Can someone explain how the cam on the right works, ive seen a couple on Facebook the last couple of days and just cannot work it out, the lobes seem to be 180, degrees apart with the cam moving at half the rate of the crank this would meen the piston would be travelling in the direction as either valve opens, i just cant see how it is possible to work
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Can someone explain this cam
- Thread starter jay760
- Start date
Sorry, post deleted I made no sense.
Max Midnight
XS650 Addict
Are they from a V Twin?
Xs650
Yea, would help to know what engine they are out of! Or maybe a link to the pages you are seeing these.
Well if it's from an XS... the obvious says there's almost no valve overlap. Is it possible it's for a blown motor... turbo or supercharger?
It's for the OW head. It was a factory race head with steeper valve angles. Due to the steeper angles the rocker pivot is moved closer to the centerline of the head, which changes the lobe shape.
https://thexscafedotcom.wordpress.com/2011/09/13/xs650-ouow72-heads/
That's funny, I've seen several posts over the years with people saying they have an OU-72 head and the differences, everyone has failed to mention their head is totally useless without this very odd looking cam
That's funny, I've seen several posts over the years with people saying they have an OU-72 head and the differences, everyone has failed to mention their head is totally useless without this very odd looking cam
Edit* Maybe the shape changed due to the shorter rocker arms, need more cam lift with a lower rocker ratio.
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Makes perfect sense to me.
I've seen very little about what actually went into the OW/OU 72, compared to the standard XS engine.
If they had to alter the rocker geometry for the narrow valve angle, the rocker pads might have been riding on opposite sides of the cam, rather than both at the top, if that makes any sense.
I've seen very little about what actually went into the OW/OU 72, compared to the standard XS engine.
If they had to alter the rocker geometry for the narrow valve angle, the rocker pads might have been riding on opposite sides of the cam, rather than both at the top, if that makes any sense.
Regardless the valve angles and rocker ratio that is an EXTREMELY wide LSA!
Often in performance applications that angle is closed up compared to road going cam timing.
Interesting to say the least.
Often in performance applications that angle is closed up compared to road going cam timing.
Interesting to say the least.
Wouldn't the LSA be referred to crankshaft degrees? Theoretically, the rockers could be L-shaped or whatever, like for example a Ducati closing rocker arm. Most of us are used to see camshafts where lifters or rockers all are "inline", and camshaft lobes placed accordingly.
