Keeping my 3.6 conversion cool

[blucille]

I’ve got an 89 3.6 installed in my 83 SC. Conversion was well done by the previous owner, dual oil coolers with fan, other parts from instant-G, Patrick motorsports and elephant.

Looking around the engine compartment, I see the engine isn’t sealed well. I know near the pulleys and belts, there are some gaping holes, and I expect at the front edge of the engine compartment, things are not sealed well.

I’m guessing I can help the engine run cooler if I seal the engine tins better.

So, do I need seal for an 83 or an 89 964. What else should I be looking at?

Thanks

[Harpo]

Good morning sonett43,

Is your car running hot?

David

[blucille]

Yes’m, hotter than I’d like. Gauge seems to hover past the half-way mark and will often hang out just short of the red zone.

[Slanski62]

Im doing a 3.6 conversion as we speak. My mechanic informed me that the front on the tims on a 3.6 have rather rounded corners. The earlier cars had square corners. So if you just put a 3.6 in without modifying the tins, you will have gaps.

[Slanski62]

[Bill Verburg]

The seals separating the upper engine compartment from the under side are there mostly for keeping hot air below at low speeds, also for keeping road mung out at all speeds.

Many race cars run w/o this separation

W/ dual coolers and fan you should have adequate cooling

first - I'd check the accuracy of the oil temperature gauge. The sender and dash gauge need to match. On my '76 I needed to swap the 993 engine senders to have the temp and pressure gauges work correctly. The pressure sender will be an issue but the temp sender is an easy swap.

[Jack Olsen]

What size lines run to the coolers? Are you sure your thermostat is opening -- and opening all the way? As others point out, air leaks in the engine tin are probably not going to make a difference in your oil temps. Is there ducting around your coolers?

The second notch is 248°, which is hot enough that many people pull over to cool down. But like Bill points out, you want to confirm that your sender and gauge are working.

[blucille]

Thanks Jack and Bill.

I’ll check the thermostat. The lines to the first cooler are factory lines and in pretty good shape, they flow well and both coolers get plenty warm. Need to pick up an infrared thermometer to verify some things. I’ll report back.

[flyn-hawn]

We used carrera tins but had to fabricate pieces to fill in the gaps where the oil cooler would go on a carrera and also in front of the chain covers on both sides to give it a more finished look. I should have taken more pictures of the rear pieces near the pulley as they came out really nice and went right into the rubber groove in the gasket on the chain cover.

[blucille]

Thanks Dave. I realized I had a problem when I recently dropped a socket extension working on some breather lines near the air filter and it fell out where the 83 3.0 would have had an oil cooler. Oh well, I’ll see what I can fab up.

[flyn-hawn]

With the carrera tins in there it also looked fairly stock once it went into the sc chassis, with the sc engine compartment rubber

[flyn-hawn]

Originally Posted by sonett43

Thanks Dave. I realized I had a problem when I recently dropped a socket extension working on some breather lines near the air filter and it fell out where the 83 3.0 would have had an oil cooler. Oh well, I’ll see what I can fab up.

I like to use paper that is similar to the office file folders to make an initial pattern. If I need to make a bend that has to stay put I will use the aluminum tape over the paper first and then use it as now it will hold its shape while you bend it. That is what you are seeing in a couple of the photos

[betterair]

DONT FORGET,....the oil coolers in the fenders must be sealed such that no air gets by them.
i have air plenums/boxes that are fed from the rt/lt holes in the iroc bumper valence .
brakes,brembo big reds are ok w/o ducts(i sealed hem with hi temp black open cell foam everywhere there was a airgap between the oil cooler and inner fender)
my 97 993 engine ss cam ,solid lifters,w itb's and ecu rarly gets ab0ve 9 o clock .only on track when the ambient is north of 80-85.
ON The engine tin side it is not dust proof from top to bottom ,but serves as a suitable separation barrier between top/bottom .

I am rumming headers and MK "R" exhaust which kicks out serious heat from the 3.6+

[betterair]

Dave , great looking engine compartment - all the business.

Can I bother you for the p/n' s of the itg filters.
Its time to replace my other british itb filters.
Thanks
Buce

[3rd_gear_Ted]

For the oil coolers, -20 AN fittings and hose to match the hard lines going up front, its all about the flow.
-12 is a problem on track with 3.6

[Duc Hunter]

I would first make sure your sender is matched to your gauge as others have said. Mine was not and was reading high erroneously. Also, mine stays plenty cool here in Fl with onlyan RS style front mount cooler. And I do not even have the body cut out behind it for more airflow yet. Only time it over heats is if its already 80C when I stop and it idles in the heat of a summer day for 10-15 min. Then its 100C. As soon as its moving a it cools back off. Also, my 3.6 does not have the seal between the tins and the body (yet).

Keep in mind too, once oil is hot it takes longer for the gauge to move back down, as oil takes longer to cool off than water.

[AllardK3]

I am surprised it’s running hot with two oil coolers. I have a similar setup with a 993 3.6 in my 81 SC and live in hot Phoenix. The car runs on the thermostat at 205 no matter how hot it is outside. The tin in the engine bay has had additional extensions added in but no airtight rubber seal... it runs a Carrera cooler with fan in the right front fender and has a decent sized mocal cooler in front in the iroc bumper.

[Sboxin]

Originally Posted by betterair

DONT FORGET,....the oil coolers in the fenders must be sealed such that no air gets by them.
i have air plenums/boxes that are fed from the rt/lt holes in the iroc bumper valence .
brakes,brembo big reds are ok w/o ducts(i sealed hem with hi temp black open cell foam everywhere there was a airgap between the oil cooler and inner fender)

Agree, the air ducting to the front coolers is essential . . . some have added the fans to
help when street stop and go driving . . . we have 3 coolers on a 3.8L race car and also
use the headlight openings as air ducts along with the signal holes in the bumper . . .

And, maybe run the best oil you can afford . . . we use Amsoil Race 15-50 = 15 quarts
and see temps of 250F at times . . .


Regards,

[Bill Verburg]

Originally Posted by Sboxin

Agree, the air ducting to the front coolers is essential . . . some have added the fans to
help when street stop and go driving . . . we have 3 coolers on a 3.8L race car and also
use the headlight openings as air ducts along with the signal holes in the bumper . . .

And, maybe run the best oil you can afford . . . we use Amsoil Race 15-50 = 15 quarts
and see temps of 250F at times . . .


Regards,

For track use 3.6 and 3.8 needs much more cooling capacity than for street use. On a stock 993 w/ a large passenger side cooler street temps will always be under control. Same on a track on a hot day will see elevated temps. For track use a second large drivers side cooler is very desirable even for a 3.6, more so w/ a 3.8

[blucille]

So, after a limited test, I have more questions....

Idling and higher revs, but in the driveway, the oil lines were seeing temps as high as 250f....but the coolers are certainly doing their jobs, return temps were typically 140-150. The gauge was just below half-way

So, where should the oil temp gauge be indicating at what temps.

Any way to check markings on the temp sender to see if it is the right one?

Oil temps at the gauge are before the coolers or after?...seems like a stupid question.

Thanks