EZ Drain Plugs for Exhaust Manifold & Engine Block on 3.0 Mercruiser?

[93 Stingray 556]

Hello All,

I'm a new member, but I've using this for research for a while now. Do you know the size of the threads for the exhaust manifold drain and the block drain? I'm thinking of installing a "EZ Drain Valve (is.gd/q3PIE0)" on both the exhaust manifold and the block. I feel like it would make things a lot easier when it comes to winterizing. However, I need the thread sizes for both locations. I think the exhaust manifold is 1/4" thread and the block might be 3/4". If you have any ideas, please let me know. Thank you in advance for your help!

 

[isaacs]

Hello All,

I'm a new member, but I've using this for research for a while now. Do you know the size of the threads for the exhaust manifold drain and the block drain? I'm thinking of installing a "EZ Drain Valve (is.gd/q3PIE0)" on both the exhaust manifold and the block. I feel like it would make things a lot easier when it comes to winterizing. However, I need the thread sizes for both locations. I think the exhaust manifold is 1/4" thread and the block might be 3/4". If you have any ideas, please let me know. Thank you in advance for your help!

Mine are all the same size (I have a total of five). It's 1/4" pipe thread--these should work just fine: https://www.amazon.com/Manifold-Rep...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

[Rick Stephens]

I think he is wanting to swap out pipe plugs for something plastic. Personally, I would not do that. I buy solid brass plugs and lube/protect the block threads with Locktite Aviation gasket sealer which doesn't ever harden. Just don't get the hollow brass plugs. They break off and cause grief.

If you add that extension that lets you use the plastic plugs you will find they are harder to keep sand and scale out of and you'll spend even more time winterizing.

 

[Scott Danforth]

I would not replace what has worked for well over 70 years for a plastic plug you can not probe with a wire

 

[alldodge]

Hello All,

I'm a new member, but I've using this for research for a while now. Do you know the size of the threads for the exhaust manifold drain and the block drain? I'm thinking of installing a "EZ Drain Valve (is.gd/q3PIE0)" on both the exhaust manifold and the block. I feel like it would make things a lot easier when it comes to winterizing. However, I need the thread sizes for both locations. I think the exhaust manifold is 1/4" thread and the block might be 3/4". If you have any ideas, please let me know. Thank you in advance for your help!

Can install the plastic ones which does make it easier. I have them on my motors

 

[Lou C]

This style has worked great for me for many years...

 

[Rick Stephens]

This style has worked great for me for many years...View attachment 329132

Hey Lou, can you easily get a wire through those? Just wondering. They been around forever.

 

[Bt Doctur]

once you remove the plug a wire/nail/screw is easily inserted to clear the drain
Typically the block is 1/4 inch pipe and the manifold is 1/8 inch pipe plugs

 

[Lou C]

Hey Lou, can you easily get a wire through those? Just wondering. They been around forever.

You can but how they work is that there is a hole thru the sides of the part with the wingnuts as you unscrew them (not all the way through to the end) it unseats from the part that is threaded into the block and the water flows round the holes in the sides and out the center hole. I always take them out and poke the hole in the part that's threaded into the block. The last couple of years for whatever reason they have not clogged with rust flakes and have drained well even without rodding them out but I still take em out to make sure. I like these because they are basically unbreakable, the threads don't strip and if you drain with the engine still warm (140* water coming out) you can just loosen, let drain and cool off then remove when it has cooled off to poke the hole. I use Evinrude gasket sealer on the threads to prevent leaks, they always come right out.

I have a spare pair left over from when I had the OMC one piece manifolds, if I can find them I'll unscrew the plugs from the fitting that goes in the block and take a pic. Just like these but with the wingnuts.

 

[Lou C]

In some applications the Merc ones with the hex might actually be easier to remove, since you could use a box end ratcheting wrench to loosen them, I usually have to use a small adjustable wrench to loosen them.

