Camshaft failure
 

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

Re: Camshaft failure
 

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.

Re: Camshaft failure
 

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...

Re: Camshaft failure
 

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

Re: Camshaft failure
 

Ben you run this car in B/S??

How??

Re: Camshaft failure
 

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.

Re: Camshaft failure
 

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.

Re: Camshaft failure
 

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

Re: Camshaft failure
 

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

Re: Camshaft failure
 

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

Re: Camshaft failure
 

This whole cam failure has me thinking. My motor has always had a lot of oil pressure - like 80 psi cold, and never less than 60 psi. I'm running a Mehling high volume pump, because it was what I had. Even with this pump, is this unusually high? Could this be a sign of blockage somewhere? I'd love to hear your thoughts. A new oil pump will definitely be in the works. Thanks.

-Ben

Re: Camshaft failure
 

Better question, what oil did you break it in with, I hope not the synthetic.

Re: Camshaft failure
 

Bob,

I broke it in with non-synthetic 10W30 if I recall.

Re: Camshaft failure
 

Ben, Look back and see if it had zinc in it, your problem may have started there. We break in all motors started at the shop with 30 or 40 wt oil, no multi wt oils or Syn ever, not till engine is run in.

Re: Camshaft failure
 

My street hot rod has a high volume pump and has 60 PSI of oil pressure all of the time with no problems. I think if the engine was broken in with a conventional motor oil, that was the start of the problem as Bob Pagano suggested. Conventional motor oils have little or no zinc in them.

Re: Camshaft failure
 

Ben,
To add to the problem of no Zinc as Bob said was the multi Viscosity oil. 10W-30 is not 30 weight oil & doesn't have the same shear or EP rating as a single weight oil. When I put an engine on the dyno it has a heavy single weight oil in it. Or it has VP break in oil in the engines with real lite ring packages. I never use a synthetic for inital start up or break in. These older engines we are racing with had oil systems that were designed before the thin oils became the vogue. Unless you build the clearances correct for thin oil (read that Multiple viscosity oil, too)I feel you are just asking for trouble using it. The way a cam gets oil is by what is tossed or spun off the crank, Rod side clearance helps. Then we put better pans & scrapers that remove this rope of oil from the crank, to cause more lifter/cam oiling problems. The other way a cam is oiled is small amounts of oil that sheds from around the lifter and drips on the cam. We reduce this by having tight lifter bores & some people still think they need oil restricters in the lifter passages. I've seen a flat cam In almost every case that I've seen backyard or Magazine engine builders block the oil drain holes in the lifter valley. I've also seen it in late model engines that are designed for roller cams and a flat lifter cam is used. Most of those blocks don't have drainback holes along the cam in the valley. What does blocking those hole really do. I think it air locks the upper part of the cam tunnel. How can oil get thrown from the crank into that area on top of the cam where the lifters ride when it is in an air lock? Common sense and careful preparation along with the right lubricants keep cams from going flat. I stay away from the tricks of the week that makes 2 more HP & cuts engine life by 50%. One more thing I preach to customers is IDLE TIME & SPEED. Low idle times & high Idle speeds keep cams & lifters oiled. (doesn't do anything for the cool sound, though) I would venture to say that in the 5 years Bob was hanging around the shop he didn't see one flat cam. If he did I can't remember. Right Bob? Did I miss anything?

Re: Camshaft failure
 

Ive been running Valvoline 20W50 "Not for Street Use" with a bottle of AC Delco Engine Oil Supplement right from the GM dealer with no trouble as of yet. I have also run 10W30 Not For Street Use but it makes my oil pressure light flicker when its hot. I was told that this oil still has zinc in it and is specialy made for flat tappet camshafts. And I broke it in on Rotella T 10W40 as per Comp Cams. And I always thought Rotella T was for the lawnmower and rototiller. :) Hope this helps.

Re: Camshaft failure
 

Thank you again to all that replied. I appreciate you taking the time to share your experience. Adger, Your in-depth thoughts on oil control is great. Bob's always spoken highly of your qualifications as an engine builder. Thanks again.

