The fan........does it pull air through the radiator, or blow air AT the radiator? The reason I ask is I finally got the correct spacer and fan for my 69.(It had a flex fan when I got the car) When I installed and started the car with the correct fan, I could sure feel the air blowing back towards the cowl.

I know this may seem silly, but plase take a look at this pic (http://www.erols.com/ruther/69conv/fan.jpg) and make sure my fan is on correct. It just didn't seem right the other way and this is the way I THOUGHT it looked in the assembly manual.

Thanks,

Jerry,

No expert here but the pic looks right to me. Also, I believe the fan sucks air through the radiator. It would seem to me that if it pushed air it would be fight against the natural air flow when driving.

But again, I could be full of hot air


And the sucking action would explain all those dang bugs impaled on the radiator fins. :eek:

HTH

Bruce

Looks good to me too. It's funny how many I have seen install a$$ backwards. Also without a shroud the fan cannot pull properly. Looks like you do have a shroud as well. graemlins/thumbsup.gif

P.S. It only sucks when you install the fan backwards and your engine overheats! :D

Easy way to test for sure. Start the car and put a piece of paper in front of the rad. Paper sticks, its sucking. Paper blows away, its pushing.

Blowing air at the rad would negate cool air coming into the rad from the front of the car.

Thanks guys! yeah, new shroud, fan, and correct spacer...I just wanted to make sure...Sure is quite a breeze in there now! :D

Thanks again,

Jerry,
Great job on the cowl and engine detailing. Looks very nice!

Dwayne

There does not appear to be a "backwards" unless there is a wierd bolt pattern, because imagine the following:
^ is towards the radiator
/ is the direction of the fan blade angle with respect to the waterpump.

If you turn that angle 180 degrees, you get the same shape/pattern/ direction of airflow.
??? :(

It's not the / though it's the cup ) of the blade that makes the difference in the volume of air it pushes.

)--> not good

(--> good


smile.gif

Originally posted by Dean:
It's not the / though it's the cup ) of the blade that makes the difference in the volume of air it pushes.
)--> not good
(--> good
smile.gif Aha! ;)

Hey Dean, fans don't push air, they pull air.
Big difference.

Jerryr,
Fan blade should pull air thru the radiator towards the engine.

I'm assuming you have a 307 engine ?
That 4 blade fan is correct for the 307, but not for the 350.
I prefer the 7 blade fan with viscous clutch. That's what came on all the 350-396 engines w/ac in 1969.
In 1969 I think you could have optioned for HD cooling on the 307 and got the 7 blade fan.


Nate

Nate,

What fan is for a 350 w/o AC?

Thanks,

Jerry,
I think the 4 blade fan could be correct. I'm not positive.
If it was my car though, I'd run the 7 blade fan with clutch. It has been proven to be the best overall. (for engine performance and cooling thru-out all rpm's).


Nate

Nate
Pulls air through the radiator and pushes it towards the firewall
smile.gif

Thanks Nate.

Well, I don't have AC, and need to run the spacer to get the correct distance between the fan and shroud. I've always heard you are not supposed to run a clutch fan with a spacer.

Also, in my assembly manual, it shows the 4 blade fan for the "V8" (which I guess could be the 307...)

The spacer is the corrct part number, along with the shroud. I'm telling you, now that I have the fan "inside" the shroud like it's supposed to, it's like a windstorm in there. I put a piece of paper of the front of the radiator, and it stuck like glue graemlins/thumbsup.gif

I believe MalibuJerry ( I believe that's right) has a 70 that's pretty much stock as can be, with a 350 and no A/C (I believe), I wonder what kind of fan he has....


Thanks,

Originally posted by jerryr:
Well, I don't have AC, and need to run the spacer to get the correct distance between the fan and shroud. I've always heard you are not supposed to run a clutch fan with a spacer.Indeed. I asked about this recently (http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=31;t=002683) and the concensus was definitely to NOT use the spacer with a clutch fan.

- John...

A stoch GM clutch is a heavy item hanging off the water pump shaft and the further you extend it the leverage amplifys the weight. I'm using an aftermarket clutch made by flex-a-lite (sold through Summit) that is about half the weight of the GM version. I run a 1 1/2" spacer or my fan would not fit in the shroud at all. My car uses a long water pump but the engine is back against the firewall. I've run the same water pump for 3 years with no signs of problems.

I opted to go this route as opposed to moving the engine forward messing with the cross member and installing a longer drive shaft. I am aware the extra weight is out there and always check for wear when under the hood checking oil or detailing...

Fan clutch rpm ratings are lower as they are not direct drive and don't see the same RPM as I understand it.

jerryr, a cruising buddy of mine in the Houston area was having problems in the hot and humid Houston summer a few years ago so he dicided to solve his problem by installing 2 fans.........one in the front and one in the back of his radiator. The one in front blew air thru the radiator and the one in back did likewise
--> <-- like this. Well needless to say the first time out he overheated badly. No air flow, both fans were working against each other. graemlins/clonk.gif

The stock 7-blade fan from my '71 Monte 350 has "front" stamped in the front of it.