Ron's 914, High oil temp Options

[Ron914]

I also am looking for information on what value of readings I should see at warm/idle. My understanding is I should be looking for ~14.7 % .

D-jet Hot idle I usually set by feel to what the engine wants. Lean out the idle mixture knob until the engine starts to hunt then dial it back 2 clicks. This will most likely have you in the high 13s.

On the 72+ cars however as the idle mixture is its own circuit knowing the idle mixture tells you little about what your overall mixture is while driving.


For your oil temps, first thing I would do is try installing one of Chris Oil pressure relief valves.

https://tangerineracing.com/shop/ols/produc...re-relief-valve

It may not fix the problem but it wont hurt (and it might fix the problem). Head temps are generally what gets impacted more by tuning and while it can have impact on oil temps, high oil temps are usually more related to extended high RPMs or an issue with cooling.

If you are sure your airflow over the cooler is unobstructed and your cooler itself is good the next thing you need to look at is adequate oil actually passing through the cooler. If your oil pressure relief spring is weak, which I can pretty much promise any 50 year old spring is, or if the piston is wedged open in a worn aluminum case bore, then you have an excess amount of oil that is NOT running through your cooler.

To large an oil pump can result in overwhelming the stock bypass valve as well resulting in oil not hitting the cooler. But start with the bypass valve, its relatively inexpensive and probably the quickest part you can swap out that has an impact on oil temps. Maybe a 10 min job with the car in the air, if that.


If you look at the diagram posted above by @emerygt350 you can see why this valve/spring is critical in maintaining proper oil temps. Its the valve/spring directly below the oil pressure switch in the diagram. When it opens, oil doesent run through the cooler.

Thank you for the comments James . I will go ahead and order Chris's relief valve and report back after installed . My cooling flaps thermo is bad but I am sure I have the flaps forced open to max airflow as shown in photo, also I I did not replace my original oil cooler ,I flushed it and saw no leaks and good flow. Is the oil pressure relief valve behind the large screw I have circled? I will recheck my timing and adjust the ECU and see if this helps .

[Ron914]

I was out on the Glen yesterday and had some fun idling for about 25 minutes waiting to get on track (fun laps, first time on the track for my oldest son). We had just finished a spirited drive in the country and then climbed the hill to the track so my car was nice and hot. I was idling with oil temps around 200 for about 5 minutes 305 degree head temps. 14.1 ish afr. The idle was every so slightly unstable/hunting. Just a tiny bit, maybe 50 rpm. I gave it two clicks richer, crawled back in and observed the outcome. Idle was stable and sitting at maybe 13.7, and over the next 15 minutes the head temps dropped to 294 and the oil temp dropped to a hair above the line, which is something like 175 on my car. I have heard from many people that idle afr readings are not particularly accurate however.


I have the tangerine bypass. I wasn't having pressure problems but I thought it was good prevent defense. And as James says, super easy to do.


I have done some pretty crazy retard and advance experiments. 20 advanced, -5 retarded etc. I have seen the oil heat up real fast under those circumstances.

What a great day on the track with your son . Looks like you have a fun get together coming up out there at the lakes . I always say someday when I can travel I will buy a trailer and try to attend all the cool events for our 914's around the country . Thanks again for your input . I will eventually get this figured out even if I have to pull the motor and start over .

[emerygt350]

That's the spot for the bypass. Big flat head is a good idea.

I think your flap arm is not as upright as mine is when it is full open. I will have to double check. The spring should hold it open in case of failure.

[JamesM]

Thank you for the comments James . I will go ahead and order Chris's relief valve and report back after installed . My cooling flaps thermo is bad but I am sure I have the flaps forced open to max airflow as shown in photo, also I I did not replace my original oil cooler ,I flushed it and saw no leaks and good flow. Is the oil pressure relief valve behind the large screw I have circled? I will recheck my timing and adjust the ECU and see if this helps .

Yes, oil pressure relief is under the big screw you have circled. Take out that plug and the spring and piston should just drop right out.

Lack of a thermostat shouldn't be an issue as far as high oil temps, if anything that would contribute to long warm up times.

The only other thing that comes to mind is the orientation/position of the passenger side air diverter flap. As was mentioned the angle of your cooling flap linkage does not appear to be in the "full hot" position despite having the cable disconnected. If something is prohibiting the flap over the oil cooler from sealing on the tin then air is not being forced over the cooler properly.

[Geezer914]

I run a 2056 with Ljet, biral cylinders, remote oil cooler, 13.5 AFR, oil pressure is 45lbs T 3400 rpm, with Brad Penn 20/50w oil. Cylinder head temps get to 95°C and the oil temp is 200° after a 45 minute to an hour on an 85° day.

[Ron914]

I run a 2056 with Ljet, biral cylinders, remote oil cooler, 13.5 AFR, oil pressure is 45lbs T 3400 rpm, with Brad Penn 20/50w oil. Cylinder head temps get to 95°C and the oil temp is 200° after a 45 minute to an hour on an 85° day.

Sounds like I might want to look into an external oil cooler . I just installed the AFR and still need to figure out about adjusting my MPS .

So cruising @ 3500 /45psi oil , your AFR shows 13.5 . I still need to get an oil pressure gauge but I will compare my values and see how close they come to yours . I ordered the oil pressure relief kit from CFR and if that doesn't help I believe he sells an oil cooler kit .

[FlacaProductions]

Hey @Ron914 - sent you an email....

[emerygt350]

I run a 2056 with Ljet, biral cylinders, remote oil cooler, 13.5 AFR, oil pressure is 45lbs T 3400 rpm, with Brad Penn 20/50w oil. Cylinder head temps get to 95°C and the oil temp is 200° after a 45 minute to an hour on an 85° day.

Your heads are way too cold. Are you sure you have the cht set correctly? How could your oil even reach 200 with heads that cold?

Of course altered compression ratios probably change some things but here is raby's stuff on head temp and this matches what I have read in the books on type 4.

[emerygt350]