COOLING A 250

Have a rebuilt 250 in a 64 GMC which is now running as hot as I am.
Last year had a cooling fan placed on the radiator to aide in cooling was getting hot at intersections , have the misfortune to live in a city with lots of them. In the process of adding the fan they found a crack in the block necessitating the use of a rebuilt engine. Its now running over 250 average. There is no fan on the water pump pulley just on the front of the radiator, and one on the top of the doghouse blowing down on the back of the engine, which seems to do nothing but make a nice humming sound after turning the engine off. Would a fan of the front of the engine help with cooling.
and did have the radiator steamed , unfortunately so am I. any ideas

Will have to look into one of the radiator caps with a temp gauge. I would have preferd a fan on the back of the radiator to pull the air through.

Just curious as to the cooling fan that was added to the radiator. How big is this fan and does it cover at least 85 to 90 percent of your rad. Is there a fan shroud with the fan? Possably just need a higher CFM fan.....providing your engine doesn't have any other cooling issues. Can you take a pic of what you have and post it for us?

here are some pix. the fan on the top of the dog house seems to pull the air up toward the top and the fan on the front of the radiator pushes the air toward the engine.[img][/img][img][/img]

syborg1964 wrote:here are some pix. the fan on the top of the dog house seems to pull the air up toward the top and the fan on the front of the radiator pushes the air toward the engine.[img][/img][img][/img]

thats useless!!! if anything, its holding the hot air in the doghouse.

think you are right, should have paid more attention to what the mechanic was up to. Should i mount it on the back of the radiator giving it one pulling and one pushing the air.

Doni is correct- try that -ill add the following= when all the manfacturer's designed & build all our vans - they could not have any "Overheating" problems!!Therefore = look @ whats making the problem?? coolant flow & airflow are the only 2 possibilitys happening- ie: radiator, thermotat, weak hoses or blockage( head gasket??,rust in water flow areas?) Start looking & eliminate the easy ones 1st. Now ill add = many years back i built a chev pickup- V-8 , auto & different used chrysler radiator. I also had a sheet metal shop fab up a shroud to mount to the radiator mounts. To this day- i am still running a metal fan on the waterpump- having never any cooling problem.Even mounted a electric fan in front of that radiator & have yet to use it.never needed it. Also ill add the "New Car" manfacturers since the mid 70's have all gone to smaller / thinner radiators -yet all have had fan shrouds on then - way before the invent of electric fans. put a shroud on it & id bet your cooling problems will be over.

am trying to find a fan that will fit on the water pump. will keep an eye out for a shroud that will work.

Matt,
I took a look at your van while it was at Protec and questioned what they were doing with the cooling. Do you know what t-stat they put in it? Also, like Donivan mentioned, when does that pusher fan come on? Did they save the water pump fan off your old engine? I have a stock radiator, stock fan, no shroud, and 160 thermostat. I have a fan (doni-Fan) mounted to push out the heat AFTER I shut the engine off.
We need to get together for a look. My business is in Bartlett and my farm is in Randolph. Give me a call.

can now run down the road, with a temp of 190. Had a fan installed on the water pump with a one inch spacer. Drove for about thirty minutes then let it sit in drive way for five to ten , while running. while trying to work on the radio. Not sure how she will do when its 100 out side in a few weeks but will be driving a car with ac, when its that hot.
thanks everybody for your help

Don, your post about exhaust heating up the radiator is the first I've heard. I'm still running with my bad exhaust (can't find time to give it up for a day) and it has to be getting a ton into the dog house as it's loose right at the manifold doughnut (and has holes near the exit.) Driving on the interstate in 80 degree weather a few days ago was already pushing me to 210 or slightly higher after keeping somewhere that I would guess was 70 mph or so. Great info and something I'd never heard before.

Hey Matt,or any of y'all in west Tn. ever had any dealings with these folks? They're in your back yard.May have some type system that might work for ya.Considering we're dealin with 45 year old radiators.
http://www.fsrproducts.com/

Doni,

I see you're using an extra electric fan to push air toward the radiator. I just got a pusher fan that was installed on a mercedes condenser A/C system. I want to incorporate it to the factory system some how. Maybe like you have it. I finally got my system to run below 170 but want the extra fan for idle and after engine is turned off. I was playing with the idea of having it installed infront of the radiator like it was installed on the mercedes on the condenser. Will that work? Did you stay away from that because of air restriction. Or should I give it a shot? I would want help on what route to go on wiring. Id like it to turn on when it reaches a certain temp. Advice. Thanks

Donivan,

Ok, I'm liking your set up. I want that extra assurance on mine, and yes get rid of those fumes and heat to prevent that heat soak once engine is off. I have my wiring already set up to take in an internal alternator just need to buy it. Whats a good amp size alternator? Is your helper fan always on or do you just turn it on once you shut off the van? I'm trying to see how I should set it up, always running or to go on at a certain temp even after shut down. To go on even after engine shuts down when the temp happens to rise would be ideal. I think a 91 corolla I recently sold worked that way. I would turn off the car and walk away and I could hear the fan go on. Now I understand. How would I go about wiring that setup and where is a proper place to put the temperature sensor in the cooling system?

66BeachCruiser

i have a second radiator laid flat and connected to heater hoses. it is hard to get a decent pic of radiator but it pretty much covers the entire area from front of van to original radiator. it has a fan on top of rad. and i have absolutly no problems with running hot.i have a 250 with high compression and big cam. without thermostat, it runs 165-170. evan towing a camper last summer in 90+ weather, never went above 185. i was running 70-85 m.p.h. and never went above 185. i disconected for winter and installed a 192 thermostat and it runs at 192. towed camper last weekend, 70 degrees, extra rad in place but disconected and fan off, it went to 200 on the hills. after hearing all the overheating issues others have, i am very pleased with this set up.

Yes =skip white has some good prices on his items - nice people also.

As a front extra fan sitting in front of rad., down at a angle as in pic Are you saying Taurus fans would be fan of choice ,if so are you also saying it draws too much amps or very little ?

I had my radiator re-cored with a "High Efficiency" (more tubes) core. About 25% more tubes! I am still running the 4 blade fan on the pump, a 160F T-Stat, and it never overheats, even in traffic, up hill, when it's 105F out. The guy who did it (Highland Park, Ca.) said:
"This is overkill," and I said, "That's what I want."
The old radiator had several tubes soldered closed (eliminated) to stop some leaks apparently, and some corrosion had built up in the others. So by getting back the tubes that were closed off, and the additional tubes in the new high efficiency core, I effectively ended up with 30% more cooling by having a re-core done.
It's important to see if the old radiator is causing flow issues, mine was anyway.
The radiator re-core was not cheap at $450, but my engine is real happy about me having it done.
I'm going to talk to Don about a 5 blade fan too.
Pics below:


Obviously the old rad.


New Rad. Tubes are closer together.


44 tubes in each row!


Very nice, solid soldering work. Very happy with the work!