May be I am missing something but if the engine was NOT built by the shop in Dallas (whoever they are) why would anyone even consider going after them. That's what is wrong with America today. There always has to be someone to blame if something goes wrong in ones life.

Nobody had to mention it.. The pressure plate fracture yelled it at me.

That simply does not happen under normal circumstances in my experience, even with exceptional track usage, and abuse.

That much CR with one set of plugs on modern fuel is asking for it. We also do not know which set of plugs were firing. If it was just the bottom set, well the cylinder pressure would be even more wigged out.

Sounds like a sperfect storm to me. Sweep the parts in a pile, and start over.. Or give up, and buy a Miata

I thought the exact same thing.

LS swap, lighter, faster, cheaper, better... ;) Same applies with the above mentioned Miata solution.

It’s not funny anymore...


Sent from my iPhone using Tapatalk

Tuff to see this Allen . Happened to me a few years back. Po failed to give me receipt for engine work he had done. Mine blew through the top. Had to buy another engine. Cost 10k in 14 and took about 4 months to find one. Got another 3.2. Good luck. Couldn’t find a 3.6.

Clutch plate and rod bolt carnage simultaneously? Could have been a hard landing from airborne event?

Show pics of rod bolt...

As I said in posts #35 and #36, I believe it was over-revved. The engine was highly stressed at 11.5 and there were/are weak links in the chain which caused all hell to break loose. Obviously, something went very wrong. These engines do not really like anything north of 6500 - and people forget this (even when they build them and use so-called special parts). This is no Ducati where you can ring it to 11K. With that amount of compression if it's wrung out to a high amount and the throttle claps down quickly for the next shift seriously crazy s**t happens.

was it ever?...

LS swaps are a huge PIA.

Most are hack jobs.

All need at least a 930 transmission or a loaf of 915 tranny’s to constantly switch out when the torque limit is exceeded at every agressive launch.

Thank you for the responses and the empathetic commiserations.
A few things to help set the record straight.
The rod bolt definitely broke and I will post a pic of it, as soon as I can get into daylight.
Only one half fell out the drain plug when we drained the oil.

The engine builder that assembled the motor long block for me is not connected to the shop I was working with in my area to correct my clutch issue.

I have seen engines detonate from over revving as a consequence of downshifting at speed, missing a gear and exploding the engine in this fashion, but never on the way up to a rev limited max rpm, particularly when the engine is balanced, has stronger than factory valve springs and has a conservative rev limiter. Also, after seeing the road location of the engine explosion (evidenced by the oil trail) There is not enough distance for the vehicle to travel from the stop sign, to have gotten to an engine speed that could threaten the engine. it was 20-30 yards.

If the rod bolt was too loose, then I think we would have heard a horrible clatter, before the explosion and Im told there was no such indication. Which leads me to suspect the rod bolt failed from a material breach or a torque problem at assembly. I have not opened the motor to have a look inside yet.

The car only ran on a single plug set-up for 8 days. It was gently operated and I switched the operational plugs at the half way mark, just to make sure both were working. After having done so much of the work on the car myself, I have become very connected to the way the car 'feels' and I detected no unusual temps, vibrations or noises during that time.

My hope through appealing to you guys, is not so much to pass blame but rather to hopefully get some informed advice from anyone who may have gone through something similar (my sincere sympathies) and go about the correction process as sensibly and frugally as possible. If there is a reasonable ownership that should be taken here, I would like that to be honored by the responsible party, but until I get more diagnosis, (and perhaps even with it) I think it's is going to be difficult to pin this issue on one person or event.

Assuming the heads and the top of the motor are all fine, what parts do you suspect I will need to replace? Or what alternate engine configurations are worth considering at this point? Is the case salvageable with a good aluminum welder?

I don’t have any knowledge whether the case can be repaired, but I’d talk to Ben (mb911) for his opinion. I think a thorough postmortem would be appropriate and I’m sure ARP would want to see that rod bolt as well.

Exactly this.

Bone-headed move to drive the car around on a single set of plugs. Also, could it be possible that this was detonation with a misplaced downshift over-rev??

Im thinking Jb Weld. Heck ts better than an LS swap. My brother got by for many years with a windowed vw

Unforunatly the case is shot. Once you tear it apart there may be salvageable parts. A case (if you can find one). Will cost 1-2k. I was able to salvage some parts. The crank shaft was saved.

Mine blew up off the light shifting from 2nd to 3rd. As some shoddy work helped it. But it was running fine right till it blew
http://forums.pelicanparts.com/uploa...1536068102.jpg

Depending on whether the shop takes any responsibility maybe you should discuss the possibilities with them. I’ve never had to make a claim like this on my garage keepers liability but I think it would cover it. This may be far cheaper for them then it would be for you. Split it with them. Offer to cover the deductible and then some. Unless they are the A to Z shop and they built it originally then I would would be more inclined that they cover it completely assuming it was builder negligence. If it turns out to be from abusive wear and tear then maybe lick your wounds. If their insurance covers it and the insurance has sufficient evidence to blame another shop for negligence they may pursue the other shop for re-imbursement. It’s nice to let the insurance companies spend money on legal fees versus you

^^^ No way I would chip in on this as an owner.

"Exiting the freeway the clutch broke." The clutch is replaced and 30 yards later the rod comes out the block.

In my best Spock voice; Driver error is the only logical explanation Captain.

I have seen rod bolts fail under the strangest of alleged circumstances. Driving through the pit lane failures, failure at start up, but something has to set that failure in motion though.

