I decided to try to max out the f1 this last weekend on the factory 6rib belt drive that I built. I did succeed getting a max boost of 22psi on a built 364
but under wot at 6000 rpm I was starting go lean so went back into the log to see how much fuel I wanted to add and noticed that oil pressure was on the low side, so the engine was pulled this morning and tore down heres what I found.
it killed the thrust bearing then started getting into the block in a couple places. this engine was assembled new with 4thous on the thrust clearance
hers some pics what do you guys think???

 

pics are loaded

 

OUCH! what is your question? so the crank counterweights touched the block?

 

what caused the thrust to go away that far allowing the crank to walk that far forward for the counter wights to get into the block

 

wow! never seen that before

 

Manual transmission?

 

I didn't notice what trans your running, but if auto and if it killed the thrust first...maybe have the converter checked out. That number 2 bearing looks really bad though too, so maybe the problem started elsewhere...

 

Good call! I'd check out the converter too. Bob

 

sorry guys auto, what would the converter do to cause this damange?
the converter has about 3/4 of a inch to come forward to bolt to the flex plate, so I dont think the input shaft is pushing on it...or not????
the bearing thats really destroyed is number 4
Im pretty sure the thrust went first allowing the crank enough room to move forward in order to get against the back of the block and mains super heating the block and main cap witch in turn tighten up the bearing clearance killing the bearings.
you can see on all three bearings the rear of the bearing is worse then the front hence the crank touching the back of the mains heating them up tightening the clearances on the rear of the bearings,
heres another pic

 

its hard to see on the crank pics but the thrust area has a 35thous grove wore in it, then you look at the thrust bearing pic the back side of it is worn about half of the front, you add the 35thous grove in the actual crank then the very thin thrust bearing hell thats about 100thous of extra clearance the crank could walk forward.
please keep giving ideas..
I have a new rotating assembly waiting to go in another block but need to find out if this will be a repeating problem.
this engine is basically raced, very little street driving it comes out to race then sits in tell the next race.

 

3/4" to get the converter to the flex plate?? That would nearly pull the converter nose out of the pump. What does the nose of the converter look like? The pump looks like?

 

too much perssure in the converter can push on the back of the crank pushing it into to the trust bearing. alot of drag racer have this issue from my understanding.

what trans and what converter do you have? and what flexplate? you should have only 3/16 i think between the converter and flexplate any more and you have to use a shim. this is what dave at yank tells me

 

hell maybe my guess is wrong on the movement of the converter, but its a built 65 with a pro yank 3400 stall
I will go out and look at the tranny and converter her in a bit

 

It has to be something in the converter or trans pushing the crank forward. Thats what kills thrust bearings.

 

I agree that it is a converter issue and 3/4" is very bad. I run the heavy side of 3/16" in a racing app.

 

Not only does the converter have to have 1/8-3/6 before the pads touch the flexplate but it also has to have room past that to flex the flex plate..otherwise it will just push the crank forward.

This is an example of a transmission that had a restricition but some of the flex is normal and if the nose of the converter bottoms out before the plate flexs it will just push the crank foreward.

http://www.youtube.com/watch?v=YEfqKoilLkI

 

I put the crank back in the block and reinstalled the engine against the tranny it has about a 1/4 of movement to bolt to the tranny not the 3/4 that I originally said(sorry my bad)
I check play on the input shaft it dose not move in or out, could the blower be pulling forward on the crank?

 

That oil is pretty dirty ,, are you sure it had plenty of oil before the dyno pulls? ,, it looks like it was ran out of oil on the pulls ,look at the thrust marks on the bores,,oil pump pick up clearance ok ,not smashed into the pan?

 

when the engine was fresh oil pressure was around 65 at 6500 and I run 71/2 quarts in the engine to make sure the pump dont go dry.
I run 20/50 vr1 synthetic in the engine that starts out new a dark blue color
I dont really know how long this damage was progressing the oil only has 800miles on it..

 

looks like its been ran out or low on oil maybe a few times with the amount of wear on the bores ,thats all i can say from experience ,, damn, Racing 20/50w is pretty thick ,, you think a volume problem from it being that thick on a stock pick up ? Just curious because we have ran a motor bone dry (sucked the pan dry) at about 1100 ft before the quarter and it showed 20 psi oil pressure under 35psi of boost at around 1000ft mark on the data logger ,the motor didnt look as bad as yours with 10/40w ..