flex fans vs stock fans

[p24-1953]

do you gain anything with one of the modern aftermartket fans( other than pretty colors) over the stock 6 blade fan? does the new style pull more or less air while sitting at a light?

[martybose]

do you gain anything with one of the modern aftermartket fans( other than pretty colors) over the stock 6 blade fan? does the new style pull more or less air while sitting at a light?

A flex fan would probably pull more air at idle, IF it isn't hitting the generator/alternator, which would be highly likely unless you space it farther forward, which isn't likely due to limited space.

Marty

[claybill]

flex fans FLEX. do you have clearance to the adiator..like a propellor. but thyer are lighter.might give you 1 hp or something at max rpm.

paint a steel one!!

bill

[p24-1953]

the pretty color comments was supposed to be sarcastic.... i am also thinking aobut getting a folgers coffee can for a exhaust pipe....

i am just wonder what we can do to increase the cooling capacity of our cars while sitting at a red light or in the drive thru. (the only time i ever see the needle creep up)

[greg g]

if you have a honey comb radiator make sure all the cells are clear, spider webs and eggs can block air flow. You mentioned temp creepig up while sitting at stops. What is the temp and how much is it moving????

Have you done the radiator flow test as noted in the service manual?

[p24-1953]

i have never seen it get more than 3/4 of the way up the temp gauge, but having damaged a prior car before due to overheating im kinda paranoid. the radiator was recored 10 years ago & at that time the distribution tube was replaced and the engine was flushed and cleaned.

[Plymouthy Adams]

Flex fan should not be needed..your stock 6 bladed fan should be more than enough..I have never seen a use for a flex fan on any car..gee if it were such a awesome effective design would not they come from the factory with one...they are cheaper to build...other than the cool colors..and looking trick...they are less efficient than stock..

as an added note..plenty of flex fans whould be available at the swap meet today in Perry Georgia at the fiargrounds...I even have a like new 18 incher that came with a car I bought long ago..second thing I threw aside, first was the welded chain steering wheel..can you ugh and dangerous too boot.

Edited April 2, 2010 by Tim Adams

[hkestes41]

I made a shroud for mine.

1) Cut a piece of thin plywood slighlty larger than the core, making sure to cut a notch to fit around the upper and lower hoses.

2) Cut another piece about 1 inch larger diameter than the fan.

3) Measure the distance from the core to what would cover about 2/3 of the fan blade.

4) Cut 4 blocks of wood as standoffs between the two pieces of plywood taking in consideration the thickness of the plywood to give you the total measurement from step 3.

5) Measure to get the proper position of the fan to the core both horizontally and vertically.

6) Using the plywood and standoffs screw or nail everything together using the measurements from step 5 to position the round plywood piece to the core plywood.

7) Get some fabric with some stretch to it and lay it on the round plywood piece, staple it in the center then staple around the perimiter of the round plywood. Once you have the fabric stapled to the round piece, stretch it down and around the back side of the core sized plywood and staple it all the way around. Now you have your form.

8) Get some fiberglass cloth and resin. Mix a batch of resin and paint it over the fabric form then start laying your fiberglass over the form. Lay up as many layer as you want to build up to a thickness you are comfortable with.

9) Once all the fiberglass is set, drill a starter hole in the round plywood and use a jigsaw to cut around the edge of the plywood to remove it from the shroud. Do the same with the core sized piece of plywood.

10) to make room for the lower hose, I then cut a notch in the shroud and used a plastic drinking cup cut on a diaginal and glassed it to the inside of the shroud to form a "pocket" for the hose to run in.

11) Sand, paint and attach with two pieces of aluminum angle screwed into the shround and core support. I also used some stick on rubber weatherstrip from Home Depot between the shroud and the radiator to seal it and prevent rattles.

Here is the shroud before I realized I had to make the pocket for the lower hose.

And here it is installed.

Edited April 2, 2010 by hkestes41

[claybill]

flex fans...yes , they do flex..they move outward toward the radiator.

there is obviously a reason they have not gained popularity.

4 blade vs 6 blade fans. 6'ers require more horsepower to moveand might build up the heat you are trying to disspell. i am not so sure they cool more tho..they are on the 230's i believe.

Solutions i have tried successfully are......

..we know that turning the heater on will drop a few needed degrees in temp...why? as water is moving along and goes thru an additional core, it will obviously loose some temperature.

in a motor swap years ago i rigged up a separate heater core and attached it to a lower frame section,using the heater lines, just to run the water another 12 feet and thru a core...it worked! just like they do with auto trans fluid, they run it thru a cooling core up front.

i dropped 10 degrees.

it is a cheap easy solution.

bill

[BobT-47P15]

When I got the motor that went into the early 49 Plym coupe, it had a

6 blade fan attached as the motor is a 1953 or 54 model. So, I just

kept it in place instead of using the 4 blade P15 fan. I mentioned this

to some mechanic somewhere in my travels, and he said that the

4 blade is actually better for moving air than the 6 blade.

