Cam damage

pommie john · Jul 16, 2011

I'm just in the middle of giving my 750 race bike an overhaul and all looks good except this damage to the cam.
Any experts want to give an opinion as to what caused it? The cam's been in there for years, and the cam follower looks perfect, a couple of ridges as per normal but no unusual wear marks or damage.

I guess I ought to change the cam, just to be safe.

ashman · Jul 17, 2011

Hi Pommie John

Looks like something has gone in your motor that shouldn't have been there, if you go to Tighte Cams over Darra they have all the cam profiles for Nortons, I have had my stardard Norton cam built up to a SS cam grind many years ago by them and it only cost $65 at the time, cheaper than a new cam and they know what they are doing, after 30 years the cam is still good.

Ashley

Hobot · Jul 17, 2011

Looks like hard chip got slung up and run through the ringer to me too. But if lifters fine and nothing standing proud, ie: actually chipped out cam surface not just indented it, likely the lifters can't feel it and is a non issue. Anal might check true ness and mag flux it too. Might find gear pump evidence and maybe caught in filer. My best guess is a chip off bottom of front cylinder bore.

pommie john · Jul 17, 2011

ashman said:
Hi Pommie John

Looks like something has gone in your motor that shouldn't have been there, if you go to Tighte Cams over Darra they have all the cam profiles for Nortons, I have had my stardard Norton cam built up to a SS cam grind many years ago by them and it only cost $65 at the time, cheaper than a new cam and they know what they are doing, after 30 years the cam is still good.

Ashley

I've got my eye on a PW3 cam and with the pound the way it is, it's a bargain to buy them from the UK. I have heard that Tighe is very expensive these days. but I'll give them a call on Monday.
Thanks.

Flo · Jul 17, 2011

Could be where there was a flaw in the mtl. & caused a small crack when it was quenched & the flaw loosened the mtl. over time.

Cam damage

pommie john

ashman

Hobot

pommie john

Flo

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