924Board.org

[Slam]

Well, our (Gracie and my) search for a viable way to get the 931 back on the road isn't turning up many options. At least not many that won't break the bank. However, by sheer happenstance I made a call today about a '77 924 and got a call back from an old friend of mine who's willing to sell me a whole running car for around $500CDN. It runs well, had a recent tune-up, is a bit rough cosmetically, needs interior work and is, gasp! an automatic. I won't even pretend to know what you're thinking. The guy's a mechanics teacher, I've known him for years and trust him. But to my way of thinking, a 924 (any 924) needs some changes and we've got a 931 here that's not going anywhere on our budget.

I'll make this quick and see where things lead...

1) Will the suspension from the 931 bolt straight into the 77 924? What I mean is, can I simply remove the entire front and rear bits from the 931 and upgrade the 924 with them? I have done a search on this but couldn't find a straight answer. I'm not talking upgrading with bits here and there, I'm talking removing the entire 924 suspension and replacing it. The 931 stuff is good. Are all the pickup points the same - after all, there's 5 years technology between them.

2) What maintenance (apart from what Haynes says) does the auto tranny need? Are these expensive? They're killer on a 944.

3) And don't trash me for this! Can the 931 head be bolted up to the 924 block. I mean, dump the 924 head and just replace it with the 931 head. I know it breathes better. No! I don't want to try to turbo the NA! What's compatibility as far as plumbing goes?

4) If we go decide the 924 isn't worth any work to make it a fun driver, will the 77 block mate with the 931 bits? Could it be used to rescue the 931 engine? My credit card cringes at this thought after the research we've done lately, though.

5) Will the 82 931 HVAC system bolt into the 924 or will we have to mod things? Is the sheet metal behind the dash the same on these cars? We'd basically take the black interior Gracie spent a month putting into the 931 and plop it into the 924. Shouldn't be too hard (famous last words...).

Forgive me the many queries. I've heard there are no stupid questions, just inquisitive idiots... So much for making it quick.
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'88 944 Auto - may or may not resurrect

[timstar92404]

I wouldn't recommend an automatic especially in a 924...... especially when you're used to driving a 931.

I thought putting a 931 head on an na would just lower your compression and you'd make even less hp.
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78 924 sold.
85.5 944

[Khal]

1. According to ESC944;

[Raceboy]

77 924 has different lower ball joints, so you'd have to change control arms too.

I wouldn't recommend parting 931, instead take that 924 NA block (if 931 one is toasted and cannot be honed), crank and perhaps rods (if you've spun 931 rod bearing) and polish the crank to next size. Then, take 931 pistons and block to the machining shop and have them measured for compatibility.
New rod and main bearings shouldn't cost you more than 100$ US (if so, I can ship them from Europe, there are Kolbenschmidts for 100$), put it all together and you have running 931 again.

If you have any further questions, I would be happy to help you, Slam

EDIT: newer style HVAC system isn't exactly bolt-on piece to older cars. -nick has gone thru this, ask him about the details. But I can promise you, it's a major PITA.
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[Ozzie]

A 77 doesnt have the full galv body and the wiring is different.
Why not put the running gear- motor etc into the later model?
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[Chrenan]

Slam, the easiest route is to take the 77 block, crank and rods and have everything cleaned and machined and use them in the 931. That is the only way to go in my opinion. That is basically what I did, bought a 77 and used the block, crank and rods for a rebuilt engine for my 1980.

This will cause the least trouble. You can always swap over some other parts from the 77 if they are better than in the 931. I'm thinking things like seats, trim etc.
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1987 951 - M193 Version for Japan

[Slam]

tim wrote

[Slam]

Why the hell do I always get my quote function backwards???
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'88 944 Auto - may or may not resurrect

[Kenodog]

I second what Chrenan said and just get another block/crank/rods and rebuild the 931.Trust me on this you guys won't be happy going from a 931 to an n/a with an autobox.

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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[Chrenan]

I wouldn't be happy going from an n/a to an n/a with an autobox.
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1987 951 - M193 Version for Japan

[Raceboy]

Slam
You won't spending more to engine repair than to fabricating 931 to na block with pistons, that WILL lower the comp ratio, because 931 head have squish (~22 cc) plus the manifolds are not compatible.
As for costs? I presume you'll have to buy thing or two when swapping supension too. No wonder if you'll find a cracked brake hose or worn out rotor, just for an example.

