need some overheating advice please

now, before anyone says anything, i know big blocks run hot and i know hot rods overheat..it's a fact of life. however, as i have been driving my recently road worthy 47 chev around, it overheats on almost every trip. even at the end of an extremely short trip, it's puking coolant and steaming like crazy. i have a 195 thermostat in it that i checked and is working. i am running a 50/50 mix of coolant and water. i even moved the mechanical fan closer to the radiator and added a shroud. still, nothing is working. and i know it's getting plenty of air flow 'cause it has no hood! even if it's a cool day and it's a 10 minute drive if overheats. i suspect there is something serious at the root of the problem, but i am lost for ideas. any suggestions? thanks-fleet

 

Ignition timing? Running Lean?

 

Stock pulleys?
What size is the radiator?
New engine?
Old engine?
Stock heads?

 

What kind of fan are you running. Does it turn the right direction? I bought an aluminum flex fan for my t-bucket just to find out it was turning clockwise instead of counter-clockwise. It doesn't cool very well that way unless your sitting still.
Roger

 

1. Get a 160 degree (or 180 degree at most) thermostat in there.

2. Hook up a by-pass hose if you're not running a heater core. The hose will run between the water pump and the intake manifold...where heater hoses would normally go.

3. Got the right head gaskets on that thing?

4. Your thermostat wouldn't be in upside down would it? (I only ask because I've seen experienced mechanics make that simple mistake!).

5. No kinks in any of you coolant hoses?

6. The water pump impeller IS indeed turning, isn't it??? (It wouldn't be the first time I've heard of an impeller slipping on the shaft!)

7. Big blocks (I'm guessing Chevy???) don't run hot by nature. I've run one with a small block radiator and you couldn't hardly get it over 180 degrees no matter what you did with it...you have a problem somewhere and just need to find and solve it.

8. Give us specifics about your ride...engine size, compression ratio, spark lead, cam specs, etc...the more we (as a collective community) know, the easier it will be to help you find your problem.

 

you say it's overheating..what temp does the gauge actually go up to?

does it overheat when you are driving at freeway speeds? it it isn't overheating then it could be an airflow through the radiator problem. if it is overheating at freeway speeds...then you have other problems to deal with

 

headgasket? ide try a block tester(it checks the gasses in coolingsystem for combustiongasses) got mine from napa for 60$ quick and easy to know for sure

 

check that thermostat......i just had a new one in my 61 that would send my gauge to the 210 mark within a 3 mile drive.....made the belt squeal a lot as well....i switched to a cut out one .....now the car is lucky to hit 150.....might be worth a shot......brandon

 

forgot to mention ...what pound cap are you running...? brandon

 

Since fleetmaster seems to be offline, I can answer some of your questions about his set up. He has a 496 big block, it was built by a local engine builder using a used block and heads. I'm pretty sure it was hot tanked and everything before he built it. The car has a walker radiator in it and Emilio has a bypass hose where the heater hoses would normally go. The car has a mechanical flex fan on it. He hasn't driven it more than a few miles at a time since we got it on the road about a month ago because of the problem. I haven't looked at it since then, but I know he's been working to get it fixed. The car's a '47 chevy coupe.

 

if it's heating up that quick , i wonder if the bottom radiator hose is collapsing?

 

yep. gotta be something easily overlooked. its the little things that get ya.

 

wow guys..thanks for the great response. i knew the HAMB would be a great place to come for advice. i'll give some of those suggestions a try in the morning. i'll just try to answer some of your guys' questions now ( thanks wayfarer for answering some). as wayfarer said, it's a 4-core walker radiator with a 13lbs cap. the engine is a 496 big block -here are some of the specs:

Eagle 4.25 stroke crank
cam: 228/238 degree @ .050
540 lift with matching springs
781 heads

What brandon said about his problem seems similar, as far (as the belt squealing) for the last week or so, the belt will squeal right when i start it, then stop shortly after. oh, and i already checked, the thermostat isn't upside down. i may have left out some answers, so if you guys have any more questions just ask. again..thanks for all the help. i really appreciate it. fleet

 

oh, and i forgot...as far as the reading on the gauge..i have been having some trouble getting accurate readings from them...so i don't know if it's right or not, but the gauge climbs up over 240..i just made the overheating assumption based on the column of steam hissing out and the gallon of coolant on the ground. ha. thanks again-fleet

 

Any driveabilty issues other than it gets hot? EI when ya step on the gas does it do something stupid or does it run okay

What ignition type, carb type/size?

 

He has a small cap distributor with a pertronix electronic unit in it and dual edelbrock carbs with progressive linkage on an edelbrock manifold. I think they're 500 cfm.

 

I rebuilt a BBC last year and used the old water pump and the thing did what you are experiencing. I changed the pump and fixed the problem. Leave the rad cap off and see if the coolant is circulating properly. If you are getting to 240F fast it seems there is a circulation problem.

 

wayfarer almost had it, they are 600cfm carbs. i put a new water pump on it fairly recently too

 

Make sure the water pump is for a v-belt and not a serpentine. They turn differant directions I believe. Make sure impeller isn't broke on water pump.

 

bttt

 

ok, slight update for you guys. i was messing around with the car, testing some of the theories i heard on here. anyways, it was idling with the rad cap off. the level of coolant jumped up rapidly ( i'm assuming the thermostat opened) and the level never dropped again, but fluid started dripping out from the overflow tube ( i have no tank attached yet). so that doesnt really seem normal, or am i completely wrong? and no, the lower hose isn't collapsing. oh, but i did find a huge problem that may be the solution or at least one of the contributing factors. the flex fan i bought for it is not the right one for the way the engine turns. it is on correctly, as per manufacturers instructions, but the blades are bent in the wrong direction. so i plan on picking up a new fan and testing that theory. thanks again for all the help-fleet