does anyone know?

Bondo

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ok, i just pulled the drain from the block. very nasty stinky water. also noticed that the petcock has a needle and screw in it. and the actuall sleeve is there for it to fit into .... 3rd and fourth pic is from the exhaust manifold. video shows the water
Ayuh,...... Toss that thing, 'n go with a brass 1/4" pipe plug,.....
 

dubs283

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Agree w/Bondo, use brass 1/4 pipe plugs in the block and manifolds.

If you have access chase the threads in the block/manifolds. Perfect seal or a quality gasket sealer on the plug threads going in helps prevent corrosion and makes annual removal much easier.

Don't install too tight, just snug enough to prevent leaking, you'll thank yourself in the fall when you remove them
 

dingbat

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Ayuh,...... Toss that thing, 'n go with a brass 1/4" pipe plug,.....
No brass on a boat. Bronze only

Brass is roughly 34% zinc. Will be eaten away the same as your zinc anode.

Bronze is alloyed with tin.
 

dubs283

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No brass on a boat. Bronze only

Bronze on any through hull fitting that is below the water line

On engines and accessories dealing with raw water delivery after it has passed through the hull brass is acceptable.

Have you ever worked on current/vintage marine engines? Quite a bit of brass fittings are installed oem
 

dingbat

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Bronze on any through hull fitting that is below the water line

On engines and accessories dealing with raw water delivery after it has passed through the hull brass is acceptable.
Acceptably to who?

Professional Boat Builder doesn’t seem to think so.
Many are unaware of the important distinction between brass and bronze, and prohibitions for use of the former in raw-water systems.

Have you ever worked on current/vintage marine engines? Quite a bit of brass fittings are installed oem
Have 9 thru hulls, 4 of which are below the water line, plus 2 seacocks and a garboard plug on my boat… all bronze.

Ten wrongs don’t make a right
 

dubs283

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Have 9 thru hulls, 4 of which are below the water line, plus 2 seacocks and a garboard plug on my boat… all bronze.

Far out, read the first line of my post #24


I don't read any argument of your post in regards to anything installed on engines/accessories

Let's go one step further and demand all engine blocks/manifolds that use raw water for cooling must be bronze and not cast iron
 

1975oday22

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Sep 2, 2022
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so far i am confused. consencus here says brass. i have no through hulls, just the 2 drains . both are on engine. . omc 3.0l gm engine that is. stringer 400 outdrive. either i find one that fits the exhaust manifold. or i will go with option 2 wich i believe Bondo has suggested. thanks for the help in this matter guys . dont need a huge debate. if it was just up to me i would just weld the damn thing shut. but not advisable. lol...... or go with a full blown car engine that has the rad and fan ..... that would work just as well. lol but without funds for the high end stuff thats a pipe dream
 

dubs283

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thanks for the help in this matter guys . dont need a huge debate.

Apologies for the rant, sunray. These posts are often used for reference/posterity so misinformation only fuels mistakes/unnecessary repairs

In your case you are not dealing with any through hull fittings so bronze shouldn't be an option.

Brass, as suggested by Bondo and based on my knowledge/experience is the material you should use. It's readily available in the size you need at a majority of local hardware stores at a reasonable price
 

Lou C

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I have those exact same drains on my 1988 OMC/Chevy V6 and if you’re going to try to get this not to leak be careful with the threads. I would pick up a Mercruiser drain plug assembly & use that; it’s nearly the same thing but the part you remove to drain is a hex head instead of the T handle. I put gasket sealer on the threads when I put ‘em back in after draining & they don’t leak & always come out.
 

therosses5

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My exhaust manifold drain plugs are leaking as well. Why do they come with the hole in them if a regular drain plugs work?
 

1975oday22

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well instead of having to order this plug i decided to do an experiment . so far i had a big enough bolt to go into the hole at the bottom of the wingnut . so i have gone ahead and packed the hole with red hightemp rv gasket. then put the bolt back in . its now sitting to cure up . i will put it back in late tonight and see what the verdict is.
 

1975oday22

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well my idea works. red hightemp rv gasket and a bolt in the t shaped piece works to stop the water from exiting the manifold. so now i will leave it at this.
 
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