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jeanette

Hi everyone,

I am in freakout mode... the trusty '79 just had major engine meltdown 300 miles from home.
Need some advice on buying a replacement engine, and where to even start.

jeanette
Totally bummed out

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morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

what do you mean meltdown?
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fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

That really sucks.
Have a friend with a truck and a trailer? If not, Uhaul will rent a truck and a tow dolly/trailer. Also the 924 can flat tow pretty well behind nearly anything, but it isn't a desired solution over that distance due to potential safety issue.

I'd post a Wanted post for a spare engine in the FS/W section and gather yourself an engine to rebuild. You can also look on Craigslist and http://car-part.com/ for donor engines (Note: the 76 motor has the 125hp high compression if you can find one, otherwise all of the NA motors should bolt right in).

In the meantime, I'd look at buying something cheap and reliable to drive (if you don't already) while you freshen the 924's motor.
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Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

jeanette · Posted: Thu Nov 13, 2014 3:39 am Post subject:

All I know right now is that Duane called (he was heading in from AZ) "somewhere south of Sacramento" and said "MAJOR problem.... piston fried..."
Right now he is trying to rent a truck + trailer, and also trying to decide to go back to AZ (all the serious tools are there, but twice the distance) or keep heading up to Humboldt (300 miles of twisties)
Sounds to me that this time it is new <---(sic) engine time, as the head was less than terrific from the previous owner (MANY years ago having it shaved ... a no-no).
Sorry if this post reads like a rambling mess, but then these cars have all been so perfect, I am having a time wrapping my head around one of them being really "un-well"

jeanette
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"person who says it cannot be done should not interrupt person who is doing it"

924RACR · Posted: Thu Nov 13, 2014 3:47 am Post subject:

Gack... my condolences...

Even if a piston's shot, and maybe a replacement head's needed - the bottom end ought to be happy. Of course, check it out, and new rings for all would be indicated - but I'd definitely be inclined to work with what you have...

Best of luck... holler if you need more suggestions/directions...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

Is this a turbo or a NA?
How can a piston be fried?
Did it run without oil?
Did it run without water?
Did it run while overheated?
This sounds like he driver is overestimating the problem/damage.
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fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

I should note that I drove mine home from Bellingham to Portland with no alternator, a cracked exhaust manifold and a shattered exhaust valve (so three cylinders). They are tough damned motors.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

fiat22turbo · Joined: 18 Jan 2006 Posts: 4040 Location: Portland, OR

jeanette · Posted: Thu Nov 13, 2014 4:44 am Post subject:

Is this a turbo or a NA?

1979 NA

How can a piston be fried?

Let's just say that a piston (I don't know which) got hot and bothered enough that it's no longer acting like a piston.
Fried maybe even crispy fried would be an apt description. It was more than poached or gently simmered to get to that state.

Did it run without oil?

To be determined, although the oil pressure had too have been good or Duane would have shut it down. Actually he would have never set off on the trip with an oil pressure/leak issue.

Did it run without water.

To be determined, although there was no over heating. This happened at 2AM on I5 freeway speed was at 80 MPH.

Did it run while overheated?

No.

This sounds like he driver is overestimating the problem/damage.

I really DO hope that is the case, but Duane has been rebuilding engines since he was a kid (something to do when not driving tractor on his parents farm).
If he says major, he is unfortunately ... right.
Then again, this was at 2AM....

Oh well, it will get fixed.
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"person who says it cannot be done should not interrupt person who is doing it"

jeanette · Posted: Thu Nov 13, 2014 5:33 am Post subject:

If an injector is plugged and fails to provide enough fuel, you can run that cylinder lean and burn a piston fairly easily.

On mine the exhaust valve shattered, likely due to the cracked manifold allowing cold air to hit the valve? Either way, piston was fine, it just ran on three cylinders and had no compression.

Also a stuck or failed lifter/bent valve can cause problems.
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This looks likely, as the car was having some problems last year with one injector not providing enough fuel. Injector was replaced, but still there were times when the start up would be on three cylinders briefly. After the car was moving, there was no other signs of missing or pinging under load.
Might be further up line from the injectors, like a fuel line. Hopefully not the fuel distributor.
Boy when you don't know, your mind can go to dark places!
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"person who says it cannot be done should not interrupt person who is doing it"

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

That is some bad luck.
When i first got my 924 more than 10 years ago, i didn't know much about engines and the first month i drove it in 3.5 cyls as one of the injector was not delivering. I bought new injectors but the situation was worse, the actual problem was the fuel pump not being able to deliver.
I did drive the car sportly back then but no engine problems...not such long trips tho.
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924RACR · Posted: Thu Nov 13, 2014 7:43 am Post subject:

Gack - but still not unrepairable.

Yeah, sounding like one cylinder might've been lean then. Leakdown and compression tests would probably be good, I'm sure Duane knows that. Borescope would be nice, but not a cheap date. One of these days I need to get one...

So might have to run a test on the CIS when the engine's sorted, make sure all 4 injectors/lines are putting out properly... switch lines/injectors between ports if one is indeed low... and if the problem doesn't move, them time to rebuild the fuel dizzy (or have the DeLorean guy rebuild yours)...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

jeanette · Posted: Fri Nov 14, 2014 12:42 pm Post subject:

Welp.... it is ugly.
I have a photo of the pistons with one obviously destroyed.... need help with posting it for the non-squeemish.
ONE piston fried to a crisp, no, actually melted on the top, the others look fine.
Car blew a water hose after a patch of rough road (almost tore in half, so a lot of water was lost very fast).
Prior to that the car was running almost too cool for the first 600 miles of the trip.
But still, that one piston had been extremely unhappy for longer than a water hose failure/overheat event.
Duane had just replaced the head (about 700 miles ago), and the injectors were all replaced.
Two months ago, Duane checked the spray pattern of the new injectors, and they were all uniform when he also replaced the fuel pump.
Brand new Wide Band was reading 14 to 14.5. even after the failure was happening.
Duane now is worried that that was too lean (?)
He also heard a noise, more like a buzz, not pingging but thought it was a rattle in the dash, when it was probably the piston starting to go south.
Duane says there a lot here that is Bonehead Award worthy, but he wants it posted as a heads up (dontdowhatidid) anyhow.
More later when we dig into it.
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"person who says it cannot be done should not interrupt person who is doing it"

jeanette · Posted: Sat Nov 15, 2014 4:46 am Post subject:

https://www.facebook.com/photo.php?fbid=10204858012627492&set=a.1784260523683.2105580.1154601427&type=1

Here is a link (I hope) to the image of the engine with the head off (Duane had it off at 3AM right after it "happened".
Pretty darned obvious that the piston is no longer a piston.
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"person who says it cannot be done should not interrupt person who is doing it"

morghen · Joined: 21 Jan 2005 Posts: 9102 Location: Romania

Cant see the picture, which piston is it?
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