I went about 1/4" deep. Plan is to use some 3/16" rod as pins and weld them in there and all the way around the snout end.

 

Silly question, but I noticed most (if not all) the projects I see on here, people use a mechanical water pump instead of an electric.

Is there any reason (other than cost) why more people aren't going to an electric water pump?

 

From what I have gathered the mechanical ones are much more reliable, cheaper, and lighter weight. The electric ones can be run with the engine off and provide more flow at low rpms.

 

That should work. When you weld it, TIG it with 309 rod. It's made for dissimilar metals, mostly used for mild to SS but that shaft is really hard, high carbon steel and becomes brittle really easy when you weld on it. That's why your other welds broke and the pulley came off. 309 should really help with it.

 

You may want to go deeper with the depth so it is at least to where the pulley flange starts just past the threaded area. I am guessing close to 1/2 inch or so...

As KB mentioned use a 309 filler rod and tig it all the way around. When you finish, let the purge cool your weld. The Purge gas will keep the oxygen away and prevent oxidation and weld contamination during the cooling process.

 

When I was drilling it I think it moved slightly or my press has some runout because it is not a tight 3/16", probably more something like 7/32 or so. What I was thinking is tap it for 1/4" thread and literally screw down bolts in there so it is a tight fit instead of a 3/16" rod being loose fitting. Then maybe tac the bolts in place so they don't move. Any thoughts on doing it this way?

I don't have a TIG unfortunately, just a 220v MIG setup.

 

Mig won't get it done properly. It will be too brittle as you have experienced. Take it to your friend and let him do it.

If drilled properly , the pins and weld should be sufficient.

I think the bolts will add to the complication of what you're trying to do.

Do I need to do one for you and mail it to you?

 

Well my thinking is the bolts will hold it mechanically in there, using bolts instead of plain rod to make sure its a tight fit. Trying to avoid welding on it at all that will weaken it, but I could weld a small piece between the bolts to keep them from backing out. I think as long as I keep the pulley from spinning on the shaft it will be ok seeing as how there shouldnt be any thrust force.

Friend isnt cheap and is 2 hours away

 

Why not ream it out to the next size pin (or have it reamed at a shop)? What size did the holes end up? If you want a tight fit, you should be using a ground dowel pin and a reamed hole. Like the crank pinning kits use IIRC. Wait, couldn't you buy a crank pinning kit and use only the drill bit and ream? Or just take it to a shop, they should have the bits, reams, and needed pins.

Another option if you're going to try to tap that hole and dont want to weld (remember shaft is much harder than the pulley so it will be hard to do) is to use safety wire on the bolts instead of welding to keep them from backing out.

 

It's not "spinning" it off the shaft. Think about it, its a sheet metal pulley with a very off center mounting hub. When you put a bunch of side load on the hub from being so off center, it literally just pushes it off the hub. The welds you put on there broke because they were very brittle from MIG welding the hardened base metal of the shaft and that sheet metal pulley flexing so much it just cracked them and broke them. Then it was able to just walk the pulley off the shaft. A good TIG weld with 309 would be more then sufficient to hold that pulley on I would think.