blown engine

[bubbad]

I own a 93 330 dancer with twin 7.4 hurth v-drives,last summer i got rope caught in props,at idle speed witch stoped engines,after cutting rope from props,i tried to restart engines and the port engine hand grenaded! 2 broken rods,dropped valve, blown head gaskets,water in oil, does anyone know what could have happened here,like a good neighbor State Farm was there! but i would like to know for future reference what this may have been .

 

[tdappleman]

Seems strange that it would happen at idle speed but I'd guess the sudden stop allowed water in through partially open exhaust valves. When you tried to start it again the water caused the damage since water does not compress - blowing the head gasket and causing the other damage. What condition were your exhaust manifolds and risers at the time of the incident? They may have been leaking all along and the rope just accelerated the result

 

[tobnpr]

I agree that's really odd...
Most of us (if you've been boating long enough) have "touched bottom" at least once at idle speed causing an engine to stall, with no damage.

 

[khaynes]

If the ropes were in both props and one engine died first. Could one engine have turned the other engine backwards and pulled water in the exhaust.

 

[AKBASSKING]

Could have caused the timing chain to jump which would have screwed up the timing, thus a piston hitting valves etc.

Or if it is fuel injected, an injector could have stuck open, filling the cylinder with fuel causing hydraulic damage

.

 

[BonBini]

Sounds like there is more to this story than rope in the props. ...Ron

 

[bubbad]

Thanks for the help,going to add 3" risers to exaust manifolds,and watch for ropes!