I think I'm in the same headspace you are BB.  You're confident in you ability, and pretty sure you did everything right, and can do it again, but there's this nagging fear that you don't know what caused it and that means the same thing could happen again. 

I'm puzzled for sure on this one.  I'd ask your machine shop.  Sometimes it just takes guys that have built a lot more engines than we have to have seen oddities like this and know the cause. 

I usually gear the car to pull all of 8000 rpm down longest straight and shift at 8000.

Screened the oil.....nothing!  Maybe it's just my attitude.  That's what Jean usually tells me.
I'm beginning to think that something caused a short lived loss of OP but due to the slow moving gauge or my slow moving brain I didn't notice it.  Some damage was done and then I buzzed it a few times getting EFI data and that wiped the mains.  The stock OP gauge finally registered zero to very low when things got bad enough.

Screwt....I'm just gonna build a new short block and get on with life.

BB1

 

My rule has always been to torque and gauge the bearings, both rod and main.  then mike the crank and determine the clearance.  I like a bit more clearance than some guys so I always hope for the outer limit.  That's always been easy to get on the V8s I've done as neither Chevys or this Ford seem to have had any significant crank wear and the cranks seem to run toward the lower limit of journal size...so Std/Std.  Then I install and torque the crank and no matter what engine I'm doing, I MUST be able to turn the crank with two fingers....that's my rule.   I discovered a major flaw in a well known Porsche/VW shop"s align bore process years ago due to that rule.  They had probably sent out a thousand or more engines with miss-aligned center mains.  The owner called me names I can't repeat here but the machinist listened and nearly fainted when he realized what had been happening...fixed the issue immediately.

The bearing wear is fairly uniform except the top shell on No. 3 main looks nearly untouched and the rear half of the No. 1 upper shell is worn way more than the front half.  This may be one of those situations where plastigage could have shown a problem but...I have never used plastigage, just mikes and telescope gages.  May have to change my ways.

I want to thank all of you for your help and suggestions.  I will probably never know exactly what caused this...just "old cars", I guess.  I'm going to use my NEW 5.0 block and will have it checked from every direction possible.

BB1
 

Last edited by Bullet Bob (6/02/2020 8:21 PM)

red351 wrote:

Why would anyone line bore if there normal bearing wear before the rebuild. You just don't take a block to shop and tell then to line bore it..... You need a reason

Now if a replacement recon crank or any crank I don't know it's true history or condition I would be worried.

Is it not straight or is it not round.
As you assemble it   Did you not spin the crank as you torque each main cap and feel for something abnormal.
I'm sure Bob did.   So my question is,  does the top half of the mains look something like the bottom in the pics? Is the wear on the tops more on each side? The front always shows more even wear top to bottom because belt pull

A lot or wide wear across the bottoms as if a bit too thigh.

To be clear, I don't tell the shop to line hone the block; I tell them to check the line bore.  That's a measurement operation, not a machining one.  I'd do it myself, but again, expensive precision tools I don't have.  If it checks fine I do nothing.  If its off I have it machined to correct it.  Most times its fine.

There are things that can effect the line bore which may not have been an issue on the engine before the rebuild.  If you swap bolts for studs in the mains for example, sometimes the additional clamping force squishes the bores out of round.  They need to be line honed to fix it.

If a bearing spun you definitely do it to make sure you have proper crush on the bearings for retention. 

Overall point being I never assume anything on an engine build.  I check and recheck everything.  Most times checking doesn't reveal a need for correction, but if it does I can address the issue long before it damages the engine. 

red351 and TKO,

You both bring up all the reasons I was ready to kill the machine shop/engine builder. This motor was the first and last time I ever paid the machine shop to assemble my motor. I was using a new crank and the machine shop convinced me that the line bore should be done to make sure everything was true for the new crank. I never had the opportunity to spin the rotating assembly during assembly. The thrust was going out of the main first and yes the bearing were worn unevenly. The engine builder blamed it on me, stating that I was over adjusting the clutch cable by having no slack in the cable and this was taking out the thrusts. on the second attempt they opened up the mains the 30 thousands which just gave me a few more miles before it took them out again. After the second failure I took my motor and trashed parts to a different machine shop, We started with a fresh block (scared of the old one), all internal parts checked, and I assembled that motor. That was over seven years ago, the lesson I learned, don't assume just because someone has a fancy sign and big shop with lots of equipment that they can do any better job than you can.

