The GMC CCKW

Hi guys

What thermostath do you use and which one should be the best?

I use a 160degr thermostath, but I replaced the radiator for a
NOS unit. The old radiator was not bad, but temp was always between
185 and 205degr and drove very good at these temperatures.
I havent done a testdrive yet as I was also converting it to 12v with great
succes!! first testdrive end of next week, my driveway is blocked by a large container

But Iam a bit afraid temperature will be to low, because I also have an LPG installation and it has to climb some hills when going uphill to Bastogne. And does (a higher) watertemperature effect the manifold for cracking??

I do have another thermostath and cardboard for behind the grill, but Iam just interested in your expericiences that are also related with enginetemperature.


Best regards,

Corné

Hi Corne,
I use a 160 degree thermostat as well
The 160 degree means the temperature at which the thermostat will open to allow coolant to flow through the system.
Not the temperature at which the engine will operate.
My vehicle usually operates at around 180 degrees , but when pulling a lot of hills the temperature will climb higher when it gets close to 200 I slow my speed and allow the temp to normalize.
When I keep my speed below 35 mph I usually have no temperature spikes ,it only occurs when I'm pushing 40 plus mph under load.
Keep an eye on your temp gage that's why it's there and you shouldn't have any problems.
Hope this helps
John

I know this is not an answer, but my CCKW operates at only 140*C.!

This is puzzling as everyone elses seems to operate much higher.

I removed the thermostat AND temp gauge, and tested them in water
on the stove.

The gauge was accurate and the thermo opened around 170.

My cooling water is not hot enough to burn me if i drain some after
running for 30 minutes or more (from the radiator stop cock, it IS hot, so it must be circulating)
My water pump is recon, with new impellor

Ambient temperature was warm ie 15-30 degree C, it never freezes around here.

I notice also the thermo is not very restrictive, it allows plenty of water to
pass, even in the fully closed state.

The only thing i can think of is maybe my radiator capacity is bigger,
it takes 13 imperial (euro) litres to fill the radiator after draining, but i am a bit doubtful,
as the radiator has to fit in its housing,
so i cant see how it could be bigger.

it runs and drives fine, the choke is only needed for starting, it is immediately opened, then i drive away.
It has never displayed the typical
symptons one experiences with vehicles that take a few minutes to fully warm up.

Should I be concerned? tony

my gauge shows 140 F, not 140 C, as i incorrectly posted a moment ago

Thanks for both answers

Well Tony Iam also afraid that mine will not be hotter than 140degr, I had the same experience last year with the Willys MB, recored radiator and 160thermostath (outside temperature around 0C or 32F) I replaced this one for a 185degr.
But a Willys is not an CCKW, thats why I asked the board
for expierences and thoughts. I do also think that engineperformance is
better with a higher watertemperature.

I will give it a try as soon as the container is of my driveway and
see if there is real difference between before and now with NOS
radiator.

I will keep you all informed

Greets,

Corné

My experience is like John Cliche's: Push it above 35 or hills and it goes past the thermostat setting.

In the cold weather it will run 150. In the summer it runs 170-180 or higher. One factor I have found is that mine tend to blow off coolant in the summer time when shut off.

Another factor (I believe) is the steam relief tube. The Chevy has a valve on it that is only to be opened when operating in steep grades. The CCKW is open all the time.

And yes, you should let the engine cool down (idle) before you shut it off after a hard run or temp above say 170.

Hi guys

I promissed to come back for this story

The weekend of 9-10-11 februar I went to the Ardennes, its about 500km
round trip, in total about 700km for me.
My average speed was about 42mph and some hills had to be taken
with 3th or 4th gear and one with 2th gear that was awesome.
And for me unbelieveble, the temperature was stuck between
175 and 180degr. but mostly constant at 180degr. no matter if
I drove uphill?downhill or highway or just idling.



GMCs lined up in Bastogne

Beautiful Group photo and the night time one is very nice too