598 ford breaking rods cylinder 2 and 6. any ideas

onefastpickup wrote:I think the Pistons are .020 in the hole if I remember  right.

any signs of contact on the head? Your bearing look like this? https://servimg.com/view/14447774/343

the bearing didn't look like it was pushed out. The upper bearing on #2 looks melted to crank the lower cap wedged between the crank and the #1 piston cant get it out to see if the bearing is still in it.

Another thing to check....make sure the bearing is not touching the radius of the journal. It can touch and still have side clearance.

Then bearings should be chamfered or narrowed.

Lem Evans wrote:Another thing to check....make sure the bearing is not touching the radius of the journal. It can touch and still have side clearance.

Then bearings should be chamfered or narrowed.

X2....if its a chamfered put in backwards it wont have enough side clearance. the narrow works either way. its easy to miss the details, for me anyway.

What lifters in it? I had this problem with and engine, crower forgot to plug one side of the oil hole and it pumped all the oil to the top. The restrictor in the block will not save an engine if you have this problem. Crower told me how to plug one side of the lifter and the engine stayed alive.

the are the crane pro series off set lifters. I had about 60 runs on this engine then installed a new cam with the changed firing order. Then I installed new bearings. Kasse oil pump and that's when the rod problems started. I had 12 runs when the first rod broke. Then had everything rebuilt or replaced then went 8 runs and broke a rod again.

From what has been said ... it is a bearing problem probably caused by an oiling problem under competition G loading; not a connecting rod problem.

I always ran the stock SC jet pump before with out any problems. I had kasse check that pump 3 time for me always came back that it was ok. It has the moroso drag chassis rear sump pan.

When you changed cam were the lifters installed link bar inboard? Some of the eliminator block had lifter bore wear problems maybe yours are bushed.

Always been towards the center

Make sure that lifter body isn't getting out of the lifter bore letting it dump oil. I remember something about smaller base cam and one type of lifter causes such a problem. I'll see if I can find the thread....

Here's what I know I removed all the other bearings none have signs of oiling issues. I measured the journal next to the rod that busted it is 2.199. I called oliver and they told me the new rod big ends would of been 2.325 the bearing that is in the other rods is 743hn that says .001 with no other markings on it. no x or - does any buddy now how to figure the actual clearance with this info. maybe it was a side clearance issue but I have no way of knowing that now.

Don't know, but I would mike it and plasti gauge it against the known good rods to see where it stands, regardless of the numbers.

good reading on the lifters.... http://www.460ford.com/forum/showthread.php?t=194842&page=2

The rod bearings should be marked upper and lower if they are installed incorrectly it will cause side clearance issue. Sometimes they are marked with a "U" or "L" after the part number. I would still investigate the lifters and cam for any oiling issue to rule that out. The engine that let go because of a lifter oiling problem for me lost the number 2 rod bearing and all the others looked fine.

what was the oil presser going down track,and going thru the lights?


and hot at idle?

Hot idle was 30 psi trap was 70 psi

.001 on the bearing is going to decrease clearance by .001 ( one thousandth )

Yeah I think there was clearance issue probably 2 tight