Sea Ray 220OV with a terminally ill 260HP Mercruiser

[Tiger_DFT]

My mechanic has informed me that my old 350/5.7 Chev mercruiser is dead. He strongly suggests buying a new long motor as mine has been cooked at some time prior to my TLC. Whilst researching how to solve this dilema I have come across NEW GM crate 350/4 bolt 300HP long motors at an excellent price ($2880AUD). This is far cheaper than I can rebiuld my 350. The question is what should I replace on this new engine to suit raw sea water cooling. I presume I should strip intake and heads and replace gaskets with Mercruiser gaskets....anything else? I'm also toying with the idea of converting to an outboard (on a pod) to make boat more suitable for being left in the water....has anyone done this and been faced with any cruel dissapointments?

All responses will be eagerly read....thanks.

Cheers
David
Perth - West Australia

 

[Dave_Snelson]

Mmmm - big project. Will the new GM motor marry up to the stern drive OK? Is it already marinised for raw water? If not, can you fit all the marinising bits like exhaust risers and primary and circulation pumps. What about all the hoses?

The O/B idea, I am not at all keen on for weight distribution reasons. Although, I can see the meit in your thinking. Some yachtsmen actually do this to a) get better reliability and servicability than their old Volvo 2-pot lump and b) free up good bilge storage space.

Cheers
Dave

 

[Col]

You need to change the thermostat, head gaskets, distributor & waterpump. Iron inlet manifold should be used along with a marine carb (Holley 625cfm)
Everything else will bolt up OK, As long as you are not mixing early 350 with a Vortec. (Manifolds are different.)

 

[oldgit]

If this is an ex auto lump are not the cams n stuff wrong for marine use.Was once told by my local Mercruiser agent that car and boat engines were set up differently to suit output requirements of car or boat.?

 

[Col]

Many cam profiles fitted to these engines. In a light boat a 260 or 280 grind would work well as you are using high revs anyway

 

[Tiger_DFT]

Thanks everybody.....I think in a nutshell that new GM crate engine with marine spec gaskets and all accessories of old engine will be the way to go.
This is a great forum!!
Cheers
David