You don't have to buy gaskets for water and oil pump, use quality sealant. That's what I've done, and I've never had a failure. Using good sealant on oil pan gasket will guarantee that you won't have oil leak.
But, you'll have to buy new crank round seals, that should be around 40 $.

My pont is, do the 931 engine repair and you'll have more fun and no regrets comparing with swapping everything into 100hp automatic 924.
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'83 924 2.6 16v Turbo, 470hp
'67 911 2.4S hotrod
'90 944 S2 Cabriolet
'78 924 Carrera GT replica
'84 928 S, sold
'91 944 S2, sold
'82 924S/931 "Gulf", sold
'84 924, turbocharged, sold.
http://www.facebook.com/vemsporsche

[doomer77]

its really a shame they lowered the hp and performance on the US cars, i feel bad for you guys..
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Why drink and drive when you can smoke and fly?
Carpe diem. and if that doesnt work; get drunk!

1980 924 n/a - engine swap begun
1989 Volvo 480ES

[Chrenan]

Don't feel too bad, our gas still costs 1/4 of yours.
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1987 951 - M193 Version for Japan

[-nick]

I could see how you might think this is a good plan, unfortunately it isn't, on several levels!

Everything in a 931 CANNOT be bolted into a 924. Especially an early 924 (pre-'79).

1) The rear torsion bar carrier mounts to the body differently than '79+ and 931 models. So you can't just swap out the rear. The early rear suspension uses a unique rear swaybar that can't be upgraded to the later swaybar without some extra brackets (even then it isn't a very good fit).

Also, the late '82's used the 944/968 style front swaybar, which won't bolt onto the 924. As well, the front control arms have a different sway mount and don't swap.

2) Have no idea about the auto tranny's other than they are report to move 924's from painfully slow to excrutiatingly slow

The hydralic brake MC on the 931 can't swap into any 924 without some pedal linkage and sheetmetal work.

3) To use the 931 head you'll need custom pistons to get the compression over 8.5:1. No way around it. You'll also need to use the 931 intake (and block off the 931 pop-off valve line). The 924na exhaust header won't mate up to the 931 head either.

4) Not sure what the trouble is with the 931 block?

5) If you have a later '82 931 (with the rotary heater fan knob), the hvac can't be swapped without some sheetmetal cutting and welding. Many of the 931 console parts can't swap as they're set up differently for the later heater.

Among other differences-

The power door mirrors can't swap onto the early 924 without drilling into the doors and adding reinforcement. For that matter, the 931 (and I think all later 924na's) have side impact bars in the doors where the early 924's do not.

The door handles / locks / latch plates aren't swappable onto an early 924.

The front fenders the 931 (and possibly all later na's) are rolled from the factory to fit five bolt, 205/55/16 tires. Those tires can rub on an early car that's been converted to 5-bolt.

I know there are other changes, these are just what comes to mind.

Anyway...

What is the problem with the 931 engine? We might be able to walk you through a more budget-friendly rebuild. None of us want to see a 931 broken up. Especially if it only needs an engine rebuild.

nick

[Gracie]

IT'S SO UNFAIR!!!!!!!!!!!!!I JUST WANT A CAR!!!!!!THAT'S NOT A BOAT!!!!!!!THAT DOESN'T MAKE ME FEEL 80!!!!!!!!THAT NO ONE LAUGHS AT!!!!!!!!ARRRRGGGGHHHHHHHHHHHRRRRHHHGGGGG!!!!!
(sorry for yelling) This comes as quite a disappointment. But thank you for the very informative reply......I would have just bought the car, (sigh) now what.....I still need an engine, at least that one had one THAT RAN! Or so....we...think..... Well, on a good note, I was a little discouraged by the fact that it was an automatic. I mean, really, kind of being a poseur.

Will the crank shaft and connecting rods from the 77 fit into the 31?
Please say yes........
many blessings upon your household.....
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Working on cars is restful for they have neither conflict nor emotion.

Time with cars is never wasted, even if all you do is stand there and curse at the unfinished impossibly curved 1/4 panel.