This is a stock 302 cleveland camshaft from a completely stock 302c engine that had done 130,000 miles.

What was the likely cause of the failure ?



These are the specs of the cam (as best i can measure)

What are the general thoughts on the cams lift, duration and lobe separation angle ?





Original Post
Oil was changed every 3000 miles. Oil used was Pennzoil 20 w 50. Rocker arms were in good condition as were the pushrods. All lifters were free and the inside of the engine was remarkably clean.

The engine was running well and was not making any rattles or noises.

But possibly not for much longer.
What failed in the valve train? What you described, everything is normal.

You are showing me pictures of a camshaft with excessive wear on the lobes aren't you?

Excessive wear would be associated with lubrication issues.

Perhaps you should define exactly what broke or failed?
quote:
Originally posted by George P:
quote:
Originally posted by Aus Ford:

... 130,000 miles ... What was the likely cause of the failure ?



Mileage



Is it just purely mileage (old age) ? Is this the fate of all old cams eventually ? Can it be prevented ?
quote:
Originally posted by Aus Ford:

Is it just purely mileage (old age) ? Is this the fate of all old cams eventually ? Can it be prevented ?

Run a zinc (ZDDP) additive with every oil change, or change to a full roller cam, lifters or rockers (lots of advantages to that).

Not sure if Aus has the same environmental regulations as the US, but ZDDP in oil here has been restricted because it poisons cat convertors, obviously not an issue in a Pantera. There might be an oil formula available labeled "Classic Car". Research to see if that formula has elevated levels of ZDDP.
quote:
Originally posted by Dave2811:
quote:
Originally posted by Aus Ford:

Is it just purely mileage (old age) ? Is this the fate of all old cams eventually ? Can it be prevented ?

Run a zinc (ZDDP) additive with every oil change, or change to a full roller cam, lifters or rockers (lots of advantages to that).

Not sure if Aus has the same environmental regulations as the US, but ZDDP in oil here has been restricted because it poisons cat convertors, obviously not an issue in a Pantera. There might be an oil formula available labeled "Classic Car". Research to see if that formula has elevated levels of ZDDP.



Yes ZDDP would be restricted here too because of cat converters, but unfortunately ZDDP has not rated a mention here, it has been reduced or removed without telling anyone.

I wonder if Diesel engine oils are a better option as they are extreme duty engines and don't have catalytic converters...?
Here in the states the ZDDP level in diesel motor oil was acceptable until the diesel motors were equipped with catalytic converters, once the diesels were equipped with cats they removed the ZDDP from diesel motor oil too. That happened less than a decade ago, I don't remember the exact year, it seems like about 2006 or something like that. My memory isn't what it used to be.

If the ZDDP level is acceptable, diesel motor oil is fine for use in gasoline engines, it just has more detergents. I used it in the 351C of my 1972 Mustang, and then my 1974 Pantera for several years with no problems.
Here's what I was told by some vendors when I called about the Zinc and Phosphorus levels in some oils back in 2009

Rotella T 15W40 - 1210ppm Zinc and 1110ppm Phosphorus (this is in the New Rotella T Triple Protection (CJ-4 blend oil)
Valvoline VR1 20W50 - 1400ppm Zinc and 1300ppm Phosphorus
Valvoline VR1 Straight 30 - 1400ppm Zinc and 1300ppm Phosphorus (same as the multi-viscosity in this regard)

Note: Rotella is a diesel oil, and because of the detergents I chose to pass on it and go with the VR1, but other oils with high Zinc and Phosphorus come from a number of manufacturers and have loyal fans (e.g. Brad Penn, Royal Purple, Amsoil etc.). A quick internet search on oils with high ZDDP should give you a list of recommendations and a couple of calls to manufacturers should get you the data points to make a choice that works for you in terms of local availability, viscosity, price and even the colour of the oil when you pour it in :-)
quote:
Why did you not like the detergents in the Rotella oil ?


The reading I'd done at the time was saying that in gasoline engines the detergents would be busy cleaning the metal on metal surfaces while the ZDDP was trying to coat those surfaces - they argued that it isn't as much of an issue in big slow diesel engines as it is in high revving gasoline engines. Rotella is supposed to have lower detergent levels than other diesel oils though, so that may be why it's been a good choice for some builders.

Here's a fairly recent article that sums up a lot of what I'd been reading some years ago on ZDDP, detergents and the progress of oils over the years ...

http://www.enginebuildermag.co...re_what_why_how.aspx

It's a bit long, but a good read - granted, if you search around a bit, you're sure to find articles that claim the opposite and say that modern oils are fine and ZDDP isn't needed; as for me, I'm not going to take that chance.
Here in the US the auto manufacturers were mandated to warranty their emissions systems for 100,000 miles; at the same time the level of ZDDP was drastically reduced in gasoline engine motor oil sold in the US. This was necessary because (as previously mentioned) ZDDP poisons catalytic converters, or shortens their life.

