I've fought a over heating problem since I got my 28 sedan running. I'll give you all the low down and maybe somebody can think of something I haven't. 427 BBC, 425 HP square port heads, fresh rebuild, block was decked, heads have had a clean up cut on them. Hyd roller, tunnel ram with 2 600 Holleys, brand new alum water pump, clockwise rotation, 160 new thermostat, ended up cutting the center out and trying that, didn't help. Large electric fan with shroud, even took it off and installed a manual 17 inch with a full shroud didn't help. I had a stainless screen in front of rad, took it out, I have standard size pullies, not under driven. First new water pump leaked, tried a moroso I had and then bought this one that is supposed to move coolant 40% better. I can drive it or just let it run for 15 minutes and all at once it starts creeping up and in no time it's on 240, plus it takes forever to cool down. When I had the electric fan, I'd let the fan run for 10 minutes to cool what was in the rad and restart it. The temp wouldn't drop at all. Normally it should drop at least 20 degrees. I thought maybe I had installed Mark V head gaskets by mistake, grabbing at straws now, so I pulled the heads and it had the right gaskets. They are felpro and run over a $100 a pair. The weird thing was the heads wasn't stuck, they slid off like nothing, I don't even have to clean the block or heads. Also there was coolant droplets all over the surface and I drained the block on each side before I tore it down. You could wipe the gaskets off and almost pass them off as new ones. This is the car in my aviator, open, no hood and it also has a 3 core champion rad, brand new. Sorry for such a drawed out post but htis thing is driving me crazy, the only time it will loose coolant is if it pukes out the over flow and I run a pressure test, it held 15 psi for 30 minutes and didn't drop.. Timing has been at anywhere from 30 to 42 total, at 42 it runs the best and even if it's 200 degrees it starts soon as you hit the key. So if there is anything I'm missing, please speak up, I'd like to drive this thing.
I am having trouble with my station wagon running hot too. Did the vingar thing and a lot of dirt came out.Had the radiator cleaned and flushed out by a radiator company.Replaced the antifreeze and water, put a new fan clutch on and a new water pump, and re adjusted the timing. I am going to take it to work Monday and see how it does. SORRY Mike, I didn't mean to hi jack your thread.Bruce.
No worries Bruce, maybe one of us will come up with something. The rad is a Champion, 3 core. Me and a friend have ran them in everything with no problems. I had one in my chevelle with an alum shroud and 2 smaller fans and even with the 4800 stall converter it never got over 190 on the hottest day.
With cap off of radiator do you see coolant flowing through as it should? Is fan correct so air is flowing through radiator front towards motor? If you have an IR thermometer check temp lower and upper hoses? Sent from my SM-S320VL using Tapatalk
Can't see down in the rad, it has 90 degree on back of the top tank where the cap goes. Both fans were pulling air. One on it now will suck a rag against the front of the rad if it gets with in a ft of it.
take off the rad if needed to splice on longer hoses... run them into a 5 gal. bucket... be ready to run your garden hose into the bucket... should tell you if it is the rad capacity... also look for bubbles...
Obvious thing, but you didn’t mention checking the lower hose. It should have a spring in it to keep it from collapsing. Sent from my iPad using The H.A.M.B. mobile app
Did you test the radiator pressure cap ? Should be at least 15 lb pressure cap and recommend testing temps with IR thermometer ant different locations on rad and engine.
Checked the cap, tried a new one, hoses are new and aren't collapsing, temps stay consistent from top and bottom hoses depending on the temp of the engine at the time. I'm pulling the rad out tomorrow and checking how water flows through it with a hose, also going to pull the new pump and remove the rear plate and inspect. I'm going back with a 160 thermostat with a hole drilled in it, 1/8 in. The block was hot tanked and all new freeze plugs. I'll also go back with the electric fan since I know that wasn't the problem. It pulls air through the whole core with the shroud it's got and kicks on at 170.
A lot of somewhat good solutions..... My .O2C= mechanical, or electric gauge? Instead of throwing the kitchen sink at it , start with what sends the # to what your looking at...... Mechanical is a straight shot. Electric has a sender/wire/gauge..... have you verified temps, what the Rad reads vs. the gauge? Might be a lil funkiness going on, and NOT sending the right temp to the dash..... Possibly- an infrared temp gun might tell you were temps are at the radiator, h20 neck, hoses, etc......... This will help diagnose, without dumping a crap load of coin! just trying to help!
