hydrolock??

JT!

Petty Officer 1st Class
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May 19, 2008
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260
finally got my project boat up & running... I launch at a local marina, travel about 400 yards into the harbour, after crossing wake from oncoming boat I heard some funny sounds. not good I thought.

first it rattled & sounded like it would stall, so I increased the rpm from 700 to 1000, rattling sound went away for 1 second, then clunk.engine stalls

when it stalled, we heard a loud gurgling sound. makes you wonder if you're sinking.
figured it was just air bubbles from the thrust... try to start motor: locked up.
what was that gurgling sound? was that an exhaust system full with water?

called a friend who came out and towed us home.

at the launch, as soon as I pulled the boat out, my son calls for me.
I hop out of the truck just in time to witness the remainder of several gallons of seawater coming from the rectangular exhaust flap below the rectangular anode on the transom shield. (Volvo 290 SP)

that sure seemed like a lot of water to come out of the exhaust?


next I will pull the plugs and crank the engine, and compression test each cylinder (5.7L GM)
at that point I will either laugh or cry.

if it is functional, what can I do to prevent this from ever happening again?

I do not currently plan to pod it and put a large outboard.
 
Last edited:

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Those square ports are idle relief ports. You will get water out of them. My first thought is you have bad gaskets between the manifolds and risers
 

jerryjerry05

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May 7, 2008
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The manifold and connecting parts will hold a few gallons of water.
The gurgle could be nothing.
You should have pulled the plugs as soon as you thought there was water in the cylinders.
Is there water?

New manifolds?
New gaskets?


The "rattle" sounds more like a u-joint or something in the drive train.

Post the results.

You say it's a project?? You only mentioned the drive and nothing about the boat, year, motor and what you did??
 

JT!

Petty Officer 1st Class
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May 19, 2008
Messages
260
well, guess it wasn't hydrolock...

#6 cylinder (2nd from front on port side) has a smashed sparkplug

engine still wont turn over.

so minimum is bad piston & valves, cylinder bore issues, connecting rod, etc
 

JT!

Petty Officer 1st Class
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May 19, 2008
Messages
260
if I look at podding the boat, what size outboard (single or dual) should I look for.

the boat is a 23' fiberglass (as seen in avatar) and it has a small block chevy 350 mated to a Volvo 290 leg. no idea on weight.
 

jerryjerry05

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That size? The minimum is a 200hp single or dual 150's maybe 125's
Where you located?
 

captmello

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Seems like a new longblock would get you on the water in a lot less time with a lot less fabrication...
 

dypcdiver

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Nov 1, 2005
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1,016
Cost of just one outboard would be more than a complete rebuilt 350 GM.
 

jerryjerry05

Supreme Mariner
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Yea I'd get another block.
That's way cheaper than even a used 225 hp outboard.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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you can build a stroker 383 for about $2k New manifolds and risers for another $500. and if you wanted a blower on it and still be under $6k
 
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