Does it really matter how many fan blades are on a slant 6 engine. The 66 has 4 blades and the 73 has 6. Both are slant 6 engines. just wondering.
does it really matter
- Thread starter trudysduster
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ok, thanks. would it hurt to put a 6 blade on a non ac car.
Some 273s had 4 blade.
Only if it moves less air than the 4 blade.
No, but the 6 blade solid mount fans sound like an airplane propeller when they rev up.
No. I'm going to do it the next time I have the radiator out of Vixen. I have a five blade solid factory offset fan I'm going to put in place of the tiny 4 blade.
how you gonna tell how much air it is mov
I didnt think it would matter a 4 blade or a 6 blade but just checking. it is a non ac car and it isnt a lot of ponies so I wouldnt think it would matter. Now if it was my 440 Duster with a lot of horsies, I would be concerned. I have a big radiator, a fan and a pusher fan and it still gets up there.
AJ/FormS
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The later model engines run retarded idle timing, and usually have delayed vacuum advance timing . With hiway type gears, the engine will always be retarded, and that is gonna send heat into the cooling system. Plus, about that time the thermostat was upped to 195*, in an emissions move. And carbs were leaned out as well.
So if your engine is in that category,
it probably needs more than the little 4-blade fan.
After 30/35 mph it won't matter so much anymore, cuz the movement of the car thru the air will be ramming air thru the rad..
thanks
In the hot summertime in traffic, you bet it can make a difference. More blades always moves more air. These little 4 blade slant 6 fans just don't move much AT ALL.
hotrod swinger
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Think of all the horsepower that’s gonna be robbed with that big fan though.
6? Maybe 7?
Are you serious. If you lose 6 or 7 HP with a bigger fan, so what. How much HP do you think it takes to turn an a/c compressor. These bigger fans are used on a/c cars to pull in more air so they dont get hot. And I am putting it on a non a/c car. so do you really think it will hurt.
AJ/FormS
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Um, If you have already made up your mind, just do it and see what happens.
BTW
you realize that that your 225 slanty might only gross 125hp right?
and at 500rpm idle has just enough power to idle in gear and not much more.
EDIT; and the powerloss will be proportional to the rpm. Actually, IIRC, proportional to the square of the rpm; meaning , when you double the rpm, it takes double double the power, so four times as much.
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Well, I have 2 other a bodies that are A/C cars and they have the same fan blade, so I figure if Chrysler didnt have a problem with it, then who am I to question them.
hotrod swinger
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That was a joke and you took the bait.
AJ/FormS
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A lot of things Chrysler did, were to pass ever-tightening emission laws, and/or to improve their profits. So just because we think ;
Ram-air takes over at around 30/35 mph. unless the engine is working hard and/or reving.
Below that, the fan is doing most of the work.
When the car is stopped and idling is the time when the fan is gonna have the hardest time, (unless you are towing.)
Any fan that can cool your low-performance engine, at idle, with the hood closed, is probably gonna get the job done for the rest of the time as well.
Any more fan than can do the job, is gonna cost you money at the gas-pump.
So;
that doesn't mean they had us or our cars best interests at heart.
Ram-air takes over at around 30/35 mph. unless the engine is working hard and/or reving.
Below that, the fan is doing most of the work.
When the car is stopped and idling is the time when the fan is gonna have the hardest time, (unless you are towing.)
Any fan that can cool your low-performance engine, at idle, with the hood closed, is probably gonna get the job done for the rest of the time as well.
Any more fan than can do the job, is gonna cost you money at the gas-pump.
So;
Would it hurt? No it won't hurt the engine. But it may hurt your wallet. You can usually get around that, by putting the fan on a clutch.
Dave999
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my aircon equipped australian Mopar with 265 cubic inch hemi 6 came with a 4 blade fan no shroud on the rad as standard. it doesn't overheat. didn't with 2bbl BBD and sensible CR doesn't with webers and 12:1 CR radiator is brass 3-pass A body size. didn't in 80+ F days in Australia and doesn't in UK both countries have their problems with traffic queus especially in the overcrowded UK on HOT days, when everyone goes to the beach 
A body style body at least from the middle forward.
if it did or if i planned to rev it past redline regulary i'd go with the viscous clutch fan and look for one with 1 offset blade. it reduces the noise and slips above a certain rpm and fan hub temperature reducing power losses.
other option is a plastic flex fan, but ive never been a fan of them.
as stated you'd be fine with either but waste power with too many blades or too big. a clutch fan can help.
Dave
A body style body at least from the middle forward.
if it did or if i planned to rev it past redline regulary i'd go with the viscous clutch fan and look for one with 1 offset blade. it reduces the noise and slips above a certain rpm and fan hub temperature reducing power losses.
other option is a plastic flex fan, but ive never been a fan
of them.as stated you'd be fine with either but waste power with too many blades or too big. a clutch fan can help.
Dave
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