Article on cam failures in Car Craft

[soundguy]

Royal purple is same as any high quality synthetic. Ams Oil has been good for 10k miles plus between oil changes for years.

 

[WHEEZER]

Wipeouts arent restricted to the #3 lobe. Its the most common, but not all the time. I made the point of proper hardening and tempering some time back. If there is the slightest difference of hardness between the cam and the lifter, things will go wrong. Of course there are/used to be additives in the oil to buffer these issues, but if the tempering was done properly, you would need the additives. Same goes for valve seats. You used to need lead to keep the valve seats and valves from cracking, but after coming up with seats which had the right hardness/temper, lead was no longer needed. Motors arent wiping from the factory because they have roller cams and ultra high tolerances/extremely clean and climate controlled assembly rooms and machine shops these days. Plus metallurgy has come a LONGGGG way since 1987. Most of the aftermarket cams arent made with much of a QC program in mind.
What I dont get, is why they dont just make the lobe offset when they make the cam?..cause they're making them from off the shelf cores and they dont want to have to bother with making new molds.

Agreed. With all the advancement in machining technology, CNC software controlled processes and so forth I don't understand what would be so hard about taking a blank core and machining a proper cam in regards to lobe placement. Surely it couldn't be THAT costly to write a program for that. Realizing of course compared to chebbies and ferds our demand is nowhere as high. And yes,clean assembly is just part of common sense practice that should be used. After replacing a wiped cam for instance, how many people have you seen not even clean the oil cooler{ provided they use one of course} or drop the pan for a proper cleaning?

 

[ThikStik]

My Comp 206/206 hyd cam spins the #3 lifter the other way, and at what appears to be the same speed as the others...at idle anyway. So I assumed Comp had a reverse taper there. Im thinking it is a goner, as visually I can detect just a little less lift and am thinking that is why my K is sporadically very hi and unpredictable. The exh valve timing has the most effect on cylinder pressures, and I suppose a lowere lift is adding alot of cylinder pressure setting off K.
Re the wear of OEM's-yes, this is what the article suggest: That rollers cams have alowed the lube to be without the zinc and be ok. So basically, our greenie friends have bilked us again. As emission controls are sancrosanct over all other concerns. The OEM's and EPA mayby, require that emiss controls last for 100,000 miles. What is the environmental cost of us poor slobs having to rebuild our motors again, again?!!
IMO this story has revealed why cams are wiping, as I said, a bad breakin/dirty rebuild, etc would crap a lobe fast. What we're seeing is 10-30 k mile deaths.
Not to belabor my previous example about my 1972 Pontiac Wagon, but how in the hell did this 72 Pontiac 400 not have a flat lobe after NO oil changes at 91k miles! Worns , yes, but not flat. I picked out gobs of metallic sludge from under the valve covers showing my Dad how bad his used car purchase was. I drove , teenage style, this car for another 50 k miles! This was in early 80's. Before quick lubes, awareness of maintenence and during a once prosperous middle class, people only drove a car for 90k miles. Lots of American v-8s never got oil changes ever, and I dare say most never recieved proper lube intervals and flat lobes werent epidemic as now.

 

[VadersV6]

Royal purple is same as any high quality synthetic. Ams Oil has been good for 10k miles plus between oil changes for years.

Well even dino oil can go 10,000 miles as long as its kept clean. The RP is always stored in new bins and the whole process ensures that it remains clean and unpolluted. Plus with synthetics, all the molecules are the same size...and very small. Thats why any leak you have will be made worse. But it improves lubricity a great deal, eliminates coking, plus the moly in RP will coat everything. That alone might be able to save cams. Molybdenum is seriously slipperly stuff. Say that 5 times!

 

[ThikStik]

I wonder if diesel oil, like Rotella, could be added. Certainly there should be some EP stuff in there.

 

[ITSNOTAGN]

the only thing i use in anything is rotella t, 15-40. i figure, if truckers wont use anything else, and those are big, high pressure turbo motors, why shouldnt I? those things never break, and i havent had any problems.

 

[ThikStik]

Why not Rotella, if the other oils are failing us in our old tech cam cars.
Hey Itsnotagn-can you say what your mpg is in that GTO?

 

[FlyinGN]

fyi- my Dads 78 Caprice wiped the cam at 80k miles and my 70 Pontiac lemans wiped its cam at 109k miles. Both had regular 5000 mile oil changes.. Oh and this was 25 years ago so its nothing new..

Frank

I hope this hasnt already been posted...anyway, its in March CC in the "Whats Your Problem" tech section. It may hold the answer as to why so many of us and other brands engines are wiping lobes. I personally have never seen it happen so much.
In the article, a guy wrote in about a wiped cam after 20k miles on his 302 Ford. The assembly was done by a good builder. Comp/Crane actually admits that something is going on out there. They think that the reduction of zinc in oils is the cause. It is being ruduced because OEM's dont want it in the crankcase where it is fouling o2sensors and cats. I also bet they dont care now because cars have roller cams now. Anyway, it seems like the cam manufacturers are aware of the problem, but they stopped short of recommending a certain oil. A lube ingineer from Quaker state recommends using race oil.
IMO we are seeing durability , not break in failures. So many are getting 5-20k miles before a failure. Not a quicker failure that would indicate bad break ins. And I know of alot of other brands that guys are losing cams on. I never lost a cam before my GN, and treat it better than all my Pontiacs. My first car was a 72 Pontiac Safari with a 400 and 92k miles that never had had an oil change. I told my Dad not to buy it. I maintained it for 50k miles and not 1 lobe failed. Yes they were worn, but never wiped. Somn is up guys!
I also know the the EPA is on the move to remove phosphors from oil...that can only bode bad for flat tappets.

Any vendor wanna make money on a flat tappet additive?

 

[VadersV6]

the only thing i use in anything is rotella t, 15-40. i figure, if truckers wont use anything else, and those are big, high pressure turbo motors, why shouldnt I? those things never break, and i havent had any problems.

Diesel fuel is an excellent upper cylinder lubricant. Its not just about the oil when you're dealing with diesels motors. The fuel is such a good lube that these motors can easily go a million miles between rebuilds. Plus, they actually warm their engines up before driving them...imagine that.

 

[ITSNOTAGN]

sorry to hijack, but i get 22-25 on the interstate, going 80-85. i average 15-17 a tank but i get on it more than most people, and a decent amount of racing. BUT, my old buick gets 27-29 on the interstate, and beleive it or not, i pulled my GTO from TX to MN, fully loaded,(total 8900 pounds) and still got 14.3mpg, so I think the Buick wins that one.

 

[GNRick]

Per March/April 2004 GSXtra:

Richard Lassiter recommends in his article to use GM EOS (engine oil supplement) at each oil change. He goes on to say that EP (extreme pressure) additives have been largely removed from all SL rated oils, as they coat the cat. coverters (a bad thing). Later in the article, he says you can use Valvoline Racing Oil. There are two versions- one does not have detergents (and lots of EP additives) and one has detergents (and less EP additives). He recommends changing the first one after every 1000 miles. You wouldn't need EOS if you use the first one. Valvoline's tech line is 800-832-6825.
In May/June issue, he interviewed a Mobil Engineer.The fellow agreed that even Mobil One Synthetic is weak in EP additives. He recommends that we use Mobil One V twin motorcycle oil. It comes in 10W-40 and 20W-50. Downside is that it costs $8/quart.

Mr. Lassiter says that if you want to compromise, mix 3 quarts of Mobile One V-twin 20W-50 with 2 quarts of regular Mobil One 10W-30 to come up with a comparable 10W-40 weight oil. This will let you save a few bucks and still get enough EP additives.