That motor should have a clutch fan not a solid fan,full fans can dam the air off @ freeway speeds.Is the vacuum advance hooked to manifold vacuum,how much timing and how fast is the timing in.
My fan is about 6 inches from the radiator even though it has a good shroud is it too far from the radiator?
I had a clutch fan, in fact a couple of them that I bought new from NAPA, and neither one would ever lock up, just shit products for new parts
I was involved with circle track racers for years that’s all those guys would run. What I have read says that aluminum will cool better because it dissipates best better
Don't know if this will help. I've got a front steer subframe on my '57 Chevy PU with a 454. I found a 4 core radiator, from a big block Mopar I believe, that would fit in the space. It's a down flow. The core is 26" wide and 18" tall and 3" thick. Mounting flange to mounting flange it is 30" wide and bottom tank to top tank it is 24" tall. The outlets are the same position as Chevy, which appears to be the same as yours. Top is 1 1/2" diameter and the lower is 1 3/4". On the engine side are two flanges with studs for mounting a shroud. It is brass and copper construction. I got it from Radiator Warehouse eleventeen plus years ago. Still not installed. Box says model # 889-4. Another thought. Maybe installing an auxiliary trans cooler and bypassing the radiator might take enough of that load off the cooling system to bring temps down to acceptable.
Your description of the water flow path through a "tri flow" radiator is news-to-me for automptive applications, although not unusual for industrial/HVAC use. Normally, a three deep core radiator has a parallel hydraulic arrangement; all the water in the top, splits in three core sections, flows downward to the bottom tank, recombines, and off to the pump. With a series arrangement, all the coolant goes through each core row, in series. There is a small thermal advantage to this arrangement, and also an improvement in heat transfer coefficient due to water velocity, It is not like having three full size radiators! The key parameter in heat exchanger design is "surface area", which is pretty much dictated by the length x width x height of the available space. The "catch" here is that the hydraulic path is only one third the normal flow area, and three times as long. Net impact is that the pressure drop is 27 times the "normal" design. This is no problem in an engineered system; you just size the pump accordingly. To merely substitute a "tri flow"radiator results in a mis-match with the original pump.
i seem to remember an article stating to paint your radiator with lacquer not rustoleum type enamel it is thick enough to insulate the tubes
Just read a similar post on the Chevy Talk website. SBC was running hot because the fan was installed backwards.
could take the fan and the shroud off and go for a ride on the freeway. you do not need either at speeds over 40 or so.... costs zero to try it. just dont get stuck at too many stoplites....
Ok, so there's been a couple free suggestions to try. I sure hope you experiment with them. Can't find a true answer unless you test all the variables. Too much stuff jamming the airflow (fan or shroud), or too much stuff jamming the coolant (restrictor in the place of the thermostat).
Personally, I would pull off the shroud and leave the fan as is and take it to the highway. I suspect the fan in the shroud is blocking air flow at highway speeds, but you may need the shroud around town. If removing the shroud reduces the highway temps, but increases the in town temps, your going to have to play with the shroud or the fan distance from the radiator to correct the in town temp rise. Gene
All good thoughts and I’m going to try some. The first thing I’m going to go is replace the factory Ford Flex fan with a solid fan and extend in into the shroud more.
I use a 17" steel mechanical fan without a clutch and I got the fans from Summit on all my cars and have never had to use a shroud. This is on my old Deuce beater and on the Ranch Wagon, I drive around in bumper to bumper traffic with no heating problems. HRP
I have ordered an 18 inch fan like this one, plus a fan spacer 1 inch longer than what I have to get the fan further into the fan shroud to see what that does. The parts will be here tomorrow so I can put them on this weekend.
