1930 Dodge Brothers Eight (DC) thermostat?

[Spinneyhill]

What temperature should the thermostat be rated at? I am interested in documented evidence. It is the same as DA after c. DA-102451, DD, DE, DH, DI, DJ, DL w/o automatic shutter, DO.

I see 1937 Dodges used a 160 (Motor's Service Manual) as did the 1930 Plymouth (see Ply33.com), so maybe that would be the one. The owner's book does not say, nor does the parts book, nor the master parts book, as far as I can see.

Mine has a "170" International Harvester model fitted, but it starts to open at 85º C and is fully open at 90º C (185 - 194º F). This explains why the gauge is reading at or above the top of "normal" - and I thought there was a gauge problem coz I replaced the thermostat with like in 1997 when I put new rings in! I even noted at the time that it still ran "hot" on the gauge. Sometimes I wonder about myself.

[stooy]

Our DeSoto 8 Runs at just below the alcohol boils point on the guage when it is floating on its thermostat.

What we did is check the calibration of our gauge by placing the sender in a pot of water and heating it up with a thermometer in the water so we could track the gauges movement and know what was going on. The only point i recall was that the marker at the bottom of the hot range was 98 degrees c.

Sorry I don't know what temperature thermostat we have.... its been 15 years since I looked at it.

[ply33]

I'll have to double check what I have on my web site, I'm pretty sure I cross to a 160° thermostat for the Plymouth but the original parts book doesn't list opening temperature.

The earliest Plymouth factory service manual is for 1934 and the temperatures listed in it for the testing the thermostat would work out to a 150° thermostat. The later Plymouths, based on a '46 to '54 factory service manual used a 160° thermostat. Interestingly, the 1936-42 service manual does not seem to list temperature ranges for checking the thermostat.

The 1934 and earlier engines don't have the full length water jacket nor do they have the water distribution tube so it seems possible to me that a cooler opening thermostat was used to mitigate hot spots on the earlier engines.

I've not seen a 150° thermostat for sale so I've crossed to a 160° that fits and works.

[Guest DodgeKCL]

My 2 cents. From a 1934-'37 Plymouth general repair manual-"The thermostat should begin to open at 150 to 155 degrees and be fully open at 172 degrees." These are all flat head 6s.

[Aussie 8]

My 2 cents. From a 1934-'37 Plymouth general repair manual-"The thermostat should begin to open at 150 to 155 degrees and be fully open at 172 degrees." These are all flat head 6s.

I have a 1930 DC8, but unfortunately I haven't been able to clock up any real distance as the big end bearings needed redoing..

Without a thermostat water is just pumped out the overflow so a modern thermostat was fitted. It now runs right to the top of the gauge but doesn't boil until the car stops. The block feels very hot to me as well.

I have just purchased a high flow thermostat which I hope will make me feel more at ease.

I will let you know how it works out.

The radiator is new. Head and block thoroughly flushed out and engine fully reconditioned.

Thermostat is a Tridon unit part number TT268-170

I hope to have it fully sorted as I intend taking it to the Dodge Bros Centenary rally at Forbes later this year.

Cheers.

Jim

[stooy]

G'day Jim,

Just a quick thing, we have found on the CF8 that after many re machining jobs on the water pump the impeller had moved forward such that the recess it used to sit back into at the front of the block was now uncovered allowing water to exist the pump, go around cylinders 1 and 2 and then go back into the radiator leaving the rear cylinders starved for cooling. It may be worth checking how far back in the block your water pump goes. The other thing some people have done to remedy this problem is place a T piece in the tempriture sender port and take a hose forward and connect it into the upper radiator hose.

I hope that makes some sense.

Cheers

Stewart