VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Lack of thermostat

Hi, chev fans, I need a little help on my 28 superior K. I'm installing a new radiator on my car and with it off, I removed the thermostat housing to check it and there isn't one in it or a restricter plate either. There are two bolts in the upper neck going to the radiator but no recess for a thermostat to sit in like the later models.
I have always heard that without a thermostat or restricter plate that the water would go thru to fast to cool the engine? This is my first experience with a early chev four and all help or opinions will be appreciated. I checked in the early chev catalog and it list a thermostat but I have not been able to see a picture of one or how it fits. The early chev shop Manual has no pics either. Thanks in advance, Johnny

Hi Johnny,

Sounds like your thermostat housing is an earlier model. The '28 thermostat fits inside the housing, not the head.

From what I've read, the thermostat helps the engine warm up quicker and helps maintain an optimal temperature. I recently put a new thermostat in one of my '28 engines. I bought the thermostat itself from a car parts store that was listed for a 1955 chevy.

Here's some pics and info about what I did: Thermostat segment of '28 engine rebuild

Cheers, Dean

Hello Johnny,

I don't have a thermostat or restrictor plate in my '28 tourer and it runs fine.
I wouldn't know if it would run cooler with a restrictor plate because I have never tried it, but might do that as an experiment one day.

John

Thanks guys, all that was very good input. Dean, my thermostat housing is identical to yours, the bolts are still in mine and are free, I just took them out to see. I notice that Gary at early chev has the plates but I think I can make one like you did. Thanks for the photos, they sure helped. Have a good day and happy motoring! Johnny

Dean is correct in saying that a thermostat heats the water up quicker. About the restriction, a honeycomb radiator has a natural restriction in the design of the radiator. This slows the rate of flow through the radiator so removing the thermostat has little effect. If you fit a modern type core in your radiator, you take out that restriction. With this core and no thermostat the car will overheat. I automatically fit a restricter plate to cars without thermostats automatically when I fit a modern core. Put this down to nearly 40 years playing with old cars.

Cheers Neil

Thanks Neil, I bought this car without an engine, it's a 26 ,then I got a good deal on a running take-out 28 engine. So when I put the engine in along with the radiator that I got with the car which is a standard core that is fairly plugged up, I could only drive up and down my drive ( about a quarter of a mile) a couple of times before it would start to steam a little. I have bought a new standard core radiator for it but hadn't considered about it not being an original type (honeycomb) . Thanks for the tip, I'm going to fit a 160* thermostat to it. I also bought a new laser heat reader so I can more accurately check it other than watching for steam! LOL! .
Lots of good info guys, Johnny

Just for the info ,Neil, how big a hole do you put in the restricter plate? Johnny

That is not true. The flow rates on any of our cooling systems is not high enough to cause cooling problems. If you don't believe this, study flow dynamics and hydrology.

Adding a restricter or thermostat might result in less coolant loss or even lower measured coolant temperature. What is actually happening is that air is being drawn into the coolant. Most often the air enters past the water pump shaft. However, though fairly rare, it can also enter past hose connections. Due to the vast difference in viscosity air can be drawn in where water will not leak out. Particularly in non-pressurized systems the air will heat up dramatically expanding the bubble size forcing coolant out of the overflow. When the engine is shut down residual heat will increase coolant temperature forcing even more coolant out. Cure the air leak and eliminate the problem.

Well Chipper, I had heard about the water pump problem before but the bushing seems to be tight on mine, it doesn't leak and seems to have grease in it. My delimena is that this engine was in a running car that a friend of mine sold and it wasn't overheating in that car. But when I bought it and installed it, now it seems to get hot too quickly so I just layed it off on the stopped up old radiator. It was appearantly running fine before without a thermostat. I was jus trying to cover all my bases while I had the radiator off. Thanks for your input, Johnny

While you have the radiator off and the thermostat cover off, I suggest you poke around in the water jacket with a coat hanger wire to loosen chunks of rust. It builds up especially bad at the rear of the head.

Then, put the thermostat housing back on temporarily without the thermostat, hook up a water hose, and flush the block and head with clean water from the house. Run the water both directions (into the water pump first and then into the thermostat housing).

Any junk you get out of the engine will help with your overheating.

Cheers, Dean

Hello Dean, the engine block looks fairly clean, I don't know the history on this engine but I suspect that it hasn't been long since it was rebuilt. It runs good and idles smoothly with good oil pressure. No smoke or blowby , top end is all tight and valves adjusted correctly so I think it's ok.
Have you lived in San Leandro a long time? I saw where you lived and it brought back a lot of memories. I spent several months down at Monterey on the old army post there doing prep training to go overseas in 1965. I had a girlfriend up in San Leandro and while up there one weekend I traded for a 1946 Mercury convertible and drove it home to Arkansas (with the top down most of the way! ) LOL! But we all did crazy things when we were 18 years old, huh!
Well, have a good day, Dean , and happy motoring! Johnny

Hi Johnny.

Yep. My wife and I have lived in the same house for the last 45 years. It doesn't seem that long.

And, yes, we do crazy things when teenagers. When I was 17, I had a Kawasaki 500 (death machine). One a trip to Healdsburg, I took it up to 135mph on a country road. What made this really stupid was the bike had a Honda 450 front end, a guitar strapped to the side, and a sleeping bag tied to the handlebars.

Dean

I have solved many vehicles overheating with a restricter plate. I normally drill 2 x 1/2 inch holes in the plate. Take my advice and fit the thermostat or restricter plate and see how it goes. You really have nothing to lose but a bit of time.

Cheers Neil

Good morning, guys, I wanted to post an update on my heating problem. It is fixed and running cool now. Thanks so much for everybodies comments and suggestions.
Per chipper's comments, and the fact that the block was fairly clean, I decided to reinstall the water neck without a restricter plate or thermostat. I installed a new radiator and have run it quite a bit and have been checking with the infrared thermometer . It has been running cool, maybe a little too cool, but the weather was only in the 40's on the days I was running it. I'm going to recheck it when I run it on some warmer days, maybe a thermostat is in order to get it up to an optimum running temp, as per what Dean implied.
Well, guys, thanks for the input, and have a good day and happy motoring! Johnny
P.S. This car is for sale, I'm ready to go on to the next project!

A thermostat will heat the coolant to what ever the rating temperature. I don't use them as I live in the Southern USA and don't drive much in cold weather here. When we go up North a thermostat might help them run a bit more efficient and have a bit more HP.