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Cam Damage


sonomaz

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Jon,

 

I think you are right about none racing applications so I will park the regrind attitude here. Isky sounds good I'll look into that after I here from Crane (should be this week).

 

Anyone mentioning lubrication,

 

The Zinc Phosphate sounds like a real prblem and you have me convinced to address this issue. However, I don't think it explains one cam lobe versus many or all cam lobes. Remember the other eleven look great!

 

Phred,

 

I realy appreciate your and everyone elses input here and I am willing to read any direction this goes (OK, maybe not any direction). I am terified of installing a new cam just to repeat what happened.

 

JC and Pyro..,

 

You're right and I know it. I don't have to pull the head but it sounds good in my head so I don't have to do the extra work. Like you said, JC, that's gonna suck!

 

Silent,

 

I can see EXACTLY that happening to me!! I took me 8 years to get it back on the road!!!

 

SRGunz,

 

Thanks for the link! I will be buying before I turn the key.

 

All,

 

This is huge help for me and quite unexpected (I don't know why, this is always what I get!!) Thank you so much for what you have contributed already. (sorry for getting mushy) Please, please keep this coming and I will keep you updated. I am expecting to hear from Crane this week so I will post here the jist of that conversation after it happens. Also I will be checking in to ask what next. And I still owe pictures of one of the other rockers. I'll try to do that when I post the Crane discussion.

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The Zinc Phosphate sounds like a real prblem and you have me convinced to address this issue. However, I don't think it explains one cam lobe versus many or all cam lobes. Remember the other eleven look great!

 

That simply may be a case of an obstructed cam spray lobe. Just because it's spraying now doesn't mean it has always sprayed! I have seen little blobules of RTV obstruct spraybars and not get dislodged causing a cam lobe failure. With all the oil blowing around, it runs for a while, but it wasn't until idle that you started hearing a 'squeak-squeak-squeak' from the valve cover. Heck, I've seen sludge block off spraybars...but it's such a solid buildup internally it doesn't get dislodged.

 

A blob of something, a chip of metal, you name it... It can get stuck in there, and then one day (after the damage is slready started) gets dislodged for some reason or another, leaving no trace of it's prior existence.

 

I worked a job in Timmins Canada where a cap chip off a 3/4" drill was floating around in a large equipment oil spray nozzle for close to 30 years before the wear was noticed on the gearing. Then it was hell to figure out 'why it wasn't there five years ago during the last inspection'---The only reason I found it was pulling inspection covers and checking the spray pattern. Depending on how I stuck a welding rod into the oiling nozzle, it could have a 'proper' spray pattern, or one that was seriously compromised. It all depended on which way the chip decided to get stuck when oil flow hit it.

 

So don't discount the possibility of simple dirt/swarf from inadequate cleaning before initial startup. Or a possible improper heat treat on any of the sliding components (rocker arm probably most likely) as the precipitant cause of the 'single lobe failure'. And adding along that line, with oil insufficient in properties to protect an already marginal component it could be a 'combination' of oil and inadequate componentry on that lobe position as well.

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Hey, all you conspericy theoricists screaming about ZDDP, listen up! I go t a call today from Mike at Crane Cams. First question out of his mouth: "What Oil are you using?" Wait it gets better: " Do you add ZDDP?" That almost clinched it right there. So the answer to his first question is Castrol GTX 10W-30. Second was obviously no.

 

I then went to the Castrol Web sight and searched on "Zinc". The question and answer guy link appeard with questions about ZDDP. The short answer is (and yes you have heard this before) ZDDP was phased out of motor oil domesticly in the 1990's becasue of ordinaces passed by the EPA. His position was the EPA left a hole between new oil requirments and old engines. He closed with Castrol is working on a solution.

 

So I got conspericy theoricists on this forum (a term of endearment I assure you), a mjor cam manufacturer asking if I used it, and a mojor motor oil manufacturer admitting there is a problem. I think that settles it. ZDDP not being in motor oil is causing problems in our engines.

 

"But wait" you say. "You kept asking why only one lobe/rocker went bad, Paul" (I heard you say it). "How does that fit in with this ZDDP thing?"

 

Well take a look at this!

 

Rocker_2E.jpg

 

When I got home tonight I took a close look at all the rockers and yep, they all look the same. This is the pad on rocker 2E. Notice the black spots in the wear area. When I first saw those I assumed the pad was somewhat pouros (we realy need spell check) and the wear had exposed the voids. But close inspection shows these are actualy pits. Notice there are no holes in the non wear area.

 

So pitting ussualy comes from excessive spot loading on a micro level that pushes the material past ultimate (not just yield) strength and when the force is reduced the "torn" piece pops out leaving and odd shapped pit. With inadaqute lubrication, i.e. no ZDDP, the loading not only becomes compression (straight down on the pad) but shear (sideways across the face) and the two forces combine to be greater than the material strength.

 

Every single rocker has the same spots as this picture. So I believe that all was not well and I lost one. I believe all was bad and No 2I went first.

 

It's late for me but I had to share. I am expecting another call from Mike tomorrow. I will update with more of what he said today and what he adds tomorrow. Short answer-out of warenty, no replacment.

 

Paul

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Heh, quick fix: Valvoline. MANY of their higher performance oils are SH grade, instead of SM or SL, and have the higher levels of ZDDP. 1.2%, infact. You can find it just about anywhere, and it's not terribly expensive. I run it in all of my cars, just because they are not all old doesn't mean it doesn't help.

