[Engine Ear]

So far so good. Drove it home with the cap off, no issues . I now have the cap on and it is working as it should. (Pulling water out of the overflow tank) I have yet to drain it and load it up with antifreeze, so I am running straight water in in. If it starts to freeze, I'll plug it in they a predicting 31 degrees for a couple hours on Sunday, lol. I plan to get to it this weekend.My heater core seems OK was plenty warm, I'll get ahold of cummins for the plugs (for future use). Maybe I'll get some brass and make them. ....The Machinery Handbook is your friend View attachment 943350

Great that you made the trip! If you make plugs, brass is a better choice than aluminum. But at the price of brass stock, probably just as well to get Cummins OEM. Yes, the machinery handbook should have all the data for class of fit and thermal expansion. If you're running straight water, might want to consider doing a flush. Cummins is selling a flush that they brag is the best. Cleaners | Cummins Filtration I've never used it.

They used to recommend: "Close the drain valve and fill the cooling system with a mixture of clean water and sodium carbonate. One pound of sodium carbonate is needed for every six gallons of water. Operate the engine for five minutes at temperature above 176 º F. Stop the engine and allow the system to cool. Open the radiator drain valve to allow the system to drain. Fill the system with high quality water. Again, operate the engine for five minutes at temperature above 176 º F. Flush the system with clean water until the draining water is clear. Allow complete draining." Sodium carbonate is just washing soda that can be had at most supermarket laundry detergent section. I've used it, and it seems to have worked. This had been copied off the Cummins web site, but I've not been able to find it lately. Suppose when they started selling their super duper cleaner, they removed the homemade recipe.

 

[bigfish95971]

Check with a machine shop with the one of the plugs and see if they have some just a few thousandths bigger for a tight fit.

 

[Raedwulf]

Here they are and they are in and seem OK

 

[Engine Ear]

A fine looking set of plugs. Nice lathe work.How much did you over size them? And how was this determined?

 

[Raedwulf]

A fine looking set of plugs. Nice lathe work.How much did you over size them? And how was this determined?

I added 1 thous.. to the oversized plugs that I didn't care for the design of, because they had a thin edge and could not be put in flat (But were tight enough to seal). I made them with a wider wall and the flange solved getting them in flat

 

[Antonm]

View attachment 944002
Here they are and they are in and seem OK

Nice work, but why go through the effort and take the time when there are a BUNCH of readily available billet freeze plugs that seal with a rubber O-ring (similar to the way the OE block heater works). Below is just a few examples, but there are a bunch out there and the prices aren't terrible.

Diesel Auto Power Bolt-On Side Freeze Plug

Check out the deal on Diesel Auto Power Bolt-On Side Freeze Plug at Diesel Auto Power

www.dieselautopower.com

Wild Diesel Billet Aluminum Freeze Plug 12v / 24v 89-15 Dodge Cummins #WD307

Check out the deal on Wild Diesel Billet Aluminum Freeze Plug 12v / 24v 89-15 Dodge Cummins #WD307 at Diesel Auto Power

www.dieselautopower.com

89-02 Dodge 5.9L Cummins Billet Side Freeze Plug

Fits 1989 to 2002 5.9L Cummins engine block. Billet side freeze plug features recess for bolt head, includes o-ring freeze plug seal and copper sealing washer with Stainless Steel cap head Allen bolt.Keating Machine Part Number: 010611-1v2

puredieselpower.com

Cummins Aluminum Freeze Plug with bar 89-07 5.9L Dodge

We have the solution for blowing freeze plugs! We now offer billet Aluminum freeze plugs with bar. The bar gets inserted into the coolant passage and allows you to tighten the freeze plug in place.This ensures that the freeze plug WILL NOT blow out under high rpms when coolant pressure is elevated.

puredieselpower.com

 

[Raedwulf]

"Nice work, but why go through the effort and take the time when there are a BUNCH of readily available billet freeze plugs that seal with a rubber O-ring (similar to the way the OE block heater works). Below is just a few examples, but there are a bunch out there and the prices aren't terrible"
well, I had seen all of them and that is what lit the lightbulb ....I had the aluminum and it took Me about an hour and didn't have to wait or lay out any money . I can still put that arm on them if there are any issues but I doubt there will be. We are going to have a hard freeze tonight, so I finished the flush and got antifreeze in it

 

[Antonm]

well, I had seen all of them and that is what lit the lightbulb ....I had the aluminum and it took Me about an hour and didn't have to wait or lay out any money . I can still put that arm on them if there are any issues but I doubt there will be. We are going to have a hard freeze tonight, so I finished the flush and got antifreeze in it

I suspect you're gonna have issues sealing a rigid aluminum plug into an iron block using an interference fit (vice the rubber O-ring all the linked ones use).

Aluminum and cast iron expand & contract at different rates, so there will be some relative motion between them. Relative motion while force is applied (from the coolant system pressure) may cause them to pop out or leak (or crack the aluminum as aluminum expands faster than cast iron).

Whatever happens (good or bad) , please update this thread to let us know how it worked out for you.
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[Raedwulf]

It's been six months and they are still fine. I lost my temp gage a month or so back and need to address that isue It's not the sending unit as I substituted a known good one the wiring to the gauge seems good it has some resistance I suspect the gauge itself. I am going to install a manual set-up

 

[Raedwulf]

A year and no problems