[ds968]

Thanks, still trying to do this through experienced friends and known commodities first ..and if that's not something which can work out for whatever reason , I'll get in touch with Bauer , and go from there .

Partial Post: Please Login or Register to read the full post.

[Chris Vais]

Anything new to report about your engine failure?

Partial Post: Please Login or Register to read the full post.

[ds968]

I was in SoCal last week, Flash and I met with a very reputable individual who is an expert at rebuilding 968 engines, and has done multiple ones over the years.. including SC'd and Turbo'd 968s . Also,he has everything needed for this job all in one place, so I'll have the car transported there for the job . Ryker knows him well, and the guy is doing this , in part as a favor to that relationship, because nowadays he is only interested in " rolling up his own sleeves " for special projects. Once I get the car there , and he opens up the engine I'll post the findings ...

Partial Post: Please Login or Register to read the full post.

[Rap]

Perhaps this is the time to get everything possible done to this engine.

Partial Post: Please Login or Register to read the full post.

[ds968]

Agreed, and although the head has been rebuilt less than three years ago, there is no way to tell how meticulously the job was done so that will be looked at as well. Also, since there were some visible metal flakes in the drained oil ( nearly microscopic and very sparse, but still .... ) the entire engine will need a thorough cleaning, and a new oil cooler , lines , etc. But above all , the condition of the cylinders is the biggest nail-biter for me, not just because of the added price if one of them is shot beyond refurbishing and I need a new block ( since sleeves are still a very much debated option ) but also the time it might add to the job . Although he does have a couple of totaled 968s in the salvage yard, so maybe he'll be willing to pull the block from one of them .. We'll see..

Partial Post: Please Login or Register to read the full post.

[Rap]

Good luck. Having gone thru this I understand the snowballing disconcerting feeling that you're experiencing. It will be over at some point. Keep your eyes peeled for that light at the end of the tunnel!

Partial Post: Please Login or Register to read the full post.

[Waylander]

while your there see if he has a spare rear hub

Partial Post: Please Login or Register to read the full post.

[az968]

I hope the mechanic is able to find the cause of the failure to know if there is a new maintenance protocol to create or a part to keep an eye on. And that the fix isn't too hard on your wallet!

Partial Post: Please Login or Register to read the full post.

[ds968]

Once he finds what broke in there to seize the engine, I think the cause can be deduced and with probably a fairly high confidence level..

Partial Post: Please Login or Register to read the full post.

[flash]

i sure wish you hadn't have lost that piece.  the suspense is killing me.

Partial Post: Please Login or Register to read the full post.

[ds968]

I know, that drove me completely nuts when I realized it's not in the plastic bag in which I put it and brought down specifically for that reason . The bag's top ( push-seal type ) clearly did not seal well enough and the piece dropped somewhere along the way , but it was not in my travel luggage . Arrrgh.    But I think the reasons Trevor, Arash, as well as my mechanic are fairly convinced it's a piston ring and not a rod bearing piece re : 1) the curvature is very mild /gradual, as opposed to a bearing curvature which is more pronounced when one looks at photos of those, 2) it's narrower than a rod bearing and 3)  the silver-ish colored flakes noticeable ( though barely so..) in the drained oil could point to aluminum cylinder scrapings..not anything which might be produced by rod bearings or crank scoring, etc..   just theory at this point . :glare:      

Partial Post: Please Login or Register to read the full post.

[flash]

it does look like a ring.  it's just not common for a ring to fail all by itself though

Partial Post: Please Login or Register to read the full post.

[jfrahm]

Yikes.  I would look for signs of detonation, which can break ring lands.  Supercharged motors are susceptible to tip-in detonation, getting boost when the engine is at light load / max spark advance for cruising and the boost comes on.  You can get a pounding before the knock detection pulls out timing or the engine switches to a higher load map.  Since unlike a turbo the supercharger is already up to speed and ready to deliver boost the boost can come on very quickly.  Sometimes when this happens you can feel a bog when I think knock detection is doing it's thing.

 

Hopefully you can find a short block.  Definitely remove clean the oil check valve in the head as well as the oil passages, variocam, etc.

 

-Joel.

Partial Post: Please Login or Register to read the full post.

[MCL968]

I am still going with the lower of the three oil control rings. Closest to the bottom of the cylinder and softer metal which would allow it to conform to the cylinder and eject with the blow-by exhaust gasses into the crankcase.

Partial Post: Please Login or Register to read the full post.

[ds968]

So then what exactly would be the component which completely seized the engine ?   

Partial Post: Please Login or Register to read the full post.

[flash]

it's not likely detonation related.  the proprietary programming i added prevents the "tip in" issues. i had a map created specifically to deal with that, as i was concerned about abrupt downshift rpm changes that can happen on an automatic.  i also mapped in a LOT more safety on the tip programming than i did on the manual programming.  i went rich deliberately, and pulled back timing in areas that were even close to being problematic.  it cost some power, but since this was the only tip kit, i felt it was better safe than sorry.

 

that being said, having the engine rev up high and stick there may have been the cause.  not sure what would make it stick.

Partial Post: Please Login or Register to read the full post.

[jfrahm]

Broken rings and lands can seize the engine for all intents.  It has even happened due to galling when assembling a re-bored or honed Alusil motor.

 

I would think to have enough timing out on cruise to prevent tip-in you'd get poor cruise MPG.  Light acceleration with boost, light throttle, closed loop is exactly where I'd expect to see a motor scuff a bore or break a ring land due to detonation.

Partial Post: Please Login or Register to read the full post.

[flash]

this is exactly why my kit is different than every other kit out there.  it's all in the programming.  you cannot have the condition you describe with mine.  i spent a LOT of time and money making sure of that.

Partial Post: Please Login or Register to read the full post.

[ds968]

The car is getting picked up this morning and transported by helicopter ( ok, fine ..by truck ) to its treatment facility in SoCal.

Partial Post: Please Login or Register to read the full post.

[Chris Vais]

So when do you begin your Cabernet Sauvignon "treatment"!!!

Partial Post: Please Login or Register to read the full post.