How much water to crack a 4.3 block

[Boater31]

Just now getting to my boat for the summer unfortunately. When I winterized last year I decided to go the no anti-freeze route for the first time. I did drain all plugs, poked around for a while and left plugs out for a while. Did the recirc hose to. The engine was as level as I could get. When I put the plugs back in it was dry and not even dripping.

The first thing I did this summer was open the plugs and surprised to see water come out. As you can see by the picture it fills a 16.9oz water bottle about 3/4 full. There was a small fraction that came out the starboard manifold as well but couldn't catch it. The boat is currently tilted toward starboard and that's where a majority of this water came from. The port manifold was dry and the port block accounted for maybe a 1/4 of what you see. The recirc hose had just a couple drops in the very bottom.

I ask if this is enough to cause cracks in the block or manifolds. I would assume this very small amount of water compared to the 2.5 gallons the block holds would be insignificant and wouldn't cause damage. I'm also curious where it came from but I'm guessing condensation caused this to accumulate.

Am I right in thinking I'm fine and keep going or should I pressure test the block.

Thanks

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[Scott Danforth]

you have no picture

also, remember, there are 5 drain locations on the 4.3, each side of the block, each manifold and the intake manifold thermostat well.

you are correct that you can accumulate a fair amount of condensation in teh spring

if your worried, pressure test the water jacket

 

[Bondo]

I'm also curious where it came from but I'm guessing condensation caused this to accumulate.

Ayuh,...... I've been winterizin' dry for Decades, 'n never seen sucha thing,......

Can't buy the condensation thing,......

To answer yer main question, muff it, 'n fire it up,..... you'll have yer answer in a few minutes,.....

 

[Boater31]

Ya yes the picture. Here it is.


​​​​​I have looked for the drain on the intake. I can't find it and the Merc 25 manual doesn't mention it either. I thought the early version had it but the newer vortex and up? didn't have it anymore.

 

[Rick Stephens]

I've been winterizing like that and I do it often in the fall when using the boat for a day and night time temps in the teens. I wouldn't ever know there was water left in the block. I leave all the plugs out, I take 2 off block, 2 off manifolds and one out of the in line by the oil cooler which I added. I pull the lower water pump hose and let er drain. Never an issue.

 

[Boater31]

I ended up pressure testing the block. It didn't hold pressure for very long but I suspect it had more to do with my testing rig then the block. I pressurized it with all the plugs out and oil filler cap off and never heard any hissing around it. I used my rig once before and it acted the same, thought I fixed its problem but guess not. I was gonna run it like Bondo said, but ran a compression test and well, need to start a new thread.

 

[Lou C]

One thing the pre Vortec does not have the drain on the front of the intake but the Vortec definitely does, it might be behind the hose leading to the manifold on the starboard side. The other thing is that the block, heads and intake hold about 2- 3 gallons of water when full so I don’t think 16 oz is enough to crack it as long as it could expand.

 

[Boater31]

Well good news. I ran it yesterday on muffs for 15-20 min, got it all up to temp and then did a oil change. No sin of water in the oil. Guess I doged that bullet. I still wonder where the water came from or it's normal.

I also found the plug on the intake. It's a square metal plug that still has fresh undisturbed paint on it that looks like it hasn't moved since it was put in. Like I said before the manual never mentions this plug and it isn't the blue plastic like the others are. So I'm kinda confused now, should this plug be coming out every year, would I need a sealent to put it back in since it's metal to metal. If it should be coming out every year why isn't it in the book or look like it's moved in the past 20 year's?