62 cam lobe wipe out

[Dan S.]

I have a 62 with a 327 300 hp that was rebuit a couple of years ago and right out of the gate (less than 20 miles on it) it wiped out the exhaust valve lobe on the rear most passsenger side cylinder. The rebuilder came out and replaced the cam and lifters. I drove the car another 20 miles and then let it sit over the winter. When I started it up this spring, the lifters were knocking and again I found a lifter wiped out this time the exhaust valve lobe on the driver side rear most cylinder and the front most cylinder on the passenger side. Unfortunately, the machine shop went out of business and before I put another cam in this engine, I wanted to find out the real cause of these failures. I am aware of bad quality lifters and cams in the industry but I find it hard to believe that two in a row can happen. One of the other concerns I have is that fact that ever since they did rebuild this engine, the engine oil pressure is very high (50 psi at idle and up to 75 as the engine is rev.'d). Can anyone out there shed light on this subject?
Thanks in advance.

[Gene M.]

Re: 62 cam lobe wipe out

Dan,
Not good news. The high oil pressure sounds like use of heavy weight oil. Try 10w30 with a good coating of cam break in on lobes. Also use an oil intended for flat tappet cam break in. Make sure to use good quality lifters (sealed power, crane). The cam is a major manufacturer? Such as Crane, Isky, or Sealed Power? Stock spec profile not a racer cam?

I've had good luck with Edelbrock cam and lifter kit #2102 (204/214 duration) a small step up from the stock 300 hp cam. A very smooth idle and no lope to it.

[Clem Z.]

Re: 62 cam lobe wipe out

make sure the lifters spin freely in their bores because if the lifter does not rotate you will wipe out a cam. always make sure the carb float bowls are full for the start so you not have to grind away on the starter. also use a oil pump primer to make sure you have oil pressure right away

[Dan S.]

Re: 62 cam lobe wipe out

make sure the lifters spin freely in their bores because if the lifter does not rotate you will wipe out a cam. always make sure the carb float bowls are full for the start so you not have to grind away on the starter. also use a oil pump primer to make sure you have oil pressure right away

They do rotate and I have used engine assembly lube and oil pump primer. Any other suggestions ?

[William C.]

Re: 62 cam lobe wipe out

If you have wiped out two lifters/cams, a complete cleaning of the pan and oil system might also be in order, in addition to Clem's fine suggestion.

[Dan S.]

Re: 62 cam lobe wipe out

Thanks Gene, Would it make a difference if I used the cannister type oil filter vs. a spin on regarding oil pressure concerns and flow ?

[Dan S.]

Re: 62 cam lobe wipe out

Thanks Bill I will.

[Dick W.]

Re: 62 cam lobe wipe out

Sounds like they put a high pressure/volume pump in your engine. Rule of thumb for adequate oil pressure is 10# per thousand rpm. Old rule, but for lack of anything better for our old engines, works.

I would also use a CJ-4 motor oil such as Shell Rotella. CJ-4 oils have more than adequate levels of ZDDP for flat tappet engines. It is available in 15w-40 or 10w-30. You might have to dig to find the 10w-30 though.

[Duke W.]

Re: 62 cam lobe wipe out

Since the guy installed what appears to be a high volume, high pressure oil pump, I'll bet he installed some aftermarket cam with aggressive dynamics and gorilla valve springs. Did he lower the compression ratio, too?

What is the cam model and cam manufacturer?

What are the valve spring force specifications?

These kind of stories about OE engines rebuilt with a bunch of aftermarket hot rods parts happen nearly every day, but guys keep handing their engine over to some "engine builder" and let him screw it up rather than managing the process and specifying OE equivalent parts from OE quality suppliers.

When new, these engines did not get any kind of "cam break-in". In fact, they got the absolutely worst treatment you can give to a new engine - many starts with short operating time, mostly idling, but lobe failures were extremely rare - almost unheard of with small blocks.

Duke

[Duke W.]

Re: 62 cam lobe wipe out

Old rule, but for lack of anything better for our old engines, works.

That was a rule of thumb for Chevy engines that were built for RACING back in the sixties. But the fact is that medium performance engines like the 327/300 rarely see more than 5000 revs, so the OE 40-45 psi is just fine. Chevrolet built tens of millions of these engines and most ran and ran with indifferent use and maintenance for well over 100K miles until they just plain wore out - usually bore wear or a burned valve.

I never had any problems with this pressure in my 327/340 despite seeing 6500 a lot, including race track hot laps. Chevrolet did decide to raise the hot oil pressure on mechanical lifter SBs in late '63, but I've always wondered if it was really necessary for road use.

