question about my boat and motor

[1966Springbok]

hey all i just bought a boat but the motor was seized with no oil in the bottom end so now my question is can i use a car 305 block but use all my marine parts in that block as in my area there is not really many omc 305 marine motors here thanks walter btw boat is a 1980 Peterborough 18.5ft closed nose runabout

 

[Bondo]

hey all i just bought a boat but the motor was seized with no oil in the bottom end so now my question is can i use a car 305 block but use all my marine parts in that block as in my area there is not really many omc 305 marine motors here thanks walter btw boat is a 1980 Peterborough 18.5ft closed nose runabout

Ayuh,...... Welcome Aboard,..... Use a Truck motor, 'n bolt yer marine stuff, On it, rather than In it,.....

Brass core plugs, 'n build it up,....

 

[1966Springbok]

ok now will the crank and pistons cam be the same or that need to be replaced too??? thanks walter

 

[Watermann]

You could also look around for 350's which should be the same set up and are in my opinion a better motor. I know there's a lot of disagreement about the car vs marine motors issue but I personally would only use a marine motor in a boat.

 

[HT32BSX115]

Howdy,

You should be able to use a GM 5.7L (350) similar year truck engine too......

 

[1966Springbok]

i forgot to mention that it is a small block 305 v8 not sure if that matters

 

[HT32BSX115]

i forgot to mention that it is a small block 305 v8 not sure if that matters

If it's a GM 305, Any GM truck 305/350 would be fine. You would need to do the things that are different to it though. Brass core-plugs and a marine circulating pump etc.

You would want a truck engine because the camshaft in a truck engine allows for a rather low RPM where optimum torque is produced. Stern drives like to operate at RPMs well below 5000 RPM.

Some car engines will be "cammed" for higher RPM operation. That type of cam can be more susceptible to (exhaust) reversion when operated with a "wet" exhaust system like our I/O's and inboards have.

 

[1966Springbok]

ok thanks all but i might have just found the one and only 305 inboard in my area haha but will keep you posted on what happens cheers

 

[Scott Danforth]

I would upgrade to a 350 long block. build it with brass core plugs, proper gaskets and a decent marine cam and then transfer over the intake, manifolds, electrics and circulating pump, etc. from the 305