Why is my car running so cool?

[Ho Hum 74]

After I put in my BAT 70 row horizontal, spoiler mount oil cooler along with a Mocal thermostat my car was running cool.

How cool you ask? Well try 120 indicated during cruise on the highway. I drove all the way to Grattan (Grand Rapids MI) from Chicago on about a 80 degree day in some traffic and then on open freeway and she wouldn't go over 120. Prior to my install my car would run about 180 at all times on the freeway.

What gives?

The Mocal thermostat is interesting. Basically it is an open circuit ALL the time. What I mean is that it allows flow of oil to the cooler AND through the short circuit (at the thermostat) back to the engine when below 180 degrees.

When the temps reach 180 degrees the thermostat closes the short circuit and forces oil to make the round trip to the oil cooler.

Help me understand the internal thermostat. Doesn't it keep oil inside the engine in order to reach 180 degrees and THEN (over 180) open it to allow it to cool? If this is the case, maybe my internal thermostat is not working.

Thanks all
Tristan

[MotoSook]

Here is how the oil circuit should work, from to Chuck M's site..

[MotoSook]

I would be surprises to learn that the Mocal t-stat does not block oil flow from the cooler when cold.

I your t-stat does not prevent flow through the cooler when cold, then the oil would hardly ever go hot enough. You would have continuous flow and cooling through the cooler up front.

[DavidI]

Is the gauge accurate? Have you had it tested? That temp seems very low.

[MotoSook]

Tristan, once we get the engine in, well go over the whole thing...sender, guage, t-stat......

[Ho Hum 74]

Souk,

I agree with you. I was surprised as well but it's definitely open when cold. It blocks the "short circuit" (back to the engine) when hot (180) and then forces oil to make the return trip to the cooler.

Tristan

[MotoSook]

I wonder if all Mocal t-stats work that way????

Hey, are you coming donw tomorrow?

[Ho Hum 74]

I called BAT (who sold me the Mocal) and they affirmed that's how it works (open when cold???). Can't come tomorrow. Need to prepare for my build as I'm sure you understand. Would love to be there though to check out the backdate!

Cheers,
Tristan

[vash]

do a test, wrap alum foil around your cooler to see if the temps go up. i am having the opposite affect, when hot, i think i am only getting a trickle going forward. i am going to have a exxon valdez affect if i decide to trouble shoot.

cliff

[MotoSook]

No problem Tristan...get it all lined up and we'll bolt that thing together in a day.

As for the cooling, unless Mocal can swap you on that actually creates a full blockage, I'd look for a used stock t-stat. We can fit it using mm-AN fittings, not rocket science...

I took my cooling system off last weekend with only a loss of about 1/2 quart..into the catch pan...the lines and the cooler were still filled, but I drained them later. I had my old "scavenger pipe to tank" hose, so I put it back in..no issues. Started the car up and moved it around for ease during the body work.

[Elombard]

Another problem is that the oil pressure when cold could blow the cooler - no????

I would have thought BAT was aware of that though, and MOCAL, both fairly reputable.

[Tim Walsh]

well you know what you need if you're running too cool? :-D a bigger engine

[Chuck Moreland]

Souk's diagram from my website is for the factory thermostat. The mocal does function differently.

Ho Hum, how are you finding an 80 degree February day in Northbrook? I moved from Chicago 20 years ago, but I don't think things have changed that much

I would first confirm your temperature guage. That you never saw greater than 180 BEFORE adding the cooler has me suspicious.

[Ho Hum 74]

Chuck,

This was last Sept on the way to Grattan. If it was 80 degrees in Chicago now then we'd all be dancing in the streets!