3.2 Engine exploded!!

[Allan Kelsey]

Yes, you read that correctly.
Its a sad day, but this is a story about what happened, with the hope that you might help me figure out where to go from here...

5 years ago I found a 1985 3.2 Carrera that was just right for me and purchased it.
I love these cars and never intended to buy or build a garage queen, but rather to drive it quite regularly.



I began the joy of slowly improving the car as time and money made it possible.
I then saved for 3 years to do a major overhaul on the car.

• New paint
• Rebuild my transmission
• Rebuild the motor and upgrade to 11.2:1 compression twin spark 3.2
• Redo the interior
• New wheels & tires
• Refresh window seals, glass and suspension

I stripped the car and pieced it out as I worked with vendors to restore my car.
I sent the engine long block to a reputable engine shop to source the final parts and assemble. Once it was assembled I picked it up, finished assembly and installed it with the new trans.

Life was good for 18 months. The engine HP increased to 255 at the crank and the car felt great. The car isn't perfect, but I did almost all the work myself and Im very proud of what I was able to accomplish with some careful planning and a lot of help from this forum. I learned a tremendous amount about my car through this process.

Then, I lost spark in the lower spark plugs.
It took a few trips to the shop to help figure it out, but we eventually identified the culprit, an ignition fault in the signal splitter.
While I was waiting for the ignition problem resolution to arrive, I was driving the car as a single plug and while exiting a nearby freeway, the clutch broke.



So I sent the car back to the shop to instal the ignition solution and investigate the broken clutch. Turned out to be a failed Kennedy Engineering Product Stage 1 clutch.
I sent it to them and they replaced the diaphragm and sent it back. The shop re-installed the new clutch and the ignition solution. Everything seemed good after the first short alignment test drive. I went in to pick up the car the next day.
Prior to arriving the shop took the car out for a quick test drive to verify all was good.
30 yards from the stop sign at the exit from their parking lot of the shop - the #6 conrod burst through the main case.



After draining the oil an ARP conrod bolt fell out of the drain plug.
It is obvious though from other shards that fell out, that the oil pump is damaged too.

After some diagnosis, it seems clear that the ARP rod bolt gave way, but whether that is from product failure or some other condition, I don't know.
I went to see the scene of the incident and the short 30 yards from the stop to the point of detonation, isn't enough distance to allow anyone to abuse the motor. Aside from which, the motor has a sensible rev limiter and stronger than factory valve springs that should prevent anyone from detonating the motor under acceleration.
Also, the shop has a strong reputation and I had the shop owner working on my car.
Im quite confident it was not their fault.

So..... Im now (probably) staring at a $15-20 000 problem.
I dont have the cash just lying around, which is why Im turnning to you guys.

Now what??

[rwest]

Man, I feel for you.

Was the bolt actually broken? Possible that maybe the builder didn’t torque that rod bolt/nut?

Best of luck in getting it sorted out.

[MARISOL78sc]

That is sickening. Maybe time to drop a 3.6 in! Best of luck and keep us posted.

[mikedsilva]

Gee, that really sucks - should we run a gofundme campaign? I think a LOT of pelicanites would chip in.

[juanbenae]

what do the piston, rings and wrist pin area of the rod look like?

[Steve@Rennsport]

Originally Posted by Allan Kelsey

After some diagnosis, it seems clear that the ARP rod bolt gave way, but whether that is from product failure or some other condition, I don't know.
I went to see the scene of the incident and the short 30 yards from the stop to the point of detonation, isn't enough distance to allow anyone to abuse the motor. Aside from which, the motor has a sensible rev limiter and stronger than factory valve springs that should prevent anyone from detonating the motor under acceleration.
Also, the shop has a strong reputation and I had the shop owner working on my car.
Im quite confident it was not their fault.

Allan,

I'm very sorry to see this as I know full well how expensive this is to repair.

Unfortunately, these issues don't just "happen" like it was an act of God; its always human factors so I'd strongly recommend having detailed forensics done to find out why this happened and how to prevent a recurrence.

