Author Topic: what cam is this? and will it fit?  (Read 699 times)

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Offline frodef2

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what cam is this? and will it fit?
« on: July 02, 2008, 01:17:27 PM »
Hi, 
I'm currently rebuilding the engine in a 76 CB750 supersport f1.
The cam that's installed in the engine is in bad shape, so I'm going to exchange it for one of the other cams that i got when i bought the bike.  I have 2 cams to choose from, one is marked "R2" the other is R9.these where the only markings i could find on the cams.
The R9 cam looks like it has a much more aggressive profile than the R2.
The PO told me that the R9 cam was a aftermarket performance cam, but i have my doubts. could this be a f2 cam? and would it fit in my 76 f1 engine?.

thanks in advance.
-Frode Johansen
76' Supersport

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: what cam is this? and will it fit?
« Reply #1 on: July 02, 2008, 08:58:04 PM »
R2 and R9 don't specify what cam you have. There is no known identification on most cams. I'd say at least measure the lift and eyeball the shape and go with the one that is bigger than your stock cam. There are ways to measure duration which I'm not sure how to do. I'm sure the cam has to be installed when you take the measurements. Has to do with valve opening and closing measurements. I believe other after market cam suppliers also used the same billets that Honda used so you will probably see R2 and R9 with other grinds too.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline 754

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Re: what cam is this? and will it fit?
« Reply #2 on: July 02, 2008, 09:02:21 PM »
Some  hot cams are clearly stamped..

good idea though to compare the 2 lifts with a dial indicator, for one it may show lobe wear you can not see..
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