Fluidyne Rad in Winter

[XfireZ51]

Today was one of the warmer, nicer days we've had in Chicagoland. The Z has been laid up for nearly 2 months so far and the prospect of $3 93Octane had me taking the car out for a quick spin. Outside temps did not get above 31F.
Motor ran well BUT it kept going in and out of Closed Loop due to the coolant temps dropping below 74C (70C) as I drove around. This was driving locally so I did not get a chance to see what happens at a hiway cruze.
If I drove the Z around in winter, I would probably keep the stock rad.

I also installed the fiberglass top w the new ZR-1 lining I got from R. DeMarco.
Exhaust sounded much more subdued BUT of course, windows remained closed also.

[mike100]

74C? If I had to venture a guess, you are running a 160 deg thermostat. The radiator should not matter as much as the t-stat number. Flow through the lower hose should be restricted near the t-stat opening point and the block coolant should continue to rise.

I had run a 160 unit in an old hot rod in 15-20 degree weather once and the heater never really got warm. The radiator was stock too. I would say the a 190 deg stock thermostat might be a good choice for winter. I should solve that problem...too bad it isn't easy to swap out.

[XfireZ51]

Originally Posted by mike100

74C? If I had to venture a guess, you are running a 160 deg thermostat. The radiator should not matter as much as the t-stat number. Flow through the lower hose should be restricted near the t-stat opening point and the block coolant should continue to rise.

I had run a 160 unit in an old hot rod in 15-20 degree weather once and the heater never really got warm. The radiator was stock too. I would say the a 190 deg stock thermostat might be a good choice for winter. I should solve that problem...too bad it isn't easy to swap out.

I have a 160 but never put it in. Specifically because an ECM motor is looking for a certain CTS Temp range. I run Closed Loop, so I'm interested in having the motor run above 80C for Learn Mode to be functional.

[mike100]

Hmmm... how much bypass does the LT5 have? In general, most systems are going to be thermostat dependent as the radiator doesn't do anything at all until the thermostat cracks open.

[bradley]

I run a 180 and when the temp get below45 degrees the car runs really cold also