Thermostat problems

wensum

wensum

Senior Member
I have a fairly well worked over motor and an aluminium radiator which always runs too cold.
I inserted a 160 degree thermostat in the top hose as supplied by Snyders with the tubular part facing down.
After a few miles there was a loud clack clacking noise, apparently the thermostat opening, shortly afterwards water was expelled from the radiator cap and very soon it was boiling (Confirmed with an infra red temperature gun)
I removed the thermostat and all was well again, but too cool.
I purchased a second thermostat, similar to the first but a slightly different type (just in case the first was faulty, but it checked OK in a pot on the stove) installed it and the identical situation reoccurred .
So I've removed that too, but as we about to head into the wintry South Island in a few weeks, I was hoping to be able to run the motor at the desired temperature.
Has anyone any thoughts on this situation? (All compressions are similar at 120psi)
Many thanks
Keith
 
I use the sleeved thermostat from Snyders. The only failure I have seen with these is when the do not open at temperature. If you have verified it's opening and that it is installed correctly I would drill 3 or 4 small holes around the tstat so it will allow some flow until it gets up to temp.
 
Greetings Keith, I removed the small split pin out of the thermostat and made sure the hole was at least 3/32. I have also found that if you take the car straight out on to the highway with out a five min fast idle warm up you will get those problems you experienced. The other thing I have found is that after 100 miles of summer high country motoring I had to top up the water (about 1/2 3/4 litre).
Enjoy your trip down here in the south, we are having temps in the early twenties (not usuall) so wintery days can't be far away.
 
Wooden wheel said:
Greetings Keith, I removed the small split pin out of the thermostat and made sure the hole was at least 3/32. I have also found that if you take the car straight out on to the highway with out a five min fast idle warm up you will get those problems you experienced. The other thing I have found is that after 100 miles of summer high country motoring I had to top up the water (about 1/2 3/4 litre).
Enjoy your trip down here in the south, we are having temps in the early twenties (not usuall) so wintery days can't be far away.
Click to expand...

Thanks for the advice, Irishmans Rally here we come with up to 10 cars from the Waitemata Branch, 7 being Model A's in one form or another, chains and spade at the ready for the worst possible situations as required!
 
wensum said:
I have a fairly well worked over motor and an aluminium radiator which always runs too cold.
I inserted a 160 degree thermostat in the top hose as supplied by Snyders with the tubular part facing down.
After a few miles there was a loud clack clacking noise, apparently the thermostat opening, shortly afterwards water was expelled from the radiator cap and very soon it was boiling (Confirmed with an infra red temperature gun)
I removed the thermostat and all was well again, but too cool.
I purchased a second thermostat, similar to the first but a slightly different type (just in case the first was faulty, but it checked OK in a pot on the stove) installed it and the identical situation reoccurred .
So I've removed that too, but as we about to head into the wintry South Island in a few weeks, I was hoping to be able to run the motor at the desired temperature.
Has anyone any thoughts on this situation? (All compressions are similar at 120psi)
Many thanks
Keith
Click to expand...

What temperature is it without the thermostat? The lower end of ideal temperature is 160. The stock Model A was designed to run at the correct operating temperatures. The thermostat does allow the engine to be at 160 faster (less cylinder wear during warm up) but it also restricts the flow and can cause the stock system to run at tempatures above 190-195 which is hot for a Model A base temperature. The hotter temperatures reduce emissions and reduce cylinder wear but eventually too hot causes other engine damages such as blown head gaskets and cracked valve seats etc. i prefer the lower temperatures.
 
Wondering if you have a temperature gauge with a large bulb inserted in the outlet neck that is stopping water from mixing in the hose while it is warming up?
 
You need the 'stat down in the hose as close to the outlet as possible. If it rises to the top it will be very slow to react upon initial warm up. Again, be sure the copper sensor part faces the engine and the pointy end toward the radiator.
 
Mine has two 1/8th " holes to allow some circulation while warming up. I've never had a problem. The hot water must be able to reach the thermostat before it boils. Ron W
 
Thanks for all the advice, the first one I drilled two additional holes adjacent to the existing one.
The second came with two holes opposite each other..
I have a motometer and without a thermostat the red never appears in the tube.
When the thermostat opens, which I presume is the loud clacking noise that I am hearing, the red in the motometer jumps up to the correct location, but within minutes, it's boiling.
Thanks for the PM from wooden wheel, I will contact you.
Keith
 
"When the thermostat opens, which I presume is the loud clacking noise that I am hearing, the red in the motometer jumps up to the correct location, but within minutes, it's boiling."

Your thermostat is faulty. Toss it and get another. It is opening too late.
I have never in my career heard a thermostat open....or close. They are silent devices
 
Is the thermostat turning sideways somewhat in the hose, causing turbulence/noise as it clacks around. Thermostat should be held securely by something...couple pieces of radiator hose that slips inside of existing, top and bottom of thermostat or .... Thermostat too loose in hose could cause all sorts of issues.
 
Keith , sounds like its upside-down, or the noise is it touching the impeller ??like do I remember a certain oil pump you built turning the wrong way ????ops better not go there, you guys calling in on trip down or back ?? Good luck, Derek
 
quickchange said:
Keith , sounds like its upside-down, or the noise is it touching the impeller ??like do I remember a certain oil pump you built turning the wrong way ????ops better not go there, you guys calling in on trip down or back ?? Good luck, Derek
Click to expand...

Thanks Derek,
It's clamped in just above the head on a Ford Falcon water pump.
It has struck me that it could be mounted up-side-down and we're having a party here tomorrow for all who assisted with the construction of the car and I'll check with them if I've been putting it in up-side-down, but I feel that I followed Snyders instructions carefully.
I don't think the oil pump was mine? It was modified as per the "Secrets of Speed" article by Charlie Yapp and with a pressure relief valve set at 25lbs appears to be doing it's job effortlessly
Cheers,
Keith

PM me and address and phone and we may make it one way or the other
 
A8270BR.jpg


Mikes afordable discription;

"Welded to 1 in. piece of thin-walled stainless pipe. Install at the top of hose, pointed end up. Will not cause leaks like the pronged ones can do. 160 Deg. Temp."

Brattons disctiption;

Install thermostat at top of hose. Pointed end up. Most authorities recommend this. The 180 degree thermostat will give a slight improvement in performance, but will raise the water temperature 20 degrees. For some cars that extra 20 degrees can cause overheating. Most customers order 160 degree unit.
 
locate at top of hose , bottom of hose ? other posts / threads recommend at the bottom of hose. Any empirical data to support which position? Later (more modern) vehicles such as the flathead Chrysler products had stats located right below or within the gooseneck.
 
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I had a feeling you were not using a stock pump. It acts like the direction of flow may be wrong. Ron W
 
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