 

[Rick Stephens]

In some applications the Merc ones with the hex might actually be easier to remove, since you could use a box end ratcheting wrench to loosen them, I usually have to use a small adjustable wrench to loosen them.

I guess I don't see any advantage over a regular solid brass plug. Same amount of work... I get it that what you have works. So do these with same amount of labor.

 

[93 Stingray 556]

Thank you all for the good comments. I am afraid that my original link for the EZ-Drain didn't work. Here's what I was talking about:

Featured Products

EZ Oil Drain Valve- The Easiest Oil Change!

www.ezoilchangevalve.com

I suppose the problem raised would be losing the ability to use a wire to clear obstructions (rust, dirt, etc.) during winterization.

IF I wanted to give this a shot, would this one work for the block:

EZ-115 [Thread size : NPT 1/4"-18]

EZ Oil Drain Valve- The Easiest Oil Change!

www.ezoilchangevalve.com

If 1/8" is the manifold drain thread size, it looks like they don't make one for that size. I imagine if I wanted to try this system, I would have some sort of an adapter to a larger thread size.

Thanks for the good info!

 

[zellerj]

I think your ez drain plug idea would work fine. They are ball valves, and you should be able to snake a wire or a nail up the valve to clear crud away so you can be sure to get all of the water out. You need a 1/4 inch NPT thread. You need to remove the fitting that is directly into the block. These are pretty tight so I suggest using a six point socket so that you don't round the corners of the head. I did the same thing with a brass ball valve.

 

[93 Stingray 556]

Hello all,

It's been a while, but I thought I would update you on what I actually went with for this project. I sourced a 1/8" Arita ball valve for the Exhaust Manifold:



This valve works great!

The engine block drain plug was more difficult. I tried to use a 1/4" EZ Drain Valve, but I was unable to tighten it due to the proximity of this flange:



I tried a 1/4" Arita valve to see if it would be different, but I had the same problem. I even thought of using some sort of 45 or 90 degree extension, but I worried that I would not be able to snake a wire through it in case of debris issues.

I finally decided on a Sierra 18-4218 Drain Tap similar to what Lou C recommended earlier:


I wish I could have put a different drain on this one, but I think the Sierra Drain Tap will work fine. The whole reason for going through this exercise was to try to install something that was "tool free," so the winterization process could be a little easier.

Thanks again for everyone's input. I hope this solution helps others who might be looking for a similar solution.

Best,
Paul

 

[Scott Danforth]

see post #4

 

[93 Stingray 556]

Well, I never planned to replace it with a plastic plug in the first place. I thought the system had room for improvement. Sheesh.

 

[Scott Danforth]

If you cant probe it to move the rocks, sand and rust flakes so it can drain, its not an improvement

 

[93 Stingray 556]

Well, I never planned to replace it with a plastic plug in the first place. I thought the system had room for improvement. Sheesh

If you cant probe it to move the rocks, sand and rust flakes so it can drain, its not an improvement

Ok great. Thanks for the tip.

 

[truckstop]

Hello all,

It's been a while, but I thought I would update you on what I actually went with for this project. I sourced a 1/8" Arita ball valve for the Exhaust Manifold:

View attachment 354200

This valve works great!

The engine block drain plug was more difficult. I tried to use a 1/4" EZ Drain Valve, but I was unable to tighten it due to the proximity of this flange:

View attachment 354201

I tried a 1/4" Arita valve to see if it would be different, but I had the same problem. I even thought of using some sort of 45 or 90 degree extension, but I worried that I would not be able to snake a wire through it in case of debris issues.

I finally decided on a Sierra 18-4218 Drain Tap similar to what Lou C recommended earlier:
View attachment 354202

I wish I could have put a different drain on this one, but I think the Sierra Drain Tap will work fine. The whole reason for going through this exercise was to try to install something that was "tool free," so the winterization process could be a little easier.

Thanks again for everyone's input. I hope this solution helps others who might be looking for a similar solution.

Best,
Paul

What, if anything, did you put on the threads? And did you use a ratcheting wrench for install or something else? Thanks!