924Board.org

[Rick MacLaren]

Hi there,

Well, aham, I blew up da 931.

It was kind of unspectacular, however, as all I noticed was a ticking sound, and lack of power that later grew to be a loud 'knock' sound...or more like a 'bang' sound. It was caused by being starved of oil on at least one occasion. I think I blew a rod bearing when the oil seeped out from the dreaded three pipe thingy.

The good news is: A NEW Porsche 931 engine short block is only $5500 CDN. Why bother with a rebuild? Is it cheaper to just rebuild it 'tricked'???

PS: Assuming I first pay back Lars the $ I owe him...

_________________
1980 Porsche 931 C2H5OH/H2O injected 15 PSI
1979 Porsche 924

[ This Message was edited by: Rick MacLaren on 2001-11-06 07:31 ]

[Zuffen]

At my cost 5 years ago a full rebuild on the 931 cost 1200.00 that was rings, bearings, seals and clutch. Timing belt and tensioners too.

I cleaned the turbo, used the old pressure plate. Everything else was new on the internals.

I think you can get the items a little cheaper now.

I polished the crank and matched weighed the piston/rod assembly.

The head was rebuilt with new guides and slight shave for the heck of it.

After it was done the engine sounded like a F1 car, it hummed with a little swoosh from the turbo, no vibration, no buzz. It would rev to the limiter under load with no hesitation. The car hit 140 on a road trip to okc and there was plenty of tach left, It was only 5 weeks old and on the end of the breakin routine so I didn't want to push it yet. It could squack the tires into third running flat out.

God how I miss that motor.

_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951

[John Mueller]

What happened to it?

[Rick MacLaren]

I've got two engines and I can crank the one in my playroom with one hand...so I think that's the one that'll get the rebuild. I'm gonna get the Porsche dealer to do it.

[larso]

Why were you starved of oil? did that hose leak while you were driving and then a few minutes later, boom smack pop?

[Rick MacLaren]

Well sort of kinda...

I took the car in after a big oil leak witnessed by another 924 guy. Black oil leaked out at idle. Later, it was discovered the dreaded T pipe had cracked. Cost? circa $900.

Then, a week later, after racing a Mitsibushi 3000 GT on the 401 (I smoked him, by the way) a big-assed waft of black and blue smoke obscured his vision for around 1 to 2 miles...I said I smoked him didn't I? No red light...I thought I was safe.

Heh heh. Very embarassing.

Anyhow, after a $250 tow to Waterloo, and a new cam, and $1200, it still didn't sound right. Clicking sound. Loud head noise. I took it easy.

Then I was on the 401 again heading to Ottawa and the click turned into a knock. The garage didn't take any responsibility for it. They claimed it was starved of oil. Still, there was never a point in time where there was no oil in the car.

So I'm getting a rebuild I guess. I certainly won't be taking it back to that garage to have them do the rebuild.

_________________
1980 Porsche 931 C2H5OH/H2O injected 15 PSI -= More Piston Metal in the Oil Pan than in the Crankcase.
1979 Porsche 924 Tweaked.

[ This Message was edited by: Rick MacLaren on 2001-11-16 05:51 ]

[924RACR]

Build your own! Only way to make sure... rings and bearings are cheap and easy, and you can also easily hotrod it...

Need assistance? I'll be around (Detroit) for a little while longer...

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Rick MacLaren]

Actually, yes I would!

[Rick MacLaren]

I'll also get new pistons, and have them re hone the walls of the pistons.

[larso]

If you are rebuilding your engine, make sure the block isn't fu**ed! you might have to get a new one. It sounds like you hammered that engine up pretty nicely, I bet your crankshaft is bonded to the block by now LOL.

[Rick MacLaren]

Yes I think so. Thankfully I have another block.

[dwak]

Rick,
Sorry to hear about your engine's demise.
A decent 931 just sold on Ebay for less than your short block or you could talk to the following:
"Subject: 924 turbo engines
Date: Mon, 24 Sep 2001 17:12:00 +0100
From: Steve.Cheetham@cwcom.net
To: DanWakelin
Thanks for your enquiry,
I have a few 924 Turbo engines in stock all priced at &550.00. each one will
be stripped and checked and rebuilt if required.
Let me know if this is of interest to you.
Steve.
Lodge Sports.UK"
Just some leads I had. I've just brought my 931's back home with nothing done. The mechanic was taking too long to get started so I told him to take a hike.
dwa

[dwak]

Rick,
I just had another thought. Why don't you buy Nova Scotia Adam's engine and put all your turbo gear on it and see what happens. Please publish your results in this forum.
dwak

[Rick MacLaren]

Well I've been in touch with Adam about exactly that same proposition. I think I've frustrated him a little, though I didn't mean to do so. He's probably a tad pissed right now so I'm not bugging him about it.

I don't think it's revealing too much of our private talk to let you know what holds me back from buying it right now. Hey, I'm open, and if there's a way to solve his need to get rid of the engine and my need for a new block, I'm all ears.

Basically I've got a mechanic whom I want to guarantee the work. To do so, he insists he's got to have a lot of paperwork on the engine to feel comfortable reinstalling and being accountable. I too feel better with paper. I can see his point.

What I do not want, I repeat, I do not want, is to install the engine and have the mechanic pointing his finger at the engine builder. Look, I've seen exactly this kind of thing happen after a blow up, and it's far too unpleasant for my tastes. I want the guy installing to put his stamp of approval on the object he's installing.

Two technology matters come up that paper can alleviate:

1. I've been concerned about the overbore. I guess Adam's engine setup looks really good, but I wanted to know whether the overbored engine will take a NEW set of forged overbored 924 Turbo pistons and will they, new pistons, be right for that particular overbore? Are there any restrictions I should know about? I don't know. I haven't pushed the potential seller on this point cause the builder ain't around. I know you make the chamber to suit the pistons, and will the chamber take more 'boring out'? I dunno.

2. I've been concerned about the crank, as has my mechanic. I've seen these engines magnafluxed, xrayed and/or blueprinted. I don't know if he has that kind of paperwork, but I'm really concerned that if I take that setup, and there's a fracture in the crank (which an xray would reveal), then I'll lose a whack of money after the install is done. Paperwork is king. My mechanic wouldn't take a chance on an undocumented engine. He will take the chance if he's putting new pistons and an xrayed crank into the box.

What would be even worse is to have any bad blood between us if I ended up installing this engine and it blew up. That's what I'm trying to prevent by seeking out the paperwork. Paperwork gives me the reassurance that it can be installed by my mechanic and he'll have nothing to worry about.

If it hasn't been obvious in my posts, I'm confident Adam's engine is likely really really good. It's just that me and my mechanic are gunshy for those reasons.

Whaddya think? Am I being too cautious here? Is there a cost effective way to use Adam's engine block for my purposes? i.e., a bored out Turbo block with new pistons, Adam's rings, Adam's bearings, etc?

_________________
1980 Porsche 931
1979 Porsche 924 Tweaked.

[ This Message was edited by: Rick MacLaren on 2001-11-19 08:50 ]

[dwak]

I don't know ,Rick. I was trying to experiment with your money not mine. Did you try the English address I gave you?
dwak