To date, I've never seen a failed ARP rod bolt (and we've installed thousands), its always a bearing/lubrication failure of some kind. It can result from a poorly made bearing, a clearance issue, dirt (especially when its #1 or #6), insufficient oil pressure or volume, and a host of other things. Detonation can trigger this as well so that should not be overlooked!!

Good luck,

[Tippy]

I guarantee you that if ARP is the culprit, they’d want their hands on that bolt!

There isn’t much worse than ‘Uncle Rodney’ showing up, other than a totally munched chassis. Feel for you.

[pmax]

Ouch !!!

Originally Posted by Allan Kelsey

[*]Rebuild the motor and upgrade to 11.2:1 compression twin spark 3.2
...
While I was waiting for the ignition problem resolution to arrive, I was driving the car as a single plug and while exiting a nearby freeway, the clutch broke.

Will running a high CR setup without the twin spark do this ?

[Bill Douglas]

If the intact bolt fell out it would suggest it was not tightened to the correct torque and just fell out. If a broken bolt fell out that is another matter that APP might want to look at it.

[EdRogers]

Originally Posted by pmax

Ouch !!!



Will running a high CR setup without the twin spark do this ?

Sounds like that high of compression on single plug would cause detonation. How many miles were run with only the single plugs working? Can this wreak havoc on the pressure plate too? Wonder if it is all connected to the dual plugs being out for a while? That has to hurt, truly. Gorgeous car, beautiful engine! Sooo much work to make it what you want. My buddy has a 2.7 that was in a 914 that has the same carnage. At that point, it’s a short list of what you can keep. Such a shame for a street car. I’m looking at my broken head studs thinking I’m lucky right now.

[john walker's workshop]

You would think there would have been a pretty nasty knocking before the letgo. Nobody heard anything?
Never seen a broken ARP bolt either. Improper torque would be my guess if it came out intact.

[3rd_gear_Ted]

What kind of pistons?
How did the divots on the end of the rod get there?
Did the flailing of the lower rod cap when the bolt let go cause those divots before full seperation?
Is the failed clutch indicative of detonation also in some way?
So much metal cracking and catastrophically failing in different parts of the engine so close together in time frame is really odd

[75 911s]

The shop is suspect. Maybe they money shifted and then lied.

Who built it?

[Trakrat]

Originally Posted by Allan Kelsey

I went in to pick up the car the next day.
Prior to arriving the shop took the car out for a quick test drive to verify all was good.

Hmmm.... soooo... regardless of the cause... the fact remains that the damage happened while it was under the shop's responsibility.

I'm not sure what you are going to do... but if this happened to me, I would make sure I recorded and/or written down everything that was spoken to me and record a timeline of everything that happened up to that point.

I would also be contacting some lawyers to discuss my legal options... because as I mentioned, the car was under the responsibility of the shop while it was in its possession.

The only option you have on your own is to take the engine apart, assess all damage and start searching online for replacement parts. But I'd still contact lawyer before going this far, if anything just to protect yourself. After all... what if you found that the damage was caused from someone revving your engine WAY TOO HIGH?!

[Geronimo '74]

Sorry to hear about your troubles.
Hopefully you will be back on the road soon

Have a chat with the shop that did your seats as well.
Those wrinkled leather seats should be redone, IMO.

[Targa Time]

Could you show us a picture of the conrod bolt?

[Flojo]

Oh dear :-(
Sorry for you.

[proporsche]

Hi Allan..very nice 911 sorry about the troubles...but as Trakrat said ..totally the shop responsibility do not take no for an answer.......i also think the torque was not on that rod correctly done...unless you and ARP peeps will find some material flows..
Ivan

[Harpo]

WOW, so sorry for your loss. Completely agree that the engine rebuilder is most likely responsible here

[Flojo]

by the way, just a detail, nothing to do with the rod-fail... I read the shop did the rebuild and upgrade... why don't they seal this area according to the tech bulletin and as everybode here knows as well