Maxx1

..... quit working.

I was out for a while with the car and when I got back, a friend stopped by and was asking about the car. I popped the hood and was showing him the engine... and the new MSD module I just put in. I put my hand on it and it was burning hot ! The coil was about the same. It's just amazing how hot it gets in there, and surprising things don't just melt down and quit working. My car has been running an oil temp of about 210 no matter what. I wonder what kind of heat soak limits those electronic items can take?

sand_man

Lot's of things can affect your operating temps:
-Incorrect ignition timing
-AFRs too lean
-Issues with the fan cooling system: air leaks, slipping V-belt, obstructions (I once saw a nasty animal nest constructed on top of the cylinders on an old 911T that I helped a guy install a new alternator on).
-Faulty oil t-stats

Maxx1

I was guessing this is about normal for these cars. There is really no place for the heat to escape other that what can be bled off the oil cooler and intercooler.

It's tight and sealed up under there unlike other cars with open areas so they can vent to the outside.

nathanUK '81 930 G50

The fan is constantly sucking cool air through the IC and then into the engine. Also a little goes through to the heat exchangers and either gets dumped under the car or is diverted into the cabin.

DDD

For what it is worth, I have gotten into the routine of popping the engine lid whenever I get back from a ride and just letting the engine cool off in the open for an hour or until the next time I think of closing the lid. Since I park it in a garage, I often just leave the lid up until the next time I get to it.

The engine heats up when you turn the car off, because that heat just sits there with no more fan or oil cooling.

Maxx1

That's explains why everything was roasting hot under there. I'll have to start doing the same.

911rudy

One other thing that most of us do to cool down the turbo is to let the engine idle for a few minutes after we park it and if you do this the oil circulating will help cool everything down in a more linear fashion. All you have to do is watch the temp gage and you will see it drop if you shut the engine down for a minute and then start it back up. I also use the "Pop-the-lid" method to help out the cooling.

DDD

With respects...this seems counter intuitive to me, because idling the car is what makes it overheat, I thought?

My understanding was that you would try to drive the car slowly for a couple miles before getting home so as to let the turbo cool off and let the oil circulate, but then turn it off and not let it idle because the air cooled engine requires air movement.

I would be interested to hear more about this theory, because I have been told to not idle the 930 more than needed.

Stratman

I put a K-27 in my car in 88. It lasted until I upgraded to the K-27hfs a year ago. And I drive the car hard when I drive it. I never let it sit and idle when I would get home from runs just stay out of the boost the last 5 minutes of the drive like DDD said.

sand_man

I'm a combination of both. Slow "off boost" driving for the last leg of my trip (a few blocks), and then maybe a few/several seconds of idle time while I gather my belongings in the car, then I turn it off.

I've noticed that the track 930s guys let them idle for a bit after a session on the track. I've had entire conversations with Rocket while his car was idling. Of course track conditions change everything.

I've also just leared that some folks running the Garrett turbos idle their engines for a few minutes to insure the center section has been properly cooled with oil.

911rudy

If you look at where the heat is when you park your car you can understand why idling your engine for a couple of minutes is helpful. The metal parts of the engine are a lot hotter while driving the car than they are when it is idling simply because you are generating more heat at higher rpm. The oil in the air cooled engine is the same as water to a water cooled engine. While it is at idle and circulating through the engine, it is removing a lot of heat from the engine and componets created by the combustion at above idle rpm. There are a lot of misconceptions about idling an engine and that it is bad for it. How can being at idle be more harmful than running at 3,500 rpm? There is a lot less heat being generated and we dont have a very good air/oil heat exchanger whether we are moving or standing still. If you could coast to your garage at idle for the last two miles before parking it, wouldn't that be the same as idling the engine for two minutes? Coasting down a steep hill in a water cooled car will make the engine temp go down because of the radiator but doing the same thing in our cars will not work. The only way to remove heat from our engines is with the oil or air. I would advise to let it idle for a couple of minutes and then pop the lid.

nathanUK '81 930 G50

My alarm has a turbo timer feature built into it. I just push a button, turn & remove the key, lock the car & set the alarm. After a minute or so the engine switches off.

911rudy

Nathan you are a lucky bastard! How did you get so many neat things on one car? Ideally an electric oil circulation pump would be the most efficient solution scince there would be no heat produced. If you pop the lid after a spin, you will be amazed at how much heat rises up from the bay. We all have our own tricks and hopefully the engineers at Stuttgart(sp) over built these things to accomodate all of them.

nathanUK '81 930 G50

Hehe, I guess I was just lucky. The reason I was interested in this car was purely for the G50 conversion. I made my mind up that my 3.2 carrera was never going to satisfy me any longer and that I needed a 5 speed 911 turbo. My budget allowed a '89 930 or a 3.3 964t. I found a few 964t's but they were not in my budget.

The previous, previous owner spent thousands & thousands on this car. I cannot believe he gave up and sold it. He told me the Powerhaus engine blowing up was the final straw. The car just got a second hand replacement engine slapped in it & then sold/swapped for a Ford Escort Cosworth.

Rudy, the only problem I see with not letting the engine idle (even with a electric oil pump running) is that as the turbo is not rotating you may not get even oil flow in the bearing?

911rudy

You bought the right way by getting a car that had all of the mods done! You may be right Nathan. I figured the oil going through the orffice would at least carry away some of the heat around the bearing. I know that just shutting it down causes cokeing problems with all turbos.
I got my car back today with the new A/C charged and it felt real cold. It was 99 F outside and the vent temp was 39 F. I also got the new center vent that connects to the old foot vent and this allows me to direct the cold air to either side at knee level. As JBL said, "I am happier than a dog with two dicks"!