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| | | | Joined: May 2007 Posts: 25 Apprentice | | Apprentice Joined: May 2007 Posts: 25 | I have a 56 235 installed in my 1953 truck. I have installed the original deluxe heater and need to know two things.
1. What pressure radiator cap should I be using?
2. what temp thermostate should I be using? | | | | | Joined: Dec 2006 Posts: 1,154 Shop Shark | | Shop Shark Joined: Dec 2006 Posts: 1,154 | We use a 4 pound cap and a 180 thermostat on our 1955-56/235 installed in our 1954 3100....T/C Steve | | | | | Joined: May 2007 Posts: 25 Apprentice | | Apprentice Joined: May 2007 Posts: 25 | The bay area weather is close to ours, Thanks for the info. Brian | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Guys,
4 pound cap - presurized or not?
I read another thread of 6 and 8 but nothing regarding presurized or not.
I assume one is for use of a recovery tank and the other is without.
Brett | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Got to go back to the science and logic I guess. How about this?
Water boils at 212 degrees (at sea level). The higher the altitude (lower pressure), the sooner the water boils due to decrease boiling point. Increase pressure = increased boiling point. For each pound of pressure (14.7 psi, one atmosphere) boiling point of water increases about 3 degrees.
Increased boiling point = increased operating temp for engine.
So a pressurized cap is better.
NEW QUESTION: Can my old 54' 235 (seal and gasket wise) handle 6 (increased bp of 18 degrees), 8 (24 degree increase), 10 (30 degree increase) pounds of pressure.
Brett | | | | | Joined: Dec 2006 Posts: 1,154 Shop Shark | | Shop Shark Joined: Dec 2006 Posts: 1,154 | My radiator is in the shop right now 235/55-57...4 lbs. cap with rubber gasket and overflow tank. Keep anti-freeze level at 3/4" above the top of the radiator tubes.....these are low pressure radiators 4-7 pounds 180 thermostat and use at least 50/50 mix...NO a higher pressure cap is not recommended as per the radiator shop. the PO had a 17 lbs cap on it and it split the top seam on the tank...just thought I'd tell you what I learned today. T/C Steve | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Thanks Steve,
Good to know - low pressure cap it is. Again, to much knowledge can be dangerous... goin to check on the still!
Brett | | | | | Joined: Dec 2006 Posts: 1,154 Shop Shark | | Shop Shark Joined: Dec 2006 Posts: 1,154 | Hey....who wants the truth if its boring...T/C Steve | | | | | Joined: Oct 2001 Posts: 3,458 Extreme Gabster | | Extreme Gabster Joined: Oct 2001 Posts: 3,458 | The block is fine with whatever pressure you want to run, its just limited by the radiator and heater core.
For highest cooling efficiency, run the highest temperature thermostat you can, since any increase in radiator temperature increases the heat transfer. It is limited by how hot you can get the water without it boiling over. A 180 degree thermostat is best for stock cooling systems. If you have a new radiator and no heater you can run a 17 pound cap with a 195 degree thermostat if you want.
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