The Stovebolt Site Forums The Shop Area Engine Shop Water Pump / Fan issues with New Harmonic - 57' Chevy 235

Alright boys, I'm having one of those cascading problems moments. Best to let the pro's take over!



I know it's a wall of text but I like to give all the facts up front. TL;DR at the end.

Vehicle / engine is a 1957 3100 Chevrolet 235 with everything mostly stock and original. Water pump is the stock long version. Of important note: I am in the middle of adding A/C and compressor and that's what started this mess.

My old harmonic went bad, and rather than spent a ton of money buying another one from Damper Dudes, I got it in my head that I'd rather have an internally balanced aftermarket one that has bolt on pulleys for easy conversions since I need a double pulley for the AC and alternator. Plus I just hate the original harmonics, they go bad too easily.

So based on threads I've read on here I drill and tap the crank. Works out great, new harmonic goes on perfectly (I will NEVER do the BFH 2x4 method in my life again!). I test it just for a minute, it runs smooth as glass. Not bad for a $60 summit damper.

However, now the water pump pulley ( a long shaft deep cone single pulley) doesn't match. I have a set of short pump double pulleys, but it requires that the pulley sits at the very end of the water pump to match with harmonic. I mean.. BARELY hanging on. I used 6 washers to bring it to the end.

Here's a picture: https://photos.app.goo.gl/S2kTfY9wrSuGpUEH7

This creates two problems: Now the original mechanical fan doesn't fit, or if it does it's like a 1/16" radiator clearance which I don't trust with road bumps and would not be on the post at all which is the bigger concern. So even assuming they make a spacer, I'd need to extend the end post for the fan to sit on.

Problem #2 is that the pulley has a REALLY bad wobble when I started it for 30 seconds. The bolts may have been loose, or maybe because I used washers as spacers but I think not.

Here's a video of the wobble: https://photos.app.goo.gl/1GXe1bZuq3oCw4Du9

Does anyone know if the 6 blade fan is thinner than the stock 4 blade? Or is there a pulley for water pumps that isn't a cone so the grooves don't sit so deep? I can move the compressor and alternator anywhere, it's just the pump, harmonic and fan that are causing issues.

I'm open to any ideas you all can throw at me. If I could just extend / adjust the actual water pump rod and find a thinner fan, I think it would fix all my problems. My only issues are I'm trying to keep as much stock as possible because the truck holds sentimental value. Thanks for any help in advance!


TL;DR: Can I extend my stock 57' 235 water pump, if it's already a long one? Do they make a spacer / extender? Is there a cheaper electric fan I can use if mechanical will not fit? Is there a thinner mechanical fan that will fit than the original 4 blade? Is there a different pulley setup I can use?

Any chance you can get your hands on a pully from a 57 265/283. The V8 pully was shorter and may do the trick.

Maybe! Still might have the fan hitting the harmonic issue, not sure. I wish they put a measurement from the cone to the pulley depth-wise but I can never seem to find it. Might have to go to a junkyard or see if the local part store will let me dig around in their back inventory...

The damper snout needs to be modified. I do it all the time. Trim about 1/4"-5/16" off the end of the snout and machine the outside of the snout where the seal rides back an equal amount. Then use a big block V8 2-sheave pulley turned backwards over the damper to drive the belts. You'll need to grind two small nibs off the pulley to allow it to sit flat against the face of the damper and use the three threaded puller holes to secure the pulley. PM me for more info if you like. NO- - - -I DO NOT make or sell these dampers, but I'll be glad to walk you through the process of making one.
Jerry

Oh wow, so a v8 big block pulley's I.D. can be big enough to actually go AROUND the damper and still mount with the same three holes? darn, that would actually work... At that depth I could possibly even use a normal long pump pulley because it would put it in range of the original damper's groove... well darn.

That only works if you use a 6" diameter damper. Look up one for a 265, 283, or 307 V8. I use a Ford 302 V8 water pump pulley and modify the shaft hole and bolt spacing when I want a 2-groove pulley on the old 216 style high water pump. The original cast iron pulley has to be machined down so the Ford pulley will fit. Having two belt grooves on the damper and the water pump gives you all sorts of mounting options for accessories like power steering and/or air conditioning.

Jerry

Dang, this damper is 6.75in diameter. Might be harder to find one that will fit that but it's still a good idea either way.