Duplex Cam Chain Alignment

[rogerguzzi]

Hello You Clever lot(creeping over!)

                                                             I am back on Spitty,s new engine after holiday and Snow clearing

I am fitting the duplex cam chain and it is 0.045" out of line (Crank sprocket lower than cam sprocket!)

Does anybody have offset dimensions for both sprockets?

Mine are Crank sprocket +0.250" back face to chain face,  Cam - 0.275" to chain face.(binned old simplex ones)

Now I could fit a lot of shims? or machine a bit off the back of the Cam Sprocket?

I do not like lots of shims 0.004" or 0.006"?

I have fitted I think +0.005" rear thrust (I think) and the crank grinder took a skim off it, so should be the same position.

I have checked the old camshaft and it is the same for slot to front face?

So what do we think?

Roger

[Pete Lewis]

There is a lot of chatter and clatter through this drive, I dont think shim stock will last without creeping and breaking up

It will be held in the register but ive had some poor results adding shim to similar problems over the years

Reface the gear sounds a proper job.

Pete

[AndyTV8]

my first reaction was to shim it..... but the more i think out it shaving the back of the cam sprocket would be the right thing to do.

....... Andy

[rogerguzzi]

Hello All

                Thank,s for the replies I think I knew what was the proper way to do it!

Its all done now and within 0.002" and there is about 0.010" to 0.015" side clearance so all will be ok!

Roger