I'm getting close to starting up a new engine build (stroked aluminum Windsor block to 427) and I'm wondering if I should be worried about oil temp. No oil cooler but do have a 7 qt sump. Do I need to monitor oil temp, and where should I put a sensor? What are acceptable oil temps?
Oil temperature
1 - 12 of 12 Posts
sensor in the pan sump .one inch up from the bottom
Joined
·
10,342 Posts
OK - there's an application - here's your bone. Street vehicles need to raise temps higher than heavily maintained racing vehicles to drive-off condensation and acids. This requires the oil to reach 175°F minimum, and a suggested maximum of 195°F (oil pan temp taken as DanH described) for several minutes. Higher temps will perform the same function, but oil life above 200°F is cut in half. The other reason to limit max oil temp is that a primary function of the oil is cooling the bearing races. At 200°F the bearing temperature is roughly 275°F, and can rapidly skyrocket when additionally loaded, causing rapid local thinning and loss of the oil boundary layer, along with rapid viscosity breakdown.
There's a lot a science behind engine oils, but that should give you your ball park target for your general application.
David
Joined
·
1,859 Posts
Simple answer.....not necessary for a street car!!
A cooler can actually keep oil too cool which is worse than warmer especially with synthetics!!
Run it awhile without and see if you're happy...if not just add the cooler later!!:tup:
My $0.02 FWIW!!
A cooler can actually keep oil too cool which is worse than warmer especially with synthetics!!
Run it awhile without and see if you're happy...if not just add the cooler later!!:tup:
My $0.02 FWIW!!
Joined
·
443 Posts
...and run a good true synthetic motor oil (ester based) after break-in like Red Line, Amzoil or Royal Purple which can take much higher operating temperatures without break down. If those oils see 230, 240 no sweat.
Also, an oil's vicosity rating as well as other (warm) performance markers are taken at 100C (212F) in the lab so that may give an idea of where it's operational temp is meant to be.
A note on synthetics: years ago I plugged a VDO oil temp gage into the pans of both my 390GT and 360 using the drain plug replacement type sensors. The 390 operated about 190-195 and the 360 was about 180-185 running penzoil crude. I then switched to synthetic (early amsoil) looking for better gas milage and did nothing else and both engines dropped 15 degrees. At the time I figured that had to be a good thing. Gas milage however didn't noticeably change at all.
A note on synthetics: years ago I plugged a VDO oil temp gage into the pans of both my 390GT and 360 using the drain plug replacement type sensors. The 390 operated about 190-195 and the 360 was about 180-185 running penzoil crude. I then switched to synthetic (early amsoil) looking for better gas milage and did nothing else and both engines dropped 15 degrees. At the time I figured that had to be a good thing. Gas milage however didn't noticeably change at all.
Joined
·
10,342 Posts
Oils are tested at many temperatures and have standardized tems for comparative analysis. Engine oils are rated at -45°F, 0°F and 212°F. They have to be rated at some standard temps, and those are it. That has no bearing on the intended operational temp range. Oils are chosen based on their viscosities and shear layer with given clearances, pressures, shear speed, bearing pressure/area and temperatures expected. There are reasons a modern BMW may run 0W20 synthetic at 235°F and an offshore endurance racing boat may run 140°F with straight 20-weight mineral-base oil. Of interest is the fact that all cars ran with 170-185°F temps (typical 160°F thermostat running temps) until Federal emissions regulations began their higher-temp impacts in the mid-1960s. Food for thought.
David
PS: PaulS posted a temperature vs wear chart but I couldn't find it easily. I'll post one of the others I have I have from AAT or SAE or USAER when I get a chance tomorrow.
1 - 12 of 12 Posts
Join the discussion
