350 Sbc.....

mrvette

mrvette

Phantom of the Opera
Joined
Mar 24, 2008
Messages
15,207
Location
NE Florida
Iron heads in a boat, rebuilt as noted on DC last season, my buddy went down on a bike accident, and layed up for 3 months off work....we finally get the new engine into the boat last fall....so about ONE decent trip on it, and so I find out today, the last decent time it ran was Febuary....

NOW we pull it out Wed nite, and so we find a valve head in the crank case, hole in the pan, tons of metal all over the joint, and obviously the engine locked up and the sump full of seawater, which we knew already....

engine shop took about ten days to look at it, and so they said it was locked up....yeh, no SHIT sherlock,.....

so anyway in hell anyone here know of any possible method a Mercruiser Alpha ONE outdrive/exhaust system can cause a problem enough with water flow or anything not noticed on gauges....to cause a VALVE HEAD to come off the stem, and wind up in the sump???

I can't....neither can anyone else....keeper/retain failed.....running rough or hard start was a carb problem I think, the oil looked GOOD, we are all really papanoid over this boat, not even named yet....but it's earned the name PARIAH.....


:rolleyes::devil::devil:
 
For a valve face to end in the sump, you need a hole in the piston or a hole in the cylinder wall.

A hole in the oil pan?
 
Belgian1979vette said:
Twin_Turbo said:
For a valve face to end in the sump, you need a hole in the piston or a hole in the cylinder wall.

A hole in the oil pan?
Click to expand...

That's what I was thinking also. Looks like there is a mayor wreckage in there.
Click to expand...

OH Christ YES, goodly chunks of metal all OVER the pan, and a gash next to the failed cylinder in the pan, near the skirt...about an inch long....

I figger a keeper/retainer went, dropped the exhaust valve and toasted the piston, it's obviously piston aluminum parts...many of them from rings down to skirt sections....plus of course that exhaust valve head that was actually missing about 30% of it's circumference...with that section torn out by the piston hitting it....we have both sections of it.....

so the question IS, is it possible any leakage from sea water getting into the cylinder could cause that valve to break and cause the problems?? I say NO, on account of even IF the cyl had enough water to cause hydraulic lock, the valve would be closed, and undamaged, NOT broken off and in pieces....

:stirpot:
 
The water flow from a MerCruiser is thru the cavitaiton plate to the water pump up thru the outdrive and into the engine. Any leak in the outdrive part of the system would cause overheating- if you stretch your imagination a bit, it's the radiator--

Enough water to cause a hydraulic lock would first bend a rod and then who knows what else- but the valves would have to be closed as you said. If it dropped a valve, then the carnage would be bad. Piston, Head, cylinder wall just for starters..
 
Toss that POS and get a cheap GM crate. When they hydro, it trashes it all.
 
big2bird said:
Toss that POS and get a cheap GM crate. When they hydro, it trashes it all.
Click to expand...

Yeh, I hear you, but at this point it's back to the local machine shop, and I dunno IF GM sells MARINE engines at all, let alone for the some 3 grand Eric has tied up in this nitemare.....

WE never pulled the heads or the valve covers...so we just don't know any more than the obvious valve head in the junk....and the water in the sump....which we drained about 5 gallons out of it....

friggin' crap, no end in site, and too boot the neighbor across the street and up a bit...he has a ~26' er with a 225 hp Mercury engine V6, last year he put in a piston and whole bunch of cleanup crap...lasted about a couple times running....

gone again...this time he putting in fuel injectors....and a oversize piston...the 15,000 repair bill he was quoted, and I shit you NOT on that price, was way the hell over what ANY similar outboard is worth.....

hell, even NEW....bunch of BULLSHIT.....

so anyway, here are two friends close by who have bad Mercury Marine products and tons of failures this summer....

which is a DeJaVU repeat of some 35 years ago, another Mercruiser buddy up north and him battling his boat....

:cussing::cussing::cussing:
 
GO cheap. Put a GM crate engine in there. THe difference is the boat stuff say "Marine" on it and B-O-A-T is short for break out another thousand. I've seen MerCruiser parts come in GM bags with the Merc label over the GM part number. And the Merc part was anywhere from 15 to 25% more. The only things you need to put on the crate that are not GM is the outdrive coupler and the seawater pump.
 
TimAT said:
GO cheap. Put a GM crate engine in there. THe difference is the boat stuff say "Marine" on it and B-O-A-T is short for break out another thousand. I've seen MerCruiser parts come in GM bags with the Merc label over the GM part number. And the Merc part was anywhere from 15 to 25% more. The only things you need to put on the crate that are not GM is the outdrive coupler and the seawater pump.
Click to expand...

The seawater pump is in the outdrive feeding that 1/2 inch copper water pipe up top to the host into the engine....then past the manis and into the normal automative?? water pump...NO?? is there a differance in the front mounted engine water pumps?? didn't seem so, and we were very careful about any overheating....VERY careful...

:ill::ill::huh:
 
TimAT said:
GO cheap. Put a GM crate engine in there. THe difference is the boat stuff say "Marine" on it and B-O-A-T is short for break out another thousand. I've seen MerCruiser parts come in GM bags with the Merc label over the GM part number. And the Merc part was anywhere from 15 to 25% more. The only things you need to put on the crate that are not GM is the outdrive coupler and the seawater pump.
Click to expand...

Yepper. That's the ticket.
 
You might want to install a Marine cam in that motor,i have herd from a good source that they are the part to go with :tomato:


:stirpot:
 
mrvette said:
TimAT said:
GO cheap. Put a GM crate engine in there. THe difference is the boat stuff say "Marine" on it and B-O-A-T is short for break out another thousand. I've seen MerCruiser parts come in GM bags with the Merc label over the GM part number. And the Merc part was anywhere from 15 to 25% more. The only things you need to put on the crate that are not GM is the outdrive coupler and the seawater pump.
Click to expand...

The seawater pump is in the outdrive feeding that 1/2 inch copper water pipe up top to the host into the engine....then past the manis and into the normal automative?? water pump...NO?? is there a differance in the front mounted engine water pumps?? didn't seem so, and we were very careful about any overheating....VERY careful...

:ill::ill::huh:
Click to expand...

Yep. The seawater pump is in the outdrive- most of the time. If it's a closed cooling engine, then there is a pickup thru the hull and a 1-1/2" line from that fitting to a pump, (looks like a dry sump oil system), and a heat exchanger. The normal open cooling system picks up thru the outdrive (seawater pump) and then into the normal automotive style water pump, circulates it thru the block and past the t'stat and sends it thru the wet manifolds overboard.

It sounds like you had a plain old fashioned "dropped a valve" event.
 
TimAT said:
It sounds like you had a plain old fashioned "dropped a valve" event.
Click to expand...

that was MY thought also....

can't win....

:eek::surrender:

Oh, edit, to show how familiar we are with this boat.....from time to driveway pull up, to engine in the pickup ready to go to shop....
22' Chaparral now....transom about 6' off the deck.....

2 hours FLAT Eric and Johnny in the boat, ME doing schlep work for tools....not so awful evil....

obviously the carb, linkage and exhaust manis totally taken apart.....

and the flywheel in my garage sitting there looking all rusted up and sad....

seawater, boats, aluminum, iron, cooling,

time to bring in stainless and MONEL....

corrode THAT muvva fockers....

....GRRRRRRRRR....
 
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Wasn't that the motor they used in the first Bat Mobile? And the 2nd Bat Mobile? And the current... Bat Mobile? :D
 
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