Looking for large rubber plugs that I can block the thermostat on an OM617 with
 

Looking at the coolant diagrams for the OM617, I see that coolant does not flow into the radiator until the engine hits ~82 C. Since I would really like to run the engine I pulled from long-gone '84 300D, I'm wondering if anyone can give me any ideas on where I could find large rubber plugs to plug the openings on the thermostat housing that go to and from the radiator. I would just loop it on itself, but the silly thing uses two differently-sized hoses... :rolleyes:

On a slightly related note, would putting some Kroil into each cylinder be a good idea if the engine has been sitting for 2-3+ years since it last ran? If so, how much Kroil should I use per cylinder?

Further research shows that my solution may well be at the local Sears Hardware... right where I need to go anyway. I'll report back with my findings.

Widgetco dot com

They have what are called Test Plugs for plumbing. They have a T handle or a Bolt Head and you turning the Handle squeezes a thick rubber ring between to Steel Washers (they have plastic ones but due to heat better off with Steel) and that expands the Rubber.
Local Hardware stores have them.

PhillyTwoTank -- Wow. That looks like the mother lode. I'll order from there if I can't find something locally.

Diesel911 -- Thanks for the tip! I'll see if I can get some.. those would certainly be a more desirable solution, as I wouldn't have to find some way to secure them to make sure they don't pop out.

I'll post pictures when I get this set up.

Yuup. I ordered a whole range of rubber stopper sizes from there a few years ago. Has definitely come in handy on numerous occasions.

how long do you intend to run the engine? just to see if it starts and runs, you don't really need a cooling system just for a test fire.

No need for coolant if you are only running the engine for less than a minute. Any more than that, you can pull the thermostat, leave the gasket in there and just let a garden hose run some water through it.

People usually suggest MMO in the cylinders. You can put any amount in as long as you crank the engine over a few times with the injectors out before you run it. Don't fill the cylinder but a few table spoons should be OK.

Better yet, plug the lower port (inlet) and fill the engine with water. Engine can be run until water starts to boil (which will be a while).

I used 1/4 cup into each cylinder on the Volvo. And, it cured the wispy gary smoke I had been having all of the time.

I did a image google search for a pic of the test plugs and they also showed a rubber pipe Cap with a Clamp. That made me thing of other things I have seen.
I have seen People use the Stock Radiator hoses and cut a piece of cylindrical Wood and stuff that into the Radiator Hose and clamp it. Liquid eventuall seeps through the Wood but it is good enough for a temp testing.

The small Pipe End Test Plugs usually just have a Wing Nut to expand them.