Engine Block Drain Plug Alternatives?

[ajkolar]

The drain plug that came in my long block rebuild a few years ago was stuck tight and I could not get it out, that is a whole different story.

At this point I now have a 3/8" hole (actually through the original 1/2" plug) and need something I can use to plug it. I picked up a 3/8" flip top live well type plug, but I am worried it won't hold up and it leaks a little (small drips) through the flip mechanism. Most of the marine / auto drain plugs I have found are 7/8" - 1" or larger. Any suggestions? I want it to be easily removed for winterizing in the fall?

Also, at this point I have very limited room to access the area to try and remove the rest of the original plug, or re-thread the hole, etc. Basically just am in need a a good quality 3/8 plug solution that will hold up, not leak, and doesn't require threads. Thanks!

 

[peanutbay1]

Re: Engine Block Drain Plug Alternatives?

There are 2 products I have used for years for this type of repair.

FIRST;
JB weld. It is a 2 part epoxy that takes about 4 hours to tighten up and about 24 hours to be machinable. I have used this to repair gear cases on dirt bikes,cylinders on PWCs among a bazillion other fixes.

SECOND;
Loctite makes an epoxy "tootsie roll" that you must mead together. It sets hard in minutes and is machinable with in 30 minutes. I have actually repaired jet ski hulls in the Jersey surf on the beach and been back out and riding in an hour. It will cure in water,oil,gas or just about anything and it is also completly chemically resistant.

Your other option is to tap the existing hole to an 1/8npt and plug the plug.

 

[ajkolar]

Re: Engine Block Drain Plug Alternatives?

I am familiar with both of those products, but I would prefer to use an actual plug that can be installed and removed easily... without having to tap the hole due to accessiblity issues...

Would a well nut work for this type of application?

 

[Bt Doctur]

Re: Engine Block Drain Plug Alternatives?

I`m not familiar with any motor using a 1/2 inch pipe plugs for drains.
Most are caller 1/4 inch pipe plugs or 1/8 pipe plugs.The casting in the block wont accept anything bigger.What kind of motor and a pic would be nice.

 

[peanutbay1]

Re: Engine Block Drain Plug Alternatives?

A well nut is a good idea in theory but the well nuts I have used (in a snowmobile windshield app.) are made of natural rubber which gets really soft with heat and I wonder if you will have dripping issues. I would try to tap the hole somehow and plug it. Small pipe taps are usually short so if you could use a short ratchet wrench maybe you could get the hole tapped. This is a tough one.......

 

[bigskiohio]

Re: Engine Block Drain Plug Alternatives?

3/8 hole is to big for 1/8 npt ,move up to 1/4 npt if you can or the jb weld
then drill and tap that or leave it solid.

 

[Bondo]

Re: Engine Block Drain Plug Alternatives?

At this point I now have a 3/8" hole (actually through the original 1/2" plug) and need something I can use to plug it. I picked up a 3/8" flip top live well type plug, but I am worried it won't hold up and it leaks a little (small drips) through the flip mechanism. Most of the marine / auto drain plugs I have found are 7/8" - 1" or larger.

Ayuh,... As noted above,... Your explanation just Don't make any Sense....

Motor Block Drains are 1/4" Pipe Thread....

Get a brass Pipe Plug that fits,+ use That... The kind you can turn with a Wrench...Hex headed...

Some fancy smancy plumbing job with petcocks,+ other crap just get plugged up with Junk from the motor...
You'll Think you drained,+ it'll still be full of water, which leads to Frozen Cracked blocks...

 

[gadget73]

Re: Engine Block Drain Plug Alternatives?

Just remember, pipe size has little bearing on real size. 1/8 pipe is more like 5/16. 1/4 pipe is about 7/16" diameter. Just throwing that out there so we're all on the same page here.

That said. I'd drill the frozen up plug out completely, or at least out enough to accept a 1/8" NPT brass plug. The opening in the block should be 1/4NPT or maybe 3/8" at most.