DP #24 Engine failure....

[Chris "drooze" Wertman]

Ok, so I feel compelled to post this #1 for many other DP Owners out there, Ma Mopar, and Gary Stanton as well as several component vendors while I may never be a fan of I would have bet just about anything their issues caused ours.

These were not the cases.

The circumstances of the failure were as follows.
The car came out of the water at 8000 rpm give or take. My issue for lack of a burnout limiter.
It freespun, no load.
Rods exited the pan.
We were having issues with oil pressure or so we may have thought, we are still unsure about the sender / gauge combo.
We had a 3 quart accumulator in place and functioning correctly.

We took apart #24 DOA Engine #2 Here is what we found.

#3 Smacked an Exhaust valve HARD
Minor/Minimal scoring to the journal on #3 (dono about #4 will have to cut that one off)
Some bluing to #3 rod. top half
NO Breakage of Rod, or cap, both intact.
Bolts both broke at mating surface.
#4 Rod Z'd from the impact of the #3 Rod and Wristpin exiting the engine in castaspophic fasion. (a very intersting sight, it looks like it was made that way) and 100% intact. just well z'd to the wrong journal.
The rest of the engine internals took massive damage as it looks like (as in we cant find and there is a lot of metal unaccounted for the wrist pin of #3) shattered or was scattered around everywhere.
It appears the bolts sheared on #3 the assmebly broke free of the crank, on a subseqent rotation, (from the side scar on the crank) the crank smacked the rod from the side, and disloged the pin from the bottom of the piston.

All rest of the engine journals and bearings looked as would be expected on an engine that had full oil flow and only 6 or 7 passes, excellent to just like they should, no galling, no scoring, no oddities of any sort, Id run em again in an instant....that nice.

No damage (visible) to cam other than a bent pin. Billet Gundrilled cam, being sent back to manufacturer to be checked for microcracks/straighness and suitablity to be run again.

Someone who was present called before I tore the heads off and said "Ive thought about it an I think you smacked that valve hard and things went bad from there" I thought about it and I agreed maybe...

After much thought and discussion here is OUR , Me and the Old Mans conculsion. With someones initial and correct call (I would mention their name but I didnt ask them if I could)

The smack on #3 at 8000 (or where ever it happened below that) set things in motion as was suggested.

Cam backlash is where I come up, we are not using a stock chain but a double roller, and there is much more play in it than a "fresh" setup, the follower/tensioner design is adequate but was designed for street use, even in the aftermarket setup we are using, when the bottom freespun it backlasked on a very heavy (and ours is 4 lbs lighter than stock) cam, that allowed the tensioner (which its design would allow) to collapse from a ) to a ! this would allow the cam to retard by at least 6 degrees and the exhaust valve made contact. We have a very significant duration and VERY agressive ramp rates.

Clay testing on the engine prior showed adequate not even "marginal" on both in and ex at the advance I was running (4 deg) So...

The springs have a killer rate and pressure and weve had no issues nor has anyone else with them over 8500....

So this conlcusion seems to be the appropriate one.

The Rods (scat) I am actually VERY suprised that any I beam forged rod made in China took....its staggering. They are mutilated but intact not broken.

The workmanship of the assembly in the case of our bottom end, no issues clearances etc all looked to be spot on.

The bolts, well they failed but under the circumstances, I dont know that any wouldnt have.

The timing set and I wont name the vendor is the ONLY item I can look to.....there is a significant lack of availablity and choices for these engines many others with different combos dont have to deal with , that will change but for right now well....were "stuck" short of a custom setup. As well not even the timing set itself but the multi plate ) shaped tesioner that could collpse to a full flat condition, this is both the original and aftermarket design.

These are the things we saw, these are the things we did and these are the conclusions we have come to.

I post them here so as to alleviate any "finger pointing" or "uncertainty"

Some of which I may have caused by what I have said and not said.

I thought the rod gave, and well, I was wrong, it and the cap are intact. bolts broke and the rest was haging through the pan.

And I thought as did my father we had oiling issues, or the potential for them, this was incorrect as well from the clear evidence shown in the engine.

Pictures to follow as we upload them after I get on the road to Houston
Ill put Mandie in Charge of that

The reason it took so long ? Well , weve been busier than you can imagine re-rigging the trailer, broken truck, new engines, and business. So....here it it.....sorry it took so long, I know of one engine guy who has been loving our failures (the engine guy many are sending their DP motors too)

Cheers all

Have a safe and happy easter......