Fluidyne Rad in Winter - ZR-1 Net Registry Forums

XfireZ51 · 11-21-2014

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 · 11-21-2014

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 · 11-21-2014

Quote:

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 · 11-21-2014

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 · 11-22-2014

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

11-21-2014	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,686	Fluidyne Rad in Winter 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.

11-21-2014	#2
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,786	Re: Fluidyne Rad in Winter 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.

11-21-2014	#4
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,786	Re: Fluidyne Rad in Winter 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.

11-22-2014	#5
bradley Join Date: Aug 2013 Location: ridgecrest ca Posts: 103	Re: Fluidyne Rad in Winter I run a 180 and when the temp get below45 degrees the car runs really cold also