Tightening Torque

[arronm]

Any one know the torque setting for the harmonic balancer on a barra six BA BF

[SuckSqueezeBangBlow]

The ellery's I have says Front pulley to Crankshaft is 125Nm. Please verify with another source as I've found a few errors in this manual before

[Wenier]

My BF manual says 125NM so sounds good.

[arronm]

Thanks guys, lets hope it doesnt come loose again

[Smoke them tyres]

Arron,

I would suggest that the loosening of the bolt is only the SYMPTOM of what you are experiencing......insufficiently controlled harmonics.

If it has come loose, check for fretting and the keyway opening up in the bore of the balancer. Just doing the bolt up to the required torque, loctiting it or doing it tighter will not solve this issue. If it has, this will also damage and open up the mating crank keyway. The balancer is easily replaceable. The crank is not.

Woodruff keys are just hopeless items. They break every sensible engineering rule.....(and should have stayed in bicycles IMO) as they are poor at side loads and also create stress risers with their square groove sharp edged form. A truly dumb device, yet the auto industry still use them en mass. A better way would be to use a round groove and matching pin like small outboards do to mount the prop. That way, the more load that is placed on it, the harder it is driven into the slot. Not trying to peel it out. A woodruff key just leans over and "opens" the slot in the crank snout. I would SERIOUSLY get a balancer that has more mass in the outer ring. My old alloy head turbo crossflow in my other car actually split the balancer up the keyway from the key leaning over and the repeated hammering from the harmonics.....balancer was too light and not capable of damping all loads it should. It was split that much, you could put it on and off the crank by hand. At the same time, the flywheel bolts also came loose about one turn each....and they were loctited in. I would also not be surprised that if driven hard, the timing chain may not last the full life that it should, as it will also suffer. Harmonics in an engine are not to be taken lightly.

Once it gets to the stage where the slots have opened up, stopping it from repeatedly doing it is a losing and futile battle.

[mic]

yup +1. I would get an atomic balancer if I were u mate. once the std one has come loose its buggered. I think the atomic one specifies about 350ftlb, which is what it should be.