DP #24 Engine failure....

[Alan Roehrich]

Drooze,
Valve contact with a piston won't cause "peening" of a bearing, nor bluing of a crank or a rod. The valve contact came when the piston got loose from the crank. You have two instances of piston to valve contact on one piston. That tells you it was coming loose once and there was minor contact. In order to hurt a rod or a rod bearing, the contact with the valve would have to be severe enough to do massive valvetrain damage, either in one location, or spread over an area.

You had a failure in #3 rod, not in the valvetrain. Period. Either the rod bolts failed because they were either over stressed or not fully preloaded, or the rod got out of round and grabbed the crank and it failed the bolts. Bluing is one of two things, poor lubrication, or a rod bore out of round. The only other possibility, and it is rare, is a crack in the crank, which, by the way causes the journal to be out of round, and usually causes an oil pressure leak.

One other possibility is the wrist pin seizing in the piston, that will either pull the rod throw out of the crank, pull the wrist pin out of the piston, or pull the rod off of the crank. It will be obvious if the wrist pin was seized.

If you've ever seen a timing chain system work, you'll know that what you're describing is nearly impossible. Timing chains don't work that way, and harmonics won't make them work that way.

You are free to believe as you wish, the parts, money, and time belong to you and your father. I've been doing this for 30 years, and Adger has been doing this about as long as I've been alive, that makes for about 80 years of combined experience, and it looks to me like neither of us feel your explanation is plausible.

[art leong]

I tend to think the valve hit the piston after the problems with the rod started. Maybe the rod bolts stretched causing the hit.
If the bearing looked good but there was heat showing on the rod could side clearance have been a problem? The bearing should have been toast way before the rod showed heat.

[Chris "drooze" Wertman]

Originally Posted by art leong

I tend to think the valve hit the piston after the problems with the rod started. Maybe the rod bolts stretched causing the hit.
If the bearing looked good but there was heat showing on the rod could side clearance have been a problem? The bearing should have been toast way before the rod showed heat.

Side clearance looked good before chassis dyno....didnt look after but cant imagine that much lunch after engine dyno....looked good was checked , but I just dono, what makes 1 fail faster than another, clearance.........

The rod bolts stretchin could have cause a hit I guess, anything over 080 would have caused an exhaust hit, in the pics though, well for it to hit that square in the pocket it still had to be attached to the rod I think and it was a tdc when it happened, but streched bolts, certianly I think now, didnt before....or a shelled bearing maybe.

The force at which it hit causing the valve train damage....thats whats got me puzzled....

[gmonde]

looking over the pictures it looks as if the bolts stretched and broke and the rest is damage from rotating mass ,,in one of the pictures of the bearing halfs it looks as if one of the tangs is missing or flat(spun bearing?)(could be caught up in the damage) ,,,one thing i would check of whats left of the 7 rods and pistons is if the big ends are still round ,,maybe the rpm is taxing the bolts or the bottom half of the rod cap is just flexing egg shape ,try to retorque the bolts to see if they will turn(they shouldnt)

i hate to see that damge on all the hard work and money that go's into this stuff

just my 2 cents gmonde

[art leong]

I think the rod bolt failure is the cause. Thats a heavy piston and rod. And when they change direction on the end of the exhaust stroke. There is a lot of force to make the change.

[Chris "drooze" Wertman]

Originally Posted by art leong

I think the rod bolt failure is the cause. Thats a heavy piston and rod. And when they change direction on the end of the exhaust stroke. There is a lot of force to make the change.

Art....I now would agree 100%.....after what Alan, and some others have said, and thinking and rethinking it through, as well as getting the spec on the bolts that were in there, AND yesterday I didnt pull it down, the old man did I was busy with other things, he left 2 rods in and the bolts were in fact "loose" or as gmonde said, well 1 on each "turned" it shouldnt have, no doubts....

Im still a little at a loss as to how exactly I did the valve train damage but if it let loose at the very top of the stroke which it would have well I guess thats where the PTV contact occured....it must have "bounced" then off that valve as there is no other damage to the chamber or piston and headed down to the "rod chipper"

I looked very carefully at the bolt shears 1 is clean the other torn to a 45 degree peak across the plane.

So I may have ovrthought the living ****e out of it, but thats ok......"I get by with a little help from my friends".......and I mean that to all that a)Talked me through, down and over it. b)were constructive and helpful and that was every single response in this thread. every single one......

Thanks to all the CR people and I mean that....

I had only what I have seen before, and it was a "chicken and egg problem" and it didnt meet occams razor, this does and it shows to be true.

The rods are actually round (im suprised I had heard others engines after being run were not) AND the rods didnt break, the bolts did, much easier to find a suitible high tensile replacment than get a rod approved.

I have 2 sets of bolts here (good) I am shocked at how close they measure within .007 each ?!? across 16....maybe its a batch thing. BUT the bolts that came out of the engine ? I quit at 5, I could SEE differences....now I didnt measure them new....but that seems like a lot of variation....Ill bring em in a bag......

2 days ago my daughter warned me what caused it and I didnt listen....we were driving down the road past a stretch of wooded marshlands, she said "daddy I know what lives in there" she exclaimed....I said really, expecting to hear owls , turtles....NINJAS, they live in the TREES ! I almost wrecked laughing....She just turned 4....a bit later in the day something was amiss and she said matter of factly....Ninjas did it.....

You would THINK Hemi Ninjas wear orange and would be easy to spot.....hmmmmm......damm ninjas...

Thanks all.....see Im trainable And grateful.......

The egg came first it would look the the chicken smacked the valve...

[Rich Biebel]

See my next post....oops...

[Rich Biebel]

Wow.....that is a terrible looking mess of parts......

From what I see...it appears to be a major failure without a spun bearing or anything related to friction in the rods or crank.

Difficult to determine what broke first as most of it is collateral damage after the initial part failure....

Is it possible there was contact with something you overlooked at very high rpm? Like a rod hitting the cam or the block somewhere......it would easily explain the abrupt failure of the rod or rod bolt .......

Something either flat broke or something was hitting something and caused the breakage......

The parts don't look to be poor at all...... even the rods look fine and the bolts appear to be decent...maybe std material, and they are usually pretty fair.....

Anytime I have an event like that I get rid of the busted up stuff as quickly as possible.....I have this thing about blown up parts....I don't want their bad Karma to attach itself to any new parts I get.......SCRAP that mess ASAP......Learn what you can from it and JUNK that stuff......LOL

[Alan Roehrich]

The pistons are not heavy, neither are the rods. You should try my stuff. And we go through the lights at over 7800 RPM.

STOP building another engine until you KNOW what went wrong. Trust me on this, I've been there. In your rush to get back to the track you will learn nothing, and spend thousands. I know, I did it. What you are going to do if you keep rushing is waste a year you could be learning, and put yourself 1-3 years behind. You will not catch up easily. Stock Eliminator is different than anything you've done.

Hang in there,

Good Luck