Sitting engine.. rusty crank and cam?

smokin247

smokin247

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I'm building a new engine for my truck but the old one has been sitting with the head off still under the hood. I have it covered pretty well, but I'm reusing the cam and crank I'm worried they will have rust on them. Should I be worried about this? If there is rust on them can I just polish it off?
Thanks for the info.

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Depends how badly they're rusted. Rust causes pitting and pitting is an indication that you're wearing through the hardened surface of the material. Once that hardened material is gone you'll take a lobe off very quickly on even a stock motor.

The crank I'm not so sure about, but any pitting whatsoever would be a show stopper to me. I keep everything drenched in oil or I grease everything by hand prior to storage for that reason.
 
smokin247 said:
I'm building a new engine for my truck but the old one has been sitting with the head off still under the hood. I have it covered pretty well, but I'm reusing the cam and crank I'm worried they will have rust on them. Should I be worried about this? If there is rust on them can I just polish it off?
Thanks for the info.

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I am sure the crank could be polished just watch your bearing clearances during reassembly. If I were putting it back together I would bring the short block to a machine shop and let them handle it. If you are worried about the internals, meaning the cam and crank I am sure the cylinders must be rusty and needing attention as well.
 
I have a new block and head and all new internals except for the cam which is a Hamilton with 500 miles and the crank and rods which had 120,000. But I didn't even think about them rusting until recently. And they've been sitting in the old engine.

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Like they said it all depends on how bad the rust is. If it's just a little surface rust you're fine, if there's any pitting at all I wouldn't use it.
 
Personally, I wouldn't use either the cam or the crank if it has rust on it. Now if you can get the crank journals cleaned up with the use of an oversize bearing I think that would be ok. But as for the cam, I wouldn't want to try it with any rust, even surface rust.

Last spring I bought my Kenworth with an 855 Cummins that had a skip. Tore the cam shaft out to find this....

Camlobe_zps1e60b161.jpg


Two injector lobes looked like this. Granted the injector lobes have constant pressure on them and on the older 855 tend to wear of the lobe, but in this case I think the engine sat for a while, got a little moisture on the lobe and formed a spot of rust. When the engine was started after sitting, it ripped the hardened surface off and caused the skip.

Just my $0.02.
 
You'd be surprised how long it takes for internals to rust if they've been covered at all. But definitely check before you start it up.
 
We can probably thank the !@#$!@#$ EPA For needlessly lowering the ZDDP content in the old-school diesel oils. Need to run a break-in additive to get a decent level of protection for flat tappet engines now.
 
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