leadfoot2

Can someone give me an idea on how much difference in temperature I can expect between the oil exiting the cooler and the oil in the pan under track usage on a 500 hp LT1 engine? I'm seeing about 295-300 degrees in the pan which seems high to me for a new engine.

trackboss

On all my race cars I've had/driven (ford small block) they run around the same in the pan. Never had a problem. Keep in mind the pan for the most part is the hottest oil because the oil just went through the engine where it was heated. It then drains into the pan where becomes available to be picked up by the oil pump. With the oil cooler properly plumbed the hot oil from the pan should be pumped first into the oil cooler and then into the motor. Temp drop depends on the efficiency of the oil cooling system. I'd say if you are 300 in the pan you are more than ok as long as you are using good quality synthetic.

-V

leadfoot2

I'm trying to get a feel for what the rise in oil temperature is when it passes through the engine under road racing conditions.

mgg

My question to you is what RPM are you shifting your car at. On my 383 / miniram motor anything under 6000rpm generates oil temps in the 260-270 range. In race conditions when shifting at 6400 still 200 rpm below max revs oil temp quickly hits 290 295 degrees. this is with a canton pan, huge oil cooler and accusump. I also switched to a mechanical gauge mounted in the pan from the electric gauge I had previously.
I find this very frustrating as I really had hoped the oil temps would be in the 250 - 260 range after all of these improvements. Water temp is still only 185 -200 max. Doesn't make sense to me. I would suggest the switch to a mechanical gauge if you are currently not using one. I did see a 5 degree difference in oil temps .
Good luck!
mgg

Sidney004

Here is an interesting summary:
http://www.bobistheoilguy.com/forums...178#Post729178
that is partially relative. If you could view the SAE paper, it might shed more light on it.

Slalom4me

$14.00 for non-members to receive by mail or download, $30 by fax.
Link to SAE document page
.

Slalom4me

I came to the conclusion that the oil filter on my C4 likely played a role
in heat gain. After installation of headers and a pan with kickouts, the
filter was well within an inch of three of the primaries and the side of
the pan blocked the front of the filter. Despite trimming and application
of DEI/ThermoTec shielding, the hose for the OEM cooler nearly touches
one primary. To address the issue, the filter for the engine was moved
to a remote location in a way that retains the OEM cooler.

Another consideration is excessive by-passing within an oil pump.

In the BITOG thread, the initial post by MolaKule includes the statement
that the oil pump contributes 8% of the heat energy imparted to the oil.
When the by-pass valve in an SBC pump opens, the oil is recirculated
to the inlet side of the pump, it is not expelled out into the sump. Oil
heated by the first pass goes around to the inlet to be further heated
by additional passes. My vote is that choosing a pump with more
volume than is required likely leads to higher than necessary oil
temperatures.

.

leadfoot2

My sentiments exactly! Im running a 383 also and put in a big radiator, external cooler, Canton pan, and an accusump and did not expect to see 300 deg oil temps. From discussions in other posts I see that 300 is not uncommon but that doesn't make me feel any more comfortable, especially in the 100+ weather in the summer here. I'm going to get my oil analyzed to be sure the engine is OK and put another temp sensor in the oil line somewhere as backup. I checked the calibration on the sensor in the pan and it was close. My fingers are crossed.

Sidney004

This is a very good idea. Terry Dyson could assist you in selecting the proper lubricant for your racing application. I have used him with very helpful input. FWIW, I now use Redline 10W-40 in my lower hp LT1.


http://www.dysonanalysis.com/

C66 Racing

Not really adding to the discussion on temps, but adding another consideration. At 300F, a typical multiviscosity 30 weight oil will have a viscosity on the order of 3.1 cSt, or about 30% of the oils viscosity at 212F (where a 30 weight is defined as having a viscosity of 9.30-12.49 cSt). It is for this reason that I use a high performance 10w40 on the track (and many run a 15w50).