62 544 overheat questions

[lelshaddai]

I have been here before with some overheating questions. I have more questions now than answers. I have a 62 544 with a 69 2.0 engine. Engine has all new gaskets, seals and lifters. Standard radiator, which seems to have good flow. and fan. Has two 7 inch electric fans in front of radiator. Has a working 160 thermostat(but has also had a 180 working thermostat) 32/36 weber carb conversion, rebuilt, standard 4 speed with rebuilt rear end with 4.1 gears. Distribution tube has had the ports enlarged. Normal antifreeze mix. Original temp gauge and sensor.

Problem: engine experiences run on/dieseling after shutoff so I assume rich or timing slightly off. However runs very well.

Situation: I drove to go to a show today, 75 miles with long stretches of 7% uphill grade. Outside temp ranged from 75 -85F degrees. (when temps get above 100f here the temp gets close to the high white mark) Cruising at 62mph on relative flat land, I was sitting just above middle on temp gauge. Once I hit the hills the temp got very close to the white high area on the gauge.

So the questions. So how accurate are the gauges, should it run that hot going up hills? Hot much will the richness effect temp? Has been very difficult to dial this car in. Electric fans are pushing correctly but seem to make car run warmer when at idle.Did not use them when running at cruising speed. Drove up without any problems at all.

[mocambique-amazone]

Hello Lelshaddai,
This gauges aren't correct mostly. Remove carfully the sender from head. Boil some water and put the sender into it. 100°C, the boiling point of water. Mark this at your instrument.
The small tube under the thermostat is still inside the head?
I don't and won't trust the original fan. Better to drive without if the car is with electric fans.
Dieseling is from sharp edges in combustion room, and/or running too lean!
Do you know the compression ratio of this engine?
A expension tank at the radiator will help too.
The fuel rubber hose has contact to the clamp of the water hose on top of the termostat. Dangerous!
Good luck, Kay

[lelshaddai]

Thank you for the input. Do not quote me on this but I check compression last year and it seemed they were all between 115-125. Although that may be the Metropolitan compression. It had a bracket that kept the fuel line off the engine. Did not notice it was missing. Thanks. When you say tube under thermostat do you mean the distribution tube? If so, yes it is still there. I will need to test the gauge when I get back from the show.

[Ron Kwas]

lel; I agree with Kay...first verify accuracy of Temp Gauge by immersing Sensor Bulb into boiling water (which boils at 100Deg C at sea level, but lower if your doing this test at the top of that grade!). Caution: Exercise extreme care extracting Sensing Bulb from Cyl Head, and handling it in general(!)...do not twist it off the Capillary tube!) See: http://www.sw-em.com/temperature_gauge_notes.htm

You first picture shows a heavily modified Coolant Distribution Tube...maybe too heavily modified!...it looks like those distribution holes are too big, possibly resulting in starving the rear cylinders of cool Coolant (and we know that's where the CS temp is sensed...hmmm...could that influence temp indicated?) See: http://www.sw-em.com/Coolant_Distrib...Pipe_Notes.htm

Kay; I don't have any problem with the original fan, and would never recommend removing it...but adding a shroud to optimize airflow of the Fan and decrease bypass will increase Radiator effectiveness.

Electric Cooling Fans are really intended to augment the original Fan and airflow through Radiator at slow roadspeeds. See: http://www.sw-em.com/Cooling_System....ic_cooling_fan

I agree upgrading to a Sealed CS with Exp Tank is a good idea, but it will only prevent Coolant loss, not help with cooler running...

Good Hunting!

[mocambique-amazone]

Hi Lelshaddai, not the distribution pipe I did mention. Under the thermostat is a short "tube" inside the head. Position is vertical, not horizontal.
This get closed by the thermostat if the thermostat get fully open and the short coolant circuit get closed. Sometimes this part is gone by corrosion.
Which plugs does this engine have? Dieseling maybe a result of wrong plugs too.

Ron: I've seen fan like this throw away on part, rhe result was a hughe damage inside the engine bay. A nightmare.
The sealed CS drops the temperature too. Because of more coolant inside the radiator and less air bubbles inside the system while engine is on high revs.

[lelshaddai]

The distribution tube was modified according to that article. Funny thing it did not change the running temp hotter or cooler. The electric fans are on a switch and only used when slow or sitting. Thermostat is working as when the temp approaches 3/4 it immediately drops upon warming up.

[Volvorama]

The 5 blade plastic fan is a great upgrade. Also look at providing means for air to flow out of the engine bay, remembering that the PV was designed for a very low power 1400cc engine. Louvres in the inner wing panels will help (did later PVs have these from the factory?). Otherwise there's the trick of raising the back of the bonnet (hood) slightly.

[Ron Kwas]

lel;

The "small tube under the Thermostat" Kay wrote of is the Bypass Pipe (4) here:

I don't recall ever seeing one corroded away, but maybe he has a different experience...
Cheers

[lelshaddai]

I will have to check on that when I get back Sunday. Another thought the car started to leak more oil on the way up. Will being low on oil heat it up?

[arcturus]

Have you tried dropping out the coolant and measuring just how much there is? Should be 8.6 ltrs. Is the rad in the PV big enough to handle this. Are you sure that all the matrix in the rad' is clear? I had a similar problem on an old Ford. Whilst coolant flowed all the way from in to out, half the tubes were blocked.