 112 for all versions.

Do you mean the M102 from the 735 turbo?


What is the duration, lift and overlap of the following stock cams from the M30:
B35
B34
B33

Oh... and what was the cam like in the M106?

[DaCan23]

Roundel did a major write up on the M30 and its versions a few months back. Might be able to verify B33,34,35 differences tomorrow after I dig it out.

[Jeff N.]

I'd like to know what the answer is. I have a mental note that the stock M30/b35 cam is a 268 duration. I'd like the full specs however...

Is there a cam grinder/refinisher perhaps that might have some information?

[DaCan23]

Actually I think pre 1987 all US M30s used a 260 Degree Cam, after 1987 they used a 264 Degree Cam. The Euro spec M30 engine had the 272 Cam. I think the schrick cam in my E24 M30 B34 is a 284 Degree one.

M102 was the 745 Turbo engine. Whats the M106?

[632 Regal]

this would definetly go in the archives if we get this info

[Bill R.]

10.9 lift so i kinda doubt that the stock cam has a higher lift...




I'd like to know what the answer is. I have a mental note that the stock M30/b35 cam is a 268 duration. I'd like the full specs however...

Is there a cam grinder/refinisher perhaps that might have some information?

[632 Regal]

doesnt anyone have a metric dial indicator and an engine hanging out?

[DaCan23]

US Specs
M30 B32 Engine - 3.0L/3.3L - 272 Degree
M30 B34 Engine - 3.5L - 260 Degree
M30 B35 Engine - 3.5L - 264 Degree (Lift 8.7 I think)

US 745i Turbo?
M102 Engine - 3.5L Turbo - 260 Degree

Euro 745i Turbo
M102 Engine - 3.5L Turbo - 264 Degree
M106 Engine - 3.5L Turbo - 264 Degree

Although early euro 745 turbos probably had the 272 degree cam. The 272 was used in pre-motornic versions.

I'll check the roundel to see if it has lift and overlap.

[DaCan23]

I think Joe has all the heads hangin in his garage and later on he'll tell us the real answers.

Has anyone grinded their cam, regardless of engine. I heard its a tough thing to do, very hard to get the timing right.

When my M30 B34 was rebuilt, I believe the rockers & valves & springs were redone too, according to Schrick's specs for the 284 degree cam. Which does have the 10.9 lift as Bill stated. Also in any cam mod, a chip is always recommended.


doesnt anyone have a metric dial indicator and an engine hanging out?

[JoeS]

But this thread is accumulating nicely. Do you remember how long ago the Roundel M30 was?

[genphreak]

... although early euro 745 turbos probably had the 272 degree cam. The 272 was used in pre-motornic versions.
I'll check the roundel to see if it has lift and overlap.mm interesting. I'd like to know if the US cam in my M30B35 is different to a euro one, or if (maybe this is dumb) a 272 from an old 533/733 is any improvement over it like the 284 is, or would its particular grind specs be too weird for Motronic to run with... (if one didn't have to fuss too much over emissions)...

[DaCan23]

It was maybe Aug/Sept I think. It was a huge story on the six bangers, but focused on the M30 & M50 mostly. Forgot to look last night.


But this thread is accumulating nicely. Do you remember how long ago the Roundel M30 was?

[DaCan23]

I'm almost positive that your Euro 535 has the 264 degree cam. With a 284 cam & chip you'd see about 40-50 HP boost I'd guess, perhaps more or less.

In the spring/summer I will be doing my injectors w/ some 19lb ones on the E24, not sure whats in there now. And then to the dyno to find out the exact power my M30 has.


mm interesting. I'd like to know if the US cam in my M30B35 is different to a euro one, or if (maybe this is dumb) a 272 from an old 533/733 is any improvement over it like the 284 is, or would its particular grind specs be too weird for Motronic to run with... (if one didn't have to fuss too much over emissions)...

[genphreak]

I'm almost positive that your Euro 535 has the 264 degree cam. With a 284 cam & chip you'd see about 40-50 HP boost I'd guess, perhaps more or less. In the spring/summer I will be doing my injectors w/ some 19lb ones on the E24, not sure whats in there now. And then to the dyno to find out the exact power my M30 has.Sound like fun in the sun at your place... Thanks for your thoughts there- I'd like to go 284- but they blow my budget, especially as I have to import it from US/UK to Oz. I was thinking I might get my old cam reground to 284 if only I could find someone to do it here. Hence my thoughts about trying a 272 version, that would be easy to source- but I was reading your engine table post just now (brilliant stuff) and noticed the 272 degree cam went with the K-Jetronic 3.3L M30 and the compression was 8.1:1 back then, so no doubt a 272 will screw things up a bit an an M30B35...

[632 Regal]

think about this, all you would be doing is increasing the compression, which higher duration cams LIKE to run better, the question is lifts and overlap at this point.

and noticed the 272 degree cam went with the K-Jetronic 3.3L M30 and the compression was 8.1:1 back then, so no doubt a 272 will screw things up a bit an an M30B35...