I have read in a couple of threads about putting a C4 A/C blower in
C3’s. Will any C4 blower motor bolt up to the housing as long as a spacer is manufactured? How about the hose from the motor to the housing?

 

The first time I did this was in 1984 or 1985, and then we had a bunch of spacers that were made by GM as part of a blower motor campaign recall issue. There were plastic and were perfect. However they are not available and you will need to improvise.

This blower motor which includes the fan, will add up to 20 percent more volume in the blowing capacity of your car. I'm not sure what this motor fit, but we found it to work best years ago and continued to sell it to this day. http://willcoxcorvette.com/product_i...ducts_id=24497

All blower motors turn the same RPM's. The difference is in the pitch and the number of blades on the fan.

You must install and/or manufacturer a ¾ “spacer to accommodate this motor!

The spacer can be made from plastic, or wood. The easiest way to make the spacer is to use wood and paint it black. To secure this to your car you’ll need to go to a hardware store and purchase some 1” pole barn metal screws. They come in the correct head size, have a neoprene washer and will be the correct thread too!

If you cut a round hole in plywood large enough for the blower fan, you can then sit the motor on top of it and trace around the outside edge for the outer lip. When finished mark your holes, drill them and them paint this black so it won’t show!

Willcox Inc.

 

If you choose to do this, the hose is the least of your worries. Making the spacer and getting it in is the "FUN" part. IF you are going to do this. MAKE SURE that you clean the front face of the evap core when the motor is out. Leaves and stuff often times block the front area of the evap core and will reduce air flow. I have done about 5-6 Vettes and they ALL have needed to be vacummed out and cleaned. But I also had the inner heater core box out so I could blow air through the evap core and vacuum it out at the same time. It is really hard, but I can barely touch the evap core through the blower motor hole from the cowl side. I do this because it is a blind area and need to make sure that all of the crap is out of the evap core box area so the air blows the best possible. And I can tell you, there have been some cars that have had ALOT of stuff in this area blocking the air.
"DUB"

 

Okay, so I saw this thread and thought, Hmmm, C4 blower motor for better AC flow, sounds like a winner (I live in Florida where the AC needs all the help it can get). Then I go out to my car to go to work... no AC fan. Talk about timing! So I go to Autozone where a '96 Vette fan motor with fan blade is $30 with lifetime warranty, and I just so happened to have exactly $30 on my rewards card! Is this great or what!

Of course it could not last. I go to take out the old fan. After removing the side vent plate and twisting my hands into all kinds of contortions, I got all the screws, wires and vent hose loose. Not so bad.

Then I realize there is no possible way that fan will come out through any space available. So it looks like if I move the coolant overflow bottle it will come out. But to move it I first have to remove the side air intake snorkel tube (This is starting to become a tar baby). I unbolt the bottle and remove the snorkel tube, but the bottle will not move far enough out of the way. It looks like I may need to unbolt the AC compressor to move it and the refrigerant lines enough to move the coolant bottle (whew...).

My question is, am I going about this right, or is there an easier way to get that fan out (and the larger C4 fan in)? (This is on an '81)

Thanks and God bless, Sensei

 

I jacked up the car years ago, cut a panel out of the fender section making a large hole there.....easy as pie to do the whole thing then....put a metal flange on the panel, screw it all together again....

paint it black or fill in with paneling adhesive or black RTV....

 

Yea, your doing it right, sux don't it? I opted for the full body off option. I made my spacer with MDF from Home Depot and painted the hellout of it with epoxy paint rattle can. Should be plenty waterproof. The fan itself is the same diameter, but longer. Your going to have to play with the vent tube for the motor once its in place, its a required part. Make sure your ac ducts are all connected and the joints are sealed, mine had a 1" gap between the dash vent duct and the diverter box, I used aluminum duct tape to fix that

 

Thanks everyone, as all of my A/C components are still removed I hope that the fans removal will be easier. So, here I go!!!

 

Sensei,
Yes you did it correctly because of the clearance issues. I wish there were an easier way but with some models it takes removing the parts you listed above. UNLESS you pay someone else to do it. Ooops...thats me....from time to time...who gets that honor.
"DUB"

 

When I did mine I followed the procedure Wilcox suggested. But I used 3/4 black ABS from McMaster Carr. A 12 x 12 sheet in 3/4 is about $25.00. It's already black so it does not have to be painted and will not rot like wood can.