Cooling Problem

[James_Douglas]

Hi All,

Although heat is rarely a problem in and around the San Francisco bay...I am having problems with the Desoto running hot when I am in stop and go traffic in the outer, and hotter, areas of Northern California.

Once at freeway speeds it runs at 180 unless I am pulling a long uphill grade and then it runs up to about 190-200. It drops back as soon as I crest the grade.

Here are the answers to the common questions:

1. The engine is rebuilt and well broken in.

2. The block was acid dipped prior to the machine shop getting it to make sure that the inside was very clean.

3.A new water distribution tube was installed.

4.The thermostat is working fine.

5.The bypass is working fine.

6.A new radiator, supposedly high efficiency, was installed.

7.A flex-o-lite light weight fan with a stronger low RPM pitch is installed.

8. No shroud.

9.Tried an electric fan as a stand along and as a addition to a standard one.

10. The carburetor is not running lean.

11. The advance is TDC.

Can anyone shed any light on my cooling issue?

Thanks, James

[greg g]

Fan belt tight???

[Plymouthy Adams]

I am not a fan of the flex fan..was the original fan determined not to be adequate...

[James_Douglas]

The belt is set to the proper tension. The light flex-o-lite fan is not a classic flex fan. It is really their cheep replacement fan. However, since it is 20% of the weight of the stock 4 blade fan, it uses less power and is easier on the water pump bearing. It also does not flex much and it has a more radical pitch for more air flow at low RPM than the stock fan.

It does pull more air than the stock fan at idle.

James

[Reg Evans]

I'd have to agree with Norm if it only reaches 200 max. and is not boiling over.

Have you tried a 160 degree thermostat for the summer months ?

[PatS....]

I'd try a shroud...seems like you have all the obvious bases covered.

Also, make sure, on the other side of the rad, that the air is being directed through the rad and not around it.

[captden29]

where do you get one of those fans? what if any benefit at higher rpm's/ dennis

[Don Coatney]

James;

My engine runs at about the same temperature as your engine. I did about 35 freeway miles earlier this week pushing my engine hard (running between 70-80 MPH) with an ambient temperature around 90. My engine ran around 180-190 on the freeway. My electric thermostatically controled fan did not run as I have the thermostat set to come on at around 190 drgrees. Once I pulled off the freeway my fan came on and my engine temperature rose to around 210 for a couple of minutes then dropped back down below 200. By the time I parked a few minutes later the engine temperature was about 195. This is normal for my engine with a high ambient temperature.

[James_Douglas]

Don,

Sounds like it may be that this is the temperature curve I will have to live with. Given that the car rarely sees high ambient temperatures, I guess I get a little unnerved when the temperature starts climbing.

James

[James_Douglas]

Sorry Flex -A-Lite:

http://www.flex-a-lite.com/auto/html/400-series-economy.html

At high RPM all fans just get in the way as the ram air going down the road is doing all the work. This fan is very light and has the largest pitch of any flan they make so it pulls more air at idle. Obviously in my case...still not enough.

James