Removing rust / polishing a camshaft?

[julianhj]

I have an RV8 camshaft that came out of my old Griff following a top-end rebuild. It's sat in the corner of the lounge, purely because I like the look of it, but it's not in top condition. There's a little bit of rust on it, and it could do with a damn good polish. How should I go about this?

[ZR1cliff]

Ive got a cam just like that

[ZR1cliff]

If know one comes in with an answer,i was thinking of using fine wire wool and WD40 to clean it.

[Tyre Smoke]

Solvol Autosol. Then a good quality beeswax.

[dieseljohn]

If you want a good finish you need to spend at least £5000 on the wax.

[julianhj]

Thanks, I'll look out for some Autosol and give it a go.

[m1spw]

dieseljohn said:

If you want a good finish you need to spend at least £5000 on the wax.

Somewhere around the £5,800 mark?






I could buy a car and insure it for that amount, spent on polish

[bmw114]

I was going to make a humourous comment but it would probably go unnoticed.

[Sam_68]

For the cost of a new cam, you would have to be very foolish not to throw it away and buy a new one. It could do some very expensive damage to your engine.

[julianhj]

Sam_68 said:

For the cost of a new cam, you would have to be very foolish not to throw it away and buy a new one. It could do some very expensive damage to your engine.

Two or three of the lobes are circular. The rebuild was thorough - I just have the old one as 'modern art' or something, it sits in the corner of the room as a momento of my old Griff.

[GavinPearson]

1500 grade wet and dry in engine oil. Go in the direction OPPOSITE to rotation. Clean well afterwards.

[mybrainhurts]

GavinPearson said:

1500 grade wet and dry in engine oil. Go in the direction OPPOSITE to rotation. Clean well afterwards.

What if he's not got a well...?

[dj111s]

mybrainhurts said:

GavinPearson said: 1500 grade wet and dry in engine oil. Go in the direction OPPOSITE to rotation. Clean well afterwards. What if he's not got a well...?

[M3 Mitch]

OK serious question Gavin - why is it important to go in the direction opposite to rotation for the cam?

And to clarify, you mean if you could put the cam in a lathe, and hold the abrasive against it, you would turn it in the opposite direction that it normally turns in the engine, right?

[GavinPearson]

The reason you want to lap any surface that is corroded or newly ground in the direction opposite to rotation is that in the fresh state there is a sawtooth profile that will cut into the mating surface and wear it away when lubricant film thickness is low, e.g. startup. if the surface is lapped so that is in the direction of rotation it is like presenting a chisel to the surface so it will make matters worse. Lapping opposite to rotation flattens out the peaks and thus gives the best chance for long life.

[L81]

GavinPearson said:

The reason you want to lap any surface that is corroded or newly ground in the direction opposite to rotation is that in the fresh state there is a sawtooth profile that will cut into the mating surface and wear it away when lubricant film thickness is low, e.g. startup. if the surface is lapped so that is in the direction of rotation it is like presenting a chisel to the surface so it will make matters worse. Lapping opposite to rotation flattens out the peaks and thus gives the best chance for long life.

I've done this with good results but I also finish off by hitting it with a polishing mop using a very fine polishing soap. Cleanliness is crucial. Of course, the best thing to do is to fit a new cam. I always insist on new cams (as I'm responsible for the engine build, I'm not willing to risk being liable for hundreds of quid because the owner is too tight to pay for a new one) but occasionally a cam is very rare & a new one can't be sourced, hence it needs cleaning up. So far I've not had any problems, but I'm not happy doing it.
Simplest thing to do is to not let the cam go rusty in the 1st place