-Ben

Re: Camshaft failure
 

Rotella Was a good choice, all their oils now have little or no zinc, unless you have old stock you better check the labels. Adger is right, no cams lost in the five years I have been there.

Re: Camshaft failure
 

Yes you are right. They are removing the zinc from Rotella as well. They are going to be removing the Comp Cams additive off the shelves as well due to curren government regulations. I recently freshened a motor for a guy in a corvette. He wanted to tame it up a bit so we pulled out the solid roller that was in the engine and stabbed a "tried, tested and true" 292 Comp Cam. I followed all the instructions for the break in....Rotella T, Comp Cams cam lube, bottle of comp cams break in additive, break in springs...ect. The break in couldn't have been better...started on lest than half a revolution, no heat, ran smooth at 3000 rpm for 30 minutes. I was so confident that we passed the break in I washed and waxed the guys car for him so he could drive it home and be proud. Half way home a lobe gave up. I called comp to see what I did wrong and all I got was, "hahah ya it happens and expect more of it". This came right from cam company!! They couldnt come good for the warrenty but sent me a hydralic roller setup for a crazy price that the owner couldn't say no to and hes driving it as we speak.

PS...Before this I was using ARP lube on all the flat tappet camshafts for break-in and this was the first time for the comp cams lube and it didn't go too well. I figured I would follow all there recomendations that way if there was any failure I would have an argument. Went back to the ARP for my new stocker cam and it seems to be mint. Food for thought....

Re: Camshaft failure
 

Oil with zinc. Valvoline Race, Joe Gibbs, Amziol and another I do not recall at the moment.

Re: Camshaft failure
 

It’s also a good idea to spend the extra $100 and have the cam nitrided. This can make a huge difference in cam wear. with Comp just ask for Item # 1-111-1 thats the add on to have the cam nitrided.

Re: Camshaft failure
 

I need to add a few more things about camshaft failure... Sorry I left this out of my last oil/ cam article. :~) .
There will be instances when you do everything as right as you possibly can and still flatten a hydraulic or solid flat tappet cam. I think the primary reason is the failure of the lifter to keep spinning. There can be several reasons for that, but the most common are lifter bore(s) too tight and grab a lifter…or a piece of grit migrates “out of hiding” and gets between the lifter and the bore….it still goes up and down but doesn’t spin….cam flat. Some of these particles get magnetized and all the washing with hot soapy water will not dislodge them….BUT….continually flush them with hot oil and……Guess where they go & what is the results.
Every engine I do gets a Sunnen precision Hone run through the lifter bores with a #13 stone in it. Ball hones & Brake Cyl hones will not do what the Sunnen hone does, make the lifter bore straight & round... The same hone I use when doing lifter bore bushings, different stone.
Crate Camaro,
Where in the world did you get the information about the Comp Additive being taken off the market? I was ordering a couple of cams & lifters today from Comp and ask about the validity of your comment. My buddy Tim Cole responded:

COMP Cams is definitely NOT going to discontinue the 159 oil additive.

I just ran out today & I order it by the case. Good stuff!
Crate Camaro,
You were on to something with the moly lube on the cam lobes. There is a less abrasive type of moly than the ARP bolt moly.
Oh, just one other point. Wash the cam & lifters and check each lifter for the proper curvature. I've found some lifters that customers get a deal on that are almost flat. When they are put on a very active came lobe they grab & don't spin. It is the curvature of the lifter plus the degree of angle/taper ground on the lobe that makes a lifter spin. The taper is also what keeps the timing gear pulld back against the front of the block. Have you ever seen a block that has had the timing gear eat into it? You can bet it was a cam lobe. problem that most likely caused it.

Ben,
Thanks for the kind words. Good luck with your re build.

Re: Camshaft failure
 

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Re: Camshaft failure
 

Adger is correct, Comp is not taking their additive off the market. GM EOS is a hit or miss deal, they have some, or they don't, you never know if or when, get it when you can, and buy a case. I'm betting the disaster that they are in now will not make that better.

Be aware that you can only get so much ZDDP to blend into motor oil, and more is not better. Excess ZDDP can cause problems, it gets into places it should not, and leaves deposits. If you have a real race motor oil that has ZDDP in it, adding the other stuff usually will not make it better.

