Do any of you V8 guys happen to know what your oil temperature is running?

Thank You!!!!!
Phillip J. Haun
Oak Harbor, WA.

I don't have a temperature gauge installed or a cooler yet, I am running a 930 box which has nicer gears at freeway speed. My guess is on the warm side if you spin it up like I do. My water temps are great but oil does its own thing. I'm interested in hearing others on this subject

Me too. I'm running a 4.3 V6 and although water temps are well managed, the Oil viscosity seemingly breaks down within just a few weeks (judging from pressure drop) and thats using full synthetic oil. I'm still considering an oil cooler, despite feedback from other posts that it not necessary.

Find someone that has a IR thermometer (they are cheap nowadays) and point it at the filter, that will give you a "idea" of where you are at.

Ferg

Hey its hot here in So. Ca. today, I am going for a drive and will check the temp at my oil filter and report back tonight..

I don't have a V8 914 but I have plenty of V8 experience with cars that have oil temperature gauges. There are a few things that cause high oil temps
1. As mentioned about RPM = HEAT.
2. High volume oil pumps can be nightmare if the engine is not set for them. The oil heats up as the vast majority of the oil squeezes by the bypass valve - they are hell on cam gears also.
3. On a flat tappet engine valve spring tension can be a killer. On my old 16V rabbit track car the oil temperature was uncontrollable after I installed slightly bigger cams with much higher rate springs (turned out they are the wrong springs) Even with a huge oil cooler the oil would hit 240F in 5 laps - water temps were just fine. Before the change I could flog that poor thing endlessly at 7000RPM.

My engine is an SBC 283 with about 260 Ft-Lb rear-wheel torque and 250 rear-wheel HP (dyno-tested).

I have an oil cooler with fan and an auto thermostat that starts the fan at 180 deg F. The oil cooler is installed on the engine support cross-bar and takes air from below the car and discharges it up into the engine compartment and out through the engine compartment lid. See pictures.

I use the original 914 oil temperature gauge which has no temperature markings on it, but I calibrated it using boiling water and an infrared thermometer. The oil temp sensor is for a Chevy oil pan drain plug. The gauge and sensor happen to work together very well. Straight up is 210 deg F. Mid-left is 160 deg F and mid-right is 260 deg F.

I also have a 7 quart low-profile oil pan. I figure that between the oil pan, the cooler, filter, there are about 9 quarts total. I run 20-50w semi-synthetic.

I find that the oil temperature is very sensitive to air temperature, airflow to the radiator, and engine RPM.

At highway speeds and cool weather (< 70 deg F) water and oil run at 160-180 deg F. Warmer weather or stop/go driving gets the oil to 210 deg F. Hard driving and high revving gets the oil into the 230 to 260 deg F range.

I also did a visual test to find out how much oil gets pumped to the top of the engine, by using a clear plastic tube to see the oil level. There is about 1 quart pumped to the top of the engine and the amount is not very sensitive to engine rpm.

Nick

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Hey Nick,
I read your thread but didn't understand the above quote. Do you mean you punched a hole in the valve cover and installed that hose so you could see how much oil rises up / ? Sounds like a good idea.

I did drive my car moderately hard, shut it down and shot my oil filter to get a reading of about 170 degrees. That seems fine to me but I'm sure when I drive it hard it must go over 200 for sure. In town I often stay in 3 rd gear because 4 th with my 930 box has a higher final drive than a 901 box. I run around a 3k allot which could raise oil temps in a SBC. Last year I drove 1200 miles up to Washington state last year, spent most of that on the freeway at 3k (80 mph or so). Didn't have any issues what so ever..
Nice cooler set up ...

I didn't "punch a hole in the valve cover". I temporarily removed the oil pan temperature sensor from the side of the pan and installed a 90 degree fitting with a clear plastic tube pointing up (see picture). This becomes a "sight glass". The oil level that I can see in the tube is the same as the oil level in the pan. I marked the height of the oil without the engine running and then with the engine running at various RPMs. The black line above the oil level represents the oil level when the engine is not running. The oil level you see is with the engine running. The difference is about 1/2" and translates to about 1 quart. That is how much oil is pumped out of the oil pan when the engine is running. I actually expected more than that. Engine RPM does not seem to make much difference, only about 1/8" fluctuation between idle and 4,000 rpm.

The reason I did this is because I was having oil starving problems when braking hard, especially going downhill. I found that the V8 conversion setup tilts the SBC downard at 3 to 4 degrees. Doesn't sound like much, but it results in about 1/2" less oil cover over the pickup - verified using the "sight glass". Hard braking and downhills make it worse. So I built an horizontally oversize pan (didn't want to go deeper because of ground clearance, but deeper would be the right way to actually solve the problem). The running oil level tells me exactly how much I can fill the pan with oil without risking contact with the crankshaft. I would rather have an occasional dip of the crank into the oil rather than oil starvation.

I now understand what you mean! The oil starvation you documented above also is good to know. I will keep that in mind when upgrading my oil cooling system and pan. It's good to know the details, thanks

I also have played with a lot of sbc's. The best oil temp is to get it to 200 and keep it there. The quicker it gets to 200 the less wear on the motor. A lot of pan capacity also helps if everything else is good but if it's hot it's hot. A overbored block has thinner cylinder walls and will run hotter water temps. A high volume pump will make a 20 degree increase in temps if the bearings have stock clearances. Sometimes water flow on a sbc can be tricky but if the temp gradually climbs at highway speeds it is usually not enough airflo. Oil helps to cool it down but hot water will heat it back up.

On the starving under braking you can go to speedway motors site and get a sbc cheater oil pan kit and it will come with some swinging gates that you can put in the pan to stop the oil from leaving the pickup area. Also the pickup needs to be about 3/8 to 7/16 depending on the highest rpm the motor spins.

Everytime the oil gets to 260 it should be changed shortly.

I once built a 327 from a 307 and it was in my wifes 69 camaro. It had a 350 that ran cool but I was trying to improve mileage and keep the same performance. It didn't happen and I had to go to a 4 row new radiator just to cool it down. It was also running higher compression though. After it got broke in the oil pressure got pretty low at idle. I consulted two different engine builders and they asked me if the cam was a little stiff to turn when i assembled it and I said it was. They said at the factory sometimes the cam bores are not straight and chev would put in ofset cam bearings to fix it. When I put the new stock size bearings in they were offset slightly and after they broke in they were loose causing low oil pressure at idle. I patched it and added a high volume oil pump and the water temps went up to 205 from 190 on a hot day with the ac on.

Really interesting stuff, I wouldn't think a high volume pump would do that, but understand how much friction would be made with tight bearings make sense. Surely there's allot to building a nice SBC.