auto motor into boat

[debt finder]

what would be the harm in putting a rebuilt 350 with 300hp into my boat ? currently i have a 350 marine with 260hp that in on its last leg . thought about rebuilding it but when i took the intake and heads off ( because i was told it was a blown head gasket ) the intake and head surface was pitted beyond fixing . also considered just getting new heads and intake but was unsure about the lower half . so any thoughts or suggestions are welcome

 

[erikgreen]

Re: auto motor into boat

Do a search on this board for similar questions... in particular look for "marineizing auto motor" or "truck motor in boat".

In short, the major parts will work provided you get marine gaskets, marine or truck camshaft, marine bolt-ons (alternator/starter/water pump) and you install brass freeze plugs.

In order for the block to fit your existing flywheel/housing/transom kit you need to match the year of the auto block to the year of your boat motor... a newer block may not fit the bell housing/flywheel, and you can't just replace that, you'd have to replace everything back to the drive.

Many motor upgrades are done by putting in a more aggressive cam, which won't always work in a boat... you want low end torque, not high end RPM, and in some cases a cam with overlap will ingest water and ruin the engine.

Erik

 

[Bondo]

Re: auto motor into boat

Ayuh,...... What Erik said,......

Your 260hp would do well with a set of Vortec heads,+ matching manifold,.....
If the bottom end was Refreshened,..... Probably make it a 280/ 290hp motor........

And,....
The changes in vintages Erik mentions is 87 for the crankshaft,+ 96 for the heads.....

 

[debt finder]

Re: auto motor into boat

my motor is a 82 350 does anyone know if the Vortec heads and matching manifold for them will work on that year motor ?

 

[Bondo]

Re: auto motor into boat

Ayuh,........ No Problem......That's what I just said.......

Your 260hp would do well with a set of Vortec heads,+ matching manifold,.....
If the bottom end was Refreshened,..... Probably make it a 280/ 290hp motor........