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Your conclusion was about in line with my reply: marginal oil allowed the forces to lunch one lobe...while others may not have failed...yet!

 

I think you understand the forces at work here, now.

 

Sinister Forces.

 

I am Dyslectic anyway ZDPP ZDDP...MEH!

 

One reason I go for the ZDDP is that I lived through the Phosphorous phase-out in heavy diesel oils for Landfill Gas in the early 1990's. "New Oils" came out, different formulations where the oil manufacturers touted this new package with superbatches of this or that to work 'better in your specific application'. Long story short, the high phosporous Pegasus we got from them didn't last WEEKS in the engines we were running, and we went back to Good Old "Blackstar 450" which when we were runing low acid fuel went for a year. Then it was down to 6 months as the acid in our feedgas went up. Eventually we were getting TAN (total Acid Number) of 4 within a quarter (three months) of running. It was at that point I started experimenting with various 'additive extender packages'. The Oil OEM was upset, they mentioned it in every Oil Analysis. But fact of the matter was through close oil sampling (weekly), and additives we were able to go back to 8000 hours on our oil changes (we're talking over 1000 gallons for an oil change, plus around 12 gallons per day of normal 'consumption' while running!) All we did was add that portion of the OEM additive package that was being depleted by our high acid content.

Additives generally are NOT something I will add to the oil, but when it becomes obvious there is a problem due to OEM Additive Packages being either deficient, or depleted, it's a way to extend oil life, or make it so damage (in my case it was bearing etching) does not occur to the engine.

 

I believe ZDDP is a required additive if you can determine the additive package is deficient from your oil's supplier.

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I have been using Royal Purple motor oil for awhile now in my turbo Z now with out any problems so I decided to call them and ask about this subject and here is what they told me. API oil classification for zinc changed when they moved from SL to SM and the SM lost most of its zinc and other anti wear additives, something to do with zinc poisoning the system. So if you are using oil that has a SL or earlier classification you are not missing zinc in your oil.

 

http://www.royalpurple.com/motor-oil.html

 

That being said he also informed me that all Royal Purple oils are SL rated and they even have an engine break in oil that has a higher level of anti wear additives, zinc included.

 

http://www.royalpurple.com/breakin-oil.html

 

Just wanted to add this to the debate.

 

HB280ZT

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API oil classification for zinc changed when they moved from SL to SM and the SM lost most of its zinc and other anti wear additives, something to do with zinc poisoning the system. So if you are using oil that has a SL or earlier classification you are not missing zinc in your oil. HB280ZT

 

Curiously I took a look at my freshly-bought Shell Delo oil for The Boy's 510 when we were in the parts store this weekend. We are getting ready for fire-up and break-in and noticed that the oil I picked up was only "SJ" rated! Which I thought odd, as it had the latest "C" rating for diesels...

 

So that would run in line with what you were told, as I checked all the other oils on the shelf that were available (even AutoZone Generic) and they all had much later "S" ratings, though some without a "C" designation, or one that was lower than the Delo.

 

There seems to be specialization in oils now and branches of 'diesel specific' and 'passenger car specific' oils are being marketed.

 

I wondered out loud if this SL-SM Change conincided with the cessation of the marketing hype around 'We will warrant your engine against oil-related failures for the life of your car if you use our oil' type of warranties from the oil companies out there. Anybody else notice the 'fading away' of that warranty claim? Curious if any of them still offer that kind of warranty?

 

That tells me they recognized something critical had changed, and they limited their exposure accordingly.

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Yep, my mother's dodge intrepid always got Valvoline SH grade oils when I was keeping up with it, now my little brother, cheapass that he is, puts in the least expensive oil he can get (a store brand SM grade mostly) every time he changes the oil. It's gone from good compression and no tailpipe smoke to uneven compression and blowing a blue cloud on acceleration in a matter of two years.

 

Now, that's not definitive, I know, but it's good enough for me.

 

By the way, he's also totaled that car by hitting a wooden mailbox...we bought it back and repaired it, got it reexamined by the state, and back on the road safely. I still don't know how he totaled a car by hitting a mailbox...

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*snipped*

I wondered out loud if this SL-SM Change conincided with the cessation of the marketing hype around 'We will warrant your engine against oil-related failures for the life of your car if you use our oil' type of warranties from the oil companies out there. Anybody else notice the 'fading away' of that warranty claim? Curious if any of them still offer that kind of warranty?

 

That tells me they recognized something critical had changed, and they limited their exposure accordingly.

 

I noticed the warranty still exists on Mobil products, as I have been doing tons of research on oils for weeks now. (Obsessive, I know!) It really is one of the most critical choices to be made for these older cars.

 

The other thing I learned is that as good as the Valvoline VR-1 may be, it might have a "problem" in that it's designed for race use, and as such they planned on frequent oil changes- for each driving session almost- something us street drivers can never expect to come close to. So sustaining the best properties over time seems to be in doubt. As good as it sounds- and I almost picked it out of the huge list of candidates I came up with for my golden girl- I'm going another way for now. And adding a touch more ZDDP to bring my total up to around .18 which I seem to recall is the optimal ratio- with too much not really great either. Obviously I'll double-check on that later.

 

Perhaps someone from Valvoline can make some comments on this subject?

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