Good point if the engine is "actually" overheating at highway speed. So far you haven't said what the temperature reading is at road speed only that you THINK it is overheating because the electric fan won't shut off at road speeds but there seems to be no other indication that is overheating and that means getting up in the 220/240 range. 185/200 going down the road is not overheating an most guys would be to hell tickled if their rigs ran that down the highway. Hell, my Cad 500 has a 195 thermostat in it and I don't consider 195 to be hot. Before you wear guys out trying to analyze a problem that may not be a problem what is the actual engine temperature on the highway?
Before you put the hose filler inline. Why don't you just jack the front up and fill it? That's what I do on mine. I have 2 radiators in my truck and the back is lower then the front. So I jack up the back and fill it up. Done! Posted using the Full Custom H.A.M.B. App!
The way your engine sits, and your radiators position reminds me of the 94 05 Camaro LT!'s that where plagued with over heating issues. Chevy even went as far as putting flathead screw bleeders through out the cooling system to purge air..... You may fix the issue, temporarily, but its ultimately gonna keep rearing its ugly head.... The intake has got to be bellow the top of the radiator. So the coolant can adjust its own level properly.... 160 thermostat is gonna compound the issue.... Chevy put the thermostat in the water pump housing, used a 195 thermostat, had the first cooling fan turn on at 213 deg, and the high cooling at 230.... They also scrapped the design shortly after....
I think it's too much total timing too. Took me a while to figure out it was my problem. I get a misfire at 3000rpm, above 200F. It gets worse at the engine gets hotter. I can drive around town, and it stays at 200F even when it's 110F out. I jump on the freeway at 70mph (about 3400rpm), and it's hitting 220 in minutes. In my case, the cam is out of time, it's too advanced when it needs to be straight up. My 2 cents.
I have '52 Chevy with a sbc. When I got the car it ran fine around town but on the freeway, it ran at 210. I was gonna add a/c, so I replaced the radiator with a triple flow, 4 row copper/brass one from US Radiator Desert Cooler series. It still ran at 200 so I checked the timing. The distributor's vacuum advance was frozen in full retard. I replaced the distributor and now she runs at 180 with the a/c on. BTW, the radiator is a direct fit.
I've been trying a few incremental changes over the past week. The electric temp gauge I have is reading 20 deg hot, so it wasn't running to hot. Just hot enough to keep the fan running all the time. I filled up the remaining gaps between the radiator and what's left of the core support, no real improvement. Added the upper hose fill location, no real improvement. switched to a 160 thermostat, It will run down the highway at 195 indicated and the fan turns off! success. I'll work on making a pretty lower air dam to replace the pressboard one I whipped up. Thanks for the ideas guys.
To me, this is the best way to tackle any issue. To often, may changes are made, and if 4 out of the 5 changes worked, but 1 doesn't, they are all scrapped as failures.... 1 at a time, is best...
I want to try my new tablet with a camera, lets see how they turn out. I decided to pull the water pump to check the divider plate and tubes. Both are present and in good shape. The clearance to the stamped impeller is a bit big at 3/16" which I can fix. Beond this, the only thing I can think of is to try a flush, the block and pump are a bit corroded Posted using the Full Custom H.A.M.B. App!
Had problems in the past with pontiac 400 running hot, but not over heating. I wound up switching to a pump with a cast iron impeller, which lowered the clearance to the plate, and made it run much cooler.
I would adapt a Ford FE style surge tank into the upper hose/water inlet. The '63-64 Fords had a similar situation with their cross-flow radiators being set so low too. Bob
Found a cast impeller. Brand new no core from napa for $38 P/n 43102 I think I see why the cast impeller may be better. The fins actually reach the center hole, while the stamped one is 0.4" away at the tip. Im working the plate a bit to get 1/16" clearance Posted using the Full Custom H.A.M.B. App!
Some of the new thermostats lack the small piddle valve hole, which allows coolant to get by. Not much, but just enough to make the thermostat work properly. I usually drill a 1/8" hole in thermostats when I install new ones.
Whelp, im sneeking up on it lol I did poke a little hole in the t-stat earlier Here's a quick rundown of what I did over the winter New cast impeller water pump I had the radiator cleaned, the guy said it was fine just a light cleaning I made this new upper cover to force more air through the radiator, see pic Upper hose filler and puke tank (which never gets full) The fan still runs while im going down the highway so I think its still an air flow problem. Next im going to try and build a bigger lower air dam. I can lower it a 2 inches and run it all the way across the radiator. Posted using the Full Custom H.A.M.B. App!
The Jalopy Journal
