5.7 omc dead.......or can it be saved

[markindaytona]

previously posted topic about overheating and steam on my 5.7 litre OMC, replaced manifolds, risers, pump,impeller, hoses belts, you name it its new. flushed the heck out of it front to back back to front got good bit of rust sand etc out,Still ovwerheated, got good jet of water from Stbd exhaust only steam from Port exhaust. Took it back to dealer they found water(fresh water) in engine says they are trying to save it, pulling it as i type. plugs on port side were wet thats where he says water poured out from when he pulled plugs,I have asked all along abouth the head and gaskets he swore it coud not be that.is it possbile to save engine ???? is this hydrolock, am I screwed or what ???? [/LIST]

 

[markindaytona]

Re: 5.7 omc dead.......or can it be saved

boat never made it back to river ran it on muffs at home only, guess that is where fresh water came from ...

 

[navigator336]

Re: 5.7 omc dead.......or can it be saved

Dealer cost on a brand new 5.7 GM Marine long block is $2500.00 (from the distributor). If you can find a dealer or mechanic with an account with the distributor willing to just take a 10% mark-up, you'll have a brand new engine for $2750.00 which is pretty close to what it will cost to rebuild the one you've got. Retail on the long block is around $3400.00.<br /><br />I don't know whether yours can be salvaged with less than a full rebuild. I supposed it will be a factor of how much damaged was done during the hydro-lock.<br /><br />Hope for the best.

 

[markindaytona]

Re: 5.7 omc dead.......or can it be saved

NAIGATOR AND ALL OTHERS; Dealer pulled engine today heads full of the wet stuff, one of the valves were concave, (cant remember the phrase he used) but he feels that was the root of all the evil, wants to send heads out to get machined, valve job nad magnafluxed ??? also wants to check something at the bottom of engine he feel has a ton of sand in it..cant remember all the mumbo jumbo he was throwing at me..but engine looked bad, none of the cylinders were scored according to his top tech. He is gonna get the boat up and running in the mean time he is redoing an 87 Four Winns Cruiser with a 4. 3 mercruiser i/o he wants to swap me into, says it has been sitting for a year,but claims it is a good boat is molded all over , meanwhile I am trying to figure out if its worth it or if after all he has done to the OMC ( all at his expense ) if he's just trying to hold on to the best deal, any dealers out there what is your thoughts???

 

[Doug Durako]

Re: 5.7 omc dead.......or can it be saved

Go to boattrader.com and other sites and search for the same year, same make, same size boat and motor he is swapping. Do the math. See if he can give you a ballpark total $$ on the 350 rebuild.<br /><br />You are giving up lots of horsepower. What is wrong with the motor and drive he is swapping? Can you get another mechanic's opinion? Don't get in a big hurry.

 

[navigator336]

Re: 5.7 omc dead.......or can it be saved

ddboater's suggestion is a good one. I think the site is actually, "boattraderonline.com". Four Winns makes good boats, but the 4.3 is not as good an engine as the 5.7 (350 chevy motor is probably one of the finest ever - you may dispute this based on your problems!). The 4.3 is essentially the 5.7 with two cylinders lopped off. The basic design was for an 8 cylinder (the 5.7) and GM needed a 6 so that designed it out of the 5.7. The 4.3 has been around a long time now so it must be pretty good.<br /><br />I believe your dealer referred to a sucked valve. If it was an exhaust valve, then you would have water in the cylinder that sucked the valve (I'm not so sure about water in multiple cylinders though).

 

[markindaytona]

Re: 5.7 omc dead.......or can it be saved

MAY HAVE CONFUSED MYSELF ON THE LAST POST, the dealer is rebuilding the 350 at his cost, i had him give me a 90 day warranty on the boat when i bought it so i have only paid for gas, belts i wanted to replace and thats it, he is trying to convince me to take the four winns w/ 4.3 merc and him keep my 22' sunbird cuddy with the 5.7, citing all the problems i have had with it, i think he is trying to keep my bird because the engine is gonna be rebuilt and is the better deal. i just bought the sunbird 2 mos ago, have yet to have a good day on the water with it have been raising hell with him as a result, heads went out to machine shop today, hopefully bird will be flying by the weekend.....meantime he says he'll get the four winns running and see if i want to make the swap....still thing he's trying to screw me

 

[markindaytona]

Re: 5.7 omc dead.......or can it be saved

latest update: dealer wants to put a neew/rebuilt 5.7 in the four winns, is this compatible? winns has a 4.3 mercruiser in it now that is seized, still no pulse yet on the 5.7 omc in the sunbird