Valuation of 1982 911 turbo

[saurkraut]

I'm looking at a 1982 911 turbo tomorrow.

144K miles

Uses a quart of oil every 1500 miles.

Body appears rust free in photos.

Dash is cracked and de-laminating.

Boost gauge is stuck at full scale.

Normal maintainence done by a Porsche dealer.

Has new tensioner.

Original jugs pistons and rings

[trader220]

That’s a pretty tough one since it has to be a ROW car so whatever miles appear on the odo don’t really even mean a whole lot since it came originally with a KM odd. It really comes down to condition and records. Doesn’t sound like its had a rebuild done so plan on that. It would have to be really clean and straight for me to even considering buying it and it’s a project no matter how you look at it. Low teens?

[saurkraut]

Thanks for the reply

I've been looking for 930 for a while now. i've seen cars that have had a rebuild below 100K miles. When do these motors typically need a rebuid?

[trader220]

There is no exact answer on that one, a lot has to do with how well they were serviced / taken car of and how they were used. I would expect the car in question is about due for one, on a miles basis thats pretty darn good for a 911 turbo motor.

The key when buying one of these cars to doing your homework. Any car with a confirmed service history via records you can see and touch is a goo dplace to start. Also they're somewhat more complex than a regular 911 and any car you're considering really should be inspected by a qualified mechanic who knows these old turbos well. Its worth the money to poney up for a proper PPI.

[copbait73]

I'm a longtime Porsche guy. Regarding Turbos, they either have had a recent rebuild or need one. Basic rebuild starts at $10K and goes up with mods. Figure this in your offer. This one is a low teens however the owner may not accept this reality.
When do they need a rebuild? It can be a soon as crank up the boost today, needs rebuild tomorrow.
I've purchased cars like this by telling them; "here is my offer, call me when it needs work and you are ready to sell".

[JFairman]

Because of the intense heat and location the exhaust valve guides on a 930 motor are usually worn out after 25,000 miles.

That is the fastest wearing part on these cars.

[trader220]

Originally Posted by JFairman

Because of the intense heat and location the exhaust valve guides on a 930 motor are usually worn out after 25,000 miles.

That is the fastest wearing part on these cars.

Come on man, these motors will go a lot longer than 25k miles

[JFairman]

Yes, the rest of the motor can last up to 150,000 - 200,000 miles other than the intermediate shaft bearings if cared for properly, but the exhaust valve guide tolerances will be worn out by 25,000 mile.
I know from experience and if the car has been driven like ALL 930's have been driven.. I totally gaurentee it no matter what fancy modern alloy guides you stick in there.

The exhaust guide oil is upside down and it has a tight oil seal on it so it doesn't get enough oil until the engine is shut off and oil from the tank slowly drains back into the case and the lower 1/4-1/3 of the lower half of the cam towers.

The exhaust guide and valve is downstream in the already heated airflow and very little air cooling is happening there.
Add to that the very high exhaust temps from the exhaust backpressure caused by the turbo (often around 25psi in the exhaust header primaries at 14psi or .9bar boost) and vacuum retard for emissions control and catalytic converter operation and the exhaust guides are worn out on average between 20,000- 30,000 miles.
Doesn't mean they won't keep working but if you wobble the valve stem sideways while doing a valve adjustment it will move sideways alot even after only 25,000 miles and by spec the valve guide is worn out but because it's so expensive to replace them so people ignore it and keep driving until other things make them decide to do a top end or complete rebuild.