camshaft pitted

carco · Dec 9, 2017

Camshaft and tappets set for several years on same contact points and pitted tappets fairly heavily. Cam pitted some also but thinking may survive however worried that tappets may not survive, and if not may take out the camshaft.
Allis Chalmers CA, 1951, second tractor I learned to operate.
Anyone that may run across this, care to explain what options I may have. So far I have found one cam to buy, but afraid that may present its own problems. Have found no tappets. Repairable reasonable??? Repairable w/lots of $$$$??

Thank you for reading,
Bob

kevinthefixer · Dec 9, 2017

Well Bob, you didn't post any pics so I can't even guess how bad they might be. Light pitting on lifters (tappets, followers, sama-same) can usually be ground out, in fact if it's very light I just glue a piece of wet 180 grit paper to a flat stone and do it by hand. Otherwise any machine shop that does valve work can surface them. The cam is another bucket of worms altogether. If you can find a machine shop that does custom hot-rod work, specifically cam grinding, you have it made; but there aren't many of them left. A new cam is always best if you can find and afford one.

Janicholson · Dec 9, 2017

Low speed tractor engines with mild valve springs are not noted for cam/lifter damage. If the pits are across the full face of
the lifter, and are deep enough after a 600 grit polishing, to feel with your fingernail, I would worry. If not run it. Modern
oils are so much better than 50+ years ago. Jim

430WLPG · Dec 9, 2017

I can resurface your tappets If you send them to me let me
know

carco · Dec 9, 2017

Thank you, will keep you in mind. Going to take to a machine shop to see what they say about cam. The tappets are probably pitted .015" deep.

carco · Dec 9, 2017

The pits will not come out w/ 600grit. I would say about .015" deep using eyeball method.
I agree with low speed engine, light valve spring pressures than we see today, and much better oil qualities of today should help the cam and tappets last better but rather deep pits.

ralph1111 · Dec 9, 2017

I may be able to help with cam and tappets if you really need to go that route, I would need to check
condition of parts also the parts are from b engine I think they are the same,some one here will know for sure
Ralph

ptfarmer · Dec 9, 2017

May not be much help, but from the AGCO online parts book.

rlp in Co. · Dec 10, 2017

I have resurfaced valve lifters on the side of a grinder wheel. Keep spinning it by hand as you grind, to keep it square.

kevinthefixer · Dec 10, 2017

(quoted from post at 23:54:51 12/09/17) I have resurfaced valve lifters on the side of a grinder wheel. Keep spinning it by hand as you grind, to keep it square.

hat's basically what a valve grinding machine does, it holds a valve stem or a lifter clamped in a V-channel and rubs it against the side of the same wheel it uses to do the valve surface. As I said, it's the cam that can be a problem. Check out Chris' project:
http://www.yesterdaystractors.com/cgi-bin/projectblog.cgi?mode=detail&blogid=335

Dick L · Dec 10, 2017

I have had camshafts for this engine reground to standard close to what people want for a used one from Ebay. I have removed lifters that were concave also. They should have a slight dome that ride on the lobes. If the lifters are not pitted or hollow where they ride on the camshaft lobes I wouldn't worry much about slight pits. They would hold a bit of oil. I know I have shared pictures of some bad concaves in the lifters but can't seem to locate them this morning.

camshaft pitted

carco

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kevinthefixer

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Janicholson

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430WLPG

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carco

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carco

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ralph1111

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ptfarmer

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rlp in Co.

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kevinthefixer

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Dick L

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