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Discussion Starter #1 (Edited)
I found a pair of 10548 "01" camshafts which I pulled out of a 1750 engine about three years ago, and I'm wondering if they're junk or not.

As far as I can tell, there are two potential issues - but bear in mind that that this is the first pair of 10548 cams I've actually owned, so what I'm describing might be entirely normal!

Yellow Arrows
Doesn't look like there's enough meat in the lobe in the 'valve closed' position - note how it's barely clear of the raw base casting. The journal seems similarly affected. It's almost as if the blank was incorrectly centred when the profile was ground at the factory. It also looks like something has been rubbing against the shaft itself, maybe even the cam follower bore in the cylinder head? :confused:

Red Arrow
When I swipe my fingertip lightly along the lobe, I can feel a 'ridge' here - but not in the sense of a lump, but a pronounced 'dropping away' of the lobe profile to the 'closed' valve position. Is this normal or should this be a smoother progression? It doesn't seem right that a valve should be made to slam shut like that.

Any help appreciated.

Thanks,

Alex.
 

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I just removed my 10548...01 cams from Julius (67 Super) and noticed that the lobe ends are getting a "pointed" feel to them. I am also wondering about the heat treatment on these cams and what to do about/with them.
 

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Alex

Your cams appear normal from what I can see. The Alfa cam has a "heel" on the lobe that gently lifts and lowers the valve off the seat. This is the ridge that you can feel. The best initial check to do is compare the ridge and lobe to all the other lobes. Usually one lobe will wear first, not all at the same time.

The mark around the rough surface is a bit more puzzling. It may be that a bucket has completely worn away and caused this... But I would advise taking the cam to an engine rebuilder (or Alfa specialist) to have a look to be sure.

Usually cams wear right on the tip of the lobe first, so this does look unusual. (Some better pics would be good).
 

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I just removed my 10548...01 cams from Julius (67 Super) and noticed that the lobe ends are getting a "pointed" feel to them. I am also wondering about the heat treatment on these cams and what to do about/with them.
A friend recently had this on his 1750 engine- the lobes on one cam were very pointy. The first he knew was a top- end rattle that sounded unlike anything else I have heard- almost like something was hitting the inside of the cam cover. In fact, a bit like the noise you get from the front of the engine when the timing chain hits it. Bad news, anyway, so new cams in order.
I wonder if this affects 1750 cams more than others?
 

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Camz... always Camz!

Agreed the cams appear "normal". Hardening of cams, in general IS very critical. Should a cam be "cleaned up" by polishing, it IS possible to get into softer metal. Only an experienced cam builder/ grinder should attempt re hardening. Often cams are "touched up" to a very slightly different profile, and will work fine... for a while:eek:! For a definative opinion:cool:, contact Richard Jemison (Alfar7) here on the BB. He can give you all the information you need. Best, :DGordon Raymond
 
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