Small block drain pipe extraction

[mavriikk]

Hello all, I am wondering what the best practice is to removing a broken drain pipe that allows you to drain the block at the end of the season.

My thinking is that a bunch of people of have come across this and I just wanted to know the best way to go about fixing it. Is it best to use some type of easy out or should I skip that pipe dream (no pun intended) and go straight to the right angle drill and attempt to tap the hole.

To be specific I am referring to the pipe below the alternator on the starboard side of the engine. It was at one point brass and has a cap on the end to open and drain the block for winter storage. Think its for sale on the moyer site as brass nipple and cap.

What I have done... I had the infamous cooling problems and blockages twards the end of my first season with my C$C 35 mk1. I removed the following and started the cleaning process.

Alternator is off going for rebuild
Starter is off going for rebuild
Side plate is off and clean. (need to start vacuuming the block)
Head is off and clean (I cannot believe how much rust and crap came out of the head. I even had to drill out a few of the water jacket holes. Several Handfuls)
Carb is off and needs cleaning. (Center jet is stripped!)
Cleaned and painted some brackets the list goes on...

I did attempt to un-thread the pipe in question, I was very careful but it turns out the pipe was so blocked that the pipe broke off and the hole still didn't drain anything. The hole it self is blocked shut. I was able to pick at it to get it to drain.

So now the water is drained at least but now I am left with the hole. I have a few ideas but it never hurts to ask for more ideas...

So let em fly... oh, and please leave out JB weld I hope that is not the answer. I would like to actually be able to put a new one in.

Thanks

-Kyle

[msauntry]

Drill it out for the next larger size. It'll be less prone to blockage and the threads are more likely to be in good metal.

[hanleyclifford]

When you tap it out for 1/4" NPT this is what it will look like. Use drill 7/16" but be careful not to go more than 3/4" beyond the hole because the cylinder is very near:

[67c&ccorv]

Which water jacket holes in the head did you have to drill out?

Anyone with me in this? :-o

[HalcyonS]

Been there done that.
Take a look at thread

http://www.moyermarine.com/forums/showthread.php?t=7000

post #17 show the tool kluge I used to recut/clean the thread.

I wouldn't bother drilling out and retapping with a bigger tap. The old one probably lasted 40 years, do you need it to last longer than that?
Just drill out with a drill slightly bigger than the ID of the pipe - ie don't drill away any of the threads in the block! Then get to work with a tapered tap.

[joe_db]

Welcome!
Fellow C&C 35 MK I owner here
Are you on the C&C list?

Hello all, I am wondering what the best practice is to removing a broken drain pipe that allows you to drain the block at the end of the season.

My thinking is that a bunch of people of have come across this and I just wanted to know the best way to go about fixing it. Is it best to use some type of easy out or should I skip that pipe dream (no pun intended) and go straight to the right angle drill and attempt to tap the hole.

To be specific I am referring to the pipe below the alternator on the starboard side of the engine. It was at one point brass and has a cap on the end to open and drain the block for winter storage. Think its for sale on the moyer site as brass nipple and cap.

What I have done... I had the infamous cooling problems and blockages twards the end of my first season with my C$C 35 mk1. I removed the following and started the cleaning process.

Alternator is off going for rebuild
Starter is off going for rebuild
Side plate is off and clean. (need to start vacuuming the block)
Head is off and clean (I cannot believe how much rust and crap came out of the head. I even had to drill out a few of the water jacket holes. Several Handfuls)
Carb is off and needs cleaning. (Center jet is stripped!)
Cleaned and painted some brackets the list goes on...

I did attempt to un-thread the pipe in question, I was very careful but it turns out the pipe was so blocked that the pipe broke off and the hole still didn't drain anything. The hole it self is blocked shut. I was able to pick at it to get it to drain.

So now the water is drained at least but now I am left with the hole. I have a few ideas but it never hurts to ask for more ideas...

So let em fly... oh, and please leave out JB weld I hope that is not the answer. I would like to actually be able to put a new one in.

Thanks

-Kyle

[hanleyclifford]

Which water jacket holes in the head did you have to drill out?

Anyone with me in this? :-o

I'm afraid to ask.

[mavriikk]

Thanks for the advice!

This is what I thought I would get for advice. I just wanted to make sure that there was no tricks.

I will drill out in hopes of using the original hole size and it the **** hits the fan then I will go oversize I guess.

As for the concern on the plugged holes on the head I drilled out. They are the holes that were basically plugged solid with rust in the area between the cylinders. One of the holes looked like it had a permanent plug that belonged, I left that one alone. See attached.

[Blue Eyes]

Broken pipe

A few drops of Liquid Wrench. Allow time to work into the rust, and light taps on the pipe should loosen it. aloha

[Mo]

Welcome!
Fellow C&C 35 MK I owner here
Are you on the C&C list?

Pic of the boat looks real good there Joe!

[sastanley]

mavriikk,

Welcome..I am sure as you get into the motor you will find lots of things to deal with. When I first got my boat, I was astonished when the same aft block drain you speak of, fell off the block into my hand. ..the previous owner (P.O.) had epoxied/marine tex'd/JB Welded it back on to the block. Since it was already out of the block, I drilled mine out & tapped to 1/4" NPT. As Hanley's pic shows..it is close to the accessory drive pulley, but still works OK.

Here is a pic of my engine from a different angle that focuses on water leaking out of newly installed sideplate studs (since solved..old pic) but, shows a 1/4" NPT pipe that is close on clearance but has worked fine, and is solidly threaded in the block.

[hanleyclifford]

Thanks Shawn - Your different angle picture shows how many good possibilities exist for using the accessory drive sheave and that nipple for establishing and checking timing, huge for the Catalina 30 fleet.

[ndutton]

It's my opinion those lengthy pipes, oil pressure sender too, are a liability. I've relocated my oil pressure array (sender, alarm switch and OPSS) to a nearby bulkhead connected with a 300PSI rated hose. The pipe was replaced with a much shorter pipe to hose adapter.

The water jacket drain pipe was removed in favor of a pipe plug.

[hanleyclifford]

It's my opinion those lengthy pipes, oil pressure sender too, are a liability. I've relocated my oil pressure array (sender, alarm switch and OPSS) to a nearby bulkhead connected with a 300PSI rated hose. The pipe was replaced with a much shorter pipe to hose adapter.

The water jacket drain pipe was removed in favor of a pipe plug.

Generally I agree with Neil on this although the 1/4" nipple is substantially stronger than the 1/8" original. Even stronger when supported as part of a cooling system.

[sastanley]

Neil, great point..

At the time I didn't know any better, and I was RWC'd, so the extension kept water from dribbling down the block..however, now that I am FWC'd, I could probably pull the long tube and put in a plug. One issue (as I am sure you know) is the extension requires a diverter of some sort to keep the drainings into the bilge and not on the cabin sole on a C-30.