[gnftrslick]

I just dropped off my 64 for a safety look over and was told that they had never seen an electric fan on the FRONT of the radiator pushing air vice on the back side of the radiator pulling like the conventional motor mounted fan. Id there any advantage or are they just trying to sell me a puller fan? --- thanks for any comments/experiences.

 

[gilby]

well, you don't want to block any air flow through the radiator on a gas engine,having the electric fans in front blocks the air flow.Have you ever noted those Big trucks,like Peterbuilt and Kw's ,they have a "Vane" in front of the radiator for heating and cooling purpose.it gets pretty cold in the Arctic snow and hot in the deserted. you don't want to do that,unless you live way up north..:dontknow:
:beer:

 

[fauxrs]

Puller fans are more efficient on the order of 18-20% based on what I've read, much as Gilby has said, a pusher fan physically blocks the radiator surface and that accounts for a fair amount of the difference. A good puller fan will be shrouded and thus pull air through virtually the entire core, an unshrouded puller or any pusher (which cannot be shrouded) are automatically less efficient due to this.

This is a good example of a shrouded puller

When those fans are running they pull through the entire core without blocking any of the core from the front.

As for your safety drop off, those guys need to get out more often, there is nothing terribly uncommon about pusher fans, its just that they tend to be used as backup fans, not for primary cooling.

 

[gnftrslick]

Thanks for the info. I guess I will have them replace with either electric pull or conventional engine fan - there is plenty of room - but will need shroud along with the fan.
Wonder if they could re-install the pusher fan on other side and reverse the flow?
Thanks again for the comments.

 

[oldtinsmith]

Fan Fair
Compared to engine-driven fans, electric fans offer the benefits of reducing engine drag and allow the fan to typically be installed in several locations. Electric fans installed in front of the radiator are called pusher fans, and behind the radiator are puller fans. Pusher fans typically impede airflow by blocking portions of the radiator's core, as opposed to a puller fan, which pulls air through the radiator and is generally about 15 percent more efficient. So if space allows, it is usually better to install the fan on the engine side of the radiator to operate as a puller, where it can draw more airflow.



Read more: http://www.chevyhiperformance.com/techarticles/148_0504_cooling_system_info/index.html#ixzz228cyEeU1

Doug

 

[84withzz4]

Push versus

I like those twin pull fans. What are the off of?

 

[steelybill]

Electric fans are not a silver bullet. They reduce the HP used by engine driven fans of course, but draw more from the alternator, which itself takes power, but likely less loss over-all than a belt driven fan. The power difference is likely not enough to feel in the seat-of-the pants dyno :smileyb:
A thermostatic fan controller would help reduce draw when the fan isn't needed, and would probably keep engine temp more even or constant, than having it run all the time.

 

[gilby]

Puller fans are more efficient on the order of 18-20% based on what I've read, much as Gilby has said, a pusher fan physically blocks the radiator surface and that accounts for a fair amount of the difference. A good puller fan will be shrouded and thus pull air through virtually the entire core, an unshrouded puller or any pusher (which cannot be shrouded) are automatically less efficient due to this.

This is a good example of a shrouded puller
http://earchitect.50megs.com/Elcamino/images/engine/DSCF1391.JPG

When those fans are running they pull through the entire core without blocking any of the core from the front.

As for your safety drop off, those guys need to get out more often, there is nothing terribly uncommon about pusher fans, its just that they tend to be used as backup fans, not for primary cooling.

..Thats the ticket right there..X2:beer:
:beer:

 

[gnftrslick]

ya the safety checker guy actually showed me the 2x pullers under the hood of a '59 ELKO with a nasty looking big block without an engine fan just getting ready to go out their door. Will probably have them just do it later this week and not have to worry about cooling - especially in San Diego area ---