have you tested the vac advance on the dist? if that is bad and you are not getting proper advance at cruising speed it will run hot......if you add up the initial , mech adv and vacuum adv. I bet it is close to 50 degrees all together at light throttle 60-70 mph cruising speed. it is common knowledge that retarded timing causes extra heat. just something to look at
Several years back I used a Spal puller with dual 11 inch fan like this one from Jegs: https://www.jegs.com/i/SPAL/063/30102052/10002/-1 Installed it on a punched 348 tri power with a 3 core aluminum radiator without a mechanical fan. On the highway the fans never ran as the relay and sensor was set at 195. The rubber flaps on the unit stay wide open on the highway allowing the forced air to pass thru with little restriction. Average highway temps stayed in the 180-185 range and that was with no advance on the distributor. May not be for everybody but in this instance it was the answer for this particular build.
as long as it runs cool in town, I would remove the shroud and go for a ride, it may be restricting airflow at speed. and costs nothing to try
The fan having zero effect at highway speeds is not always true. If the grill area is not big enough to get the air in and through the radiator, the fan has to pull it though, even at highway speeds. Pulling the grill will tell you if it's an air flow problem. Maybe some air ducts in front of radiator to direct the air to condenser and radiator. A couple of big heater cores shoved up into the fenders will increase the coolant capacity and dissipate some heat even if they are not in a direct air flow path.
I don’t know, but I may breakdown and put on an electric fan, I have never been a big fan of them, but if it will fix my issues I get over that
This is a photograph of my 63 Chevy 2 door post car. I has an original Harrison radiator, no engine fan, cammed up 355 SBC, uel njecwith Vintage Air. The dual fan set up is from a 2006 Toyota Camry that fits the Harrison radiator like a glove. Its a low cost effective way to cool the SBC. This car cannot be overheated A/C on or off. They can be found easily and cheaply at a pick and pull yard. Definitely way cheaper then adding a quality fan such a Spall. Trust me when I tell you these fans almost never come on.
The hood should have an air dam that forces all air to come thru the radiator and not backwash hot engine air over the top of the radiator
Oldsman, Picture this. As you are rolling down the highway at 60 mph, nearly all of the air hitting your car's grill will want to pass through your radiator. That is more air then any fan can pull, and the car's speed it trying to push it through the radiator. That rushing air has to pass through the radiator, and through the shroud opening, and get past the fan blades to be effective. If the fan fits closely to the opening in the shroud, the fan blades will only allow as much air to pass through as the blades can pull, which is less then what the car's speed wants to push through. The fan blades become a big spinning disc and the combination of the shroud and the fan effectively are blocking a good share of the air flow. This creates a higher engine temperature at highway speeds, if everything else is correct. When you slow down, the amount of air hitting the front of your car is reduced. When the reduction of the air flow matches what the fan can pull through the shroud and radiator, the engine temperature starts going back down. Its pretty simple to test, you either remove the fan, or you remove the fan shroud, (either will work, but you probably don't want to do both) and give it the highway test. What may happen is that the temp at highway speeds goes down, but the temp at low, in town speeds goes up (the reason you don't want o do both). Depending on the car, many will run fine at low speeds with just the fan and no shroud, that is why I suggested removing the shroud for the test. Gene
If it’s getting hot with the AC on add an electric fan that is switched to come on when the AC is running. My OT pickup came from the factory with a clutch fan and an electric fan that comes on when you turn on the AC. I’ve seen this set up on police cars too. Sent from my iPhone using Tapatalk
My new fan and spacer came yesterday. I painted the fan, and will install everything later today. I’m also going to move the trans cooler so that it isn’t in front of the radiator blocking airflow. I’ll post what it did after I drive it again tomorrow
Trust me when I tell you, it definitely will over heat going slow with no fan. Ive seen plenty of cars that utilize an engine driven fan behind the radiator and an electric fan in front of the radiator. Doubt it could hurt anything. Have you thought of installing a 16-18 inch Spal fan in front of the radiator? At t.his point what do you have to lose. You've done almost everytig else other HAMB members have suggested. Up to now everything in this topic seems to be contrary to logical thinking. Sure you don't have a blown head gasket?
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