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340 engine thermostat

18652 Views 23 Replies 7 Participants Last post by  Volunteer
Hello all. I've got a siily question but I'm going to ask it anyway. Is the 195 degree t-stat the correct unit to use on my '73 340 engine? It's a '73 engine in my '70 swinger. It warms up to OK 195 degrees, then when I get it out on the road cruising, it creeps up 205, then up to 210 sometimes but hovers around 205. It just seems a little bit too warm, or is it? Should I go with a 180 degree or leave it alone? It doesn't overheat, not yet anyway, and the car has an electric cooling fan as well, just in case. Any thoughts? Thanks, Steve.
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· Premium Member
6,103 Posts
I think it was too, Cudapete. My suggestion is to find a location near the radiator, determine how much room you have and start junkyard shopping for something that fits in the space. Clutch fans are clutch fans, as long as the bolt pattern is correct, any one should work just fine. Once you get a shroud, then you might have to look at spacers, so something else to get at the junkyard so the fan is deep enough.

· Administrator
1974 Plymouth Valiant - 2013 Dodge Dart - 2013 Chrysler 300C
25,569 Posts
Funny thing, I have the opposite problem, I can't seem to get the temp to budge. Either I mis-installed the thermostat, put in a bad one, or the temp sensor's wrong. Using a/c in stop and go traffic I should be able to get hot water.

· Registered
401 Posts
I beleive in 1970 the overflow canister was ......the ground
:D Yeh, - - too funny. Wonder if o.p. is still an active member - as this is older thread.
Not sure about A-bodies but first E-body with 'catch-can' was the '74 model. They utilized a very unique and ultra-rare round cap with predominantly white disc on top. Most replacement caps have a 'dual-seal' config. which adds a larger (flat) rubber seal around the perimeter - to allow tight seal against top of rad. neck. As liquid in system cools down, the smaller, inner seal will pull down (as they do in all applications) to allow the developing vacuum to pull in liquid from catch-can. Outer seal maintains its' integrity so random air cannot enter the system. One other added benefit of a dual-seal or 'recovery' rad cap is that it permits the system to be totally filled, unlike the earlier units which used an overflow hose to spill excess hot liquid onto the ground. A sealed system which is properly run full to the top, can also contain up to two quarts of extra coolant - thus contributing to better overall cooling potential.
May I add that anyone in similar situation should have their radiator inspected and 'flow-tested' at a good shop.
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