Cam and lifter question

[dirtpoor]

I bought this cam and lifters for the 305 that's in my cruck. They have less then 2000 miles on them . I now have a 350 to drop in and I want to reuse the cam . I think it was CCC that told me not to reuse the lifters always replace them when used in a different engine. Do I need to break them in like i did when the cam and lifters where new

[hotrodelco]

Use the old lifters, just don't mix them up.

[WhisperPC]

Originally Posted by hotrodelco

Use the old lifters, just don't mix them up.

The issue is that cams & lifters are very precise parts. There's a small dome on the bottom of the lifter, and a slight angle across the face of the cam lobe. These two combine to cause the lifter to spin in the bore, giving even wear on the side of the lifter and the bore, and making sure that the bore stays properly oiled. When you put a used lifter on a used cam, unless the wear pattern on the bottom of the lifter exactly matches the wear pattern on the cam lobe, you're likely to cup the bottom of the lifter, destroying it. Even the small deviations that we have with modern maching methods are enough to generate different wear patterns on the cam and lifters.

If you want to reuse a cam & lifters in the same engine, you can, but only use the lifter on the lobe that it's been broken in on. If you're not 100% sure that you're putting the lifters back on the same lobes they came off of, get a new set of lifters, and do a break-in cycle on them.

If you're reusing the cam & lifters in the same engine, you probably don't need a new break-in cycle, but I'd still slather the cam in break-in lube, to make sure that it's properly lubed at the start. This is cheap insurance.


If you're moving the cam & lifters to a different engine, the lifter bores will be in slightly different locations, which could change the wear pattern on the cam & lifers. If it does, you'll have the same situation as you would with moving the lifters to different cam lobes, and you'll be needing to replace both the cam & lifters.

Considering that a new set of stock replacement lifters is <$80, I wouldn't take the chance, but the decision is yours.

[JJLT1]

new lifters are cheap insurance,, and yes break them in..
degree the cam also..

[steelybill]

I agree with JJ & Whisper. New lifters, with a break-in run, is cheap insurance.

[woody31]

i have reused old stuff before,,because thats all i can afford,,,IF you decide to reuse the old lifters,,take a empty egg carton,one that had 18 eggs in it,,,that way you can mark the carton,,i.e.i.e....you get the idea,,,along with the cylinder # of each lifter,,,that way they dont get mixed up,,and if its gonna be a few days before re assembly,,,oil down the lifters after you marked the box,,,wrap the open box with plastic wrap to keep the dust out...close the lid and write on the box top,,so you dont forget where they areit works,,,my old cam in lumpy is 10 yrs old,,,if it will make it one more season i will freshen it up,,,yea right,,,,

[steelybill]

Sometimes we have to remove lifters for some other reason, and a chunk of 2X6 lumber makes a decent block to hold them in their proper position. Using a wood boring bit the right size for the lifters, and another row of holes for the push rods, keeps all the parts in the correct location.

And the rocker arms can be slid over the push rods also, to keep all the mated parts in order.
I've had a block like this for many years., and it's easy enough to make one.

[boogsawaste]

Change them and break them in. Not all blocks are 100% the same. Why run the risk of wiping a lobe and having to buy the whole thing and install again? I have re used in different blocks before, but won't anymore.

[LOCKJAW]

The lifters will have developed wear patterns on the sides from the bores in the block. It seems prudent to stick a new set in. If the old ones start wearing and scuffing you might damage the motor. Spend the bucks for new ones..my .02

[dirtpoor]

Thanks for all the advice and tips. I will be buying a new set of lifters this week. The block of wood tip sounds like a very good idea

[Haastalavista]

No do not change the lifters. You have already broke them in together and they can now only be used together. The lifters must be used on the same lobe they were used on originally.

[boogsawaste]

Originally Posted by Haastalavista

No do not change the lifters. You have already broke them in together and they can now only be used together. The lifters must be used on the same lobe they were used on originally.

Too much risk going to a new block and used lifters as their mating surfaces would have to be 100% exact as they were in the previous engine. Just not worth the risk of ruining a good cam to save a couple bucks. Will end up spending a lot more if it fails.

Just put in new lifters, assembly lube, and break it in as a new cam for the best chance for success.

[Jack_K]

Originally Posted by boogsawaste

Too much risk going to a new block and used lifters as their mating surfaces would have to be 100% exact as they were in the previous engine. Just not worth the risk of ruining a good cam to save a couple bucks. Will end up spending a lot more if it fails.

Just put in new lifters, assembly lube, and break it in as a new cam for the best chance for success.

I'm not a mechanical engineer or a metalurgist, but I just don't see how used lifters in a different block could ruin the engine. The most force on a lifter is downward. Granted the lifter may "wobble" a bit in the bore, but if the engine is oiling properly, there should be no significant contact or wear. The lifters can spin in the bores so the wear should be even.

I have used mixed lifters on cams in the past, before I knew any better (60's and 70's), and never had a problem. I always checked the bottoms to be sure they weren't cupped, though. If one was cupped I'd simply replace that one.

Of course, it's always better to play it safe.

Jack

[boogsawaste]

The problem is that they wear exactly how they are oriented in said engine. Now when they are stuck into another things can be off, such as the lifter bores. Think about it, take a set of vortec heads and measure the clearance for the .480 lift they are rated at being safe to run stock. Some go over that, some fall short. Now this is gm making these since what, 96? They aren't all perfect from the factory. Now take a couple 30 year old engines made who knows when and how many years apart with varying mileage, varying metallurgy, and whatever other variables. Small differences can make a difference here. Sbc's don't have the best oiling for the cam either.

So with this said, there's no reason to not spend a couple bucks and risk it wiping a lobe. Its happened before and while i don't know how much the chance of it flattening increases, its there. Shouldn't ruin the whole engine, but to have to swap it all again and buy a new cam, lifters, gaskets, oil, etc...no thanks. Just my .02 for what it's worth.

[WhisperPC]

Originally Posted by Jack_K

I'm not a mechanical engineer or a metalurgist, but I just don't see how used lifters in a different block could ruin the engine. The most force on a lifter is downward. Granted the lifter may "wobble" a bit in the bore, but if the engine is oiling properly, there should be no significant contact or wear. The lifters can spin in the bores so the wear should be even.

I have used mixed lifters on cams in the past, before I knew any better (60's and 70's), and never had a problem. I always checked the bottoms to be sure they weren't cupped, though. If one was cupped I'd simply replace that one.

Of course, it's always better to play it safe.

Nobody said it would ruin the engine, only that it could ruin the cam & lifters.

The issue with moving to a new block is that the position and angle of the lifter bores is likely to be different. The machining of 30 years ago wasn't as accurate or repeatable as it is today. This means that at least one of the lifter bores (probably several of them) will be off by enough to move the wear pattern. This will result in accelerated wear of the lifter base, which will cause accelerated lobe wear.

The end result is decreased cam & lifter life. How much? I don't know. It would depend on several factors, including average RPM, peak RPM, engine run hours, oil type, oil condition, spring rate, rocker arms, cam profile, hardness of cam and lifter base, and probably several others that I can't think of off the top of my head.

Bottom line -- Reuse of lifters in a different engine will shorten the life of the cam and lifters. How much is dependent on the exact current condition of the cam and lifters. Whether or not this is acceptable is a decision that can only be made by the end user.

Whether you decide to use new or old lifters when moving to a different block, a break-in must be performed.

This is one of many reasons for moving to roller cam & lifters.