Cam lobe centres and Valve clearances

[Ben Coyle Racing]

Ok so I did a rebuild on my race engine


I found a few things that didnt seem right with this motor...

I had a inlet valve clearance of 0.40MM !! The rest where all 0.30+ ( could this be the reason it rattled so much? )

And my exhaust clearances where 0.20 - 0.30 mm

It seemed to me that the pillock who built it last had got it all wrong, even some of the old shims had been grounded down!

My cam lobe centre was 117 degrees on the inlet before I had touched it

From what I know, I thought the lobe centres and valve clearances was wrong, what do you guys think?

I've now changed the cam lobe centre to 107 degrees and my inlet clearances to 0.20mm


Whats your veiws on this ? Do you think that it was out?

[RedexRobB]

Iirc, aren't the exhaust clearances meant to be larger than inlet? Sounds like he's been using inches instead of mm's.

[Ben Coyle Racing]

Exactly, i've changed them now so they're spot on, its getting put in bike tomorow so should be good to see how it goes