260 hp

[Ranchoronnie]

How much horsepower can I put to a 260 mercuruiser

 

[Scott Danforth]

Welcome aboard

You don't state what year, so we cant determine prop rating vs flywheel rating. However you motor would have 260hp if it is in perfect condition

Is the question how much HP can you get from the SBC engine, or how much HP you can put thru the drive? Which drive? Which SBC?

 

[Scott06]

Welcome aboard

You don't state what year, so we cant determine prop rating vs flywheel rating. However you motor would have 260hp if it is in perfect condition

Is the question how much HP can you get from the SBC engine, or how much HP you can put thru the drive? Which drive? Which SBC?

would also add in which hull.

I assume he is asking how much hp can a Mecruiser drive with a 260 label on it? Would think that is a gen one drive 300 hp or so, maybe 340 ish (383) if you are gentle on holeshot ?

If its in a light hull vs heavier hull will make a diff, either way use a marine cam ...

 

[Scott Danforth]

need to know drive, or at a minimum which year. the sticker could be on the original drive or even a later drive.

most of the drives with the 260 decal on it from the factory were MC and MR drives if I recall. that would be 300hp limit as the factory attempted 330hp big blocks and that was a warranty nightmare. however there are plenty of 383's putting out 350hp in front of alpha and earlier drives.

as @Scott06 stated, need to be gentle on hole-shot, and I will add, need to run a rev limiter that cuts ignition if you come out of the water under heavy throttle. re-entry will grenade the drive.

But that begs another question @Ranchoronnie . what are you attempting to do? remember, hot-rodding a boat motor is not anything like hot-rodding a car. think more like a truck pulling a trailer and you are limited by the wet exhaust to less than 270 degrees total duration (not the .05" spec)

 

[QBhoy]

It’s more about the torque and being easy on throttle in a state that will see high loads or conditions of strain through these things. Your 260 decaled drive gives reference to the engine behind the drive. Most usually a 5.7 4 barrel carb in particular. As said..almost certainly she’ll be an early or pre alpha, a fair old age too. I’d go easy on the old girl. I run likely about or just over 300hp through my gen 2 alpha. But only once do I remember ever opening the throttle fully from a stand still. Can’t be good for them.