Question about stock fans?

[67ChevyRedneck]

So I've been running a hood splitter fan for the past 3 years (flex fan) and I recently converted my truck from a long water pump to a short water pump. The fan now sticks out of the fan shroud. Rather than buy another spacer for the flex fan, I'd rather fix the truck properly with a "normal fan."

I've WAY overblown my budged on my Vintage Air install and am running short on funds and the 4th is coming up These trucks had a solid fan originally, correct? Is there a late model vehicle that I can get a clutch fan off of? Does anyone have any overheating problems with one? What kind of price do most yards ask for one? What is everyone else running for a fan?

It needs to be able to fit within the shroud on a short water pump truck in the "correct" V-8 position. I think the fan would need to be approximately 3" to 3 1/2" away from the pulley to operate properly within the shroud.

Thanks

[estig70]

not sure about what year clutch fan would work but an early GM for a v8 truck should work. as far as being out of the shroud may need to replace shroud w/ one made for a short nose water pump. correct me if I'm wrong but I think there was difference in depth of the shrouds for short and long water pumps. good luck!!!

Eric

[67ChevyRedneck]

All 67-72 trucks had short water pumps. Trucks switched to long pumps in '73. I think GM cars switched in '68 or so.

[estig70]

Originally Posted by 67ChevyRedneck

All 67-72 trucks had short water pumps. Trucks switched to long pumps in '73. I think GM cars switched in '68 or so.

those were my thoughts. maybe a clutch fan from a 73 up v8 truck would work, and I'm thinking there was a difference in depth of the shrouds used for long pumps versus the short in this same era. I don't know for sure just a thought.

Eric

[estig70]

Originally Posted by 67ChevyRedneck

All 67-72 trucks had short water pumps. Trucks switched to long pumps in '73. I think GM cars switched in '68 or so.

those were my thoughts. maybe a clutch fan from a 73 up v8 truck would work, and I'm thinking there was a difference in depth of the shrouds used for long pumps versus the short in this same era. I don't know for sure just a thought.

Eric

[jgrh64]

I'm running a 7 blade & clutch in mine with a slightly healthier 350 no problems. I thought it was a stock set up but from what everyones saying it must be a later model, maybe same as motor( 1978 K-20 4 bolt main)

[67ChevyRedneck]

I've got to figure something out.... I got the A/C charged today... works awesome

New problem, engine overheating in traffic

I know it's got to be because the fan. It's currently 1/2 out of the shroud and when I put my hand in front of the radiator it has nowhere near the pull it used to. Before the A/C install my truck had a long water pump, now it has a short, so the fan moved about an inch, inch and a half closer to the motor.

A 78 motor probably has a long water pump?

What are people using for fans for short water pumps? A stock one?

I can order a 3" spacer for my fan which should fix my problem, but I'd rather replace the fan if I can

[Longhorn Man]

your fan is supposed to be 1/2in and 1/2 pout of the shroud.
Stock, *I THINK* came with a clutch if it had A/C

[67ChevyRedneck]

Hmmmm, just found this online

If your vehicle came from the factory with a fan shroud, did you remove it? Lots of people get rid of the fan shroud, thinking it's nothing more than an unsightly finger guard. Wrong! It's actually a key part of the cooling system.

Of course, to work properly, the fan and the fan shroud have to be installed properly. According to Walt Diederich of Perma-Cool, if you're running a stock fan shroud, 50 percent of the pitch of the fan blade should be inside the shroud and 50 percent should be outside. This allows the fan to drive heat over and out into the engine compartment, rather than ramming it into the front of engine.

So my fan is in the correct position?

I have a 3 core automatic radiator.... maybe it's not big enough?

[67ChevyRedneck]

Originally Posted by Longhorn Man

your fan is supposed to be 1/2in and 1/2 pout of the shroud.
Stock, *I THINK* came with a clutch if it had A/C

I posted right after you did.... do you know of any newer clutch fans that would fit?

