I am at my wits end on this one guys. Maybe being a mechanic for years has given me tunnel vision on this problem, so here goes. My currebt car is a 1948 Olds 98 convertible with a 45 olds engine, 400 TH trans. I am using a Griffen cross flow radiator, 2 rows of 1 1/4 tubes. I have a fan shroud on the car. Originally I used the fan clutch that came on the engine, but have switched to a fan found on Ford pickups in the late 70's to early 80's. I can't get this engine to run cool, I overhauled it when I built the car, I now have 13,000 miles on the car. We took the car about 40 miles to attend a rodders funeral today, and was stuck for about 15 minutes for construction work. The temp starter creeping up to around 225, reved up the ehgine and dropped the tremp some. As soon as we started moving again, the temp tropped to around 210-212 which I can live with. Keep in mind todays temp was 102. I have been fighting this problem from day one. Any ideas???????????
The gauge reads correctly, I have checked itn with an infra red thermometer, and it is within 1 or 2 degrees. When I got back in to town and shut it off, it was running warm agin, not nearly as hot, and it did puke a little
Sounds like the same deal I had. Same radiator with slightly beefed early 70's Olds 350. Couldn't get happy with the most powerful spiral electric fan with a shroud no matter what. Finally came down to a 7 blade clutch set up with a 180 stat and built a header panel to keep air directly though the core and not up and over. No problems in gridlock or up steep mountains on near 100 degree days. Good luck!
If you're an old mechanic you know the obvious things to look for. I'm just bumping it to the top for someone else to see. I'm sure you shot the hoses and all over the radiator with infrared? All the exhaust outlets?
If the temp went down when you reved it up maybe the water pump in not circulating the coolant properly or the fan is not turning fast enough. How about pulley diameters...Could the pump pulley be too large or the crank pulley too small to drive the pump fast enough?
I have the pulleys on the engine that Olds used on it originally. I have swapped water pumps from different manufatures 3 times. Like I msaid I am my wits end
Are you missing any original shrowding on the olds body, I am not real familiar with your perticular body so I am just throwing ideas out here. Gm was known for putting a plate between the grill and the top of the radiator. Maybe not as late as your car, but I had a 40s chevy for instance that was not cooling worth a flip. it had a plat that went from the top of the radiator to the grill that had been removed for asthetic reasons, I found a different plate to replace the missing plate and the problem was solved. here is the deal, any air that can go around or over your radiator does not have to pass through it. I have even seen guys stuff foam rubber around the edges or the radiator and drop their temps a few degrees. I was originally going to say it sounded like you had a water pump problem but it sounds like you have covered your basses on that. I use a flow cooler on my cars and they do everything the ads say that they will do, they make a cheap kit that is just a plate that you install on te back of the impellar and it works wonders as well for cars that they don't make a pump for. I have a friend that uses water wetter and swears by it as well. I haven't tried it yet but he has had big engines in small compartments and says it really works. Like you said it is really hot out these days and maybe that is the problem but you should give it every chance you can.
get rid of the temp gage with numbers on it, and get one like they had in cars from the 60s or so that just says "C" and "H". Then you won't worry about it. H was somewhere around 270.....
Exactly, with antifreeze and a 13-17 lb cap you're not going to boil (the only thing to worry about) 3 degrees for every lb of pressure and anti freeze has a higher boiling point than water. with a recovery system you have no worries about 212 degrees of water. you are safe to 240-260 degrees
Don't know if this will help but, I traded my '51 Ford for a '52 Chevy. Knowing the original builder of the '52 Chevy, I asked if anything was wrong with the car. He said it overheated on the freeway. Figuring it was not enough air flow, I figured I could fix it, so I made the trade. The first thing I tried was taking the radiator to a radiator shop to check the condition. They cleaned it out and said it was ready to go. I re-installed the radiator, changed the thermostat to a 160 and checked the air flow at idle. The car had a flex fan with a full shroud. I took a manila folder and held it to the front of the radiator. The fan sucked the folder so tight, I had to turn the engine off to pull it off. Figuring the problem was solved, I went on a poker run at 6 am. The car ran at 180 down the freeway. The poker run started at 9am so we drove up and down hills through the canyons, she ran at 180. At noon, headed home down the freeway and hit traffic. The temp creeped up to 210 and stayed there, even when traffic cleared. Stayed at 210 all the way home no matter how fast I went. I was going to add a/c and decided not to mess around. I bought a triple pass, direct-fit, copper/brass radiator and installed that. Again, I checked the air flow, which was great! I drove up a long hill by my house and she got to 210 again. WTF! So I decided to check the timing. The vacuum advance was frozen and she was running retarded. I put another distributor in her and now she runs at 160 unless I turn the a/c on, they she runs at 180, on a hot day stuck in traffic.
This car looks like a 50 Olds, and all the original sheouding is in place. Thw only part that I modified was the top cover for the radiator, and I smoothed it out (got rid of the hump over the radiator because I used a crossflow instead if the original vertical drop style radiator. Like I said, it did puke out some coolant yesterday. By the way, I am running a 180 stat from Stewart components.
What Porknbeaner said about ducting the air through the radiator. I use water wetter too. Works for me...............
the cover looks like the one in sir woosh's picture. It is the factory one, just cut down and flattened out to cover the crossflow radiator, It does cover the whole top of the radiator, and all of the original side pieces are in place. I would think that all of the air would be forced through the radiator the way that I built it.
