Driving one of the cars (2.0L with dual carbs) and see a consistent 230-240F on the dipstick temp gauge. The gauge is accurate (tested in boiling water). Normal driving.... 90F day, mixed speeds with 60 to 70 mph max, flat terrain.

The PO had pulled the tins to repaint them so I assume mice nests are not a problem.

I will check the oil cooler and the bellows this weekend; however, I don't expect any issues there.

So, other than investigating to see if there is a lean condition with the carbs (which impacts CHT more than oil temp...correct?), It looks like my options for remediation are limited to an oil cooler. I've done a search and find most threads are for 6 conversions or homemade setups. Of the few kits available, is there any consensus on a good affordable solution?

what weight oil are you using?

Not sure what's in it right now....

I don't think there is a "kit".

I would figure out the reason for your temps and not a band-aid solution, you shouldn't need a cooler for normal driving.
Lean causes the head temps to go up first, but your oil will go up in temp as well. What's your timing? what's your jetting? Is the cooler fins clogged? Etc?
Really you need an O2 meter, buy, beg, borrow or steal one. There's fairly cheap DIY kit on the net.



Assume nothing.

Do you have a thermostat hooked up for the air flappers that re-direct air over the stock oil cooler?
If properly setup, and the thermostat has failed, the flappers should provide ample cooling over the stock oil cooler.

You stated that someone removed and painted the tin....they may have put it back on and jammed the flapper that re-directs air over the cooler.

that side tin, passenger side, can be removed while the motor is in the car.
You may also be able to stick a scope in there to verify the flapper is in the correct position.

for a kit, look at CB performance.

Rich

i agree with everything thats been said so far. also oil viscosity makes a difference. in stock form, the oil cooler is bypassed at like 46 psi. so thick (hot) oil at upper rpm wont get cooled. i live in the southern california desert and i run a synthetic 30w in all my aircooled cars.

Hmmm....good thoughts to ponder.

Stupid question (and I could look it up but I'll ask it here), what would an O2 gauge tell me? If I am running lean/rich?

I'll check the flapper for the oil cooler first...that should be an easy check.

I agree that 90F isn't that hot and should not require an oil cooler. I have read some threads in my search where people had checked everything and still had cars that ran hot. Maybe this car is one of them. However, I am not ready to say that. I would prefer to make sure that everything works as designed first.

02 sensor will measure the mixture so it will let you know rich/lean conditions.

Have you checked the timing on your car?
A few degrees to advanced will really make it run hot.
also, these cars are designed to run a bit rich which helps keep the whole motor cooler.

Tight valves also make the motor run hotter.

rich

that sounds like a good plan..... make sure all the tin and flaps are there and working. then give it a good tune. timing, valve adj, plugs, the whole 9 yards, thennnnn plan for the next coarse of action.

Thanks, all. Looks like a busy day soon as I check all this stuff!

At a recent DE at Summit Point, I saw 252F on my dipstick thermometer (Brad Penn 20-50, euro D-Jet, ambient temps in the 80's) so I installed an Earls thermostat sandwich oil cooler adapter and connected up the cooler. Still thought it got hot when returning from an auto-x and driving in stop & go traffic in DC (didn't stop & read thermometer) but will see how it affects temps this weekend at another Summit DE. It's not supposed to be so hot but it will be track driving; if there is anything interesting, I'll post.

The cheap narrow-band O2 sensors will tell you almost exactly NOTHING. They kinda suck unless you're trying to keep a car with modern digital EFI in the mixture range that lets its catalytic converter work the best (and minimizes pollutants).

You need the wide-band O2 meter if you're going to try to check your mixture.

I will echo Mark Henry's comment above about "Assume nothing."

I wound up with a couple of paper towels in my fan a month or two ago which caused very high oil temps in normal driving. And any time the engine tin has been apart, it is possible for the flaps to get left out "because they just get in the way", or for them to get stuck and not able to open fully.

I recently installed a large Earl's cooler, together with their t-stat and "sandwich" adapter. I put it under the rear trunk floor, figuring that a larger size would make up for a poorer location (than the nose of the car). It does, but not completely. See my "will it be done before Parade" thread for pics of what I did.

Oil temps still got to 240F up around Reno on a 100F+ day at 75-85 MPH with this setup. I backed off down to 65-70 MPH and the temps dropped to the 225F range.

--DD

test the bellows with a heat gun or really good hair dryer. i found you can test the correct cabling/operation of the flappers just by having a partner watch the flapper arm move while you're heating the bellows.

I'm also interested. After Chris adjusted the Ljet last weekend the head temps dropped by a good 25-30 degrees. I noticed that the engine oil temps were also lower, but would like to keep them consistently under 220.

Running a 2056 w Ljet, a Raby 9550 cam, and 20w-50 green juice, 9:1 compression.

And yes, it's fun!

i believe 212 is considered normal operating temperature for engine oil. thats the number i shoot for. and 10 psi per 1000 rpm at operating temp.

Some knowledgeable people prefer to see oil temp of 180F. I'm in the 212F camp myself, though mine will often run hotter than that.

--DD

im in the 212 camp myself. atleast that what i shoot for. but running synthetic it can withstand way higher temps, with minimal loss of viscosity, at least when compaired to dino oil.

If you run at 180 you never get all of the moisture out of the oil and it begins to make that nasty butter. I am in the 212 camp, too.

no one mentioned timing, I know this can have a major effect on cyl head temps...not sure about oil temps. Worth checking methinks.

Actually, water will outgas from oil at 180F. It takes longer, but it does happen.

--DD

I normally set up an external cooler so the fan turns on a 190.

Standard thermoswitches for coolers kick on at 180*.

Newbie here so go easy. I have had my '75 2.0 liter for 6 months. It was over 80 today in the bay and coming home at 85-90 up the 280, the cylinder head temp went up higher than I've seen it before - maybe a quarter inch off the red portion.
Click to view attachment
Does anyone have a correlation between the dash gauge and the actual temperature of the heads and the oil - and what' too hot?

There was no effect on how the car ran...and it cooled down to bang in the middle of the gauge once I was back in foggy San Fran...

John

That's oil temp, not head temp.

The exact temps represented by the different areas on the gauge can vary from car to car. You can calibrate yours with a thermometer down the dipstick (several retailers sell these) or by removing the sender and setting it up in a pan of boiling water or in a pan of hot oil with a fry thermometer.

--DD

I didn't see any mention of the type of front spoiler/air dam you might be running.

The flex dam causes cars to overheat without a front mounted oil cooler.

Also, are the air diffusers still in place on the under side of the car right in front of the engine compartment?


My motor runs at 180-190° on the track when it's a 111° day.

I run a large front mounted Setrab oil cooler, Mocal thermostat and a large inlet/exit with a shroud in the front trunk.


KT

flex dam, is that a front air dam? how do you reckon it causes high temps? I'd be thinking it would help reduce the air pressure under the car and thus aid in engine cooling air flow. That is just my assumption, how do you figure it causes higher temps? I must not be thinking about it right.

if your oil sump (typical location for a temp measurement) is at 180F I can assure you that some of the oil some of the time exceeds 212F. if yoru sump is at 212F I can asssure your some of your oil some of the time exceeds 244F.

think about the oil in the heads, one of the hotter parts of the motor, oil that flows thru there is in direct contact with 300F+ metal. if you feel you need 212F oil to remove water, I can assure you that a 180F sump temp will meet your boiling point temperature needs.