Roller tappets were already being employed by the auto manufacturers; they had gone into service years earlier (1980s) when the levels of ZDDP had been previously reduced to extend the life of catalytic converters. But with the 100,000 mile warranty looming in the near future, the auto manufacturers introduced distributorless ignitions and crankshaft driven oil pumps too (no distributor gear needed). The changes they made to the engines indicate the auto manufacturers knew the flat tappets & distributor gears needed ZDDP; end of argument! The government & auto industry didn't bother to inform the owners of older vehicles however.

There were 4 other factors that contributed to the camshaft & distributor gear failure problems we experienced more than a decade ago.

(1) Advances in camshaft grinding equipment made it possible for aftermarket cam grinders to grind street cams that had lift rates similar to the lift rates of race cams in the 1970s.

(2) With the industrialization of some of the Asian nations one or more of the camshaft manufacturers began sending some of their manufacturing over-seas, where quality control wasn't up to North American & European standards.

(3) A decade or so after the advent of the roller cam (in the 1980s) some enthusiasts had never learned how to properly break-in a flat tappet camshaft.

(4) The camshaft manufacturers began selling retro-fit roller cams for engines originally equipped with flat tappet cams. And none of them seemed to understand what materials the distributor gears should be manufactured from to compliment these cams. Some of them were selling bronze gears for street applications! Holy Cow!

All of these factors came to a head around the year 2001, and an unusually high rate of flat tappet camshaft failures & distributor gear failures began occurring.

As an interim measure some of us switched to using diesel motor oils in the mid 2000s, I'm not aware of anybody having any problems with them. But that interim solution didn't last too long, because within a few years the ZDDP level of diesel motor oil sold in the US was also reduced.

It took a few years, but eventually the camshaft grinders, the SEMA industry, and the motor oil industry sorted stuff out. Motor oils with a higher content of ZDDP have been introduced as oils for race engines or older engines, quality control has improved, Crane Cams made steel distributor gears available for cams ground on their steel cores, and the public has been educated about breaking-in flat tappet cams. The folks who manufacture or sell camshafts are better educated regarding the spring rate limitations of flat tappets, and Harvey Crane's concepts of hydraulic intensity, minor intensity and major intensity are better understood in terms of how they impact valve train wear.

Nobody has ever admitted guilt, all the companies involved want to blame other portions of the industry, nobody wants to admit liability, but we don't hear of failures like we used to.

-G
Small block Fords, i.e., 260, 289, 302, 351w that use the rail type rocker arm system and the cast rocker arms show more wear on the valve train than do the Clevelands but they have their issues also.

In MY experience with those engines, worn components such as the valve stem and rocker arm tips also indicate wear to the lifter surface and the camshaft lobe.

Along with the push rod they are oiled as an assembly.

As the tips wear, oil pressure to those components are reduced.

The camshaft lobe has the largest contact area along with the lifter. With less oiling it will show greater wear.

Multi-viscosity oils start breaking down immediately. Visosity such as 10w-30 or whatever is only that brand new inside the container.

As soon as you use it the viscosity polymers begin to break down.

By 3,000 miles, your 10-30 is now a 5-5 or somewhere around that.

The valve train is the most demading on viscosity. The bearings don't care as much.

I saw this on a friends Pro-stock BB Chevy. It would have 100 psi at the starting line and when it would come back to the pits, 10 psi.

Granted there were other things happening internally, but 95% of that was that the viscosity of the oil just got destroyed...AND it wasn't mult-grade either!

I constantly do oil changes on cars with more than 7,000 miles on the oil. Constantly is a good description. New vehicles too. Many on leases and the owners don't care.

Wear like this IS oiling related. Is it wear and tear? Yes, but wear and tear caused by insufficient oiling properties.

Incidentally, you want to use maximum ZDDT, not a minimal amount like many of these oils offer.

When you drain the oil from the pan, you clearly see the ZDDT floating on the top of the oil like an oil slick.

It is a whiteish/greyish slick floating on top of the oil.

On those SB Fords, I have had to replace entire valve trains on engines with as little as about 75,000 miles.

I always advise that in addition to the accessable top end parts I am changing, that the cam should be changed and the valve guides are probably elongated too and should be redone.

