Cam Shaft Question . . .

[TimNC]

I have read somewhere that up through 1975 most 02s came with a stock 264 cam, but the 1976 "49 state" cars came with something different. Which cam was "stock" for the 1976 "49 state" cars? And are there ID markings on stock BMW cams to ID the different degrees of duration? Thanks, TC

[c.d.iesel]

1976 2002 is 264 cam

[Jack]

I think it was the diff that was different on the 49 state car. 3.64 to 3.91

[Vroomer]

When did the compression ratio change to 8.3 to 1. From 8.5 to 1?

~Vroomer

[john_a]

I have read somewhere that up through 1975 most 02s came with a stock 264 cam, but the 1976 "49 state" cars came with something different. Which cam was "stock" for the 1976 "49 state" cars? And are there ID markings on stock BMW cams to ID the different degrees of duration? Thanks, TC

The "49 state" cam for 1976 is unique, not the same as the other years before and after.

The standard 264 cam 11 31 0 631 014 appears on 02 & E21 up to 9/79 when the distributor drive gear was reversed. These cams have #2 stamped on the drive gear flange.

The 49 state 1976 cam 11 31 1 261 613 is very slightly different in profile & costs about $50 more. I don't think BMW ever published any cam timing specs for it. You'd be hard pressed to see the difference without some exacting work with a degree wheel or preferably, a Cam Doctor tool. This cam has the #5 stamp.

Of course, the Sport cams were produced in between these two, and had stamped numbers #3 & #4, for the 11 31 0 631 009 (300 degree) and 11 31 0 631 010 (324 degree) versions respectively.

[slash02]

I have read somewhere that up through 1975 most 02s came with a stock 264 cam, but the 1976 "49 state" cars came with something different. Which cam was "stock" for the 1976 "49 state" cars? And are there ID markings on stock BMW cams to ID the different degrees of duration? Thanks, TC

The "49 state" cam for 1976 is unique, not the same as the other years before and after.

The standard 264 cam 11 31 0 631 014 appears on 02 & E21 up to 9/79 when the distributor drive gear was reversed. These cams have #2 stamped on the drive gear flange.

The 49 state 1976 cam 11 31 1 261 613 is very slightly different in profile & costs about $50 more. I don't think BMW ever published any cam timing specs for it. You'd be hard pressed to see the difference without some exacting work with a degree wheel or preferably, a Cam Doctor tool. This cam has the #5 stamp.

Of course, the Sport cams were produced in between these two, and had stamped numbers #3 & #4, for the 11 31 0 631 009 (300 degree) and 11 31 0 631 010 (324 degree) versions respectively.

So what is this cam then?

[Guest Anonymous]

I have read somewhere that up through 1975 most 02s came with a stock 264 cam, but the 1976 "49 state" cars came with something different. Which cam was "stock" for the 1976 "49 state" cars? And are there ID markings on stock BMW cams to ID the different degrees of duration? Thanks, TC

The "49 state" cam for 1976 is unique, not the same as the other years before and after.

The standard 264 cam 11 31 0 631 014 appears on 02 & E21 up to 9/79 when the distributor drive gear was reversed. These cams have #2 stamped on the drive gear flange.

The 49 state 1976 cam 11 31 1 261 613 is very slightly different in profile & costs about $50 more. I don't think BMW ever published any cam timing specs for it. You'd be hard pressed to see the difference without some exacting work with a degree wheel or preferably, a Cam Doctor tool. This cam has the #5 stamp.

Of course, the Sport cams were produced in between these two, and had stamped numbers #3 & #4, for the 11 31 0 631 009 (300 degree) and 11 31 0 631 010 (324 degree) versions respectively.

So what is this cam then?

That's just a picture of the casting numbers, no way to tell for certain what cam profile was machined from that one. Part numbers do not appear cast onto the BMW cam.

Unless you have a brand new cam with the part # label attached, the part number won't be visible.

The only ID mark I wrote about being visible on the cam itself was stamped on the drive gear flange. Most OE M10 cams, but not all, show this stamp. A plain 264 stock cam shows #2. What does yours show?

Of course, even if there's a stamped number, the cam could have been reground at some later date to a different profile. When that has been done, the base circle usually measures smaller than stock.

[Mike Self]

later (carb cars, not tii's) were only 8:1.

mike