1928 OHV cams

[richard.harvey]

I am inspecting a 1929 OHV motor I recently purchased that externally looks like a model E twin port. Internally the rod seem to be from 1927 twin port E. No drama. I am wondering how to identify which cam I have. There is the standard 1928 model C and D cam with is also run in the SV, the standard E cam and the racing E cam. Is there a way to telling them apart from surface marking? Mine is stamped with the number 42 on the cam face and this is the only marking. Black Ariels lists the timing. Is there a way to measure the timing without assembling the motor?

By the way, I am looking for a serviceable 1928 tank if you know of one as well as front wheel with brake plate and other bits.

[paul.jameson]

Post a photo of the cam on this forum and I'm sure we can tell you what it is.

[richard.harvey]

OK will try

[nevhunter]

They are pretty "TAME" ones. Nev

[nevhunter]

On the matter of checking the timing without assembling you need a timing disc and a dial indicator. Setcam up in Vee blocks and you can derive "Duration of lift" Ignore the first .010" ten thou. (or a bit more) to allow for a "ramp" thamt may or not be there.. You can then apply your figures to a suggested symmetry. A common TAME cam will have 30 degrees before TDC to 60 after BDC for the inlet, which will be 30 +180+60 = 270 duration. Your cam turns at half speed so that will be 135 at the cam. Nev

[marcus whatling]

Just been setting up my Cam Timing on a 1928 Model C managed to get it very close to the factory spec with about 7.8mm lift .

[paul.jameson]

Richard,

Your cam looks somewhere between an F cam and an A6/664. It might be an A6/664 which has been somewhat worn.