I think this motor is just ment to run hot. The engineers of the 50's probly never thought we would have a traffic light every 20 feet. I have changed the coolant, flushed the radiator put a new thermostate and still will heat up pretty quick at triffic lights. Before I go and make a fan shroud, are there any more ideas? Thanks
Do you have a gauge on it? If so, what's it normally run at, and what does it heat up to when sitting still? What thermostat are you running? 160, 180, or 195 degree? Are the fins on your radiator in good shape? I had a car that ran hotter and hotter, but didn't leak coolant. When I looked at the radiator, I was kinda shocked to see that most of the fins had rotted and fell out! The radiator can't do it's job if the fins are brittle, missing, caked with crud or blocked. To see if they are in decent shape, run your finger over them with about as much pressure as you'd use to casually scratch an itch. They shouldn't fold over or flake off. If they do, you need a new radiator. Also...are you running a heater? Don't ask me why, but GM engines cool better in most cases if you loop a bypass hose between the two heater hose outlets (when not running a heater core). (I tried this on a Camaro I had with no heater. At first I just threaded pipe plugs into the heater hose outlets, but the car ran hot. Put the nipples back in and looped a section of hose between 'em. Car ran at normal temp! (Doesn't look as tidy, but it works better!)).
Fan shroud, NEW RADIATOR, I always use a cheap Flex-a Lite black plastic fan...I can't tell you how many times I had a "GOOD" radiator and couldn't get the temp down...put in a new one and the problems solved (this is on race cars, drivers, hot rods)...just my three cents.
Mine runs 180 all the time once it's warmed up. I some times have to sit in heavy traffic if I bring it back here to West Haven & I've never gotten over 190. Are you sure you're fanblade is'nt on backwards?? Billy
That funny about the heater loop, cause I was just looking at how the loop looked and was about to put plugs in. The termostate is a 180, and the radiator is great. I've been told these motors just run hot at a stop, and there is nothing I can do about it.
two of the fan blades were hitting the crank pully when I first got the car, but only needed a little tweek to fix that. Which way should the fan blow air, in or out? Sounds like a dumb question to me!
The 235 in my truck doesn't overheat in traffic. Ran a little warn when I got it, replaced the stock fan with a flex fan no more problems...
Cabbie, you need to tell us how hot it is running, or tell us why you think it is overheating. Are you SURE the radiator is good? I had the 5 year old radiator in my late model giving me FITS last summer when I went through it running hot on the highway. I flushed it 3 times, changed the hoses, bypassed the heater core (thinking it might have had a pinhole leak and didn't let the system pressurize) put a 16 PSI radiator cap on it. All in all, it was a month before I just bought a new radiator at NAPA, and that was the problem. It runs as cool as ever now. The 235 in Munson's 59 Apache ran great for me yesterday, in 110+ degree heat and in traffic, the only time it got a little hot was when I was driving at about 55 MPH or so. Also, remember that water boils at 212 fahrenheit. Add the pressurization of the system, the fact that the coolant raises the boiling point, etc. Now, if it is over about 230 or so, you might want to start worrying.
mine runs fine. I had the rad. flushed, straightened all the fins, I use a 185 thermostat and a stock fan blade , 50/50 antifrezze and water no over heating probs. and it gets hot out here. how is the timing? I had a car with too much advance and it ran hot untill I fixed it by retarding the timing. what does it idle at? mine idlles at about 700 rmp. too fast an idle will make it run hot.
[ QUOTE ] Which way should the fan blow air, in or out? Sounds like a dumb question to me! [/ QUOTE ] With the engine running put a piece of paper in front of the radiator, if the fan is drawing air thru the radiator the paper should stay against the radiator when you let it go. Billy
Never had that kind of problem with my 235? Even at a gazillion degrees. At a stoplight, I can look at the gauge and actually SEE the needle go down a few degrees when the thermostat opens.
cabbie, this is only an opinion, but consider: if an engine cools ok at speed but not at idle, you have an air flow problem, not a radiator problem. the only difference is that the vehicle is moving and the rpm's are up. logically a radiator problem would worsen when the rpm's are higher and the engine is creating more heat. but what you have is just the opposite. what i'm hearing you say is that when air is flowing through the radiator it cools ok, but not when the car is stopped. by way of shroud, fan, etc., see if you can't get air moving through the radiator even when stopped and i believe you'll have solved the problem. $0.02
A good rule of thumb is if it runs cool when moving the radiator is good, if it runs hot at a light it means that there is an airflow problem, fan or shroud....
Check the color of your plugs. Make sure you are in time. A lean mixture ( white burn on plugs) and advanced timing on an old 235 without hard valve seats will cook. My old "56 235 with a 100 thou on her will idle all day long, and never runs hot. As they were designed to do. You have been given bogus info man. Chevy 6 bangers don't run hot. ------------------------------------------------------------ "OPOSSUM BENDERS" Central Mo. Chapter
my 54 could idle 'till it ran out of gas and still run cool. I would check your timing, if its running rich or lean, that stuff.... Although mine seemed to run cooler with more advace... The ONLY time my car ever overheated, or even got hot for that matter was when the pin in the distributor gear got halfway sheard off. The timing was so off, It was all I could do to keep it running, and it overheated before I could pull over. I could open and close the points twice by turning the rotor by hand....
Living in Livermore (yes it gets hot there, but not that hot) you should be fine with a 235. I drove mine around oakland for years and commuted across the bay bridge with a 235. In Paso I'd get some heat problems a few years back when it was like 105* outside. I put an electric fan on mine with a thermostat you could set to the desired temp... never had a problem... even when I swapped out to a 327.
I think the mixture and timing is most likely the problem. I have the car timed and the vaccum advance is working, but the carb is a piece of crap. the motor tends to miss at idle, no matter what i do is wont fire on all 6 at idle. Im gonna try to get a new carb and see whats up. Also its funny how no one pointed out the fan belt. I am gonna change that as well.
i think its your fan belt..... try puttin it on the other way.. flipping it around so it spins the other direction... if the timing is real far advanced then you will have heat issues. i think that may be it in conjunction with the radiator..
i fooled around with overheating (boiling over) issues for 2 summers with my 45,000 mile 235. i replaced everything EXCEPT the water puump. wanna venture a guess on what finally solved the problem? it wasn't until i pulled it off that you could tell it was leaking. the boilovers had coated everything under the hood with a nice brown film, so it disguised the dribbling from the pump. mf
It nevver boils over, it just gets to the dot for the hot mark. I don' tknow what temp that is. What degree should the timing be set at. Right now I have it set at 0 dgrees at TDC.
Thanks to every one!!! I can cruise my cool car with a cool motor. Timing and a fan belt were all I needed.
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