Nowadays Sprint Cup engines don't use more than about 40 psi despite revving to 9500. Why? Because pumping more oil at higher pressure takes power, which could otherwise go to the rear wheels, and they figured out how to make the engines live with minimum oil pressure/flow. The same applies to coolant flow - the less you can get away with, the less the parasitic loss from the coolant pump.

If you talk to some "engine builder" (yeah, they all build "great" racing engines) and he wants to lower the CR, install a high volume, high pressure oil pump, and an aftermarket cam with gorilla springs - run like hell!

The OE 929 cam lobes and 068 springs with careful height setup will rev to over 6500 without lifter pump-up, but unless you massage the heads it won't make useable power beyond 5000.

[Dan S.]

Re: 62 cam lobe wipe out

I am not one of "these guys" but Thanks Duke for your opinions. In restrospect, I had been dealing with this machine shop for years (I used to manage an auto repair garage) and had had no problems with their work. Unfortunately for me, the owner got sick and his operation went down hill. And according to the owner of the shop (first cam replacement) they did use oe equilvalent parts. I am not prevy to info such as lower compression ratios or gorilla valve springs.
But thanks anyways for your opinions.

[Thomas H.]

Re: 62 cam lobe wipe out

I have a 62 with a 327 300 hp that was rebuit a couple of years ago and right out of the gate (less than 20 miles on it) it wiped out the exhaust valve lobe on the rear most passsenger side cylinder. The rebuilder came out and replaced the cam and lifters. I drove the car another 20 miles and then let it sit over the winter. When I started it up this spring, the lifters were knocking and again I found a lifter wiped out this time the exhaust valve lobe on the driver side rear most cylinder and the front most cylinder on the passenger side. Unfortunately, the machine shop went out of business and before I put another cam in this engine, I wanted to find out the real cause of these failures. I am aware of bad quality lifters and cams in the industry but I find it hard to believe that two in a row can happen. One of the other concerns I have is that fact that ever since they did rebuild this engine, the engine oil pressure is very high (50 psi at idle and up to 75 as the engine is rev.'d). Can anyone out there shed light on this subject?
Thanks in advance.

Dan,

I may be jinxing myself here, but I have never had any cam issues in the engines I have put together over the years. I buy well know manufacturers parts (matched sets) and follow their break in instructions. It is important, as many have pointed out, that you don't have overkill valve springs installed and that they are shimmed properly to provide the correct seat pressures at the specified height.

Again as others have suggested, Shell Rotella and the cam manufacturer specified break in lube will work well.

Last year I got my 60 running and broken in just fine using the above suggestions.

I am not a "professional" engine builder, so maybe I'm a little more apt to follow the instructions the cam manufacturer sends with their products. Again, I have never had any issues doing things this way.

Good luck

Tom

[Timothy B.]

Re: 62 cam lobe wipe out

Dan,

One other thing to think about is the high oil pressure could be caused by some restriction in the oil galleries that provide oil to the lifters and pushrods for up top valve guide/spring oiling. If there is a restriction IMO, the pressure would go high like what you are seeing.

The only way I know to test for a restriction with the engine in the car is prime the oil pump and watch for oil to leak out of the pushrod/rocker arm interface under the valve cover for each valve. This test is best done with a old distributor without the driven gear and the main shaftset up to be driven by a electric hand drill. You should be able to get the pressure to 30lbs which should allow oil to travel completely to the top of the motor.

Don't disregard what Bill and Clem said, the lifter rotation and cleaning the old particles out of the pan could also have contributed.

[Joe R.]

Re: 62 cam lobe wipe out

Dan,

Maybe I'm wrong, but I would think you would need to tear down the engine completely and take it to a machine shop to get rid of as much loose metal as possible after flattening the cam. Did you do a post-mortem inspection on the oil pump and filter? In addition to the CJ-4 rec you already received, I would add a quart of GM Engine Oil Supplement (EOS) for break in.

Joe

[Paul D.]

Re: 62 cam lobe wipe out

Had a friend of mine built a 402" for his '71 Camaro. He used a Co#p Hyd cam and lifter,spring set,otherwise stock. Not to wild for the big block. Anyway #8 exhaust lifter went south and put a bunch of metal through the engine. Long story short cost $1500 to clean up the damage to lower end.I know he broke in the engine to manuf specs and had about 50 miles on whole set up. We primed till we got oil(rotella) up to the rockers and adjusted the valve train to zero + 1/2 turn.I could rotate all pushrods by hand. There was no noise from the valve train(during break in) or no loose rocker nut when we tore it down. On BBC the oil gallery on side of block had metal in it,and brand new 77 bearings were scared. Very costly lesson learned..............P