Is an external oil cooler required for a /6 conversion? The Palma Green car needs a bit of work prior to the install, so we have a bit of time. Newly rebuilt 2.7 will be fit with Webers and driven on the street only.
TIA

Some say not for 2.4 and smaller
But I have 3 oil coolers on my 2.1/6

And most agree that 2.7 or larger needs one

I don't have one on my 2.7, stock engine with CIS. Never even hints of getting too warm, even on a 1,000 drive from lower Kalifornia home.

I don't like external coolers if they are not needed. More stuff to drain at oil change time, more stuff to leak over time etc.

You can always add one later if you see temps running on the toasty side.

My thoughts exactly, keep the oil temps below 220 and rock.

Where is the best place to obtain the temp (location of highest temp). maybe on the inlet line to the cooler?

If you need an external oil cooler, you'll know pretty fast.

I also live in a very mild climate area. Had to install T-Stat and flaps on my Bug because it would take forever to warm up and even then, still not get hot enough to burn all the water out of the oil (think foamy oil cap) = yuck.

Our old 73 911T MFI car ran fine on the street but we ran the car in PCA DE events regularly with both of us being instructors, ran hot afters about 3 laps. That was a real pain and since we ran back to back, I had to do something. I fabricated oil lines with a Mocal thermostat and a factory loop cooler in the front fender. It kept it below 220 degrees F with the two of us wringing its neck and that didn’t change when I rebuilt it to 2.4E spec. Some need it, some don’t and it depends on your mission.

I’ve put myself on the list for a set of Ben’s oil lines and yes, it upsets me to punch holes in my factory -6, but that’s it and they will bury me in that car. Anyway, some need it and some don’t. It just seems that all of mine do.

Charlie

When I had a 2.7 it over heated without an external cooler in So Cal. Biggest issue was stuck in traffic in the summer time.. make sure you add fans with a fan thermostat.

My 2.4t engine starts to get warm up to the 230s even just cruising on the highway. I will be adding one. Right now it's CAF outside so this can wait to temps above 70.

I have had four engines in my -6 conversion. Two were E spec 2.4L, one was RS+ spec 2.7 with MOD S cams and current engine is 2.5 with Mod S cams. The 2.4's were fine, the 2.7 would overheat if outside temps were over 80. The 2.5 will hit 230 on the highway in 90+ deg. I think it depends, low HP 2.7 in good condition might be ok. I am planning another 2.7 for next -6 conversion and has front cooler as part of plan.

john

My 2.7 was running on the upper end of acceptable. If I got stuck in traffic, it would get too hot. I paid for a whole new oil cooler system and waiting to see how it turns out........

I have a 2.2 with S piston and Mod-Solex cams. And only stock engine cooler. Never goes above 210 even when pounding on it to 7000 redline. My gauge is pretty close but I do check with a laser infrared gun on the oil filter, cam housing and lower case/oil drain plug. Never see 200 deg. Also check header temperature for each cylinder for any major variance. Best, Mark

I have had a few different oil coolers in my Sixes over the decades. The cheapest cooler system was the one that came on my current Six and was installed around 1980 according to the PO. It was just 1/2" copper plumbing pipe soldered together to run from the engine oil cooler up the long and across the nose and back to the engine. The former owner told me the 3.0 motor never over heated. I never drove the car on the streets enough to confirm that. But here are some pictures of that system. Crude, but easy to build.

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I also had this very effective oil cooler system on another Six I owned. I was running a 3.0 in that too. This was 2 VW 411 oil coolers (cheap) mounted one in each fog light grill opening and connected with SS braided line that ran to a thermostat mounted on the engine firewall on the passenger side. The downside was no fog lights. But relatively inexpensive and easy to do. This was in about 1985, so pardon the low-quality work. This was my daily driver and it was a nice car but not show worthy for sure.

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I personally really like the GT front oil cooler setup I have in my current car. It is very clean and effective. We modified the valance for the cooler opening and chose not to the corresponding bumper modification. We pulled 5 black nose plugs out to allow air to enter and figured if that was not sufficient, we could modify the bumper later. Thus far it has worked very well and I have sat in stopped traffic for approximately 40 minutes in 100+ degree heat. Now in that stopped traffic the engine did get up to about 235 degrees, but that is still not bad. And as soon as we started moving it dropped right down to about 190.

The only thing I do not like about my current setup is the thermostat was mounted in the front trunk near the oil cooler despite my request to mount it on the passenger side engine firewall. Not a huge problem; the next time we work on my car (when the rain stops) we are going to begin the process of moving the thermostat to the engine firewall where it belongs. Fortunately the thermostat was mounted with double sided tape, so no holes. We will remove that and make up new hoses to go from the driver's footwell connection right to the cooler- should look very clean.

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Some engines run cooler than others. Proper tuning helps. Driving at a good clip without going below 3k makes a big difference. It’s nice when it just works out.

Hopefully I can get this together this year to report back. Life just seems to take a priority most often.

Does running a fast idle when stuck in slow traffic help any, do we know? There’s that handy knob right there.

Yes, I believe it does as the engine fan moves air - at least on a 6. But I think the 4 is the same.

Engine running at higher revs = more combustion - airflow? Dependent on ambient temperature. I don't think on a hot day you are running any cooler...

*air-cool/oil-cool

When you're stuck in traffic, the problem isn't ambient air temperature, it's the heat radiating off the hot asphalt.