Camshaft failure

[Ben Kallies]

I suspect that my camshaft may be on it’s way out on my 454/365 B/S Corvette. I discovered a metallic-looking substance in the oil during the last couple of oil changes so I pulled the valve covers to have a look. A number of the rocker arms have as much as .030 clearance. Bear in mind that this is a hydraulic flat tappet cam, and the motor was running less than a week ago.
I have a couple of questions related to this: First, should I be worried about the rest of the motor in regards to wear from oil contamination? Specifically, the rod and main bearings? Secondly, aside from pulling the intake manifold and removing the lifters, are there any other good methods to verify cam failure? Thank you in advance for your help.

-Ben Kallies
3869

[Alan Roehrich]

You'll be able to see a failed cam by pulling the intake, you'll see the dead lobes through the big drain back holes, but the metallic oil and the excessive lash have already verified the problem.

Yes, it will be everywhere oil goes in the engine. In the bearings, behind the rear cam bearing, in the oil pump, on the pistons, in the pushrods, on the rockers, I've even seen the iron dust in valve guides. Be prepared for a full rebuild, with rings and bearings. It is the right way to do it.

[richie 2]

pull the sparkplugs, set up a dial indicater on any intake/ exh retainer, turn the engine over by hand slowly and check total valve lift. compare that reading with the cam specs. a couple of thousance diference is normal wear, major differance usually means worn out lobe. if you plull the liters first (keeping them in order) a worn liter will tell what lobes to check. all the debris in the oil is not good for rod/main brgs. hope this helps...

[Ben Kallies]

Thank you both for your input. I'll be honest with you - I was hoping that someone would say to just run some fresh oil through the engine to clean it out, and I'd be ok. The problem is that this engine is due for some serious performance upgrades, and I know that once it's out of the car, it's not going back in until I've spent way too much money, and probably aged about five years. I guess i need to go through the "parts for sale" shelf and see what I can unload. Thanks again.

-Ben

[junior barns]

Ben you run this car in B/S??

How??

[Alan Roehrich]

A 71 Corvette 454/365 4 speed lists at 9.41 pounds per HP. That's a natural "C" car.

I understand your reluctance to pull it Ben, but you'll be money ahead. Trying to patch it is only asking for catastrophic failure that will only cost more to repair, or more likely, replace.

[Jeff Lee]

My car was liking the view of the top of the gaurdrails; I on the other hand was not. So it was parked until I could get it fixed. Talk about a daisy change of events, there isn't a part on the car not getting attention with major re-work. Yep, I know how your feeling on this!
One more thing, I had a Schubeck lifter explode and I tried the "flush it with oil" tactic. I made the next two races which I thought were important. Wrong. The remnants attacked everything and believe me, a "diamond like finish" is not good on the rest of the engine!
Tear it apart, upgrade as you need and come back stronger.

[Ben Kallies]

Thank you all for your input. I have been using Mobil 1 synthetic 5W30. Only recently have I been made aware of it's lack of zinc. I switched to Valvoline VV853, but it's obviously too late. The damage is done. I'll probably be throwing in a bottle of oil additive as well from here on in.

-Ben

[Ben Kallies]

I know that I may be listening to the sound of crickets shortly, but my father always said, "there's no harm in asking." Would anyone like to share some recommendations on cams, lifters, bearings, rings, oil pumps, etc? I take calls too....(414)545-2442

-Ben

[njk53]

I thought that if you ran a synthetic oil you did not need a zinc additive. Any comments?