Improper torqueing of rod bolts i.e. stretching too far upon install can cause a long drawn out failure. Overrev (most common, causes overstretching) causes failure. Lack of oil (sounds doubtful in this situation) causes failure. Light pinging for an extended period weakens things, thus causing future unexpected failure. Light detonation/pinging is difficult to detect, but IMO that is the smoking gun that set this particular failure in motion.

I feel for you, but this is the price of admission one pays when building and running a very custom arrangement, or just running one of these cars in general. Stuff happens, and from a liability perspective it is not possible to say it's one specific issue with a specific cause for there to be tort action.

i dont understand why in this world there always has to be someone else to blame. ( yeah I get it, America is the land of litigation" )
Engine is built way beyond Porsches original spec, intentionally driven in a less than optimum condition, and when it explodes " lets start suing people"

Engine mods is a high stakes game, if you are in the game it comes with risk.
I would have thought completely different if it had been a completely stock motor that grenaded after an engine rebuild by a professional Porsche certified mechanic to stock.

sorry , just my opinion , I'm sure others wont agree.

I agree with theiceman. But the OP is not looking to blame or litigate, he's looking for rebuilding advice. It's the other posters who are getting their hackles up. Some of those are not in the USA, I'd add ;)

There’s liability in the business of building engines and repairing cars there’s also a downside to getting paid $20,000 to rebuild a motor. It can be a high-stakes game for the shop as well If they did something wrong. It’s not all peaches and cream you want to get paid the big bucks to build motors there may also be circumstances like this where you get to chip in and help out. I’m certainly not recommending suing I’m recommending having a discussion with the shop and see what they may be willing to do to help. I may be naïve in thinking this but I feel that upon tear down the cause can be narrowed down.

I would say he’s getting his ducks in a row and that may include involving the shop but he doesn’t want to be out of line and accuse somebody if the consensus is that it’s not their fault

Anyone notice the centrifugal oil flinging on the PP?

Exactly. No sense whatsoever chasing that rabbit.

I'm just looking forward to seeing the carnage on disassembly. The light pinging caused the rod nut to back out = failure. other rod nuts will be found to be loose as well. That's my pre-disassembly guess.

Race engines are going to be no warranties expressed or implied, and it would be nearly impossible to prove negligence in court. In this case its clearly better to move on. It's good to want to understand the failure to prevent an encore performance, but the car owner should be holding the bag here, unfortunately.

There is a Pelican that has been posting about bringing a new case to market. User name Catorce (or something similar). I haven’t seen an update recently but maybe you could start with one of his new cases and salvage enough from the old motor to keep rebuild costs to a minimum. That’s probably cheaper than a whole new engine.

I would definitely vote for having a 3rd party engine build to do a tear-down to find the smoking gun. Doesn’t make sense to re-create this engine if you don’t know the cause of failure.

My 2 cents on Blame. There’s three party’s involved. No one will except blame because others were involved. That’s it. Do you want to pay to take it to court? Use the money for new engine. Or sell car as roller. I would take apart the engine yourself. Yes the bolt broke but was it manufactured for a twin plug engine? If so than that’s the best place to start. If not move on and see what can be salvaged.

Oh and the guy making cases was making 3.6 cases.

Not as I understood it. It could be used for several different displacements.

Good grief, the OP hasn’t asked who to blame. He’s asking opinions on root cause and how he could/should move forward from here. Fair ask. Others are reading too much into it.

I have had this happen to a race motor, it sucks. Rod bolts break because they are over stressed, either from installation error(low probability), or material issue(if real ARP-very low to zero probability), or over revs(most likely).

Given 18 months from build to failure, you can pretty much eliminate the engine builder. Even if he made a mistake, it's too late to prove it with any certainty. If you are reasonably certain you haven't done anything (the flywheel could point to you), the most likely culprit is the current shop. Over revved it on the first test drive and took it out to make sure it was ok, again, no way to prove anything so a dead end.

As to what is damaged, it could be a lot. If the intermediate shaft got destroyed, all the valves could be bent, and possible the heads also. When I did something similar, I had nothing left but an intake manifold and carb. Even cracked the trans case. No way to tell till you look inside.

On the other hand, an optimist would say maybe everything can be saved. But you would have to have multiple lottery winner good luck. Most likely the entire crankcase and everything inside is junk, as is at least one cylinder/piston/head. If your heads are good, an engine builder would be your best bet in finding what you need.

Best to start looking for a complete engine

The shop where it broke may have some options to help. Sometimes when it happens under their watch they are willing to help out in some way. Ya never know but reaching out to see if the have any motor options or relationships at their disposal would be a suggestion. I bet they would be willing to help in some way.

The one thing that a lot of car customizers, hot rodders neglect to think about is how a judge will see circumstances like this. When a judge hears something like a $30,000 engine build or a $50,000 paint and body restoration the shop better be prepared for some consequences if their product or service fails. After all an oil change is $24.99 and a paint job is $299 on all the TV commercials

You get a judgement.
It don't end there.
Get out the hazmat suit.

No it’s 3.6 case. The thread talks about the possibility of other cases. Don’t think it is ready yet. I think it’s hard to cast and machine a case :D

That's interesting.

http://forums.pelicanparts.com/uploa...1535933756.jpg

Also, are those cracks between 12 and 3 o'clock on the PP ?

Yes, and at 3 oclock

Check clutch pedal travel.

does that year have an over rev limiter. many ass holes have thought they could handle a porsches acceleration....ask me how I know..