Just meassured my old cam lobes with a vernier to see how worn they actually were, and each one is down about 1mm from the Haynes manual spec but it doesnt give any +/- tolerances.

Is that a lot for a cam thats done 6000miles?
What are the tolerances for a cam?

Thanks.

 

Are you measuring from the base circle to the highest point on the lobe?

This seems like quite a lot of wear, dont forget, with the ratio of the rocker being 1:1.65, this will be magnified at the valve to 1.65mm reduced lift. There are no real tolerances as such, just when it knocks or power loss is noticable, bin it!

 

Yes mate I am.

 

Maybe the Haynes manual is wrong ?, as you are using(I assume) std hydraulic tappets I would not worry, if they are all the same, it is more likely to be a error.
tabetha

 

I'm an idiot!!!!!! I was using the Haynes manual for reference againt an old Piper 285T

Sorry peeps!
Anyone know what the Measurements should be fro a Piper 285T?