I advise putting in roller rocker arms probably more than most, and when the price is mentioned, probably install the least. Big Grin

There's more to it than just not enough ZDDT.
quote:
Originally posted by PanteraDoug:
Small block Fords, i.e., 260, 289, 302, 351w that use the rail type rocker arm system and the cast rocker arms show more wear on the valve train than do the Clevelands but they have their issues also.



Wear like this IS oiling related. Is it wear and tear? Yes, but wear and tear caused by insufficient oiling properties.



On those SB Fords, I have had to replace entire valve trains on engines with as little as about 75,000 miles.

I always advise that in addition to the accessable top end parts I am changing, that the cam should be changed and the valve guides are probably elongated too and should be redone.

I advise putting in roller rocker arms probably more than most, and when the price is mentioned, probably install the least. Big Grin

There's more to it than just not enough ZDDT.




Just to be clear for everyone the worn cam in the original photo is from a 302 Cleveland NOT a 302 Windsor, so we are talking about Cleveland engines not the Ford smallblocks.


I must say i had always been disinterested in roller rockers, i had felt that the standard Ford rockers were perfectly ok.

Until i took some off a engine that had only 6,000 miles on it. The valve tip and pushrod cup were fine, perfect in fact but the sled fulcrum and surface inside the rocker arm were shocking.

This corresponded to the wear i had seen on all stock Cleveland rocker arms of all mileages, but the thing that surprised me was that this level of wear had taken place so soon after a rebuild. The load and fiction on the fulcrum must be immense and replacing the "sled" with a roller bearing would have to be advantageous.

So i fitted a set of roller rockers to the engine and was pleased to find the engine ran more quietly and revved more freely which i hadn't really expected to be able to notice.



So this leads me to think are we all at some stage going to have to upgrade to roller camshafts to avoid the type of cam wear as shown in my original photo ?

That cam had done 130,000 miles but i have pulled down a 351C that had done 230,000 miles and the cam was in much better shape than the 130,000 mile cam. Both engines had been well looked after.



I recently read a article by Crane Cams where they blamed premature camshaft wear on the more common fitting of windage trays and modified sumps, their thought being that the reduced amount of oil "splash" on the camshaft from better oil control was reducing cam lobe lubrication.

Comp cams now lifters available with a oil hole in the centre of the face to provide "positive cam lubrication".

Comp cams provide a tool (believe it or not) to cut grooves in the lifter bores to feed oil from the lifter gallery to the cam lobes.

Cutting grooves in the lifter bores to feed oil from the lifter gallery to the cam lobes in a Cleveland seems a ridiculous concept to me. We talk of fitting lifter bore bushes to prevent the leaks from the oil gallery now Comp Cams is suggesting to increase the leaks. Clevelands leak enough there as is.

I think Crane's suggestion of windage trays causing cam wear is also faulty. Even with a windage tray and better oil control in the bottom end there is still a tremendous amount of oil exiting the crank bearings and being thrown on to the camshaft by the crank.

There is clearly a automotive parts manufacturer's blame game going on.
With mileage the concern, I would agree that roller cams would help the situation wear wise.

I am thinking though that the added mass to the lifter assemblies will raise the risk of valve spring failure.

I also think that these considerations are just illustrating the compromises inherent in this type of a design. Overhead cam engines seem to run on forever in comparison.

I mentioned Ford small blocks simply because they share design features along with the Cleveland.

I have seen less rocker arm wear on the tips on the stamped steel rocker arms of the Cleveland than the cast iron tips of the small blocks but the problem is still there, i.e., the scuffing motion across the valve stems.

Remember that when these engines were new they were designed with a packaging level in mind by their manufacturers. This is what you got for the money spent.

Chevys I will point out, have the same valve train issues with mileage for essentially the same reasons.

My opinion of the rocker arms is that the fulcrums of the rockers themselves is a relatively small issue. That irregardless of whether or not it is a ball or another shape is essentially a cheap type of bearing.

The push rod pockets are as well.

The tips are what need to be rollerized.

Roller lifters were not only introduced in production engines as a result of the ZDDT issue but also as a way of reducing parasitic energy losses in a fleet fuel economy battle considering the building of mass quantities of engines. Gaining a few tenths of a mile per gallon because of less friction in the valve train shows some in the fleet averages.

That is a just positive benefit of environmental green government requirements that inadvertently helps performance.

As one engineer pointed out, high efficiency is high performance.

Sometimes the bumbling numbnuts that we elect to government actually do something positive, even if it was accidental and they had no idea they did? Roll Eyes
Had the same problem on a project build,new cams before this was widely known. looked just like yours, it was the lack of ZDDP in the oils, I've gone to Valvoline VR1 20W50 with no problems, I run 5000mi on oil changes, also I might note that cheap oil filters can be a problem too.
Good luck, Mark
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