I know this thread is a little old but I have a few questions. First I recently got a motor running that I had mostly assembled over a year ago. I made sure to coat the roller rockers well with assembly lube and just before starting it topped off the oil by pouring through both valve covers. Now thats its running fine and maintains steady oil pressure, how can I tell if I "wiped a lobe". I don't think the hydraulic lifters I used were new, they came from a used roller block (I'm using the original Comet short block) Also what does "wearing out a cam" mean? Thanks for the info.
this is my break in procedure put in 10w-30 start engine and run at 2500 RPMS for 20 minutes. Stop engine. let cool down completely. Start engine and go for a drive. change oil around 500-750 miles, to get rid of the metal in the oil, and there will be metal flakes. put in another round of 10w-30 run for 3000 miles.. change to any type oil you want to use, but i used castrol syntec and i have never wiped out a cam, lobe, or anything..
if they are ...roller lifters...go drive it...no break in... if you "wipe a lobe" you will have...1 rocker not moving... do you have a...roller cam...? ...Frank...
After reflecting, I installed a new Comp flat tappet cam and i'm pretty sure it came with new hydraulic flat tappet lifters. So matching the equipment isn't a problem. My real question is that if the motor sat for over a year w/ assembly lube but without being started how abrasive was that first startup? I still wonder how quickly you can "wear out a cam", and if that just means you'll gradually lose power as it wears down.
With the two cams I had that wiped a single lobe each, both were done in the 1st thirty minutes. But neither happened because of the lack of cam lube or additive. It was either bad lifters or too much lube. The failed lifters failed to spin on startup. If the cam fails from lack of additive, that will happen over a longer period of time and you'll have mulitiple lobe/lifter failures.
I have a similar question. When i rebuilt the 460 in my pickup 6 years ago, it ran fine for ~3500 miles, then it wiped the cam (2 lobes). What could have caused that? i was running mobile 1 synthetic at the time. Anyhow, i put a new cam in... wiped different lobe in about a weeks worth of driving, a third went in, wiped it during break-in. Is there anything i should look at in the block, or was the failures due to the break-in/ zink oil problems listed above? is it ok to use the short block with 4 cam lobes worth of metal in it?
I'd look real hard at the lifters you used. They by any chance were'nt the same brand all three times ? Check the lifter bottoms to see that they're finished correctly, they should have a slight convex face (slightly higher in the center of the bottom face). Too much lube can cause the cam lobe to fail to get enough traction on the lifter to get it spinning, that will cause a failure.The cam lobes have a rough finish for a reason.(they're "Parkerized") A lifter that's hard to spin in it's bore will as well. Check to see that each rotates freely in it's bore. After my two failures, I only apply a thin film of cam lube to the lifter bottom, oil only on the sides.
What about his valve springs? Couldn't too much pressure wipe a lobe regardless of assembly lube? Were all of these cams with the same heads and if so are the valve springs different from original?
Yea, too stiff springs can, but that hasn't seemed to be the case with the failures in the past few years.
Are you using the old lifters when you swap cams? Are you breaking the cam in properly? Have you checked the lifter bore to cam lobe alignment? Are you using Mobil 1 right from the start?
New lifters for each cam. They were broke in according to Manufacture (edelbrock first, then 2 comp). the alignment was correct on the lifter bores. Broke in with Motorcraft non-synthetic (don't remember the weight) the springs were the Comp matched single with a dampener inside. I don't know the seat pressure or much about them, the machine shop did all that work and wasn't to forthcomming with info. The major question i have is if the short block is usable with the 4 lobes worth of metal in it? I had it balanced and all with hypertec pistons and 9.5 comp (stock heads) so i kinda want to use the bottom end again if it's not destroyed.
All the oil that washed that metal from the cam had to go through the pump and filter before going back into the engine so unless the filter was by-passing (which all but Fram do) then you are probably OK. Pull a couple of main bearing caps to find out for sure. Caps #1 and 4 will tell the tale.
