Cam wear question and lifter valley find

**Edward J.** · May 2, 2010, 03:55 PM

Re: Cam wear question and lifter valley find

Gary, the cam lobe inspection should be easy now that the intake is off, by rotating the crank around by hand you will see the egg shape lobes,while looking for lobes that have unuseal wear on them, they all should look the same, the goldish color is normal- typical varnish. the nut looks to be for the coil ,one of the wire retainers.

**Joe L.** · May 2, 2010, 04:50 PM

Re: Cam wear question and lifter valley find

Originally posted by Gary Cox (30260)

I decided to tackle the numerous oil leaks on my 427/400HP car. I think the engine was freshened up about 1991. I think the cam bearings and lifters were replaced, but not the cam. My guess is the cam has about 65K miles.

Comments on the cam lobe wear appearance? Is the goldish color the normal cam surface color (not worn by the lifter)? I guess I was not aware the lifters do not stay over the center of the cam lobe?

Note the loose nut found in the lifter valley

Gary------

The cam lobe wear-in pattern looks very normal and, actually, quite excellent. Flat tappet valve lifters are not completely flat on the cam interface surface. They are actually slightly convex. So, they do not contact the full width of the camshaft lobes. As the lifters or cam wears, they contact more of the width of the lobe. Yours that I can see look just about as they should in the NEW condition. So, that's a good thing. If all of the lobes show a pattern like this, you're in great shape.

It's a very good thing that the nut stayed where it is. It would not be a good thing for it to get lower in the engine. The strange thing is that it looks like it has no oil, at all, on its surface. Are you sure that this did not fall in after you took the manifold off?

In any event, I can't imagine how this nut would have gotten there. I don't think it could have happened when the engine was originally built since I don't think the engine plant would have even had a nut this size in their inventory. If it got there the last time the engine was opened up, I do not see how it would have remained there all this while and, especially, without even what appears to be any oil on its surface.

**Clem Z.** · May 2, 2010, 05:03 PM

Re: Cam wear question and lifter valley find

Originally posted by Joe Lucia (12484)

Gary------

The cam lobe wear-in pattern looks very normal and, actually, quite excellent. Flat tappet valve lifters are not completely flat on the cam interface surface. They are actually slightly convex. So, they do not contact the full width of the camshaft lobes. As the lifters or cam wears, they contact more of the width of the lobe. Yours that I can see look just about as they should in the NEW condition. So, that's a good thing. If all of the lobes show a pattern like this, you're in great shape.

It's a very good thing that the nut stayed where it is. It would not be a good thing for it to get lower in the engine. The strange thing is that it looks like it has no oil, at all, on its surface. Are you sure that this did not fall in after you took the manifold off?

In any event, I can't imagine how this nut would have gotten there. I don't think it could have happened when the engine was originally built since I don't think the engine plant would have even had a nut this size in their inventory. If it got there the last time the engine was opened up, I do not see how it would have remained there all this while and, especially, without even what appears to be any oil on its surface.

i agree with the amount of oil flowing thru the engine that small a nut would have washed into the oil pan

**Gary C.** · May 2, 2010, 06:26 PM

Re: Cam wear question and lifter valley find

I will have to double check, but was careful with the disassembly and do not recall dropping a nut from the coil. I removed the nut from the oil puddle and wiped it off before putting it back for the photo.

Happy to know the lifter wear looks normal. None of the lobes are worn down, I was just questioning the wear pattern.

Thanks for the replies.

**John H.** · May 2, 2010, 07:42 PM

Re: Cam wear question and lifter valley find

Originally posted by Gary Cox (30260)

I guess I was not aware the lifters do not stay over the center of the cam lobe?

Gary -

You'll also note that the lifter bores aren't centered on the cam lobes; it's designed that way so the lifters will rotate in their bores.

**Gary C.** · May 2, 2010, 07:49 PM

Re: Cam wear question and lifter valley find

I guess it will always be a mystery. As I thought I have both of the coil nuts that I removed and now I have this extra nut. The nut was nearly submerged in oil in the approximate location shown.

My other thought was it could have been lodged somewhere on top of the manifold from days gone by, but i did clean off the manifold well prior to removal so that no debris would fall into the engine, even blew everything off very well with compressed air just before intake removal.

**Robert G.** · May 2, 2010, 07:55 PM

Re: Cam wear question and lifter valley find

The only nut of that size that I can think of near the engine are the ignition coil nuts.

**Joe L.** · May 3, 2010, 12:39 AM

Re: Cam wear question and lifter valley find

Originally posted by Gary Cox (30260)

I will have to double check, but was careful with the disassembly and do not recall dropping a nut from the coil. I removed the nut from the oil puddle and wiped it off before putting it back for the photo.

Happy to know the lifter wear looks normal. None of the lobes are worn down, I was just questioning the wear pattern.

Thanks for the replies.

Gary-----

OK, now I understand why the nut has no oil on the top. It could be that it got into the engine at some previous time when it was opened up and by some miracle it stayed in the lifter valley area. The important thing is that you'll have it out of there now.

**Robert G.** · May 6, 2010, 08:44 AM

Re: Cam wear question and lifter valley find

Originally posted by John Hinckley (29964)

Gary -

You'll also note that the lifter bores aren't centered on the cam lobes; it's designed that way so the lifters will rotate in their bores.

Is that still the case with engines today (with roller lifters, etc)? I didn't realize that was how they made the lifters rotate, so what effect does this have on lifters with a 'rounded' lobe? I've never seen one, but it must damage the lifter as well?

**Edward J.** · May 6, 2010, 10:26 AM

Re: Cam wear question and lifter valley find

Bob, roller lifter engines don't have cam problems, but the older small blocks chevys. did have some problems but were rare for the number of engines they built.

when the the cam lobe was worn the lifter would not open and close the valve or valves, you would hear a poping sound from the exhaust or carburator depending on which valve failed intake or exhuast.

**Clem Z.** · May 6, 2010, 11:01 AM

Re: Cam wear question and lifter valley find

Originally posted by Robert Gallagher (17477)

Is that still the case with engines today (with roller lifters, etc)? I didn't realize that was how they made the lifters rotate, so what effect does this have on lifters with a 'rounded' lobe? I've never seen one, but it must damage the lifter as well?

you can retro fit roller cams into older engines because the cams are made to fit the lifter location same as the flat tappet cams