too much oil pressure?, high OT on the freeway Options

[VaccaRabite]

My 2056 is getting elevated oil temps on the freeway. I am using a high volume pump, and seeing about 40 pounds of pressure on the freeway when my oil is up to temp.

What I think is happening is that there is too much pressure, and the oil is not being pumped through the oil cooler due to the check valve closing the passage. However, this is just a guess, as I don't have any way to test it. All I know is that when I am driving at revs, oil temp goes up and if I keep driving at higher revs the oil temps stay up). if I drop revs, oil temps fall back into place, but I can't do that on the freeway without building a lot of head heat.

Before I go through the trouble and expense of adding an oil cooler, I want to make sure that I have checked out the simple fixes first.

What do I do to make sure oil if going through the oil cooler? What is the point where pressure cuts off passage through the cooler?

All tin is in place, and fan housing flaps divert air over the oil cooler 100% of the time (no thermostat in place, so the flaps are always set to cool).

Zach

[underthetire]

I get 40 PSI at 210 deg on the Fwy as well. Fought this a long time, some reasons I found are
Sound pad not anchored correctly to the firewall, allowing it to move closing off the air intake.

Heater flappers and loose tin. Mine did a huge drop in temp when I pulled of the heater crap and blocked the air ports from the shroud. I believe it was just blowing air around the big gaps in the ducting. Once I got the header in, temps dropped even more. I would think bad flapper valves could cause this as well?

Switched oil to a part synthetic.

Mine used to climb up to about 240 on the freeway before this (80 deg day or so) now i'm down to 190-200 or so.

[VaccaRabite]

Heater flappers and loose tin. Mine did a huge drop in temp when I pulled of the heater crap and blocked the air ports from the shroud. I believe it was just blowing air around the big gaps in the ducting. Once I got the header in, temps dropped even more. I would think bad flapper valves could cause this as well?

Mine used to climb up to about 240 on the freeway before this (80 deg day or so) now i'm down to 190-200 or so.

I could try blocking the vents at the bottom of the car. My car has no heat (I use headers) so all the fan and heat ducting is out of the car. I also don't have the rubber pad on the firewall.

However, my fan shroud vents are vented to open air. I had read somewhere that capping them could be bad for cooling as it caused cavitation. But I don't think it would be that hard to cap and test them.

Your oil temps are what mine are right now on the freeway - until I pull off the freeway and take the B roads home.

Zach

[Spoke]

I could try blocking the vents at the bottom of the car.

These are the tubes that used to go to the heat exchangers, correct?

If you think about it, with all the HE stuff in place, blowing air in the HE would cause some backpressure and limit some of the volume of air flowing.

Now you have removed the HE and all the tubing so the little stub of the tube on the fan assembly has no backpressure and would allow more air to escape to the atmosphere instead of being forced across the cylinders and oil cooler.

Kinda like if you put a big hole in the top of the fan shroud. The air will blow out through the hole where there is no backpressure instead of going across the cylinders and oil cooler where there is some resistance to air flow.

You don't want any air escaping from the fan shroud that could be going to the cylinders and oil cooler.

[jhadler]

I forgot who originally mentioned the cavitation issue with block off the HE ports (Jake probably?). But I do see how it's possible if you're not venting enough pressure that you can decrease the efficiency of the fan by retaining too much pressure downstream of the fan blades.

Perhaps a small hole in the block-off plate to allow some of that excess pressure to bleed off?

-Josh2

I could try blocking the vents at the bottom of the car.

These are the tubes that used to go to the heat exchangers, correct?

If you think about it, with all the HE stuff in place, blowing air in the HE would cause some backpressure and limit some of the volume of air flowing.

Now you have removed the HE and all the tubing so the little stub of the tube on the fan assembly has no backpressure and would allow more air to escape to the atmosphere instead of being forced across the cylinders and oil cooler.

Kinda like if you put a big hole in the top of the fan shroud. The air will blow out through the hole where there is no backpressure instead of going across the cylinders and oil cooler where there is some resistance to air flow.

You don't want any air escaping from the fan shroud that could be going to the cylinders and oil cooler.