Uh Oh, Failure Analysis, Stroker questions, cleaning roller lifters and rockers.

[DuckRyder]

Apologies in advance if y’all have seen this on another forum, going to try to condense it into one post in case there are any unique visitors to forums.

Seems like I’ve lost a Rod bearing in the 390.

I built this engine a number of years back (like 2005ish) but it has very few miles.

It began to knock and the oil filter is full of copper (or bronze) and some much smaller magnetic particles. I have not gotten into the engine yet, but I’m guessing the crank is going to be scrap along with probably the rod.

It is a .30 over 390, has a Crower street roller and HIPPO rollers and Erson Roller Rockers

My questions are two fold:

1) If the crank is bad - I will likely just do a stroker. Is there any reason to chose something other that a cast crank 4.250 rotating assembly for a street application? I don’t see it making over 450HP... though it spins pretty hard to 6500 or so RPM.

2) Any tips for cleaning the parts, particularly the roller rockers and lifters?



The block is the original 360 truck block (as near as I can tell) it was decked, align honed, bored with torque plates... assuming it isn’t damaged from this incident I’d like to reuse it at the current bore. It has about 3500 miles on it.

In fact I’m hoping to reuse everything that isn’t damaged.

It currently has L2291F30 at zero (.004ish) deck and Victor head gaskets. I calculated the static compression ratio back then at 10.6:1. Once I get it all apart, re checking all measurements before buying parts is in order.

Mahle catalog shows a piston matching SCATS specs @ Compression height of 1.325 (incidentally they also show a 28cc piston that would get the compression down, but I don’t see an off the shelf kit using that piston.) Might definitely be worth a call to Barry or Brent to see what they can do.

The Cam is a Crower Part Number: 16462 Mechanical Roller (280R). INT/EXH - Dur @ .050” Lift:234°/244° RR:1.76/1.76Gross Lift:.580”/.582”
LSA:110° RPM:2500 to 6000 Redline:7500 (I really like this cam, I hope it is OK and I can make it work)

It does have an adjustable timing set.

It is fuel injected with a Holley Terminator Stealth, MSD pro billet distributor if it matters. Has a FPP (Which I think is the same as Blue Thunder) single 4V CJ intake which is a poor match to the heads... and Hooker truck headers.





No real evidence of metal in the upper end



Some flakes of copper / bronze in valley



No evidence of issues on pistons









No obvious damage to rods or crank (no blue/black rods etc...)



Don’t remember these marks but all rods seem to have them, so I am thinking its from balancing/machine shop fixtures...

5 is where it sounded like knock came from.

I did note that there seems to be excessive side clearances so checking that is on the list for tomorrow.

It seems to have zero end play, which I also don’t recall and will bear investigation...



Dist gear seems a little sharp so will clean and inspect that as well...









Well I would say the mystery about what is wrong is solved. This is number 7.

Now the question is why?

It still doesn’t have any end play, but the thrust bearing looks ok.

This was one of the copper colored rods, i asked about this back when I built it, but the consensus was some of them are just like that...

Other things I’m aware of are:

I had a converter incompatibility issue with a flex plate and it wiped the front pump in the trans, this was right after it was reinstalled, I was expecting to find issues with the trust bearing.

When the heads were ported epoxy was used to port match the CJ style intake to the MR style heads, last time I had the intake off one was found to be MIA (wish I recalled which CYL, probably should have written that down.)

I think my tolerance for trying to rebuild it as a 390 is badly waining... guess I need to get some more measuring done...

[Barry_R]

If I were to guess it looks like it pulled the lining away from the bearing's backing.
Possible cavitation - interrupted oil supply or poor crank/rod/bearing geometry or clearance.
Or a defective bearing....tough to prove

[jayb]

Those Scat stroker crank packages are good for 7000 RPM and 650+ HP, so you should have no issue with running one if you decide to go that route.

[338Raptor]

Are the other bearings in the early stages of the same condition, or do they look OK other than a bit of debris from these failed bearings?

[DuckRyder]

Good Morning.

I’ll also mention that I’ve done UOAs on it and the copper never settled down on it though it wasn’t in truly alarming amounts.

The engine ran fine and sounded fine until it developed a knock that went from “gee that sounds faintly like a rod knock” to “thats a rod” in about 8 miles.

It may not be clear in the picture but these are ten under FM performance bearings.

Barry, I’m not aware of any starvation incidences, and I can’t find my build notes, but will say all clearances were plastiguaged and there were no concerns I recall, and I think I would recall. I do note some evidence of uneven wear on the other bearings.

Jay, thanks don’t imagine it’ll ever see 650 hp and it is done by 7000...

