powerscreen cams and collet to guide clearance

[canamant]

I'm trying to sort out the cams and cylinderhead on my powerscreen motor which will be going into my Slabby 1100 racebike.  Not being one to just bolt stuff together, I've produced 2 camgraphs and measured piston to valve clearances from 20 deg BTDC to TDC for exhaust and TDC to 20 deg ATDC for inlet in 5 degree steps.  Clearances are fine here. The cams are massively different, inlet being quite racey in profile and timing and exhaust being very conservative.  Both cams have a "B" stamped into them on the end.  Any ideas what this is ?  

Also, on full lift. there is only 0.014 inch  (0.36mm) clearance betweeen the valve collets and the inlet valve oil seal/valve guide.  You woul dusually expect a minimum of 0.050 inch (1.25mm) to allow for valve float on a race engine.  Even though these are road engines, you would expect more than 14 thou clearance.  Has anyone out there  got specs on this clearance in this engine or measured this clearanc ?.  I'm just wondering if a previous owner has swapped a cam and not checked clearances.  Slabby 750 cams will give about 0.080inch (2mm) clearance on my other race engines.  My reground cams won't even turn over as the cam lift in this power screen head is greater than the valve collet to valve guide distance.

Thanks

[Lachie04]

B should be DOT head cam

Some more info here

http://old-skool-suzuki.proboards.com/thread/1385/gsxr1100-cams-bandit-1200-numbers?page=2

 

[canamant]

Wow.  Looks like someone DID just bolt them in and hope for the best.  Sprockets aren't even slotted to get timing right.  

Dot heads must be subtly different to get the clearance

 

[dupersunc]

Dot heads are quite a bit different. Longer valves for a start.