Modified cam

[cleverusername]

I replaced the rotten cam on the Sprint engine with a used one from winns. Replacing the head and found I couldn't get the timing chain round the cam cog. Odd, can't recall that problem with the old cam.

I just compared the two, the new cam has the cog on a push fit on the cam, on the old one the cog ran in the tinwear mounting. This could be a real pain, because changing the timing chain in future will involve undoing the head bolts. Has anyone else come across something like this?

[xvivalve]

Nope. I cannot imagine a scenario where you'd need to remove head bolts to change the timing chain.

[Jon Tilson]

The boss that the cam wheel fits on has a threaded bit that mounts to the support bracket. You bolt the chain and sprocket to this for head removal.
The boss is a push fit in the front of the cam. You can rotate the sprocket so the bolts and holes all line up. I suspect you boss is a tight fit in the new cam. Pull it all off and just make sure the boss fits the cam and try again.

I drop the cam sprocket with chain attached down through the head slot and engage the other sprockets and then fit the cam sprocket to the cam with the straight run down to the crank pretty tight. Then push down the curved guide to take up the slack.

Jonners