Thermostat styles
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=2650
Printed Date: January-16-2025 at 2:55am
Topic: Thermostat styles
Posted By: Tim D
Subject: Thermostat styles
Date Posted: October-24-2005 at 1:39pm
Here are two thermostats, the rusty one is 142 degree and the other is 140 degree. They are very different in design, both are marine. Has anyone else seen this?
 ------------- Tim D |
Replies:
Posted By: GottaSki
Date Posted: October-24-2005 at 2:27pm
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The one on the left is a low volume item, the one on the right is high-volume, similar to the RobertShaw brand,
I suspect, depending upon the marinization, the back-pressure from the low-vol is sometimes required to keep water moving in the right places. BUT If I had a choice, the one on the right lets the water move best for heavy-working vehicles. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: AWhite70
Date Posted: October-24-2005 at 7:39pm
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Thermostats are something near and dear to me. I've actually dealt with both of the above thermostats in my job (designing diesel engine cooling systems).
The thermostat on the left is a standard elcheapo reverse poppet thermostat. The stat on the right is of a pressure balanced design, as GottaSki says probably produced by RobertShaw. The opening of the thermostat on the left is effected by the pressure in the cooling system. Once the stat opens slightly and relieves some of the pressure the thermostat can close again (partially or completely). I've seen this cycle happen up to 10 times in my company's engines before the stat will stay open. The thermostat on the right has a more balanced pressure on either side of the valve and is effected to a much lesser extent by cooling system pressure. The result is a much more steady and stable thermostat opening. Both thermostats are actuated by a wax "pill" or motor. Basically there's a little chamber of wax and as it heats up and melts it expands which pushes a piston and opens the thermostat. Personally I recommend the thermostat style on the right. We are no longer using the thermostat on the left in new designs due to the above mentioned problems. |
Posted By: 64 Skier
Date Posted: October-26-2005 at 6:39am
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Great Post. I could not figure out why the elcheapo I had installed would produce tempersture swings. I bought and reinstalled a thermostat from SkiDim and the temperature swings are gone.
Do you guy's know what SkiDim sells. It looked nothing like the thermostat on the "left". ------------- 64 Skier 66" HO VTX and 67" HO Triumph http://www.correctcraftfan.com/diaries/details.asp?ID=1071&sort=&pagenum=3&yrstart=1971&yrend=1975 - 71CC |
Posted By: 81nautique
Date Posted: October-26-2005 at 9:45am
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64,
I just got my new tstat for the spring from skidim last week. It's a 143 and looks like the one on the right. Alan ------------- You can’t change the wind but you can adjust your sails |