Water Pumps

[Bryan]

59 minutes ago, Matt Wilson said:

My understanding is that people in this situation tap the holes in the block so that a plug can be screwed in there, with some sealant on the threads, of course.  This prevents coolant from going through the internal bypass passages.  They then install the external bypass water outlet (thermostat housing) on the head, with the small bypass hose that accompanies such a setup. 

 

I believe one of George Ashe's sons told me that's what George does in these situations, and that's what I'm planning to do with the 251 that I'm coverting to a 265.  I plan to use the external bypass pieces from my old 230 engine. 

 

In the photo below, you can see that I tapped both the vertical hole and the horizontal hole.  I expect to use the plug in only one of those holes, but I tapped then both to give myself flexibility.  I used a 1/2-13 tpi tap.  I may have had to drill the hole to the correct size first, so it would tap more easily, but I don't recall for sure.

Thanks..I just came from the garage and measured the front of the hole. It's exactly 0.4375" or 7/16 smooth.  Which would get a 1/2-13 plug. The hole on top of the elbow was a little larger.  I also was cleaning the threads up on the hole next to it for the water pump..someone bunged the threads up.

[Bryan]

On 4/2/2022 at 4:13 PM, Matt Wilson said:

My understanding is that people in this situation tap the holes in the block so that a plug can be screwed in there, with some sealant on the threads, of course.  This prevents coolant from going through the internal bypass passages.  They then install the external bypass water outlet (thermostat housing) on the head, with the small bypass hose that accompanies such a setup. 

 

I believe one of George Ashe's sons told me that's what George does in these situations, and that's what I'm planning to do with the 251 that I'm coverting to a 265.  I plan to use the external bypass pieces from my old 230 engine. 

 

In the photo below, you can see that I tapped both the vertical hole and the horizontal hole.  I expect to use the plug in only one of those holes, but I tapped then both to give myself flexibility.  I used a 1/2-13 tpi tap.  I may have had to drill the hole to the correct size first, so it would tap more easily, but I don't recall for sure.

Bought the tap. Finding a straight plug took a while.  Amazon, Ebay etc kept showing NPT plugs that I didn't want. Finally found this.  https://www.tractorsupply.com/tsc/product/hillman-socket-set-screw-1-2-in-13-x-1-2-in?cm_vc=-10005

[Matt Wilson]

Glad you found it.  I have one somewhere around here.  I hope I can find it when the time comes to assemble everything.  If not, then now I know where I can find one, thanks to you.

 

Be aware that tapping that hole was a bit of a challenge for me.  Not that bad, mind you, but I remember having to work the tap back and forth (clockwise & counterclockwise) over and over, advancing little by little till I reached the end of each hole.  I guess the cast iron was resistant, but I eventually prevailed.

 

Good luck!

[Bryan]

The tap I bought went quickly.  I didn't like the plug I bought with an allen head fitting, the allen hole was too deep and it looked like about 1/8" metal thickness to the back. So I adapted a bolt. Started with a grinder, then dremel, then a hand file and sandpaper on a glass block to finish it. 

[Bryan]

Looks easy, but I took that screw out about 15 times to work on it. Didn't want to grind with it in the block. I'm going to find if I kept my old water pump also, and see if I can switch the rear plate with the new one I have. Need to find or make a gasket.

Edited April 7, 2022 by Bryan

[Bryan]

Does anybody know what THIS hole is for?    Little hole in pump that goes directly to big hole in block.  It's not the bypass hole I just plugged.

[TodFitch]

2 hours ago, Bryan said:

Does anybody know what THIS hole is for?    Little hole in pump that goes directly to big hole in block.  It's not the bypass hole I just plugged.

Don’t know but they thought it was important enough to have on all the water pumps going all the way back to at least 1933.

[JBNeal]

the small hole in the water pump backing plate acts like a nozzle that directs pressurized coolant into the water jacket on the distributor side of the combustion chambers.  This and the distribution tube action allow the combustion chambers to be completely surrounded by coolant.

[DStaack]

This information has been a great help to me. I started to pull my water pump a few days ago as the pump was leaking pretty significantly. I learned I have a internal bypass and that the previous owner had closed the bypass on the water pump side but left open the pump on the block side. The internal bypass is filled with a lot of crap and as I started to clear it out I am realizing that I will most likely need to pull the head to make sure all the dirt and such isn't a bigger issue. 

 

My question is more to clarify that I understand what is being said. The internal is the better way to go from what I understand but if I can't clear all the crap out of it and go to a external I need to make sure to close the internal bypass on both sides and then just purchase the stuff to switch to a external bypass?

 

This is what was running on the truck previously as they had close the pump side and just ran a hose from the top of the water pump to the heater control in the rear of the block. Is there anything i should do concerning the corrosion in the block or the amount of crud in other parts of the motor. I added a few pictures to let you have an idea of what I am looking at. 

[tcouch]

DStaack, what did you do with your engine?