Hi All, question on water temp My 322 nailhead in 53 f-100 is running a 180 themostat and will run between 185-195. on the highway at 3100 rpm it may creep towards 200, but what I would like to know is, when you come off the Highway it will creep to 205 and then slowly come back down. Is this normal or is there something that i should look at? Vacuum advance is hooked up to manifold vacuum. 34 degrees mechanical advance. New cross flow rad. New water pump. New thermostat. Any and all info appreciated. B.
Sounds like heat soak. When you get off the highway, you are slowing the water down and the heat is having a chance to transfer into the water. By the end of the ramp, or shortly after, is it dropping again? If so, that's the rush of water that moved slowly moved through the rad cooling it off.
It takes a little bit more than the off ramp to cool back, maybe 5 minutes or so. but it takes 30 or so minutes to get up to max Temp. I think that your idea is very probable, the nailhead has the sending unit in the side of the block under the cast exhaust manifold and I was'nt sure if this would magnify the situation or not. Thanks for your reply, does any one else find the same temp creep with their motors? just curious. Thanks B.
I would try a drain and flush. Best done with thermostat out. Whist at it put in a new one. Can't hurt, you'll be surprised how much **** you get out of it............
check your bottom hose. i had the same exact thing happen and it turns out that my hose was collapsing at high rpms, like highway speed. especially on warm days. to solve it, i took one of those "universal" bendy hoses with the wire in it, took a piece of the wire out and stuck that in. i also have used a piece of pipe in between to keep it from collapsing. started happening on my cad powered lincoln this summer on a long hot summer drive. as others said, as well. cleaning/flushing is always good. start there and see what you got. if no change, try the hose. However, you say you've got a new radiator right?
Yeah, it sounds less like heat soak if it doesn't come right back down. I would protect the sending unit if it's too close, but it shouldn't read too far off if it's in the proximity.
Thanks for the suggestions Guys. New thermostat is in it, the rad is new, I don't have a shroud on it. It will idle all day in the heat and stay cool though. The motor is clean inside, I'm going to check that bottom hose. I know that it is wire reinforced but it sounds like that might be the problem. The carb is also a new, Eldebrock 650 I wondered could it be a touch lean out of the box? causing temp creep. Thanks again! B.
You are describing normal behavior for the 322 nailhead. This is made worse if still using the dynaflow. A good pressure cap and 50% coolant will let it go to at least 230* before boiling over. On the other hand 50% coolant transfers heat less efficiently than plane water and at 230* you will have some or a lot of heat knock. Those wetter water products don't seem to make much difference on the nailhead. It get real worrisome if using the stock Buick or Ford guage of that era which will be pegged hot at 200*. Just drive it and watch for any deviation from the current behavior. Willie
The sending unit is in the hottest spot, something Chevy didn't do till '68, so you will see more heat in this location than say at the thermostat. On the highway you have the motor up making heat, then you slow down and the coolant flow slows and quits pulling the heat off as fast, no big deal, it cools down in a bit. If it bothers you put a shroud on it, I think I would anyway, You'd be surprised how much more efficient your cooling system will be. If I remember correctly, the first shrouds I ever saw were on larger cars in the 50's, maybe the Buick actually came with one.
Thanks guy's for all the info.... it's appreciated. I wouldn't have thought that the sending unit was in the hottest spot... that's good to know. I would have thought the heads would be the hottest place. Other than the water temp puzzling me this Motor is great, I have never had anything to do with a Nailhead before I bought my Truck, but I'm a great fan of them now!
Another question for you Fedman, my temp sending unit is right behind the intake manifold on the upper part of the head on the driver's side. Yours is under the exhaust manifold?
Ace, my sending unit is under the p***enger side manifold, in the water jacket. I believe that this stock location for Buick.
interesting. i just looked at mine to make sure it was indeed on the head behind the intake manifold and it is. i've never seen one under the exhaust manifold. weird.
A quick and easy way to check the radiator is to rub your hands across the surface and if there are spots cooler than others those areas are blocked.
Put a fan shroud on it and do you have a panel above and below the radiator between the grille opening and the radiator support....This directs the air thru the radiator and doesn't let it go over the top of it under the hood or out the bottom under the truck....
HotRodrod 33, yes I have a panel below and on top of the Rad, just no shroud. I checked the rad number yesterday and it is a from a 69-71 Ford p***enger car Mustang, Brougham, etc. Small block and big block. 3 core I would think that it has enough capacity to keep it cool. Thanks for all the input everyone.
I just thought that I would post the fix for this "problem" to help anyone that might be interested. The problem was the sending unit placement in the side of the block. I switched it up to the front of the p***enger head outlet and now it runs right on the 180 stat temp. plus or minus a few degrees. It was a head scratcher for me, but I sure like seeing that temp gauge steady with the stat temp. Thanks again to all that helped with suggestions.
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