Harmonic Balance ?

[ddraddy]

Will a Harmonic Balance off a 305 work on a 350 Mercruiser the 305 is thinner than the 350 Thanks

 

[mkast]

Re: Harmonic Balance ?

Why would you want to?<br />The balancer is setup for the crank it came on.<br />You could run the 305 on the 350 crank, if, you get the engine rebalanced.

 

[rodbolt]

Re: Harmonic Balance ?

actually the 350 and 305 crankls are identical, except for balancing.<br /> most have the same forging numbers, however the balancers should not be swapped.

 

[ddraddy]

Re: Harmonic Balance ?

The boat is still in the water,I have an old 305 I was taking parts of of { I live 50m from marinia} I was hopeing to have a drop in ready when I pull the boat {they charge by the HR} Yes you are right I will have to pull the old engine Thanks

 

[Buttanic]

Re: Harmonic Balance ?

All small block Chevy except the old 400 cu in are internally balanced so the harmonic dampner has no effect on balance. They were made in several different diameter but are interchangeable without affecting engine balance. The term harmonic balancer is not really correct as it does not balance anything. It is correctly a harmonic dampner which absorbs torsional (twisting) vibrations in the crankshaft which is different from rotational balance. Rotational balance prevents the engine from vibrating and is done by adding or subtracting weifgt from the crankshafts counterweights depending on the weight of the piston and connecting rods.

 

[ddraddy]

Re: Harmonic Balance ?

Thanks for the great advice Buttanic I was Stationed at Navel Support Activity in N O back in the 70s{home of the concrete boats on the West bank} I hope you are doing OK after the storm last year. Thanks again and Stay COOL

 

[Bondo]

Re: Harmonic Balance ?

ddraddy,.... <br />Are you Changing Engines,..??.. Or Harmonic Balancers,..??...

 

[ddraddy]

Re: Harmonic Balance ?

I have a 1985 SeaRay sundancer that came with twin 305 Chevy Merc, I repowered withh 350 chevy Merc 260HP fresh water cooled. I lost a bearing on the port and must replace the motor again. I have the 305 motor that I am using all miss parts,but I was not sure about the balance.I do not live near marina[Reedville Va] I want to be able to drop motor in to save a few bucks Thanks

 

[Buttanic]

Re: Harmonic Balance ?

One thing I forgot. The Chevy changed the timing mark position on the balancers over the years. I would have to look up when the change was made so if you are not sure you would have to verify that the timing mark in in the correct position,

 

[Buttanic]

Re: Harmonic Balance ?

The timing mark position change was made in 1969 so you should be OK using the 305 dampner.