Ford 302 Lubrication-related failure

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Interesting...I doubt 20/50 oil caused it,as mentioned,thousands of drag racers use it.
Those roller lifters appear to have either got sideways or the engine was reved beyond the cam design.The roller pins coming loose is a sign of extreme abuse.
The rollers will get sideways if the cam allows the lifter to rise above or below the forked retainer.Those little wheels on the lifters don't work worth a [censored] running sideways.
Over running the cam or "Valve float" with a roller cam can be fatal to the valve train,and that's what it looks like.
Hi volume pumps can often cause problems by overloading the distributor and cam gear.
 
time for an frpp boss block! i always loved the trick flow stage 1 cam.. had a mean 306 back in the day (302 with 30 over bore..

use a 10-30 this time. shoud be fine.
 
Guys...



Lubrication-related failure


is not


Oil-CAUSED failure.



The point is NOT that the oil blew up the engine. The point is that the lubrication SYSTEM, which includes the oil AND the hardware, had a flaw. The oil's viscosity and the oil pick-up were MISMATCHED. Neither one was "wrong" per se.
 
Originally Posted By: Truckedup
Interesting...I doubt 20/50 oil caused it,as mentioned,thousands of drag racers use it.
Those roller lifters appear to have either got sideways or the engine was reved beyond the cam design.The roller pins coming loose is a sign of extreme abuse.
The rollers will get sideways if the cam allows the lifter to rise above or below the forked retainer.Those little wheels on the lifters don't work worth a [censored] running sideways.
Over running the cam or "Valve float" with a roller cam can be fatal to the valve train,and that's what it looks like.
Hi volume pumps can often cause problems by overloading the distributor and cam gear.


I do believe I CLEARLY stated in the original post that the oil did NOT cause the failure.

And clearly stated what DID cause the failure. And WHY the failure occurred in the manner it did.

It was NOT valve float.

It was CAVITATION that caused OIL STARVATION in the lifter bores (and the cylinders) that is CLEARLY VISIBLE in the pictures I posted, and caused pronounced SCORING.

When the lifters began to STICK in the bores, they got smacked by the cam, which is what knocked the pins loose.

Does nobody bother to READ the original post in these sort of threads?
 
Originally Posted By: hardcore302
time for an frpp boss block! i always loved the trick flow stage 1 cam.. had a mean 306 back in the day (302 with 30 over bore..

use a 10-30 this time. shoud be fine.


Yes, your old 4-bolt block is a much stouter piece than this one was.
 
Originally Posted By: Boss302fan
I just had a Boss 302 engine rebuilt by one of the best in the industry and he said to go with VR-1 20W50 or Joe Gibbs Hot Rod 15W50. It all comes down to clearances and who builds the engine. My engine like all Boss 302 engines required 7 quarts in the pan. Most likely his problems were not caused by the oil.


BINGO. Your engine was built around a 50-weight. This one was built around a 30-weight, and then run with a tiny pick-up in a deeper pan with 20w50 to an RPM point that caused excessive cavitation, and oil starvation.

That is why there are "pock" marks in the bearings. They got AIR bubbles in them. That is why there is scoring in all the lifter bores, cylinder bores and on the piston skirts.

The irony is that (and the light crowd is going to LOVE this) if he had run an "evil" 5w20 in it, rather than the 20w50, it likely would have survived.
 
Some more pictures:

Bore where the pin had come out and started chewing it up:
nate8507.jpg


Bore where the dog-bone broke and the lifter rotated:
nate8508.jpg


"pock" marked bearing from air bubbles due to cavitation:
nate8509.jpg


Scored cylinder:
nate8510.jpg


Scored piston:
nate8511.jpg


More damaged bearings:
nate8512.jpg
 
Originally Posted By: OVERK1LL
Originally Posted By: Boss302fan
I just had a Boss 302 engine rebuilt by one of the best in the industry and he said to go with VR-1 20W50 or Joe Gibbs Hot Rod 15W50. It all comes down to clearances and who builds the engine. My engine like all Boss 302 engines required 7 quarts in the pan. Most likely his problems were not caused by the oil.


BINGO. Your engine was built around a 50-weight. This one was built around a 30-weight, and then run with a tiny pick-up in a deeper pan with 20w50 to an RPM point that caused excessive cavitation, and oil starvation.

That is why there are "pock" marks in the bearings. They got AIR bubbles in them. That is why there is scoring in all the lifter bores, cylinder bores and on the piston skirts.

The irony is that (and the light crowd is going to LOVE this) if he had run an "evil" 5w20 in it, rather than the 20w50, it likely would have survived.


Totally agree with you except on the 5W20 oil. LOL...
 
LOL! Seriously, my cam grinder ran 5w20 in his stock-clearanced 302 that he spun past 7K with the stock oiling system.

The reason for the cavitation is the high RPM + heavy oil. The pump simply is unable to suck oil from the pan at the rate in which it is being requested to do so by virtue of the RPM at which it is being spun. Then you end up with it simply sucking air. Which causes bad things to happen. The lighter oil would have flowed more freely through the pick-up, and would have extended the RPM cavitation-point ceiling.

Your engine draws oil from directly beneath the pump through a short little pick up with a decent sized end on it.

