Rust on a cam

T

ToniH

Well-known member
Joined
Apr 2, 2008
Messages
49
Location
Finland
I bought a new cam and it was rusty right out of the box. Very little storage grease on it. :( Well, too heavy object and too far away to send it back so looking for options. What do you say - is this a major problem or only cosmetical?

Luckily bearing surfaces have absolutely no rust. Lobes and spaces between them have some. Cannot feel them with a fingertip but can sense the roughness with my fingernail.

Here is a image to show the problem. Note, that I have increased contrast on the image so its not that bad with naked eye. Also all uneven things which are metal color are in fact oil.



So, what is the best course of action:
1. emery cloth + oil
2. take it to machine shop for repolish
3. scrap it
4. something else?

Thanks!
 
Hate to say it but that nice billet roller is toast. You can't have it reground.

You would have been better off if there was a little pitting on the bearing surfaces, rust on the lobes finishes the cam off.

I would contact the seller.
 
It is actually a GM LT4 Hot cam. Is the verdict same or can this cam be repolished?
 
Last edited:
Xander, you really damn sure about that?? I have run FLAT TAPPET cams like that, believe it or not....had them last years....

I would think a ROLLER cam would/shout be fine.....

however, I would not be pleased either.....not for new merchandise.....:pprrtt::gurney:
 
I've now had several local guys say it should be ok - one of them quite respectable machine shop guy. Many asked first if its a roller cam and when I confirmed the response was "don't worry, its ok". Well, maybe I will take it to another machine shop for final pro opinion.

Not very happy but sending it back is not an option due shipping costs so if indeed its unusable it was few hundred bucks down the drain. :mad:
 
It's your engine, I myself wouldn't run a cam as rusted as that, I thiink the pitted areas will work as a file and you will also have corrosion come off and go through the engine

I installed a billet roller in a 428 FE engine with very minor pitting compared to yours ( only 1 lobe) because the owner didn't want to buy a new cam, took out the roller in a couple of thousand miles

Try cleaning it up with some fine emery after soaking it in light machine oil for a night
 
I would think that for a roller it should be fine but if it was my engine I most likely wouldn't install this cam. I'd be mad as hell at the seller for not protecting it as they should have done. Any chance you paid with a credit card ? Sending this cam half way around the globe shouldn't cost more than $50 ...
 
I agree with TT on this one. The pitted area's will start getting larger with time. If the oil pump & filter want catch the metal flakes, your engine will be toast. It's just not worth the chance.
 
I understand what you guys are saying. Obviously I don't want to install it if it is pitted.

But, why cannot it be repolished and then maybe rehardened like any other cam? Would it not be like new after that (surface smoothnesswise)? Machine shops custom grind old cams all the time (and have done it for 100 years), what makes this GM cam so special it cannot be done?
 
ToniH said:
I understand what you guys are saying. Obviously I don't want to install it if it is pitted.

But, why cannot it be repolished and then maybe rehardened like any other cam? Would it not be like new after that (surface smoothnesswise)? Machine shops custom grind old cams all the time (and have done it for 100 years), what makes this GM cam so special it cannot be done?
Click to expand...

I don't know the answer, but I'd guess that having a cam "repolished" would use only a very minor abrasive to get rid of extremely small surface irregularities. If the cam was pitted you would need to take it down maybe 4 - 6/1000ths of an inch, and that would change the profile.

Take it to a machine shop! Ask them if they'll do it. Most machine shops around here are pretty honest, they won't try and make money off of me if they know the part needs to be replaced. Find a busy shop, busy shops tend to have lots of customers because they do good work.
 
You can have it reground and have a smaller base circle. Dunno how much it would cost though.
 
Yes, i will take into a shop and ask. Shops here have been making "racier" cams by regrinding them for decades so even if they need to take some material off I am sure they can redesign it so it works fine. It is quite mild to start with.

I mean if it can be done to this type of cam at all? That is what I was wondering as earlier it was said that it cannot be reground at all??
 
It can't be repolished, it can be reground and rehardened but I'm willing ot bet a new cam will be more cost effective
 
ToniH said:
Yes, i will take into a shop and ask. Shops here have been making "racier" cams by regrinding them for decades so even if they need to take some material off I am sure they can redesign it so it works fine. It is quite mild to start with.

I mean if it can be done to this type of cam at all? That is what I was wondering as earlier it was said that it cannot be reground at all??
Click to expand...

Mild?! Why? :twitch:
 
You must log in or register to reply here.
Top