Topic: Heating problems

[Pantdino]

My math shows 70 C = 158 F, 80C = 176F, and 90C = 194F.

70 is definitely too cool and will lead to premature engine wear.
80 is the coolest you should run for a long time.
90 is probably the best.

Jim

[ChrisD]

OK thanks,
I will replace that thermostat ASAP. No need to wear out the engine even if it is going to be replaced soon with a 1050 one

[Paul vander Heyden]

Chris,

If you have installed the front radiator, in addition to the rear one, make sure that the water flows in the following order.

into pump from output of front radiator ( at the bottom of the front radiator) via one of the pipes under the car.
through block thenout of the head
coming out of the head through the thermostat or restrictor plate
from restrictor to top tank of rear radiator (should be the highest point in the system)
through rear radiator to bottom hose outlet
from bottom hose outlet on rear radiator to input of the front radiator (at the top of the front radiator) via the other pipe under the car.

The diameter of the pipes/hoses going to the front radiator should be approx 25mm inside diameter.  Larger is OK but not required.

The electric fan mounted on the rear radiator, does it have a shroud around it?   This is VERY IMPORTANT, if not the fan will just suck air around the radiator rather than through it and the effectiveness will be reduced by over 50%.

If the engine RPM is 875, then the pump RPM is 430 RPM or so.  You can change the pulley on the pump to a slightly smaller one and increase the output of the mechanical pump.  Alternatively, set the idle RPM slightly higher to 1000 RPM.

Regarding temperatures.  If the system has a pressure cap (14 lbs) and you are running 30% coolant (no more as it becomes inefficient at higher concentrations), then the actual boiling point of the fluid is probably closer to 112 degrees Celcius.  Yes, with the cooling capacity you have now it should be possible to keep the  coolant temperature below 100 degrees Celcius.

Hope this helps.

Paul Vanderheijden

www.scuderiatopolino.com

[ChrisD]

Paul,
I have installed a front radiator,
the water flow I have is like you describe it,
the tubing under the car is copper with outside diameter 28mm witch means it is about 25mm internal diameter
and I have installed a smaller pulley to the water pump. there is no rear electric fan, just the mechanical one from the water pump witch works ok with the smaller pulley, and yes it has a shroud. Looking at the engine compartment looks like I still have the 767 engine in it. Evrything is in place and you can only tell it has a diferent engine because of the oil filter on the left of the engine and the extra oil radiator.
My coolant is about 30% and so far the maximum temp I saw was 75 degrees celcius and that is because of the old lower thermostat I had with my old setup. I will replace it with a higher one (maybe 85 degrees) to allow the engine to work in normal temperatures.

I just mentioned that setup to let people know this kind of setup works just fine and has the advantage of having cabin heating too. Might look like a detale but it is important to a street car in a country with cold winters. I know the pump I used is hard to find but you could easily make an adaptor plate to install one from Seat 133 or even cut and weld up the 767 one.

Chris