That's about all I recall of the comment......don't remember if he

explained the reasoning. Has anyone else heard that thought?

[Barabbas]

I like it--very clever. Do you have any more pictures of the process?

[Powerhouse]

I bought one of those nylon light weight fans...6 blades...had to cut the blades quite a lot to clear the generator and such. Don't know if it cools better...it was under $20. I've got a flex fan sittin' around...maybe I will try it out and see if I can make it fit.

BEST thing to do, besides full boil out of block, is get a spare heater core and run some hoses to it...like mentioned above somewhere...

Heater cores - cheap

Hose - cheap

Finding a place to install it - PRICELESS.

HAHAHA

[Lou Earle]

YOUR 53 SHOULD HAVE A SHROUD- COVERING ABOUT 1/2 THE FAN AREA.

Also if your 12 volt put a pusher fan in front of a/c or radiator core.

FYI my 48 runs a 6v gen an a/c compressor and a 12 v alternator and has never gotten over 195 or so in traffic- I have turned on the 12 fv fan then and cooled right down.

[BobT-47P15]

I recall from having the 54 Plymouth that the fan did have a shroud.

But, of course, the P15 has none. So eventually I will probably just

put the 4 blade fan back on and call it good.

I see some good and interesting ideas presented above.

[hkestes41]

I like it--very clever. Do you have any more pictures of the process?

I have to admit this was not my idea, picked it up off the HAMB. I didn't take pictures during the build process however here are some pictures from the original HAMB thread.

[dezeldoc]

I made a shroud for mine.

1) Cut a piece of thin plywood slighlty larger than the core, making sure to cut a notch to fit around the upper and lower hoses.

2) Cut another piece about 1 inch larger diameter than the fan.

3) Measure the distance from the core to what would cover about 2/3 of the fan blade.

4) Cut 4 blocks of wood as standoffs between the two pieces of plywood taking in consideration the thickness of the plywood to give you the total measurement from step 3.

5) Measure to get the proper position of the fan to the core both horizontally and vertically.

6) Using the plywood and standoffs screw or nail everything together using the measurements from step 5 to position the round plywood piece to the core plywood.

7) Get some fabric with some stretch to it and lay it on the round plywood piece, staple it in the center then staple around the perimiter of the round plywood. Once you have the fabric stapled to the round piece, stretch it down and around the back side of the core sized plywood and staple it all the way around. Now you have your form.

8) Get some fiberglass cloth and resin. Mix a batch of resin and paint it over the fabric form then start laying your fiberglass over the form. Lay up as many layer as you want to build up to a thickness you are comfortable with.

9) Once all the fiberglass is set, drill a starter hole in the round plywood and use a jigsaw to cut around the edge of the plywood to remove it from the shroud. Do the same with the core sized piece of plywood.

10) to make room for the lower hose, I then cut a notch in the shroud and used a plastic drinking cup cut on a diaginal and glassed it to the inside of the shroud to form a "pocket" for the hose to run in.

11) Sand, paint and attach with two pieces of aluminum angle screwed into the shround and core support. I also used some stick on rubber weatherstrip from Home Depot between the shroud and the radiator to seal it and prevent rattles.

Here is the shroud before I realized I had to make the pocket for the lower hose.

And here it is installed.

Best advice given so far, other than checking the core to make sure it is flowing and not plugged! this will direct all the air over the core and not pull from everywhere else.

[Barabbas]

Thanks for the info---I'll bookmark this thread, this is definitely going on my to do list

[chopt50wgn]

A belt driven fan will only spin as fast as the pump does. If you go to a smaller pump pulley that will overdrive the pump which will allow it to turn 10-15% faster at idle which in turn will turn the fans the same.

[Plymouthy Adams]

and..on that same note...you move the water too fast through the engine you will be less efficient in heat x-fer as the water will not be in the block long enough to absorb the heat from the block and take to to the radiator to have it removed..

most folks that run without a thermostat..will at minimum run a restrictor plate to control this exchange rate..

some low ptich fan, (flex in general) by design will flatten out at speed and thus actually hinder the flow of air through the radiator and creating a hotspot where no temp exchange occurs..this was a very common scenario with the Sunbeam Tiger...their stock mtal fan had that characteric..I replaced my stock Ford pump with another design that affords me much more room to run a huge Chrysler asymetric design blade..can idle all day in 100 plus temp without overheat..

and on the power robbing note..it was assumed the flex fans would pull less power..actually the huge asymetrical fans that Chrylser used when compared to a flex fan on the dyno..the Chrysler unit generate on average 10-20 hp more...grant you this was on V8 engine..

Edited April 3, 2010 by Tim Adams