Re-using Used Lifters on Another Cam

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NM
good choice
we used Isky in lots of foreign stuff
and in our E Jag
Till we got Kenny Harmon to get some billets
the Jag lobes are narrow so they do not hit the buckets
Kenny gave us a half inch wide lobe and we machined channels in the buckets for clearance
Isky's grind was for a the large Jag bucket vs others
That's where you can really see the difference lifter diameter makes
on the other hand Ed Winfield converted his #2 Offy grind for the Rambler
 
dartfreak75 said:
Or it means you had a problem and never knew it. Just because you think its ok doesnt mean everything is really ok! I had a 318 that ran "fine" I went to change the valve cover gaskets and found a broken rocker and a bent push rod that cylinder was completely gone it had been running on 7ish cylinders for God know how long. It never made a noise or anything. So i can see it to be possible to run a cam with used lifters and get a flat cam on one lobe or 3 and never know it and run it that way. I guess you would find out when you changed your oil tho. Maybe lol
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It ran fine ? I doubt it. with a broken rocker and bent push rod and running on 7 cylinders , it would be obvious something was wrong.
and believe me, a flat cam and bad lifters would be obvious. at least to me !
 
fishmens67 said:
It ran fine ? I doubt it. with a broken rocker and bent push rod and running on 7 cylinders , it would be obvious something was wrong.
and believe me, a flat cam and bad lifters would be obvious. at least to me !
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It ran like an everyday driver with 250k miles. I dont really get on my everyday driver it got me to work and back everyday for over 10 years idk how long it had been like that. I will say after I fixed it, it ran alot better and got better fuel mileage!
 
nm9stheham said:
Thanks guys. Honest replies IMHO. This was for flat tappet lifters (.842 Chevy size), no info on the engines, but probably stock stuff, with similar spring pressures as in SBM's .

The context was that a new guy to engines was considering putting some the used hydraulic lifters from his old head into a 40 year old head with a solid cam that had been setting for 30 years. I was saying no way you should do that and then foolishly said it would have a '99% chance' of failure.... trying to make sure this new guy got a sense of the risk. Then the person I quoted above claims to have done it successfully ' a dozen times' but with no description of the setups, and seems to equate new lifter failure as somehow as likely too.

I can't in good conscience let a new guys put his engine at risk. And I have asked how one would qualify a used lifter to be adequately good to re-use; not sure what to think of that matter.
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I have reused lifters in a MOPAR. As said above, the bottom must be convex, not flat, not concave. Never a problem. However, NEVER, and I mean NEVER have I seen a reusable lifter come out of a Chevrolet. Don't even look, and that is with their worthless stock springs.
 
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toolmanmike said:
That's just a flat face. Automotive lifters have a crown so they spin in the bores.
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That tool has a radius adjustment on it...several different radius are used depending on the lifter application. The stone is fixed but the arbor angle is adjustable. The lifter resurfacer I used in the 60's was part of our valve grinder and was on the backside of the bench...run by one motor via a belt drive.

Here's another video from a different shop.

 
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Krooser said:
That tool has a radius adjustment on it...several different radius are used depending on the lifter application.
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Thanks very much, KR. When the operator re-sharpened the facing wheel, it looks like the way the little arm moves with the tool would indeed put a radiused face on the stone.

If you were the person who commented on re-using the Chevy lifters on those warranty repairs: Did the re-used ones get re-faced like this?
 
toolmanmike said:
That's just a flat face. Automotive lifters have a crown so they spin in the bores.
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You gotta look at how the stone gets re-faced in the 2nd video to see that a curvature gets put on the stone face. The pivot for the refacing tool is angled downward a bit, which results in a curved finish on the stone.
 
nm9stheham said:
You gotta look at how the stone gets re-faced in the 2nd video to see that a curvature gets put on the stone face. The pivot for the refacing tool is angled downward a bit, which results in a curved finish on the stone.
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I watched the video several times while he dressed the wheel. I couldn't tell if the pivot pin for the dressing tool was parallel too the floor or not. [Assuming that the wheel spindle and the lifter spindle are both parallel to the floor]. But since the close up pics of the lifters at the end of the video shows a 'crown' and not a point on the face, I assume you are correct, sir. ----- Pretty rough surface finish, though.
 
I don't believe the theory that putting a 'crown' or spherical radius on the end of a lifter will make a lifter rotate. If anything, it will prevent it from rotating. The straight profile of a camshaft lobe will simply slide over the highest point of the crown [the center of the lifter]. This would exert the least amount of rotating force on the lifter.