I had a 40 Ford that ran hotter than a 4 balled tom cat, it had a 4 row Griffin aluminum radiator and I constantly had a problem, I tried everything the people at Griffin suggested, shrouds,different fans, different thermostats, even a water wetter solution, nothing worked. After my continued complaining they finally told me to pull the radiator and bring it to their manufacturing facility in Townville, South Carolina and they would make me a new one, when I carried it in I was met buy the owner Buddy Griffin and he said he wanted to see if the radiator was the problem, he layed it up on a huge band saw and cut the top and bottom tanks off. Low and behold more than half of the tubes were blocked by the epoxy they use to glue the finned tube to the tanks. The new tank they made for me worked flawless but I started have problems with it leaking after about 6 years. I just use copper/brass radiators now in all my cars. HRP
I've used a temp gun and verified gauge readings, 2 gauges, mech. Hotrodprimer, that's why I'm going to pull the rad and try to check it the best I can. It's hard to tell what's it's doing because when it starts getting hot it gets there quick. If it's 200, by the time you shoot 3 or 4 places with a temp gun and run to check the gauge, it's 240. Tried the gauge in the head and the intake. I bought the rad several monthes ago when I started buying stuff for this car. It sat in the garage in an open box for several mths, it was capped up but several times I'd have to put a cap back on where the hoses go, everybody that came in seemed to want to look at it for some reason. I'm wondering if a mud dobber might have got in it. Letting the fan run, electric, for 10 minutes with engine off then starting it the temp should drop 20 degrees or so from the cooled water in the rad but it didn't change at all. That to me sounds like a circulation problem.
When it is running and the temp starts to get up over 180 to 200 what is the temp difference from the top to bottom of the radiator. Coolant could be passing to fast or slow. I know we like to see 12 to 16 degrees drop. Have you used a temp gun to see if you can find were the temp make a jump, Like at the water pump, thermostat housing back to front and left to right side of the block. That might help find were coolant is being held up or blocked. Good luck.
Have you checked for air lock in your system, if the engine is a bit higher than the radiator an air lock can occur.
My two cents , a lumpy cam and low vacuum , and or no vacuum advance at idle spells a boiler . It will spit water when it reaches 212* in the radiator . Water has an expansion rate of 1700 to 1 , from liquid to gas . So you will grow a huge amount of liquid as temp rises . You have a great total advance , but at what RPM are you getting this total ? Most people including me , think the vacuum advance is not needed on a HP engine . If you drive it on the street , it’s your best friend for many reasons . It took me many head scratching hours , days , weeks , months to finally realize that if OEM didn’t need that clunky looking thing , if they saved it on every car sold by not installing it , they would have made millions more in profit. You may have a correct vacuum advance unit on your car and missed reading that you have one . If not find a buddy that has a stock distributer and try it temp ., to see if it helps out your issue . Low vacuum readings at idle are a killer on heat up issues , that engine is nothing more than a huge compressor , the more air you move through it the cooler it will run at idle . I have a few diesels in my junk sitting around here that have over 17 to 1 compression , one of them has a radiator from a 225 Cu in gas engine , I drive it daily without a coolant fan present , and it will only reach the temp of the thermostat installed . Winter runs , the radiator is completely covered and never will reach temp to open the stat at idle . You could park this thing in the middle of the equator at high noon let it idle and it will never open the stat . These are just examples of thinking high compression and fan , radiator are the cause . I really think you need to look elsewhere . A wise old man told me years ago KISS , Keep It Simple Stupid , every time something stumps me I think back on his words and the answer seems to be found .
How about some info on the motor,is it a mark IV,what year,you said the head gaskets look like the had never been in a motor when you took them off and the was coolant on some surfaces.Doesn't sound like the was crush on them.Did you check to make sure the head bolt aren't out of thread and not pulling the heads down
My buddy 32 ford runs cooler with the hood and sides on it has a 351 Cleveland . Did you check for exhaust gases in the cooling system?
Like Pete above, I've had several big block Chevelle's and they always tend to run hot unless they were running at hwy speed down the road. In traffic or idling, you could always watch the temp creep up. They just like to have a lot of air flowing through the radiator and they like the coolant moving through the engine. Note, if it's not steaming, it's not overheating. The fact that your head gaskets were in excellent shape when you pulled the heads indicates that it's not too hot.
Maybe it's not one thing but 2 or 3 little things. Seems like you have to much total advance to me and why does it vary? Did you ever check for TDC and harmonic to pointer relation ship? How much of the fan is sticking out the back side of shroud? It's a BBC do you have the 90 deg. rubber hose from top water pump to manifold? I know that is supposed to be for highway driving though, just throwing darts at the wall! Again, got pic's?
Engine coolant capacity: this was on a factory 454 SS monte carlo 20.8 liter / 22 U.S. qt / 18.3 imp. qt
Engine coolant capacity:same car with a 350. Both of these cars had cross flow radiator with rad cap on opposite sides of top hose 16.1 liter / 17 U.S. qt / 14.2 imp. qt
HOTRODPRIMER; "Low and behold more than half of the tubes were blocked by the epoxy they use to glue the finned tube to the tanks." You can bet that wasn't the first or only one that he found plugged if he went straight to the cutting!
It gets hot so suddenly, that I'm thinking it's not air flow or exhaust gas streaming. I believe something is hindering the flow of the coolant. Only one other thought. You said fresh build. I hope you don't have tight bearings. As in wrong size. Can you turn the engine over by hand fairly easily? Sent from my VS835 using The H.A.M.B. mobile app
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