Balancing A Two Blade Aluminum Repro Fan

[Michael P.]

When balancing one of the repro aluminum 2 blade fans is there a proper place on the heavy blade to remove some of the weight? I understand one process using a spare pump shaft and the two razor blades to balance the shaft on but are there any more pertinant tips to the process? Thanks...

[Russ/40]

My understanding is they are already balanced. I just fired mine up with the one from Brattons, and it seems to be very smooth.

[Mike Mc]

I just put mine on. There doesn't appear to be a balance problem. Regards, Mike.

[BRENT in 10-uh-C]

I bought a fan balancer from Tom W. and have been checking them with frequency since I got that thing, and they are not as close as one might think.

[Dave in MN]

I helped trace down a severe shutter at the front of an engine I had rebuilt last summer and it was the aluminum fan. The fan was then balanced and the problem was solved.

There were some fans that made it to the retailers a few years back that were way off... I agree with Brent, check them!

Dave in MN
www.durableperformance.net

[Michael P.]

Sponsored Links (Register now to hide all advertisements)

Ok, But can anyone answer my question as to where is the best area to grind/shave metal off on the heavy side? I am familiar with balancing lawn mower blades and do so 4-6 times a year but no one cares what a lawn mower blade looks like and the grinding off of metal is a no brainer but on a fan blade made to push cooling air should it be done closer to the hub, closer to the tip, trailing edge, none of those places?

[Carb Guy]

Maybe Tom W. will jump in and give some of his expert advice on this blade thing. He has done a lot on these blades.

[Art Bjornestad]

I just bought a new improved Bratton fan and after checking the balance, ground off about 3/16" from the very end of the heavy blade.

[Tom Wesenberg]

Originally Posted by Michael P.

Ok, But can anyone answer my question as to where is the best area to grind/shave metal off on the heavy side? I am familiar with balancing lawn mower blades and do so 4-6 times a year but no one cares what a lawn mower blade looks like and the grinding off of metal is a no brainer but on a fan blade made to push cooling air should it be done closer to the hub, closer to the tip, trailing edge, none of those places?

I use a small ball bearing balancer just like the one Brent bought from me.

IF THE BLADES STOP IN A HORIZONTAL POSITION, THAT MEANS THEY ARE NOT PARALLEL TO EACH OTHER! And, if this is the case you may not be able to balance the fan.

I grind or sand the blade surface smooth, then if a bit of thinning will balance the fan that's one way to do it, or grind a bit off the blade tip if you have one blade that dips down. I also drill holes (about 1/4") into the front of the hub. don't drill deep enough to go through the rear of the hub and don't drill where it may enter the belt groove. I estimate how many holes to drill and how deep they need to be, then I drill a smaller hole sideways connecting the 1/4" holes. This way when I pour molten lead into the holes it will be locked in place. By filling from the front side it isn't really visible when mounted on the car.

I'd like to buy the fans without the powdercoat, since I wind up sanding most of it off anyway.