However, lifters do turn. I've taken out lifters from late 1960's Chevy 307 motors and they looked like the inside of a mixing bowl. The Mopar ones look a dinner plate. [A rare occurrence].
To make those shapes they have to rotate. And this happens long after the 'crown' has disappeared.

There has been many discussions of poor results of changing camshafts due to lobe and lifter wear. The opinions generally claim it is caused by the quality of the metal and the heat treating process. This seems to have gotten worse in the last decade or two. Some camshaft manufacturers are buying Chinese Charley blanks and finish grinding them here --- or--- having them totally finished there.

Another issue is heat treatment. Nitriding costs money. It is a time thing. The longer it stays in the oven, the deeper the case hardness goes. But, 2 days in the oven costs a lot more money than 2 hours in the oven. So...…….
 
Krooser said:
Cams lobes are not ground flat...they have a slight taper to allow the lifter to rotate.
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Yep, along with the lifter crown. The combination makes it happen. I wonder when they figured that out?
 
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pt70 said:
I don't believe the theory that putting a 'crown' or spherical radius on the end of a lifter will make a lifter rotate. If anything, it will prevent it from rotating. The straight profile of a camshaft lobe will simply slide over the highest point of the crown [the center of the lifter]. This would exert the least amount of rotating force on the lifter.

However, lifters do turn. I've taken out lifters from late 1960's Chevy 307 motors and they looked like the inside of a mixing bowl. The Mopar ones look a dinner plate. [A rare occurrence].
To make those shapes they have to rotate. And this happens long after the 'crown' has disappeared.

There has been many discussions of poor results of changing camshafts due to lobe and lifter wear. The opinions generally claim it is caused by the quality of the metal and the heat treating process. This seems to have gotten worse in the last decade or two. Some camshaft manufacturers are buying Chinese Charley blanks and finish grinding them here --- or--- having them totally finished there.

Another issue is heat treatment. Nitriding costs money. It is a time thing. The longer it stays in the oven, the deeper the case hardness goes. But, 2 days in the oven costs a lot more money than 2 hours in the oven. So...…….
Click to expand...


Seriously? You should learn when to keep your keyboard static.
 
Krooser said:
Cams lobes are not ground flat...they have a slight taper to allow the lifter to rotate.

Plus the lifter bores are offset from the lobe to help.

Inside Trend's High-Tech Flat Tappet Lifters
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Interesting video about those high end lifters made from tool steel. Likely super expensive.

Never realized the cam lobe was tapered. Or that the lifter end was spherical ground. Then again, I've never seen a lifter surface with grinding marks as rough as the lifters shown in the second grinder video. Most lifters I've seen have a high [almost mirror] surface finish. The grinding machine looks like something out of the 1950's. I wonder if Model A Fords had them?

So I decided to do some checking on an old 340 camshaft. It had CWC cast on one end, blue and red paint near the ends, and numbers 1196 stamped on the end. ~.505 lift. Aftermarket cam with new lifters. Checked the lifter ends: 4 were convex, 5 were concave, the rest were flat. About .002 high crown. All had a high surface finish. All the lifters were rotating.

Then checked the cam, looked like it had low miles. The tops of the lobes were shiny, the base circle area had most of its black color from heat treating. The base of the lobe measured .002 different from one side of the lobe to the other. The height of the lobe also measured .002 different. The angle of the taper direction changed from lifter to lifter. Probably 50/50. [guess]. It was a casting. File tested for hardness. The as cast core seemed soft. The lobes were harder. But not as hard as expected. Maybe Rc 45-50.[guess]
 
Part 2:
So I wondered why the harder lifters wore more than the softer cams [say Rc 55 vs. Rc50]. Cannot come up with an answer unless the camshaft has better alloy properties.

So I took the crowned lifter and painted it. Took another lifter and laid it sideways over the crown and pressed and wiggled it slightly to duplicate a cam lobe. I got a contact patch of 1/8'' x 1/16''. To be generous, call it .01 square inches of contact. Then take a stiff HP valve spring with 310 pounds open pressure. Multiply that times 1.6 rocker ratio and it equals ~500 pounds static pressure on the lifter and lobe. So, 500 pounds divided by .01 sq.in. = 50,000 lbs/sq.in. That's already mild steel strength, then add friction and acceleration forces on top of that, plus a safety factor. Kind of explains why lifters are hardened and why they still wear.
 
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