3.2L - Engine Thermostat Question

[Magnum]

Hi all

I'd really appreciate a logic-check and advise on this:

Background - My new "sports Purpose" (..refer long hood section....confusing I know ) has an effectively standard 3.2L Carrera engine. The car has an auxiliary oil cooling modification/upgrade with large cooler installed into front spoiler, standard hard lines but no external thermostat for this system (as would normally be standard).

The issue - the engine is not getting up to heat and remains steady between 55 - 65 centigrade even after hard use. The front "auxiliary" oil cooler (and lines to & from) are at same temperature as the engine after use (I've just used my new specially acquired tool - infrared temp gun ) and, as there is no auxiliary external thermostat for this system, the engine oil is likely circulating all the time throughout the entire system because 55 - 65 degrees C is way under temperature for the engine thermostat to open up (which normally happens at about 88 deg C my research tells me).

My conclusion is therefore that either the engine thermostat has been removed and blanked, or is stuck open - both of which scenarios (given there is no external auxiliary thermostat) would explain continuous circulation of oil throughout the engine plus simultaneously the auxiliary cooling system.

So question is - before removing all the gubbins on top of engine or dropping the engine (perhaps partially) is there a way to check this and even possibly remove thermostat? Any contortionist tricks, special tools, dentist mirror etc.

Many thanks

[911hillclimber]

IMHO changing or exploring the stat on the engine on a 3.2 would be murder with it in the car. I would think you would need mirrors and 'X File' arms and hands, unless you remove the inlet manifold?
The stat is sealed with a large dia O ring and is a TIGHT fit in the engine case needing screw drivers to prise it out (they notch the housing to assist...)

If you have the factory trombone type external cooler (I have) then there is a stat in the rear wheel arch housing as well as the engine one.

Both mine are open under even gentle driving.

My engine runs at 180F but 190 in long traffic, and the cooler pipes are fully flowing and very hot.

Maybe drop the drive train do the stat with ease, service the tappets etc and put it back to get the most out of the effort?

[Magnum]

Ok!

I've cracked this - the diagram below (thanks gents on Pelican board) indicates that there are effectively two pumped circuits with the engine thermostat controlling only the engine-mounted cooler - so this is not the culprit! I simply need to plumb in the auxiliary cooling circuit thermostat in that/scavenge loop.

Next project identified....was getting a little bored just driving!

Any feedback on the mocal/setrab in-line alternative to the very, very expensive Porsche thermostat (with its more difficult plumbing with additional hoses required for right angles etc)?

I've read that the disadvantage is that the mocal/setrab version don't include a pressure relief valve that allows oil flow back if there is an obstruction in front oil cooler - frankly I can't realistically see this scenario happening whilst out driving and further you'd notice oil temp going up, pressure doing funny things etc?

Enjoy the diagram - makes much more sense now!



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[Crispy]

Looking at the diagram and guessing your've just removing the aux stat which would cool the the returning oil to the tank, I have ran other cars like this and also experienced lower temps
As a quick test could you cover the aux oil cooler stopping air flow hopefully raising temps
The small cooler isn't amazingly efficient being air cooled off the engine fan via the barrels

[Magnum]

Thanks @Crispy

Strangely there was no aux stat installed when I received the car so it had always run cold - have ordered a Mocal unit from Merlin and will plumb in on arrival. Temps should then increase and maintain at acceptable running levels but the next question is whether both the engine and aux circuits open at effectively the same temperature, dropping temps down rapidly.

I guess as long as it's about/just above the standard engine stat opening temperature it's OK as Porsche would've theoretically calculated this opening at about optimum running temp?

Cheers

[andytat]

Magnus.

I have used the Mocal auxiliary thermostat on a number of engine
conversions with no problems. Make sure the pipes to and from the
front cooler are as large as they need to be so that there is enough
flow.

Cheers.

Andy

[Magnum]

Thank you Andy

The car has -12 fittings/pipework (so pleased I now know what that is ) so have ordered accordingly - I think I'm fine?

I'll report back once the hard work is in - it's been a good learning experience so far, and lots more to go with plumbing in, then testing etc!

Cheers

[Crispy]

Following the diagram, all the oil thats returned to the tank regardless of if the engine based cooler stat is open or closed is being cooled by the 2nd cooler thats got the stat deleted
So all the oil being fed to the engine is in a cooled state (warm to touch) which is prob ok for a race car but not a road car!!

I too have used mocal inline oil stats in past and have one on my currently retired track car ( water cooled ),also been used as a work commute manages oil temp so