Running fanless / fan sizing and mounting

[goglio704]

I've been running one of my 5 speed cars and the automatic without fans. Neither has running AC at this point. It doesn't seem to be a problem so far. I have kicked on the heat a few times in stop and go traffic, but the temp was only slightly elevated.

I'm thinking strongly about adding a 12" or 16" electric fan. The aftermarket fans typically mount to the radiator core. I have never liked that personally, but I have seen trans coolers mounted that way without problems for many miles. I should be able to fab something up using the mounting points for the fan shroud. Maybe two pieces of flatstock running horizontally attached to the factory flanges on the radiator. Before I go to that trouble, I wanted to get some opinions on mounting fans to the core.

[rlaggren]

Since the car I may look at buying comes w/out fan, I'm interested also.

It's my understanding that the fan shroud is a critical part of the cooling system for many cars - probably because the cooling system operates close to capacity and the shroud provides optimum air flow. But obviously that's not the case with your cars. <g>

Still, my preference would be to utilize some type of shroud if it's not too much trouble. One of my travel issues is the dessert. Highway travel should be fine but gravel roads at 5-15 mph w/AC would be hotter. Also towing (teardrop or other light weight trailer - max 2000# most likely 1300#) would need more cooling.

Rufus

[Carimbo]

Are you planning to mount it pusher or puller? Puller seems to be more efficient, better even if it can retain the shroud. Viewed from the side, the edge of the shroud should bisect the midline of the fan's fins. Like the original form. Not sure if your electric fan dimensions would allow this. Downside is that you don't open as much space in front of the engine for other maintenance tasks.

I have another car w/ an aftermarket elec. fan mounted w/ those thru-pins through the radiator core. Hasn't caused a problem over 40,000 miles but I would prefer the flat stock to frame mount method. The radiator core is brass? copper? and probably does not benefit from the extra stress of the vibration and weight of the fan assy.

Stop'n'go traffic or extended idling rarely elevates the temp. on my LD28 Maxi. Heavy loading will, as in charging up a steep hill at higher revs on a hot day, or (attempted) sustained high speeds over mountain passes. Wintertime I run w/ cardboard between the grille/ condenser, partially blocking the airflow in an effort to reach operating temp. sooner. This does not seem to cause elevated temps in the winter.

[davehoos]

australian 910 series 2 uses an electric fan attached to the radiator

copper strip soldered to tank and a the side band.
it is controlled by water switch 85 deg at bottom of radiator it was used with a shut down timer to reduce head failure.with a/c a pusher fan was fitted on the right side.

you need to look at fan specs.last time i looked it worked out that a 13-14 inch fan had more CFM per current draw.a single 16 inch fan was good.

motor size.most of the fans used are 80-120 watt range.these are booster fans.ideal for installation that requires little air flow.ie in winter time.if you look at factory installs you find they are 180+ watts. another important over looked feature is that the water temp must reach 80+ cel and the engine bay should not exceed 50cel.its easy to over cool the engine and not worry about a fan when hot.

fan shroud.a problem is that the fan draws air hopefully through the radiator,you mount the fan against the radiator it pulls air through the core dia of the fan. the problem is that its easy to draw hot air from the other part of the radiator core and not cool air from in front of the car..so you need to block off/duct air through. when the car gains speed this ducting can reduce air flow.

i like fans fitted to european cars, alfa volvo etc. these large 2 speed fans are good if you can find one. you dont bother to buy one.

if you run a hose from the thermostat area through an aux cooler with EG 10 inch fan or a barrel fan [interiour blower fan] mounted in a position like inner wing using an electric pump.you find than a radiator fan is not needed other than A/C.in this case you need a small fan.interiour heater water is not the hottest.

[asavage]

I've posted a bunch on my (favourable) opinions and experiences with several electric fans in this post.

I have not had a core failure related to hanging fans on the core. I like non-shrouded electric fans: the fan(s) should come on when cooling airflow is needed, and not at speed. At speed, road airflow does the cooling. At low road speed, the fan provides airflow. A bit of recirculation isn't a big deal on our large-engine-bay Maximas.

Flatbar is cheap. If you want to take the time to make an independent frame for your add-on fan(s), I applaud you. But I don't think it's necessary.