Mercruiser 350 5.7 Block Cracked Need to replace

[No show]

I am new to this forum or any forum for that matter so forgive me because I am not too sure how to navigate in forums. I will also post picture of crack and above the crack looks like another one on the head but it isn't also I wanted to post a pix of a really cool boat we put in the ocean at work yesterday
My crack almost seems like a buckle out like a little lip. I wanted to peg it with pipe plugs and pipe dope but I don't think it's possible. It's almost like a long hole. I think I'm screwed on this one. If it was a midway crack without a lip out I would attempt to peg it . It's also just too close to heads. I am supposed to look at a motor tomorrow basically a short block with roller lifters supposedly under 50 hrs, Has heads and aluminum manifold . Yes a marine engine. I'm pretty much of a part changer rather than a mechanic.But I think I can handle this one But the only way for me to have these toys is to lay down on my back and fix myself . It would be really nice to lay down several thousand and take to a Marina but that is not an option.
The guy wants around 800. for motor and he wont budge He says this is a give this ain't no car engine.
Any advice on the swap I already got the Throttle and choke cables off labeling and putting nuts back where they came from, Disconnected power cable most stuff in visible site. I have to disconnect power steering and fuel line. I have exhaust elbows off and basically going to move to the back of motor. not to mention the mounting bolts. the back is my concern. the alpha drive is off. He mentioned something about being careful with coupler?? I just don't want to screw this up. I have the kids swing set I built that everyone wants gone. LOL and a 2000lb electric winch. Any guidance would be greatly appreciated. Any advice what to look for on this motor too

 

[JustJason]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

The crack in your picture is definitely not repairable. As far as a long block goes. 800 bucks isn't bad at all for a long block.
However..... Your going to want to have this engine on a cradle (not a stand but a cradle) and your going to want to pull all the plugs and check the compression. After that your going to want to run the engine and have a listen to the bottom end with a stethoscope. After that it's still a crap shoot at best. Does this guy have any reciepts of where he got the motor? 50 Hour s and 500 Hours can be the same thing to a seller sometimes.

 

[Bondo]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

Caution,.... Double Post....

I am new to this forum or any forum for that matter so forgive me because I am not too sure how to navigate in forums.

Ayuh,.... Go to your previous post,+ Repost on It,...
That'll bring it back to the top of the forum,...
And,...
We won't have to reread the same post, about the Same Problem...

 

[littlebookworm]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

I suggest you pick up a service manual to guide you through. Make sure the engine you want to buy will fit. Some have a one-piece rear seal and some have a two-piece. They are not easily inter-changeable. If you've got all the wires, fuel lines, and cables disconnected, you're well on your way to pulling the engine. In the rear, you have two long bolts to the rear mount of the bell housing. They go vertically. They may be very tight, but hopefully you can loosen them relatively easily. There are two lag bolts on the side of each front mount. Remove them. It's easier to pull and re-install the engine with the mounts attached. Hook up your chain and lift slowly. Look for any wires, etc. that you forgot to disconnect. To install, just reverse the process. The coupler is attached to the flywheel and should not be a problem. You need to replace the double wound lock washers and fiber washers at the rear mount. You will also need an engine alignment tool to set up your engine once it's installed. It's available on ebay and some rental places. Again, a service manual will help. Be VERY careful when you have the engine in the air. A swing set is not strong or sturdy enough to lift one. Rent an engine hoist for the day. Make sure it can raise an engine high enough to clear the transom. I've done two of these already, as well as over 50 auto engines over the years. Let us know how it all works out. Be careful and good luck. Hy

 

[Cptkid570]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

Very good and recent thread on here about installing a remanufactured long block into your boat... may be a good read for you:

http://forums.iboats.com/showthread.php?t=293289

fyi -- rapido marine is a place out of Miami that sells remanufactured marine engines.. they will ship them anywhere http://www.rapidomarine.com/

 

[No show]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

I suggest you pick up a service manual to guide you through. Make sure the engine you want to buy will fit. Some have a one-piece rear seal and some have a two-piece. They are not easily inter-changeable. If you've got all the wires, fuel lines, and cables disconnected, you're well on your way to pulling the engine. In the rear, you have two long bolts to the rear mount of the bell housing. They go vertically. They may be very tight, but hopefully you can loosen them relatively easily. There are two lag bolts on the side of each front mount. Remove them. It's easier to pull and re-install the engine with the mounts attached. Hook up your chain and lift slowly. Look for any wires, etc. that you forgot to disconnect. To install, just reverse the process. The coupler is attached to the flywheel and should not be a problem. You need to replace the double wound lock washers and fiber washers at the rear mount. You will also need an engine alignment tool to set up your engine once it's installed. It's available on ebay and some rental places. Again, a service manual will help. Be VERY careful when you have the engine in the air. A swing set is not strong or sturdy enough to lift one. Rent an engine hoist for the day. Make sure it can raise an engine high enough to clear the transom. I've done two of these already, as well as over 50 auto engines over the years. Let us know how it all works out. Be careful and good luck. Hy

Thank you all for your response. well I jumped the gun and bought the motor today. The swing set I built is pretty heavy. I dont know how we are going to lift it . I do have engine hoist available but I think the back of the boat is too high it won't clear it is aprox 64" to ground. I have the manual and have been reading it.the numbers on back of block are 39700100 I believe is 69-85/86 Chev whats coming out is Mercruiser A680678 . Hopefully the seal is the same. My fingers are crossed my life is a crapshoot, I got to stop taking my stupid pills. Didn't give compression test, The guy who sold it to me said he would swing by and give a hand I'm hoping for the best

 

[Cptkid570]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

I used a comealong (wench) to hoist the engine out of my boat:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=30329

you can find them at any hardware store..

 

[wca_tim]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

I may be out of place saying anything because I've done it in the past (before I knew better). Please don't use a come along to lift an engine. There are just too manay ways one can break or be released unintentionally. The difference in cost between using a cheap chinese made comealong and renting an engine hoise or at the least a good chainfall is not worth the risk of dropping the engine through the deck or bottom let along hurting or killing yourself or one of your family or friends...

 

[coastalcruiser]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

The best thing is to rent a chain fall style of hoist.

good idea

 

[Cptkid570]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

when I used a comealong, I also used a safety rope and probably spent more time keeping the safety rope adjusted than I did actually wenching up and down the engine... Not saying a comealong is the way to go, just saying that I was very careful about it..

 

[coastalcruiser]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

in my case if you look at the 8' ladder for reference.there is no way I would want to mess with a come along.
The chain hoist allows you to stand clear. If it falls you wont be falling on top of it...

 

[No show]

Re: Mercruiser 350 5.7 Block Cracked Need to replace

I may be out of place saying anything because I've done it in the past (before I knew better). Please don't use a come along to lift an engine. There are just too manay ways one can break or be released unintentionally. The difference in cost between using a cheap chinese made comealong and renting an engine hoise or at the least a good chainfall is not worth the risk of dropping the engine through the deck or bottom let along hurting or killing yourself or one of your family or friends...

Don't worry I bought a chain hoist today, Not using a electric winch.