The 302HO draws the oil from the BACK of the pan, through a huge long pick-up tube.

Front-sump 302 pick-up:
interchange8.gif


BOSS 302 pick-up:
interchange11.gif


Stock-style 302HO pick-up:
mmfp_0706_13_z+1993_ford_svt_cobra_boss_block+oil_pump_pickup.jpg


Hamburger pick-up:
5630.jpg
 
Anyway,what did the crank and rod bearing look like? Bearings wiped out by the cavitation problem?I'm no Ford guy,but on SBC's with roller lifters it's common to restrict the oil drain back and splash to the roller lifters because they need less oil.
 
Looks like this is a case where both transient and nontransient cavitation may have occurred on a regular basis. The latter also creates not so benign acoustic phenomena -- works like a catalyst and accelerate damage exponentially.
 
Last edited:
Originally Posted By: Truckedup
Anyway,what did the crank and rod bearing look like? Bearings wiped out by the cavitation problem?I'm no Ford guy,but on SBC's with roller lifters it's common to restrict the oil drain back and splash to the roller lifters because they need less oil.


You can see the crank bearings in my previous post.

Rod bearings were similar.

No need to restrict anything on an 8.2 deck Windsor. This was simply a case of a pile of "incorrects" going on at once that led to the failure you see in the pictures.

To elaborate:

With a stock pan and pick-up, this likely wouldn't have happened.

With a much lighter weight of oil, this likely wouldn't have happened.

But that was not the case. You have an engine clearanced for a 30-weight, trying to draw heavy oil through a small pick-up and long pick-up tube, at an RPM at which it was never intended to be spun to and the result was the inability for the pump to supply oil to the engine.
 
Originally Posted By: Y_K
Looks like this is a case where both transient and nontransient cavitation may have occurred on a regular basis. The latter also creates not so benign acoustic phenomena -- works like a catalyst and accelerate damage exponentially.


Interesting, I'll have to look into that.

Keep in mind, the engine MIGHT have had 1,000Km on it. And I believe 3 or 4 track passes.
 
Originally Posted By: Truckedup
Quote:
Does nobody bother to READ the original post in these sort of threads?

Obiviously not,we all just go on and on in our own little minds
33.gif



Well, every point/observation you made had been clearly addressed in my original post. Just a little frustrating to have questions asked and speculations being made when it was all in the first post in this thread.
 
Originally Posted By: Truckedup
Interesting...I doubt 20/50 oil caused it,as mentioned,thousands of drag racers use it.
Those roller lifters appear to have either got sideways or the engine was reved beyond the cam design.The roller pins coming loose is a sign of extreme abuse.
The rollers will get sideways if the cam allows the lifter to rise above or below the forked retainer.Those little wheels on the lifters don't work worth a [censored] running sideways.
Over running the cam or "Valve float" with a roller cam can be fatal to the valve train,and that's what it looks like.
Hi volume pumps can often cause problems by overloading the distributor and cam gear.
grin2.gif
The lifters go then the leaks out of the lifter bore .
 
Sorry for all the stupid questions........Your engine damage is different from what I've seen from oil starvation.The pump sucks air at full throttle from cornering G loads or a bad pump pick up and the crank bearings wipe out instantly.Maybe even spun bearings.Your bearings appear no where near that.I'm just surprized that the bearings kinda survive and the roller cam ,that should tolerate a "pressurized" oil interuption, has a drastic failure.
Then again,I've learned something new.
 
Originally Posted By: OVERK1LL
Originally Posted By: Boss302fan
I just had a Boss 302 engine rebuilt by one of the best in the industry and he said to go with VR-1 20W50 or Joe Gibbs Hot Rod 15W50. It all comes down to clearances and who builds the engine. My engine like all Boss 302 engines required 7 quarts in the pan. Most likely his problems were not caused by the oil.


BINGO. Your engine was built around a 50-weight. This one was built around a 30-weight, and then run with a tiny pick-up in a deeper pan with 20w50 to an RPM point that caused excessive cavitation, and oil starvation.

That is why there are "pock" marks in the bearings. They got AIR bubbles in them. That is why there is scoring in all the lifter bores, cylinder bores and on the piston skirts.

The irony is that (and the light crowd is going to LOVE this) if he had run an "evil" 5w20 in it, rather than the 20w50, it likely would have survived.


I like this statement it is worth repeating.
Originally Posted By: OVERK1LL
[ BINGO. Your engine was built around a 50-weight. This one was built around a 30-weight, and then run with a tiny pick-up in a deeper pan with 20w50 to an RPM point that caused excessive cavitation, and oil starvation.


I think the engineers at Ford know what oil is best for their applications. In this example while the engine builder might have been the very best builder there is, he might need to reconsider his oil recommendations though.
27.gif


I know guys in my profession that are master craftsman, but don't know squat about which product works best in certain questionable applications. Seems like the same thing is going on here. Nicely built engine with an impressive parts list, wrong oil choice. JMO
 
Oil pickups and pumps change and if the engine has been rebuilt, you should go with what the builder recommends. If it is an original build and stock then you should follow Ford recommendations.

I thought he already stated that it was not oil related.
 
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