Ram Air Question: Fan Type
 

For 67 & up, what was the standard cooling fan that came with a Ram Air car?

- 4 blade steel fan

- 5 blade flex fan

Thanks!

I'll stick my neck out there and suggest the five blade;
As I have understood the four blade fixed unit was more for the bread and butter engines, but the five blade was put on all (non-A/C) 4bbl performance motors...

If nothing else, someone may chime in to correct me ;)

Should be 5 blade flex. 9798940

From what I have seen lately on concourse gold and original RA I and RA II cars is the steel 4 blade. I am doing more research on the topic, but it looks like the 68 RA cars use the 4 blade.

It would be interesting to learn what you find in your research. The factory literature shows the 5 blade fan. I wonder what fan is on the unrestored black convertible deuce.....anyone have any pics of the engine compartment with the correct view angle to see the fan? I think Jim Mino's car had the 5 blade fan....

I wouldn't be surprised if many owners swapped the 5 blade for a 4 blade shortly after delivery in hopes of free hp....especially in the cooler climates. Probably not a good idea in the desert Southwest though...:)

My '69 RA3 4-speed no-air GTO came with the 5-blade flex.

My survivor 68 ram air car has its original four blade fan.

REALLY!!

Now that is down right surprising!!

Here's a picture of the fan.

I think there is a strong case for the 4 blade fan on the 68 Ram Air cars. The dealer brochures make multiple references to the 5 blade flex fan (Power-Flex code 684) as standard equipment for GTOs.....but that doesn't prohibit the use of a different fan for the ram air engines.

The illustrated facts and features brochure shows photos of the family of available engines but the photo for the ram air engine is a close up of the air cleaner so the fan isn't visible in that photo so we can't draw any conclusions from that page.

Probably the smoking gun is the MPC book. It specifically lists 9798940 for the 67-68 F/8-T/8 400 Ram Air application. I originally assumed that part number is the 5 blade flex fan but if I flip to the previous page I see that same part number listed for multiple applications with the additional description as being a 4 blade fan (2 5/16" pitch).

When I bought my car it had a 4 blade fan but the engine had already been changed so I don't know if that fan was original or not. Based on the MPC book....the 4 blade fan is correct for Ram Air cars in 67-68. I hope I have it laying around still.....

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Good info. Thanks for posting. More ammunition for the 4 blade fan as correct for these cars.

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Did any application use the optional 7 blade flex fan as standard?

I don't think there ever was a factory seven blade flex fan;

As I have come to understand, this is how Pontiac V8 fans were:
- 4 blade fixed
- 5 blade flex
- 7 blade fixed; clutched

It is also worth noting that generally speaking the different fans used different spacers.

The four blade pictured above does have a spacer that I generally associate with the flex fans...

I am very glad that I posted here, because this has been a great discussion so far!

Yep, just checked the option, it says 7 blade fan and clutch HD. Option 514 .... same fan as standard with 582 AC.

There was a discussion about the 4 blade fan on FirstGenFirebird

https://firstgenfirebird.org/forums/...=228979&page=1

Also, here is a picture of the Aegean blue 68 RAII at the nationals in 2013 with the 4 blade fan

Attachment 466140

Disagree, have owned 2 of the factory 7 blade variable pitch, ie, flex fans. The factory 7 blade flex fan is just not something that is commonly run across.

4 blade......................19" diam 2 5/16" pitch #97xxxxx (later replacent is 9798940)

5 blade var pitch.........19" diam 2 5/16" pitch #9791346
(first use '67 models, a few made it onto '70 model GTO's before replaced by 480033)

7 blade var pitch.........19" diam 2 1/2" pitch #9796135 (HDC usage, have only found on big cars)

Not even going to get into all the different 7 blade different diam AC fans, too many styles.

Great reference photo. Same adapter style as shown in the photo of the RA I GTO posted earlier. Fantastic info and comes just in time for my build!

This is the fan I was curious about. Not sure which exact variant it was, but was shown in a spread of optional parts on a 68 GTO ... seen with various RA components in the foreground. Looks somewhat variable pitch to me ... but might be standard AC fan. Would appear from the hub that it's a clutch fan.

http://forums.maxperformanceinc.com/...1&d=1508909056

Correct, the 7 blade flex direct drive fans are a factory part with a part number. I believe they were more common in Chevrolet applications. I have about 5 or 6 of them here. I used to by them all the time and upgrade the cars with them for better cooling.....man those things move some serious air.
In the 1980's I used to run across them all the time at swap meets for $20-$30, I'd just snatch them up.
I don't use them as much anymore because they soak up some HP, lol I have one car here that is currently still running one. I switched all my other cars over to 7 blade clutch.
Dad's 69 GTO had the factory 5 blade flex, but he has also switched that car over to a 7 blade clutch.

Yep that's a 7 blade clutch fan.