Blown Mercruiser 5.0 Alpha. Low hours. Replacement options

[keith]

Thanks for all of the great advice everyone.

I decided to have them pull the heads and take a look myself at the situation. If the cylinders look good I will go ahead with machining the heads and valve job and see what happens. If the cylinders look good I will have them change the manifolds too. I would rather have a new fuel injected engine in there. Hopefully I can delay that expense for a few years.
They are pulling the heads on Friday.

[pelican]

Originally Posted by keith

Thanks for all of the great advice everyone.

I decided to have them pull the heads and take a look myself at the situation. If the cylinders look good I will go ahead with machining the heads and valve job and see what happens. If the cylinders look good I will have them change the manifolds too. I would rather have a new fuel injected engine in there. Hopefully I can delay that expense for a few years.
They are pulling the heads on Friday.

once manifolds are pulled off - it will be apparent if the manifolds/risers caused the problem.

if indeed the manifold/risers caused this condition - the motor was taking in sea water.water in the oil,it may or may not have been present,but,the motor was "burning" seawater,due to valve overlap ...

with all that:

a common problem often encountered,after having the cylinder heads rebuilt - a "valve job"
the motor will have an oil consumption problem.blow by,on the rings will cause this.the seawater in the cylinders causes wear on the rings - just inspecting the cylinders,will not pick this up...if water was in the oil,this causes a problem with the cam bearings,causing a low oil pressure situation ....


lots of "stuff" to all this huh ??

[keith]

Pulled the heads and there was rust on the two of the cylinder walls and the valves were toasted and mushroomed. Engine is gone. I am still waiting on prices for 5.7 mpi and 5.7 carb. He is recommending the Mercruiser reman units but doesn't know the availability or pricing yet.

[keith]

Is there a difference on the installation for swapping my carb (alpha) motor with an mpi 5.7? If they can't get it done in time I am debating on doing it myself at my friends shop. I don't want to get into anything too crazy though.
Is the harness the same?
Will the exhaust bolt up?
Do I have to change anything in the outdrive?
Is the fuel pump on the engine?
Is there a return line, which would mean tank modification?

Thanks