Break in oil needed for used camshaft?

I've rebuilt my engine with new bearings, ground crankshaft, honed block, new rings, but I reused my lifters and camshaft (after inspection).

What I understand is that break in oil is mainly used for the camshaft. So is it needed now?

 

It's a well spent $75 bucks.

 

Ok thanks all. Will use the break in oil.

 

1. Were the used lifters disassembled and cleaned ONE AT A TIME? Each lifter is a tiny oil filter, the oil passage into the lifter is fairly large, but the clearance the oil squeezes out of is microscopic. Sludge and grit get into the lifter, can't get back out. Is the lifter bottom still showing some crown, and swirl-marks from the lifter spinning on the lobe? If not, it should come apart.

2. Was the cam any good? No excess wear on any lobe? Fully-polished over the nose, but only a partial polishing down both flanks, and the base circle? If not, it should come apart.

3. Did you keep the lifters in order, on both banks? If not, it should come apart.

4. WHAT VALVE SPRINGS? If you've got stock or near-stock stiffness, I don't see any need at all for "break-in" oil. As valve spring pressure increases, my answer might be different.

5. Did you use thick, Moly-based paste assembly lube between lifter and cam lobe? If so, you need to change the oil filter at ~20 minutes run time. "I" would not change the oil, just the filter--but most folks don't see it that way. I hate the idea of flushing $75 worth of oil after less than an hour of run-time. If you didn't use thick Moly-based paste lube, the oil filter should be good long past 20 minutes. 1000 miles, perhaps.

 

If you kept track of where each lifter was you should be OK, but, it doesn't hurt to put some assembly lube on he lobes. If you took the lifters out and didn't keep track of which hole they cam out of, I would replace the cam and lifters. Lifters are broken-in with the individual lobe and should never be changed from lobe to lobe.

 

I don't know. I took it to the machineshop documented each to where they go. I don't know if they were disassembled. The bottoms all were showing some crown. Swirl marks I don't know.

Yes, cam looks like new. It only has 10k miles on it. (as the lifters)

Well, I did, but the machineshop tossed them al together...

Stock. Hm, well I already ordered it.

Not sure if it is Moly-based, but I used Clevite bearing guard. Luckily I know someone at the oil shop, so I have a very decent price for oil.

 

10K miles on cam and lifters, lifters still have crown? Soft, stock valve springs?

You could get by with that even though they screwed-up the lifter placement.

...but if you don't, consider where all the metal that gets worn off the lifter bottoms and cam lobes is going to end up.

Suggestion: Get a pair of stock, sheet-metal valve covers from the Treasure Yard. Cut a slot in them, paint a vertical stripe on the upper part of the pushrods. When you start the engine, look through the valve covers at the stripe on the pushrods. IF (big IF) the pushrods are all spinning (they won't all spin at the same speed) you should be OK. If one or more doesn't spin, or spins extremely slowly, there could be problems. The valve covers hold in "most" of the oil, minimizing clean-up.

This is my set of "Pontiac" valve covers:










Clevite Bearing Guard is liquid, oily-looking stuff. Not paste. (Right?) If so, you'll be fine on the oil filter. Cut it apart when you do change it, look for metal in the pleats of the filter media.

 

Sounds like there is some doubt as to the lifter placement. Do yourself a favor and replace the cam and lifters.

Bob H.

 

I say re use the cam but use new lifters.

 

That was my exact thought when I first read this...

 

Yep, and put cam lube on the cam and new lifters just like you're going to break it in as you would a new cam.

 

At this point I'm X3, new lifters (if they're clean and of good quality - I've read some horror stories here about poor quality w/new hydraulic lifters recently!).

And a post script for anyone who stumbles across this thread in the future, reusing a nice matched set of healthy cam/lifters in a different block, you're gambling again. Heaven only knows what the tolerances are in the original machining of the front of the block vs the lifter bores. In a different block, the once-healthy cam/lifters get to meet up again in a whole new way. That's another roll of the dice.

Again, healthy camshaft + new HAPPY lifters is a wise move in my opinion. Break it in as if all new.

Devon