Ate up camshaft.pics

[JeffKeryk]

When Zinc was reduced in oils to protect catalytic converters, many of us classic car owners started using Shell Rotella 15x40 Diesel oil as it had 1000 to 1200 PPM zinc.
This was to protect our flat tappet engines, particuliarly those with increast valve spring seat pressures.
Many with stock spring pressures seemed to do fine with 10w30 dino oils...
A large number of cams damage to lobes were reported; many of which were from 1 aftermarket manufacturer.
One thought it was due to a bad batch of cams with insufficient metal hardness.
Current Rotella is thought to have zinc content too low.

Unless this engine has increased valve spring pressure, perhaps the cam quality is not up to snuff.
Finally, if I ever pull apart my Vette or Oldsey (original) engines again, I will stab a mild hydrolic roller and be done with it.

 

[caprice_2nv]

Originally Posted by GoldDot40
Originally Posted by GMBoy
I don't understand why the engine rebuilder thinks he knows more about the engine than the Toyota engineers by recommending a 15w/40 diesel oil. I'm not saying that is what caused this damage but surely that thick oil is not needed. I would ask the owner to use the correct spec oil next time.

That will depended on what the bearings spec'd at. If the tolerances were a little on the "loose" side during assembly, it would absolutely warrant using 15W40, 15W50, or 20W50 weight. Once an engine is overhauled and the factory tolerances change...Toyota engineering is out the window.


Exactly. Not only that, if that was the case and the vehicle was being worked hard towing or off roading, etc in hot weather all the time that would absolutely be the best choice in oil (20w50 or 15w40). The 15w40 could be a good compromise in the eyes of the builder. The fact that it would have a bit higher level of zddp wouldn't hurt. The choice in grade shouldn't even be a question here, although zddp content maybe worth discussing, the issue is likely parts quality or assembly error.

 

[bullwinkle]

Chris-if you hear what cam the rebuilder used, please post it so we know to NEVER use that manufacturer for ANYTHING! That's a soft, non-heat-treated cam issue for sure, looks just like the junk GM cams of the '70s & '80s. If anything, Delo is a BETTER than needed oil for a non-high spring pressure Toyota, and should have been more than good enough (although I would have used 10W30 due to colder temps in winter here).

 

[OVERKILL]

This engine's valvetrain setup, which sounds like it consists of a sliding follower that's part of the rocker arm assembly, would seem to be basically identical to Honda's SOHC setup from the same timeframe. I don't recall Honda having issues with camshafts failing (that I've ever heard of) and these engines, due to having very little valvetrain mass, would require very light springs. Thus, one would conclude that the issue of wear at the follower/cam interface shouldn't be one, and definitely would not require increased levels of AW additives over what was available in standard PCMO's at the time, which is all these engines spec'd.

The SBC issue touched-on by caprice_2nv and JeffKeryk was indeed due to improper camshaft production. The cams weren't properly hardened and would self destruct regardless of what oil was used. SBF's of the same era as well as Mopar mills didn't have this issue, providing further indication that it had nothing to do with lubricant formulation.

To me, what happened with the engine depicted in the OP is similar to the GM situation and the aftermarket FT cams situation that JeffKeryk touched-on. No oil was going to prevent that. Reminds of that Chinese radiator thread.

 

[caprice_2nv]

Originally Posted by JeffKeryk
When Zinc was reduced in oils to protect catalytic converters, many of us classic car owners started using Shell Rotella 15x40 Diesel oil as it had 1000 to 1200 PPM zinc.
This was to protect our flat tappet engines, particuliarly those with increast valve spring seat pressures.
Many with stock spring pressures seemed to do fine with 10w30 dino oils...
A large number of cams damage to lobes were reported; many of which were from 1 aftermarket manufacturer.
One thought it was due to a bad batch of cams with insufficient metal hardness.
Current Rotella is thought to have zinc content too low.

Unless this engine has increased valve spring pressure, perhaps the cam quality is not up to snuff.
Finally, if I ever pull apart my Vette or Oldsey (original) engines again, I will stab a mild hydrolic roller and be done with it.


This is absolutely the most common consensus I've read, so I believe it to be the most accurate.

My Chevy and Olds engines are basically like an extremely tamed down version of the ones you have, so they will probably last a long time on any oil. If I was to upgrade my stock camshaft I would have to worry more and would prefer a roller but they're like 3x as expensive and it's not just a bolt in operation as far as I know. There are modifications to make it work. I don't have enough tools or experience to do it at home so it's a weekend at my friend's place to install a camshaft. Sticking with flat tappet would be the only feasible way for me to do it. Plus it's not worth spending a couple grand to cam swap a 2-300k mile engine.

 

[tig1]

Originally Posted by caprice_2nv
Originally Posted by tig1
It would appear the oil is way too thick, but I would think the real problem is a soft cam. No doubt the rest of the engine is toast with the metal in the engine.


Why would the oil be way too thick? It's not cold there. I don't use 15w40 in my old 80s stuff but I'm sure it wouldn't cause any problem. I just prefer 0w40 or other grades.

