5 blade vs 6 blade

[Chester C.]

My friend has a 61 vette all original. It runs around 180/195 on hot days. He would like to have it run cooler for his comfort and mostly his nagging wife. Corvette Central has a 6 blade fan with clutch. It just makes common sense to me that an extra blade would move more air and thus run a little cooler. Please, we are not looking for the usual make sure your radiator, air flow and all that is up to par because it is. Just would like to hear from anybody that may be using the CC fan/clutch. The CC number is 241130, thanks

[David L.]

Re: 5 blade vs 6 blade

I do not know anything about the 241130 Corvette Central fan but this is my story.

The normal fan used on 60-67 Corvettes has 5 steel blades, 17 1/8" dia., 3.00" bolt circle, and 1 5/8" pitch (GM # 3770529).
On my 1966 w/327 engine I store my original fan in the garage and use a 1968 Chevrolet passenger car w/AC fan. It has 7 aluminum blades, 18" dia., 3.00" bolt circle, and 2" pitch. I bought it in a salvage yard for $10 back in the 1990's. The part number 3931002 is stamped on each blade. The 3931002 fan was only installed on 1968 passengers cars but also serves as a replacement for the 63-64 and 66-68 Corvettes w/AC 5-blade 18" dia. fans, GM # 3789562 and 3863137.

Is there enough clearance on a 1961 to use a 18" dia. fan?

Dave

[Michael W.]

Re: 5 blade vs 6 blade

Given that the standard thermostat is a 180 degree unit, even a fan bigger than Uranus would not cause the engine to run cooler than 180. Excursions to 195 are expected, typical and have most probably occurred since the day the car was delivered

Possibly you could ask your friend to inquire of his beloved wife (if they're still on speaking terms) what temperature she would like to see on the gauge. Some of the smarter cookies here could most likely draft up a re-engineering scheme to drop the temps by a few degrees and cause it to hold steady even under the most demanding conditions.

Alternatively, the scheme used by many OEMs on modern day cars where the temperature gauge always sits frozen in the middle of the normal range (unless there's a true overheat) could be employed.

[Mark D.]

Re: 5 blade vs 6 blade

even a fan bigger than Uranus

Bigger 'an what?!!

[Joe R.]

Re: 5 blade vs 6 blade

Trade in the wife on a younger model that either wears a bikini or nothing at all! Or sell the 61 and buy a C5 or C6 and keep the old wife!

Jokes aside, he has no chance of cooling that 61 down in the cockpit today with temps in the 100 degree range. A 61 has NO insulation and very thin carpet. My C4 operates in that range but with all the insulation and AC it was quite comfortable today.

OK, you have sucked me in! This has gotta be a joke! Right?

JR

[Terry M.]

Re: 5 blade vs 6 blade

Go for the C6; in the long run it will be less expensive. The wife can set her own temperature for her side. The divorce and trade in on the younger high-maintenance model will kill the bank account.

[Terry D.]

Re: 5 blade vs 6 blade

Might kill the bank account, but look at the fun and admiration from all your buddies. Image is everything!! LOL

[Dick W.]

Re: 5 blade vs 6 blade

Looks like the clown brigade has arrived The busdriver, the crazy canuck, and the hog farmer

[Tim T.]

Re: 5 blade vs 6 blade

yea, but it would be no fun without them.

[Joe L.]

Re: 5 blade vs 6 blade

My friend has a 61 vette all original. It runs around 180/195 on hot days. He would like to have it run cooler for his comfort and mostly his nagging wife. Corvette Central has a 6 blade fan with clutch. It just makes common sense to me that an extra blade would move more air and thus run a little cooler. Please, we are not looking for the usual make sure your radiator, air flow and all that is up to par because it is. Just would like to hear from anybody that may be using the CC fan/clutch. The CC number is 241130, thanks

Chester------


I can tell you this: once-upon-a-time in an attempt to improve cooling I replaced the original 5 blade GM #3888366 fan blade assembly on my original owner 1969 with a 7 blade GM #3955182. The effect on cooling turned out to be negligible.

[Joe R.]

Re: 5 blade vs 6 blade

Chester------


I can tell you this: once-upon-a-time in an attempt to improve cooling I replaced the original 5 blade GM #3888366 fan blade assembly on my original owner 1969 with a 7 blade GM #3955182. The effect on cooling turned out to be negligible.

Joe,

But it made a lot more noise didn't it? Some people think that's the fan working harder! Harder at blocking the air coming thru the radiator that is!

JR

[Kingston W.]

Re: 5 blade vs 6 blade

My '63 is also built without any carpet insulation, so what I did was wrap the exhaust pipes from below the exhaust manifold to the mufflers out back. The fiberglass wrap is available from Summit Racing and removes heat off the floor boards and firewall very well. I could have added insulation or jute under the carpet but I wanted the car to stay original in appearances. Since I only take the '63 out on hot summer days in Nevada my wife was very pleased with the results. BTW, once you wrap the exhaust, it's an old racer trick to take the hot exhaust far from the engine, it sounds nasty out back once it hits the cooler air.

Kingston.

[Scott K.]

Re: 5 blade vs 6 blade

My friend has a 61 vette all original. It runs around 180/195 on hot days. He would like to have it run cooler for his comfort and mostly his nagging wife. Corvette Central has a 6 blade fan with clutch. It just makes common sense to me that an extra blade would move more air and thus run a little cooler. Please, we are not looking for the usual make sure your radiator, air flow and all that is up to par because it is. Just would like to hear from anybody that may be using the CC fan/clutch. The CC number is 241130, thanks

The pitch on the blade provides for temperature difference, whereas the amount of blades will affect the noise level of the fan. Have you tried using a 170* thermostat? Also, lining the cabin floor and firewall with heat reflective material such as Hushmat will keep temps under control in the car.

[Michael D.]

Re: 5 blade vs 6 blade

...He would like to have it run cooler for his...nagging wife...

Does he have supporting documentation confirming the aforementioned wife does, indeed, nag?

[Kingston W.]

Re: 5 blade vs 6 blade

Let's not lose site of the original problem; his engine runs at 180 degrees but his wife must run at 98.8 degrees or less. I'm sticking to my original advice of adding wrap to the exhaust pipes and this will reduce CABIN TEMPERATURE immediately. Let the engine run at any temp. it wants. I live in Nevada and I only take the car out on fantastic nice days usually in the 90's or 100's. Wife enjoys the ride.