cooling a 1965 impalla

Grumpy · Oct 1, 2015

My 1965 impala ss 396 overheats in traffic. Runs 180 cruising then goes to 200 after a minute in traffic. Yes I live in Florida! Engine rebuilt last year with summitK1301 cam, edelbrock 750 carb, headers, alum intake. Not much over stock. Alum champion Radiator cools engine fluid and TH400 trans fluid. This is a cruiser not a race car.

I want to scrap the engine fan, cheap shroud, and old iron pump and add two 12" electric fans with temp relay. What cfm fans do you recommend? Do I need a metal shroud or are the ones on each fan enough?

Also adding alum water pump. Standard or high perf?
Recomendatations appreciated!
Thanks
Ron

Dorman 620-118 Radiator Fan Assembly

https://www.summitracing.com/parts/...se1-_-dorman&gclid=CPGMgLCu09ACFUpMDQodAckHvg

the electric fan you choose will always be more efficient if its matched to a fan shroud , to select a fan or dual fans youll need to know the height and width AND avalable HEIGHT clearance between the rear surface of the radiator and any accesories on the front of the engine that might prevent mounting the fans and shroud assembly, Id also point out that a high amp capacity alternator tends to be far more effective as it can provide the current required to spin the fans at the full rpm they are designed to operate at, while the 30amp-40 plus amp draw that a couple high capacity electric fans require may over work the standard 90-110 amp alternators. Id be looking for a 2500cfm-3000cfm fan(s) and shroud if I could find ones that fit the current space linitations and my budget limitations, and adding an aux trans fluid cooler to reduce the heat load on the radiator will help

a great deal of heat that radiator deals with is the result of the hot transmission fluid in the lower radiator, adding an additional trans fluid cooler often tends to reduce the radiator heat load and allow it to cool the engine coolant much more efficiently. in an ideal world youll have about 2 square inches of radiator surface area for each horse power the engine produces

keep in mind that your alternator out-put should be high enough to allow the fans to operate at full speed any time they are turned on, its common for guys to add electric fans and find the electrical draw makes the fans operate at part speed until the engine rpms increase the alternator power output (YOULL NEED TO USE A MULTI METTER IN MANY CASES TO DIAGNOSE THIS)
most of the higher cost fans come with metal or occasionally plastic mount brackets
http://www.summitracing.com/parts/SUM-329725/

full shroud fans (below) are more efficient than a fan alone or partial shroud (above)
http://bigdogperformanceparts.com/p...mbo-1960-1965-chevy-impala-bel-air-cc281combo

http://www.summitracing.com/parts/HYP-4026/

http://www.summitracing.com/parts/HDA-3653/

http://www.summitracing.com/parts/SUM-381101/

a fan shroud , used with a fan,tends to increase cooling efficiency
http://www.summitracing.com/parts/SUM-381010/?rtype=10

http://www.summitracing.com/parts/HFM-ZFCT/

when theres 8 of those cushion disks, logic says they are used as washers , placed between the ends of the mount ties (two on each connecting mount tie,four on each side, and on opposite sides of the radiator core)and used to protect the radiator fins to prevent the plastic ties from damaging the radiator fins

In many cases they come with 4 long plastic strips that resemble thin knitting needles the idea is for the pad to have that long thin plastic knitting needle, like support connector, pass thru the pads so they spread the clamp force, the pads are like large washers, the thin plastic strip passes thru the radiator between the radiator fins, and the fan brackets or those washer like pads have a one way clamp that grips the plastic connector in each corner holding it firmly (usually as a pull fan )to the inner radiator surface, (occasionally on the outer surface as a push fan)the excess is trimmed off with nippers, this makes for a fairly sturdy and easily mounted pull or push fan attachment
keep in mind that your alternator out-put should be high enough to allow the fans to operate at full speed any time they are turned on, its common for guys to add electric fans and find the electrical draw makes the fans operate at part speed until the engine rpms increase the alternator power output (YOULL NEED TO USE A MULTI METTER IN MANY CASES TO DIAGNOSE THIS)
the answer too what cooling system is most likely to both cool the car/truck efficiently and fit your budget,would mostly depend on your budget limitations,
but a large 3-4 tube aluminum radiator with a a 140-to-200 amp alternator
https://www.dbelectrical.com/produc...0-5-7l-7-4l-chevy-truck-93-94-95-200-amp.html
https://www.summitracing.com/parts/tff-8173nep/applications/year/1996

I'd point out that a 7-8 quart baffled oil pan helps cool an engine.
and dual or a large single electric fan with a matched ducted shroud and the ability to move,
2500 fcm-3000 cfm of air should provide adequate cooling for most engines.
adding an auxiliary oil cooler certainly helps

http://garage.grumpysperformance.com/index.php?threads/do-i-need-the-fan-shroud.13847/

and if you have an automatic transmission Id add a electrical fan cooled trans fluid cooler

Grumpy · Jul 16, 2016

http://garage.grumpysperformance.com/index.php?threads/radiator-hose-spring.10712/#post-46681

http://garage.grumpysperformance.com/index.php?threads/thoughts-on-cooling.149/

http://garage.grumpysperformance.com/index.php?threads/how-the-cooling-system-works-basics.853/

http://garage.grumpysperformance.co...ing-system-flow-rates-and-heat-transfer.9880/

you may also want to hold the engine rpms at about 3000 rpm for awhile and carefully inspect the LOWER radiator hose, if its old it may be collapsing partially under the water pumps suction reducing coolant flow

cooling a 1965 impalla

Grumpy

The Grumpy Grease Monkey mechanical engineer.

Grumpy

The Grumpy Grease Monkey mechanical engineer.