338, certainly none of the others look anywhere near this bad and none appear to be shedding layers. They do show excessive and uneven wear.















EDITED to ADD: One other thing, flashpoint was low on latest samples, some evidence old fuel pump may have been leaking internally. Fuel reported between trace and 2.3%. This labs fuel numbers not viewed as particularly consistent though.

[Barry_R]

Sticking with my cavitation guess. 
Excess wear in a very narrow area on the other bearings.
I think you have excess clearance coupled with a poorly made bearing.
Again - no way anybody can "prove it"....

BTW - plastigage is better than nothing - but just barely better....

[My427stang]

So,
- front sump engine making power - potential oil supply issues
- bearing wear on all the bearings - potential oil supply issue
- delaminated or failed bearing - potential oil supply issue
- odd wear on the "good" bearing (especially last picture) -likely clearance issue, maybe big end isn't round

I think I would do this

1 - Start at the block, using a bore gauge, check every saddle for taper and size when torqued, no bearing.  If they are, have it align honed (I know mains aren't your issue, but its the foundation of a house)
2 - Take the bearings out of each rod, do the same, see if they are in spec AND where they are in the spec (big or small) AND how much taper.  If you stay 390, replace or repair the bad rods, but the colored rod being colored is still not an issue.
3 - crank needs work, your call if you stay 390 or go stroker, but measuring now may not tell you much. 

During assembly, use a bore gauge and mic for clearances.  Hit the numbers, whatever it takes. 

Then, if you are running a stock pan, get something bigger / baffled and restrict the top end

My hunch is, engine was looser in some places than you thought, tighter in some places, and likely a good run starved it at one point.  None of those rod bearings look like what I would want to see.

AND, as stated on the other forum, dump that distributor gear and be sure it's on the right place, go steel and never worry about it.

Last, I gave up on Epoxy on an intake manifold a long time ago (for a street vehicle) The port will pull on the top, not great to have a step on the bottom, but not as bad as people say.  Either get a med riser intake, or just make sure the top and sides match the best you can and ignore the floor IMHO.

[338Raptor]

Was your positive fuel in the oil sample result from the previous oil change or oil that was removed post failure?  If it’s from the previous oil change then the problem may have progressed. Fuel dilution of your oil would cause all of this, especially with loose tolerances.

[DuckRyder]

Barry, when you say cavitation you mean through the oil pump I assume? Or some particular hydrodynamic between the crank/oil/bearing? Point taken on plastiguage, never again.

Ross, points well taken, will do. Thanks for your help over there and here.

Extra info: has a CJ style windage tray and a Milodon “CJ" pan, M57HV pump. Open to suggestions on alternates that will fit 2wd truck. Thinking perhaps a “blue printed pump” I know Precision Oil Pumps is one vendor there.

338, the post failure sample had <.5% fuel, it was about 600 miles after the change and conversion to EFI (eliminating the mechanical pump) sorry for confusion. FWIW this particular lab says less than 2.0% is no concern, but also their numbers are not considered very reliable on this measure.

[My427stang]

I am not sure the pump would be the cause, seems like it'd have to have some serious clearances to be the culprit, but who knows but it could certainly get gulps of air and foamy oil if things were low or not right.  Doug's pumps are awesome, and absolutely nothing wrong with putting a new one if after the crap went through for good insurance

I posted on the other forum too, but things I thought about this morning, I make sure your pickup is where it's supposed to be compared to the floor (I see a LOT that and many need to be shaped, some even cut and weld), make sure it doesn't have a bad weld that can suck air, run some restrictors if you don't, and then run the oil level high if you really want a backup

I am not sure there is a better pan, maybe some with better baffles, but I haven't done much 2WD truck stuff.  Cody L may be the guy to answer as he is pulling the wheels on launch with his

[Barry_R]

Barry, when you say cavitation you mean through the oil pump I assume? Or some particular hydrodynamic between the crank/oil/bearing? Point taken on plastiguage, never again.

At the bearing/crankshaft interface.  If you have too much clearance or not enough oil or both you can generate a sort of a vacuum there where the oil film "pops" away from the bearing face taking bearing material with it - especially if the bearing material is not properly adhered to the steel backing.

[wayne]

How much oil did you run in it a fe can always use a qt or two more when running their pan gets on the low side a lot stays up top,

[DuckRyder]

Ross, will add it to my to do list.

Barry, understood, so apart from choosing quality bearing and verifying clearances > not much I can do about it.

Wayne, 6 QTS.

[6667fan]

I sent you a pm concerning parts.

JB

[DuckRyder]

First let me say that the pictures make it look worse than it is and I cannot feel any of these scratches, though they look nasty.

Also I left Crower a message about rebuilding the lifters.

I think the cam and lifters are useable...