CaptDistraction

(Warning in advance, rambling ahead)

Background: Built a new coyote/roadrunner motor a while back. Went overboard on cooling and sensor package, and now have some weird symptoms that may be bad gauges or setup.

Setup: MMR1000/Roadrunner, Fluidyne radiator, MMR head cooling mod, Boss 302 Oil cooler, homebrew Air/Oil cooler (-10AN lines, supposed 20,500 BTU core), 302S Grilles, speedhut gauges in stock location with T, and in Moroso 10QT pan (total 12 QT capacity for system). 302S hood, wrapped headers (stock).

Symptoms:
Oil temps read 140 if not below if the ambient air is 70* or below and car is highway cruising. Can go 50 miles without fully warming the oil (as read by the gauge).
Oil pressure reads 70-90 on start, settles to about 20, and once coolant reaches about 160, oil reads no pressure on the speedhut gauge unless you blip the throttle (obviously I have pressure or the stock pressure switch would flip - I know it works unfortunately). That or my motor seems to run just fine without any oil pressure (jk)...

I did install a 180* oil thermostat last week to try to combat the temperature problem

Testing: I bought an IR thermometer to test with this evening.
After a 15 minute drive and 5 minutes of idling, the gauge showed 160 (climbed from 145 when I first parked). The Pan as shot by the thermo was 161, the oil cooler lines were 178 and 170 respectively at their fittings. The cooler core was 158 as best as I could shoot it. I am thinking something about that pan may be such that the sensor is getting more of a reading of the pan itself, which may be slightly lower temp than the oil itself. Still not sure why that would be the coolest place in the oiling system. This was all sitting idling in the garage without the car's fan operating. When it did operate, all temps dropped about 5-7*.

Some images of the setup:






Can't see the gauge wiring, but I have good grounds on both gauges, oil temp is in insert in side of pan with an appropriate brass NPT adapter.

~70mph after 30 minutes continuous running, ~68* ambient. Pressure looks good, temp can't be right.
http://www.chris-wynne.com/coyote/oiltemp.JPG[/img]

My thoughts:
The system is too large a capacity for street use, however actual oil temps are higher than the gauge is reading. Is it possible both my gauges just read somewhat low? I'd be inclined to believe both read between 10-20% low. I'll email speedhut for further guidance, but anyone else have some thoughts on a car that seemingly runs too cool?

dmichaels

You could be overcooling just cruising around. I had an external air to oil cooler on my last car and oil temps as indicated on my temp gauge would get pretty cool in the colder times of the year. Try taping off the front of the external oil cooler as to inhibit airflow and see if you get higher more normal temps. Also could you remove the gauge and run some tests with a known temp source to check gauge accuracy?

CaptDistraction

Another update: Colder day (44 out) but I did wrap the core.

It didn't seem to make a meaningful difference on a 25 minute drive.

Some more pictures:

The sender in the pan (note the secondary ground wrapped around it):


the cooler core:

AlsCobra

I would say you're over cooling a little but the oil temps are only gonna get as warm as your engine. The oil pressure I would be more concerned with. May be a problem with your oil pump or suction tube. The oil temp doesn't sound like an issue if your thermostat is only 180.