Oil thermostat.

[coomo]

Today was strip oil lines day.With some heat from gas bottles, a couple of huge spanners locked together, and plently of grunt.Managed to get two nuts loose.The tihrd was more resistant.Then it went bang.
Car is 78SC, with "Trombone" oil cooler.I will uprate to later carrera type.Plus will use braided lines.
Re the oil thermostat.What options do you guys recommend? replace with factory stlye, or is there something trick out there that does a better job?

[juanbenae]

as I recall mocal makes a replacement, non Porsche one.

[coomo]

Originally Posted by juanbenae

as I recall mocal makes a replacement, non Porsche one.

Thankyou!

[Walt Fricke]

Mocal is not as good as the Porsche oil thermostat. I see Mocal says you can get one with just about any thread, but those I have seen advertised (and the one I used) have AN type threads, so you need adapters to fit any of the Porsche plumbing on.

Maybe Mocal has changed, but back when they neglected to do something simple, like cast in some arrows, so you could tell which were the in and which the out ports. It is critical to get that right I think. Supposedly you could tell by which side the bolt heads were on.

Mine promptly failed - the seal on the moving piston (a cone shape) was an O ring, and the oil flow shoved the O ring off its groove. It couldn't go far because it was around a pin, but without it in place the valve didn't seal, and some hot oil always got short circuited and didn't reach the coolers.

I'd look for a used Porsche one. If your wax filled cylinder - which is what moves the piston - works, you could reuse that if the replacement has a dead wax unit, and you can buy the wax part separately. It is the same part which makes the oil thermostat in the engine work.

The stock part has two moving cylinders - the one which is temperature affected, and one which opens if the oil pressure is too high, which it well might be with cold oil on a cold day. The idea is to limit the pressure on the cooler under those circumstances. And maybe cold oil might have trouble getting back to the tank in adequate volume? To be sure, he factory coolers - especially the not so useful trombone - seem better able to handle pressure than the cooler mounted on the engine. But Porsche thought this important. Mocal does not.

Why do you want flexible lines? The stock ones are durable and flow well. -12 line is a little smaller (though I think it flows fine). And all that fiddling around with thread adapters.

You can straighten some pretty serious kinks and flattened areas of the metal pipes. There is a giant discussion on this forum - or the engine forum - on how to do this, lots of pictures of the successful home brew setups guys used. Worked for me.

If a line is cracked or broken, there is a copper pipe coupler size which fits nicely over the stock tubing diameter, and it can be soldered, or better silver soldered, in place.

But bummer it broke like that. You must be some strong guy. I bet everyone who has ever had to wrestle with these has put plenty of anti-seize on all the threads of everything when reinstalling,

[Steam Driver]

Elephant Racing has one. Somewhat improved in my opinion as it has caps with hexes on them, not the practically useless slots!

[coomo]

Thanks for advice & experience!

[Walt Fricke]

Steam Driver - I have often wondered why Porsche used that slot system. Used it on the two oil pressure system plugs, too. There is a "proper" tool for them, like a socket screwdriver, with the tip curved to match the curved slots, and a steel ring around the outside so the tip stays put and can't slide sideways. I made one, but the steel of my screw driver tip part wasn't strong enough - maybe welding it in cost all its temper - and it just bent.

Luckily, a plumber's wrench gets a good bite - so good, indeed, that you can crack the casting it appears.

I wonder what other mechanical applications used plugs like these? Is there a name for them?

One also wonders why Porsche used barrel nuts for exhaust headers, some of the cam carrier studs, and the head bolts. A shoulder nut is strong enough, spreads the load as well, and keeps the socket size small enough to reach into the holes these reside in. Do 356s have any barrel nuts? The 1200 on VWs didn't.