Engine rebuild

[BeniR]

Hi

I?m new in boating and I need your help


I have this boat back home(Montenegro) and this year one of this engine snap the camshaft in half I would like to know what parts I have to buy to rebuild the engine ?

And what?s the HP on this engines

p.s if I like to buy 2 new diesel engine what kind of engine they will fit ?

I appreciate all your help
Thank you
Benny

 

[Bondo]

Re: Engine rebuild

View attachment 217408
View attachment 217409
View attachment 217410

Hi

I’m new in boating and I need your help


I have this boat back home(Montenegro) and this year one of this engine snap the camshaft in half I would like to know what parts I have to buy to rebuild the engine ?

And what’s the HP on this engines

p.s if I like to buy 2 new diesel engine what kind of engine they will fit ?

I appreciate all your help
Thank you
Benny

Ayuh,.... Welcome Aboard Benny,.... Ya gotta tear the motor down, inspect all it's pieces, 'n then replace the bad parts,...

No way to do that from here,...

As for goin' with Diesels,... None will mount, 'n run with yer drivelines,...
'course, I'm assumin' ya got Alpha 1 drives behind the 4.3s...

 

[alldodge]

Re: Engine rebuild

:welcome: to iboats

HP is about 180 for 2bbl and 190 for 4bbl

Probably would be better to just replace it with a new long block

 

[littlebookworm]

Re: Engine rebuild

Snapping a camshaft is not easy. The only time I ever saw that happen was decades ago when I worked in my father's auto shop. The timing chain on a Chevy smallblock had snapped at highway speed, locking the cam. That engine was shot and had to be replaced. What caused your cam to break? You need to tear down the upper part of the engine and examine the upper block extremely carefully to see if your engine can even be saved. If nothing major is broken, you then have to see what needs replacement New cam bearings are obviously in order, and, depending on the configuration of your engine bay, you may or may not be able to get a cam bearing puller/installer in place with the engine in the boat. Hy

 

[jcbache]

Re: Engine rebuild

I've seen plenty of bent pushrods and a few busted rocker arms, but never a snapped camshaft.... I'd like to see a picture of that.

 

[harleyman1975]

Re: Engine rebuild

I am wondering if he maybe broke the crankshaft and is just using the wrong english term. Looks like perhaps English is a second language for this gentleman. Possibly from someplace other than the U.S. may make obtaining a new/rebuilt longblock cost prohibative. So Benny are you certain it is the CAMSHAFT that broke? Have you disassembled the engine yet? Which engine is it...port or starboard? Is there enough room to service engine in boat or will you need to remove it?

 

[Walt T]

Re: Engine rebuild

The cam broke because the engine got frozen and pushed the cam journals out of alignment which then cracked or bent it. Crank or start and it will break at the new weak point.

 

[BeniR]

Re: Engine rebuild

Hi

thank you all for your help...yes english is my second language!

its a starboard engine they remove engine and replace with refurbished engine block but i would like to rebuild old block so i can keep it as spare, my mechanic is telling me only camshaft broke but i would like to replace cam,pistons everything what comes in between cam and pistons....we call it snap in half you call it BROKE sorry on that ( i live in New York) boat is overseaz back in my country i have to buy all parts here and not sure what to buy!

if i rebuild old engine for spare would i be able to use as port and starboard?

p.s also im thinking to buy 2 new diesel engines something like 3.0L v4,v6 any help were or what kind engines would work with my alpha one drives?

thank you
benny

 

[BeniR]

Re: Engine rebuild

Sorry guys it is CRANKSHAFT!!!

 

[alldodge]

Re: Engine rebuild

if i rebuild old engine for spare would i be able to use as port and starboard?

p.s also im thinking to buy 2 new diesel engines something like 3.0L v4,v6 any help were or what kind engines would work with my alpha one drives?

I don't think a rebuild is on the mix with a crankshaft problem. That being said, if you did rebuild this one or another you can use it one either side. Neither of your engines is counter rotating.

As for using diesels, in my opinion I don't see this as being able to work. The alpha drives cannot handle the torque of the diesel unless you get a low HP one. With a low HP diesel you would not like the way the boat preformed. It is do-able but the drive ratio and the issue of torque may be to much.

 

[NHGuy]

Re: Engine rebuild

Only time I ever saw a broken crankshaft it was because of liquid in the combustion chamber. One of our technicians had a set of fuel injectors on order. He had removed some of the old injectors and the fuel rail was sitting there above the engine. Well, unbeknownst to him the fuel that was sitting in the rail dripped into the combustion chamber. He hadn't released the fuel pressure and drained the rail. A step that's very clear in the instructions.
The parts came, he then bolted things together and cranked the motor. When the piston came up, either the fluid would not compress like air, or that big quantity of fuel ignited. And bang, there went the crank.. .
The reason I am telling you this is if your crank broke I hope you took steps to make sure no water can get in the NEW engine. In our marine engines the most common spot to allow water into the combustion chambers is the exhaust risers and exhaust manifolds. If you reused the old exhaust with the new engine check the exhaust to be sure it's not allowing water into the exhaust tract.
For details and how to's check out the technical information at the top of the forum. Here > http://forums.iboats.com/mercruiser...cellaneous-mercruiser-information-329915.html