Wow! Getting mysterious now........ I had to work harder to cool this drivetrain than any other, and with your time and experiance, I don't figure you are overlooking much of anything. I did notice a difference in both getting the distance to a minimum between the fan and heater core, and switching to straight distilled water with the wetter additive. Right or wrong, I just compared the different ops till I got it to stay between 180 to 195. Ideal temp according to someone who's been in it longer than I've been around. Was also informed that 160 wasn't warm enough. Yeah, I know......picky picky.
A couple of things come to mind. First of all, these 455 Olds engines make a lot of heat, they just seem to run warmer than something like a sbc for some reason. My Son has one in his rpu and it gets up to operating temperature really fast, whereas my other cars take a while to get there. Secondly, is the entire finned area of your radiator open to the front of the car? Some early cars had smallish openings for the air to come through as the radiators were narrower. You also have an engine room that was made for a skinny inline motor and now you have blocked some of the places where hot air can escape the engine room. Any cool air that is trying to come in will hit a brick wall of hot air and stop dead. Lastly, try pulling out the thermostat and putting in a restrictor plate instead. Mondello told us to do that on our motor and it really did make a difference. Air was getting trapped under the thermostat, even though we burped it a few times, and with the restrictor plate all the air purged out immediately and the car ran cooler. With the restrictor in place we were able to put in all the coolant at one time and watch the bubbles come out, instead of having to put in some coolant, then burp and add more. Don
Don, thanks for the thoughts. This 98 has a cavernous engine compartment, originally housed the last year of the Olds straight 8. The entire radiator finned area is exposed to air flow. The engine compartment has plenty of room around the engine, and also is open at the back, so it should let out all of the heat. Years ago a friend of mine had a 40 pickup with a 455 engine, and one year at the NSRA nation als in Oklahoma city drove this all around the fairgrounds and never overheated. He currently has a 47 Buick roadmaster with a 455, doesn't have near the radiator that I do, and has never had the problems that I have with my beast. Thanks for everyones thoughts and ideas.
Changed a 460 ford out of 70s f-250 into 62 merc and all the sudden it was getting hot at speed, only thing changed was single to dual exh. it must have leaned carb out just enough to cause this, put another carb on and all was good again.
if you can stay around 100* of ambient temperature your ok. Check your idle speed and make sure it's not to low (water flow). Make sure the carb is not to lean at idle also & the timing is not retarded at idle (vacuum advance). Butch
I have had the distributor reworked timing is right on, and the Q-jet is the same carb that was on the 73 98 that the engine came from, rebult at the time the conv was built. Like I said, I am my wits end.
could there possibly be a restriction in the cooling jacket of the block somehow? like someone at some point pounding a freeze plug into the block rather than removing it? i know you said it was rebuilt, but perhaps some rock like sediment in the block? only reason i put that out there is i had an o/t 71 camaro that ran hot on longer than around town trips, but didn't boil over. after much head scratching i discovered the lower portion of the block cooling jacket was plugged with sediment [car sat a long time], so much so, i pulled the block drain plugs and nothing came out. one four hour acid flush later, it never ran past 1/4 on the gauge. of note, before the flush the coolant looked perfect, no junk floating in it. as it seems you've covered everything else, i just thought i'd toss that out there.
I knocked out the frost plugs myself, and cleaned the block in a Cuda clesner before taking the block to he machine shop for the boring job. I had Dan clean the block again at his shop in his hot tank. The cat that the engine came out of was a 1073, and I owned the car from 1977 on. I regulary flushed the cooling system, so with the work dione when it was rebuilt, I doubt it, but I guess anything is possible. The system was flushed about a year ago when I changed from Dexcool antifreeze to the good old green coolant. I used Dexcool at first because it is supposed to be kind on aluminum, and I have a Griffin Aluminum radiator.
Oldsman, I'm not an Olds kind of guy. Is there a chance that there is a mixture of parts? I know you said 455, but is there differant configurations of heads that would restrict flow, like a 400 SBC head on a 350 block?
1. Is the fan sticking out of the shroud slightly 2. drill a 1/8" hole in the thermostat to vent any trapped air. 3. is the lower pan still in place in front of the radiator 4. have you bypassed the heater, how? 5. where is you temp gauge sender mounted? intake? head? 6. when I lived in NE we had to wear gloves to keep from burning our hands on hot tools left in the sun.......LOL 7. tested the cap 8. radiator is above engine (thermostat) .02
Hey, You mentioned that you tried 3 different water pumps? Did you try any of the Hi Volume pumps? I had a similar problem with a 289 ford and that pump finally did the trick...
Running lean? Are you using the proper mix of anti freeze and water? Too much antifreeze in the mix will make it run hotter. Drain and refill with a good 50/50 mix. You'd be surprized at how many "hot runners" I fixed that way!!
it has 50-50 mix of coolant. Temb sen der is in the intake. All the parts, heads, block and intake are all from the same 455 from a 73 98. I use a Stewart stat, they have 3 3/16 holes drilled in them. Fan is out of the shroud slightly, and all the original metal work uner the radiator is in place. As far as a high volumepump, I have not tried that yet.
Ditto, #11,...re; pressure cap !! This is often forgotten about,..... Good old physics works every time....... 4TTRUK
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