[Stocker]

Originally Posted by Longhorn Man

your fan is supposed to be 1/2in and 1/2 out of the shroud.
Stock, *I THINK* came with a clutch if it had A/C

Correct on both points...

[67ChevyRedneck]

I looked on autozones site and I can buy a new fan and clutch for $80. Stock style. I hope that would fix my cooling problem?

[Stocker]

Originally Posted by jgrh64

I'm running a 7 blade & clutch in mine with a slightly healthier 350 no problems. I thought it was a stock set up but from what everyones saying it must be a later model, maybe same as motor( 1978 K-20 4 bolt main)

My '72 has a stock 7-blade clutch fan...

[67ChevyRedneck]

I've been looking through parts catalogs and parts places online and I'm only coming up with a 6 blade fan. Anyone know where I can get a 7 blade one?

[Stocker]

67CR, what does your fan feel like if you rotate it by hand? It should be a bit gooey, kinda like it's in molasses...

[Stocker]

Originally Posted by 67ChevyRedneck

Anyone know where I can get a 7 blade one?

Might have the best luck in junkyards -- look for larger GM rear-drive V8 cars, esp. Caddy, Olds, Buick... or full-size trucks. Just be sure to measure twice, buy once!

[PICKMUP]

Your truck in stock form had a 7-blade clutch fan and 4-row radiator for AC (a 5-blade clutch fan for non-AC). Don't even think about that cheapie 4-blade solid fan.
Later clutches will work fine, but the fans were bigger in diameter and often hit the shroud...that can be fun LOL.
AC makes them run hotter, so get the big radiator...new, not used and half plugged up.

[67ChevyRedneck]

Originally Posted by Stocker

67CR, what does your fan feel like if you rotate it by hand? It should be a bit gooey, kinda like it's in molasses...

It's a cheap crappy 18" flex fan.

[67ChevyRedneck]

Originally Posted by PICKMUP

Your truck in stock form had a 7-blade clutch fan and 4-row radiator for AC (a 5-blade clutch fan for non-AC). Don't even think about that cheapie 4-blade solid fan.
Later clutches will work fine, but the fans were bigger in diameter and often hit the shroud...that can be fun LOL.
AC makes them run hotter, so get the big radiator...new, not used and half plugged up.

What sucks is... my 3 core radiator was $200 new 2 years ago.... I'd really like to NOT buy another one

[Stocker]

Oh shoot, I know you said flex fan earlier, then I somehow got confused & thought you had a clutch fan that wasn't working right! Auggghhhh!!


I'd definitely try a good fan before giving up on your radiator. My OEM radiator was a 3-row (with factory A/C; maybe 67s were different) and it worked great until it finally rotted out a year or two ago.

[67ChevyRedneck]

^That's what I'm hoping.... FINGERS CROSSED!

It did fine on the "open road" but 35 minutes in traffic and 94 degrees outside today got her up to 210-220 range.

I was totally unprepared for this swap. I had to change things I didn't think I'd have to change, buy tools I didn't have, pay someone to evacuate the system (they were totally cool and used my R-134A and charged it for free ) ... Basically, I'm about $1,600 into an $1,100 system. I figured about $1,400 would do it....

[Stocker]

Originally Posted by 67ChevyRedneck

It did fine on the "open road" but 35 minutes in traffic and 94 degrees outside today got her up to 210-220 range.

So cooling is OK at highway speed (when airflow is sufficient that a fan is rarely needed) -- this makes me think the radiator is good.

At lower speeds, airflow is reduced and a fan is needed to move enough air through the core. This is when you are running hot -- and it sure seems to point to the fan.

[jorgensensc]

When i needed a flex fan I hit the J-yard witha tape measure. I had to find a 17" because it was hitting the Bel Air shroud. Should cost you about 20.00. You are doing right by ditching the flex fan!! My suggestion is to add an electric pusher fan on the front with a trinary pressure switch so that the electric fan will come on with the A.C.. It would help cool the engine down considerably in traffic.JMHO.
Shawn

[jkeady]

What kind of thermostat are you running?

[3/4tonterror]

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