My boat has the OMC Cobra 5.7L 260HP engine. At least it did. It sprung a
couple of water leaks and took out the heads, manifolds, and block. Anyway,
I am finally getting around to replacing the engine and I am considering the
new 350 Vortec engine rated at 315HP. From what I have been reading, it
should bolt right up ok, and all of my old mounting brackets should still
bolt up ok, but can the outdrive unit safely and reliably handle the extra
55 HP? And is there anything else that might come up and bite me in the
butt?

Thanks

Most of the chevy small blocks are totally interchangeable until the last
few years. I think the vortex has some differences but it may have the same
external bolt patterms for accessories. It was designed for computer efi
and that will add a lot to your costs. You might also look at the
aftermarket crate motors from chevy. They can be traditionally carburated.

"NoOne N Particular" wrote in message
om...
My boat has the OMC Cobra 5.7L 260HP engine. At least it did. It sprung
a couple of water leaks and took out the heads, manifolds, and block.
Anyway, I am finally getting around to replacing the engine and I am
considering the new 350 Vortec engine rated at 315HP. From what I have
been reading, it should bolt right up ok, and all of my old mounting
brackets should still bolt up ok, but can the outdrive unit safely and
reliably handle the extra 55 HP? And is there anything else that might
come up and bite me in the butt?

Thanks

But the question was "can the outdrive unit safely and reliably handle the
extra horsepower?

Wayne

"JamesgangNC" wrote in message
news
Most of the chevy small blocks are totally interchangeable until the last
few years. I think the vortex has some differences but it may have the
same external bolt patterms for accessories. It was designed for computer
efi and that will add a lot to your costs. You might also look at the
aftermarket crate motors from chevy. They can be traditionally
carburated.

"NoOne N Particular" wrote in message
om...
My boat has the OMC Cobra 5.7L 260HP engine. At least it did. It sprung
a couple of water leaks and took out the heads, manifolds, and block.
Anyway, I am finally getting around to replacing the engine and I am
considering the new 350 Vortec engine rated at 315HP. From what I have
been reading, it should bolt right up ok, and all of my old mounting
brackets should still bolt up ok, but can the outdrive unit safely and
reliably handle the extra 55 HP? And is there anything else that might
come up and bite me in the butt?

Thanks

Don't know anything about omc's, just small blocks and mercs. I will say
that the extra hp is not that low down in the rpm band so if the boat is not
very heavy the difference to the outdrive may not be that much. I would not
worry about it. It's not like you're switching to a big block.

"NoOne N Particular" wrote in message
.. .
But the question was "can the outdrive unit safely and reliably handle the
extra horsepower?

Wayne

"JamesgangNC" wrote in message
news
Most of the chevy small blocks are totally interchangeable until the last
few years. I think the vortex has some differences but it may have the
same external bolt patterms for accessories. It was designed for
computer efi and that will add a lot to your costs. You might also look
at the aftermarket crate motors from chevy. They can be traditionally
carburated.

"NoOne N Particular" wrote in message
om...
My boat has the OMC Cobra 5.7L 260HP engine. At least it did. It
sprung a couple of water leaks and took out the heads, manifolds, and
block. Anyway, I am finally getting around to replacing the engine and I
am considering the new 350 Vortec engine rated at 315HP. From what I
have been reading, it should bolt right up ok, and all of my old
mounting brackets should still bolt up ok, but can the outdrive unit
safely and reliably handle the extra 55 HP? And is there anything else
that might come up and bite me in the butt?

Thanks

OMC used two 350 cu. in GM engines. The lower horsepower version was called a
5.7 litre and used with a Cobra drive. The higher horsepower version was called
a 350 and was used with the King Cobra drive. So, the recommended drive if you
go to the 315 hp engine would be a King Cobra and using a Cobra drive on
anything over about 275 hp would be questionable.

NoOne N Particular wrote:

My boat has the OMC Cobra 5.7L 260HP engine. At least it did. It sprung a
couple of water leaks and took out the heads, manifolds, and block. Anyway,
I am finally getting around to replacing the engine and I am considering the
new 350 Vortec engine rated at 315HP. From what I have been reading, it
should bolt right up ok, and all of my old mounting brackets should still
bolt up ok, but can the outdrive unit safely and reliably handle the extra
55 HP? And is there anything else that might come up and bite me in the
butt?

Thanks

NoOne N Particular wrote:


My boat has the OMC Cobra 5.7L 260HP engine. At least it did. It
sprung a
couple of water leaks and took out the heads, manifolds, and block.
Anyway,
I am finally getting around to replacing the engine and I am
considering the
new 350 Vortec engine rated at 315HP. From what I have been reading, it
should bolt right up ok, and all of my old mounting brackets should still
bolt up ok, but can the outdrive unit safely and reliably handle the
extra
55 HP? And is there anything else that might come up and bite me in the
butt?

Thanks



Jim Kelly wrote:

OMC used two 350 cu. in GM engines. The lower horsepower version was called a
5.7 litre and used with a Cobra drive. The higher horsepower version was called
a 350 and was used with the King Cobra drive. So, the recommended drive if you
go to the 315 hp engine would be a King Cobra and using a Cobra drive on
anything over about 275 hp would be questionable.

Or, if still unsure, the cone-clutch(King Cobra unit) type should be
able to handle it... it was also used with the Ford 460 / 330 hp. The
clutch dog Cobra will be beyond design limits above 260-275 hp as Jim
Kelly writes, and will be lunched quickly if not babied.

Rob