298....tr6060.....67mm@20 psi.....in progress!

[Bobby]

not really it is all in how you look at it.

plus you can make more power pound for pound of boost, and our kit is almost half the price and includes every thing but the install and tune. our kit also will make 700 strait out of the box

 

[one eyed willy]

Oil-less triple ball bearing 67mm turbo upgrade!

 

[Bobby]

man that looks soo good in there

 

[Mike K]

That just gave me a hard on...

 

[Bobby]

lol

 

[Doug M]

sexy for sure..lol

 

[retfr8flyr]

That looks great!! Oil less is the only way to go.


Earl

 

[one eyed willy]

Last Sunday was doing some datalogging/tuning for low RPM drive ability. WOT has been dialed in for some time now. On the way home I was doing a 4th gear WOT pull, 17psi, around 6000 rpm the boost dropped and lots of oil smoke started pouring out......soon as I saw the smoke I knew what happened!

First issue found...


What can I do about a bad crank trigger wheel?

Oil pan....

Heads off.....

Piston out.....

Heads look ok, time to get the block to a machine shop for boring.

 

[retfr8flyr]

Damn I hate to see that, good luck with the rebuild.



Earl

 

[JeremyH]

Were those the mahle pistons that you were iffy about running awhile back?

 

[one eyed willy]

Were those the mahle pistons that you were iffy about running awhile back?

Yup! I'm not sure if the broken crank wheel contributed to the problem? I also don't believe my rings ever fully seated. Since the motor went in I have been adding oil to it.

Ill drop the block off on Monday for boring and cleaning, then order the custom pistons once they can tell me how much they end up boring.

Did you see the crank wheel? Anyone make a billet version?

 

[GB10]

MMR does, but you have to use a different timing chain gear since the wheel is thicker. They are the only ones I know of that make one, so you might have to get it from them

Most likely your trigger wheel threw off your timing which lead to the detonation in that cylinder.

 

[AbdullaGT500]

Most likely your trigger wheel threw off your timing which lead to the detonation in that cylinder.

This^ Sorry to see this, I wonder if you can have an OEM crank trigger wheel cryo treated?

 

[bmaxwell]

So another motor?? Damn...

 

[ZmanM3]

That sucks, on the other hand you are becoming very skilled at engine building. Too bad it is costing toy a ton.

 

[tmcolegr]

I'm going to speculate the crankshaft trigger wheel is a separate failure mode than the piston failure as only 1 piston failed**. Had the trigger wheel been the root cause, more than 1 piston would be damaged.

Trigger Wheel Failure
I agree the trigger wheel failure was most likely caused by the harmonic balancer being insufficiently retained (not necessarily loose). What brand timing gear, balancer and retaining bolt? If OEM bolt, was bolt reused at time of installation? If you have the motor completely disassembled, I would suggest installing the timing gear, trigger wheel and harmonic balancer on the snout of the crankshaft and confirm the balancer, when tightened with the original hardware, does/doesn't properly secure the trigger wheel. Another method would be to install the timing gear and balancer only without the trigger wheel using the original retaining hardware. Measure the gap between the balancer and timing gear, then compare that dimension to the thickness of the trigger wheel. Is it possible the harmonic balancer retaining washer is bottoming out on the snout of the crankshaft prior to the balancer properly retaining the trigger wheel and timing gear?

Piston Failure
A single piston failure more than likely is caused by a condition which is cylinder specific: a bad COP or spark plug not firing correctly can allow or contribute to unburned fuel washing down the cylinder. Even an injector that is stuck open, has a faulty spray pattern or one that is leaking fuel into the cylinder could result in the similar failure or detonation.

**Are you absolutely certain only 1 piston has damage? If multiple pistons have damage the root cause could have been a single contributing factor or a combination of factors: timing, fuel quality, AFR or even the 4032 piston composition at your boost levels.

Conclusion
Don't have any preconceived ideas about what caused either of your failures or you most likely will see both again.

PS: if during the reassembly process you want to borrow any of the OEM 4.6L 3V specific tooling, I'm only a phone call away.

 

[one eyed willy]

Pulled the rest of the pistons and they look fine. I found a few interesting things. I bought this motor after it had been rebuilt last year($2k). 1 rod didn't match the rest, all are stamped "Manley" except one that was stamped "livernois by Manley", also different bearings used. I'm pretty sure all the rings didn't seat correctly from the amount of blow by I would get and the amount of oil it consumed.

So who knows what real condition the pistons were in. Now I'm debating what to do next, rebuild myself or send it off to livernois.

 

[Saleen S281]

Damn man...good luck with the rebuild. Seems like the start of one of those "Got a new 5.0/Shelby" threads.

 

[JeremyH]

Damn man...good luck with the rebuild. Seems like the start of one of those "Got a new 5.0/Shelby" threads.

Look in his sig where it says built not bought.... lol


On the birght side at least you know the turbo is good since there is no engine oil running through it!

Hopefully you are just an overbore and new set of pistons away from gettign her fixed. 2618 flavor of course.

 

[Bobby]

damn sorry to hear. i have the same problem with the crank trigger on my stock motor but it didnt hurt anything. that will cause the timing to change drastically