Some of the synthetic oils use ZDDP, some use other additives. Some work, some do not.

The big block Chevy is notorious for eating cams. You'll often get a block that will just eat flat tappet cams, period. That is the best reason I can give you for boring the lifter bores out with a BHJ fixture and bushing the lifter bores. You'll note blocks that eat cams often score the front behind the timing gear. That is also often caused by an out of position lifter bore. Or three. Or four.

NEVER buy a cheap lifter. You cannot possibly save enough money to pay for the risk. One flat cam lobe will cost you a complete rebuild. Now, was saving $50 really worth all of that? Cheap cams are the same way. What you save won't buy a gasket set and a case of oil and a filter.

Bill is also correct, the nitrided cam is the way to go. When combined with a true high quality lifter, and the correct break in procedure, the results are excellent. What you're after here is to have enough crown on the lifter face, and enough taper on the lobe to make the lifter spin. But you also need the lifter and cam to be hard enough to slide on each other. Finally, the finish on both pieces has to leave them slick enough not to stick to each other.

Re: Camshaft failure
 

A couple of questions:

1) Is the zinc and single-weight oil necessary for break-in with a roller cam BBC? Using Total Seal gapless second rings.

2) Is an additive necessary for an already-broken-in hydraulic flat-tappet SBC?

For both these engines, I plan on using (at least until I run out of it) older Castrol GTX 20W-50. I've had a few cases of the oil around since I used to run both cars back in the early 90's. I've already been using it in engine #2 since I put in new rings and bearings (just reused the camshaft and put the lifters and pushrods in the same locations).

Regards,

Re: Camshaft failure
 

On a similar note, I pulled my SS motor out to exchange for a summertime bracket motor. It has never seen anything but Gibbs XP3 except for 3 heads up runs where it had XP0. The pan had about 2 cups full of sludge that felt like cam moly lube mixed with oil. When rubbed between the fingers it disappeared. The bearings were perfect but the sludge concerned me. I called Hetler, who said he has seen this with those using XP0 after other Gibbs oils. He felt it had something to do with the additives in Gibbs oil.
Any other experiences like this, or comments?

Re: Camshaft failure
 

It's something in the Joe Gibbs oil. When we pulled the engine out of the Camaro, there was 2" of that stuff in the bottom of the pan. It never had anything but XP2 in it after we broke it in on Rotella. I think it is how Joe Gibbs oil reacts to gasoline. It appears to be fairly common.

Re: Camshaft failure
 

Roller camshafts don't break in. But a good mineral base oil is really necessary for initial ring seating in most cases. No comment of the gapless second ring (and yeah, I run Total Seal, just no gapless rings at all, ever).

I suppose a certain amount of ZDDP is necessary, in most cases with flat tappet cams, although I also think some synthetic oils have a good enough extreme pressure package that they work without ZDDP.

Re: Camshaft failure
 

So bottom line, what are you guys using for oil/additives in your race car?

Re: Camshaft failure
 

Ok.
On the subject of the roller cam engine break in. I always use a heavy single grade oil that has zinc in it. Think of it this way::: Roller cam rollers need to roll, not skid on the cam.you still need oil that has a good EP rating or the load on the rollers to cam goes metal to metal. What does the Zinc do for this case? Think of it in the same light as what lead used to do for gasoline.
It helps build up compatable wear surfaces. I can tell the difference in an engine raced on pump gas and one that is run on race gas only. (most race gas still has lead) The guides, valves, seats pistons cylinder walls and rings are all areas that develop compatable wear surfaces when using leaded gas. Zinc is for oil what lead is for gas.
Also, Do your self a favor & stay away from any synthetics for break in. I have seen it with blow by meter on the dyno. The rings have a hard time sealing, IF they seat. .
Has anyone had the sludge analized? Could it be the moly in the oil falling out against the cool surface of the bottom of the pan?

Re: Camshaft failure
 

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Re: Camshaft failure
 

I have had no issues out of Valvoline VR1 and Valvoline NSL oils