I would bet 15w40 is one of the allowed grades in the owners manual for that truck. The grade shouldn't even be mentioned unless it was being run in a cold climate.

The information in the linked forum looks very helpful.

Why?
Originally Posted by dogememe
People put 10w-40 and 20w-50 in those engines all the time. Oil wasn't the issue here.

I tried 15-50 M1 in a 4 cyl Ford and the engine was far more sluggish than the 5-30 it called for.

 

[kschachn]

Originally Posted by tig1
I tried 15-50 M1 in a 4 cyl Ford and the engine was far more sluggish than the 5-30 it called for.

But it didn't damage the camshaft.

 

[tom slick]

Anything from 10w-30 to 20w-50 are common in these engines. 20w-50 and 15w-40 being very common for hot summers.

 

[Propflux01]

The real question is how much of that camshaft circulated in the oil system before this was discovered?

 

[kschachn]

Originally Posted by Propflux01
The real question is how much of that camshaft circulated in the oil system before this was discovered?

Wouldn't it be all of it?

Much of that failure may not show up in a standard UOA however. When I performed UOA on hydraulic systems that were experiencing catastrophic failure they often did not exhibit grossly elevated UOA results unless an acid digestion was performed.

 

[kstanf150]

There's bigger problems here than the eye can see !

Lots of under lying problems here

 

[bbhero]

Originally Posted by kschachn
Originally Posted by tig1
I tried 15-50 M1 in a 4 cyl Ford and the engine was far more sluggish than the 5-30 it called for.

But it didn't damage the camshaft.


Exactly right ^^^^^^

Unless that motor was run in a much colder area where a 15w was a bad idea/practice...

 

[tig1]

Originally Posted by kschachn
Originally Posted by tig1
I tried 15-50 M1 in a 4 cyl Ford and the engine was far more sluggish than the 5-30 it called for.

But it didn't damage the camshaft.

And I never said it did. However too heavy oils for an engine certainly is not a plus.

 

[GMBoy]

Originally Posted by caprice_2nv
Originally Posted by GoldDot40
Originally Posted by GMBoy
I don't understand why the engine rebuilder thinks he knows more about the engine than the Toyota engineers by recommending a 15w/40 diesel oil. I'm not saying that is what caused this damage but surely that thick oil is not needed. I would ask the owner to use the correct spec oil next time.

That will depended on what the bearings spec'd at. If the tolerances were a little on the "loose" side during assembly, it would absolutely warrant using 15W40, 15W50, or 20W50 weight. Once an engine is overhauled and the factory tolerances change...Toyota engineering is out the window.


Exactly. Not only that, if that was the case and the vehicle was being worked hard towing or off roading, etc in hot weather all the time that would absolutely be the best choice in oil (20w50 or 15w40). The 15w40 could be a good compromise in the eyes of the builder. The fact that it would have a bit higher level of zddp wouldn't hurt. The choice in grade shouldn't even be a question here, although zddp content maybe worth discussing, the issue is likely parts quality or assembly error.


I thought the whole idea of a rebuild is to get back to the original specs? You also don't need thicker oil for towing and hot weather - a good synthetic 5W/30 will hold up fine. The thicker oil may actually run a little hotter from what I have read - may not be true so don't hold me to that.

 

[tiger862]

I would check cam tower clearance as oil pressure can be loss there causing oil starvation on top end along with lower pressure hot. Just a thought. I had a new rebuild customer was complaining about gauge dropped on hot idle in gear. Motor was rebuilt by a master tech at Toyota but was on vacation so I got it with less than 1500 miles. After all test I checked towers then pulled head and had to get aluminum weld with line bore as it was cheaper and shop ate it. Common oversight.

 

[caprice_2nv]

Originally Posted by tig1
Originally Posted by kschachn
Originally Posted by tig1
I tried 15-50 M1 in a 4 cyl Ford and the engine was far more sluggish than the 5-30 it called for.

But it didn't damage the camshaft.

And I never said it did. However too heavy oils for an engine certainly is not a plus.


Except it's not too heavy in this case. Just like a 5w30 is not too heavy in your modern Ford's. It arguably could be more ideal if not for the fact that it seems like oil companies put more effort into 0w20s compared to equivalent 5w30s.

 

[GoldDot40]

Originally Posted by GMBoy

I thought the whole idea of a rebuild is to get back to the original specs? You also don't need thicker oil for towing and hot weather - a good synthetic 5W/30 will hold up fine. The thicker oil may actually run a little hotter from what I have read - may not be true so don't hold me to that.

How many engines have you built/assembled personally? Most high mileage overhauls leaves you 2 options. Either you replace the crankshaft or have it tunred. Used crankshafts almost always require the journals to be polished up to make sure free of imperfections due to grooves cut into the journal(s). You have to have it turned (ground) down which means you remove material. To compensate, you use over size (thicker) bearings to keep the clearances within a window of acceptance. That window could still leave the tolerances a bit more than they were from the factory of a virgin engine.

If you ran the factory spec'd oil in one of these "loosely" assembled engines, the oil pressure usually will be extremely low. You compensate for that with a higher viscosity oil.