CB750 Cams - Advise

[philward]

Advice and opinion please - I have 3 cams of which 2 profiles are the same and 1 is different. In the attached picture, the one on the left with a 'sharper profile' came out the K6 doner engine (which doesn't mean its a K6 cam!). The one on the right is from my parts bin and is of an unknown origin and has a rounder softer cam profile. Marks on L/H cam is marked R9 (and other similar cam not in the picture is marked  R11} . The RH cam is marked  C1 . Any guidance on what models they are from? The LH cam is in good order on the bearings and cam lobes - and within tolerance - but the cam shape seem 'sharp'. The other cams are not perfect. Obviously need to put the right cam in so any help appreciated.
Thanks

[Trigger]

May be my eye sight at this time of night but, the one on the right doesn't look like a 750 sohc cam. No slot in the end ?
I will investigate tomorrow, could be F2 or K7/K8.

[philward]

Just checked and your right Graham (as usual!) but the cam is defo a 750 based on dimensions, tacho drive, etc. I've done a bit of research on google images and it looks like the cam on the left that came out of the K6 is a K6. Which is good as its in good nick. Could the other RH cam (which has a worn cam lobe anyway) be an aftermarket cam - with having a rounder profile for a longer opening duration?

[Trigger]

The one on the left is K6 and F1 That is one chunky set of lobes on the right one

[philward]

Thanks Graham - tomorrow nights job to put it in

[Trigger]

The cam on the right looks like the same type of lobes you would find on a DP315, are you sure it doesn't have this number stamped on it Phil.

[philward]

Will check tonight Graham, but its knackered anyway on one lobe - it looks like due to lack of oil
What is a DP315?

[Laverda Dave]

Phil, if you wish to use the damaged cam it might be worth your while contacting Mike Newman at Newman Cams?  They might be able to regrind or metal spray it for you as they were going to do for my CB250RS cam.
Dave

[philward]

Phil, if you wish to use the damaged cam it might be worth your while contacting Mike Newman at Newman Cams?  They might be able to regrind or metal spray it for you as they were going to do for my CB250RS cam.
Dave

Thanks Dave - I will be using the other cam now I know its a standard K6 but depending on what Trig says its from, I may use it on my next build
Phil

[philward]

Graham - marks on that cam are D1 & CWC stamped marks and just spotted NORRIS R 'etched' on a flat on shaft between 1 & 2 . Looks like a performance cam - bought an engine off DK a few years ago that had high compression 836 kit and triple valve springs in (I remember getting advice from you on them) probably from that engine

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[Trigger]

it will be a Norris race cam then  Used for high revving, mainly on drag bikes. Would not see any benefit for road use as the duration will be about 290 and 280 degrees. That's unless you want to get to the next set of traffic lights before anyone else.