Well, decision is made.  I'm going to take my brandy new 1995 E7SE block which was cast in May of 1995, a salvageable crank, a brand new set of brand X (prolly forged in the land of WU) rods (with 3/8" ARP bolts), the flex plate and the harmonic balancer to the machine shop tomorrow.  The block measures 4" + or - .0002 which is just what's marked on it from the factory.  Problem is,  it's been setting around for 25 years, 15 of which were in Laguna Beach, CA, and it has some surface rust.  Some of the rust went a bit deeper in the bores so it may need a bore job.   I'll also have it checked for square and straight.  When it's done I'll have a new short block with all new parts including oil pump.  I also am going to have the rotating assy. balanced.  I will check out the heads which I expect are okay.  I'll use new Ford (made in Slobovia) lifters and the jury is still out on the cam.  The Comp XE-266 runs fine though I've been fighting idle since I installed it, but I'm going to go to something with a bit less lift...it has .555.  I've also decided to rebuild and install the 4R70W trans and use my newly found tuning skills to set up a 94 Mustang W4H0 computer to run the engine and trans. 
May also do a new exhaust system as I've never liked what we have.

So...hopefully this will all be finished and proven in time for next year's bash...you are planning on Sept. or Oct. aren't you Ed?

So why did the engine fail?  Well, much as it pains me to say so, I suspect it's my fault.  Of all the engines I've built, I never used RTV for general sealing.  This is the first and only SBF I've done and the only engine I used RTV on.  Now don't get me wrong, I was very careful not to use more than I thought it needed but the facts is the facts and I found more RTV bits in the pick-up screen than I think is good.  Some of the smaller bit's had to make it through the screen and into the pump.  It's certainly possible that one of those bits could have held the oil pump relief valve open for a while and that is on me.
Maybe that didn't happen but it's the only thing I can see as a possibility.

Whatever the reason I will not be using RTV in the same way in the future.  I'm going back to Old #2...Permatex Aviation Formagasket #2.  Used it for years and never had anything like this happen.

BB1

One thing I learned from way back is when the screen get block somewhat, it sucks back and things start to bypass and goes through the works. A good detergent oil after yrs of using cheap oil is going to be a problem soon after. I would say how I know that.

Sounds like a good plan of action BB!

There are two absolute no-no's in piston engine aviation. No Teflon tape allowed and No RTV allowed.
Permatex aviation form-a-gasket is some great stuff.

Bullet Bob wrote:

RV6 wrote:

There are two absolute no-no's in piston engine aviation. No Teflon tape allowed and No RTV allowed.
Permatex aviation form-a-gasket is some great stuff.

I'm not sure that was the problem butt (TS&T) I'm gonna be sure if there's a next time that it wasn't.  Problem is though, I'm not sure how to keep the damned pan from leaking at the corners at the front and rear seal without a little dab of the stuff.  May have to invent something.

BB1
 

I have a hard time believing a dab at the corner of the pan caused your problems. Is there a chance your WOT runs to 6K pumped all the oil out of the pan? 
 

TKOPerformance wrote:

RV6 wrote:

Bullet Bob wrote:

I'm not sure that was the problem butt (TS&T) I'm gonna be sure if there's a next time that it wasn't.  Problem is though, I'm not sure how to keep the damned pan from leaking at the corners at the front and rear seal without a little dab of the stuff.  May have to invent something.

BB1
 

That was my thinking too.  But a standard volume pump shouldn't do that.  Unless it couldn't drain back fast enough for some reason...
I have a hard time believing a dab at the corner of the pan caused your problems. Is there a chance your WOT runs to 6K pumped all the oil out of the pan? 
 

 

Well, anything is possible, I guess.  The pulls were to 5300 max according to the data logs, the lifters are stock, the heads have stock sized open drain back holes but they do use guide plates...Hummm, never thought of those 'til now. 
You know, I'll take another look at those heads and see if the guide plates block off the pushrod holes.  If so I know how to run a die grinder and will see if some relief troughs might be added. 
Thanks, Tom.  This was mentioned earlier by one of the guys but I couldn't see how that could happen then.  One person...maybe DC...mentioned that the oversized pushrods block drain back.  the guide plates might be doing the same thing.  I'll be checking.

BB1