CRANKSHAFT balancing Australia

I need some info where to do crankshaft balancing in Australia or other south east Asia region that can set a balance factor that we request..
hope other members from Australia can put in some info.. cheers

OZ has long history of super duper hot rodding of everything in the world of motorsports, so if no response here, just look up some race engine builders or local motorcycle clubs for a bunch of suggestions. I'd had a bent crank that none of the motorcycle crank places or Nortoneer's said was recoverable but found a Marine Crank shop in California that did the deed cheap and race level recovered. So don't just stop shopping if running out regular motorcycle or engine crank balancing shops.

Its Monday so others should of chimed in by now, in mean time here's some leads to ping. BTW get the alternator rotor balanced along with all the crank items.

http://www.google.com/#hl=en&sugexp=les ... 33&bih=416

Martin, where in Australia are you located?

Hobot, do you mean - have the rotor discretely balanced - or bolted up to the crank inclusive, for the process?

Well send them everything that you can that attaches and moves with the crankshaft. I don't know it they balance the alternator rotor separately form crank assembly or not. Ms Peels rotor came back with a series of drill holes half way around it. As the rotor is symmetrical - likely done separate so just adds a bit more evenly balanced flywheel effect that don't affect the Balance Factor or dynamic balancing. Unbalance rotor would tend to make the crank end wobble. Pinon gears so small mass and OD not likely anything to bother with.

Where did they drill? Lateral, or circumferential/radially? & was is in the magnets or just through the matrix?
Any fears that it might be prone to flying apart from being motheaten like that?
I have seen racing applications where most of the magnetic material has been removed & replaced by a lighter epoxy matrix.

Bob Mead , Balancing Specialities in Auckland, reputed to be one of the best on motorcycle cranks in New Zealand
Follow the link for contact details, no sign of a website
Regards Mike
http://yellow.co.nz/y/balancing-specialties

Brisbane Engine Balancing in Capalaba in Brisbane did a few of my Nortons, I recommend them,

Performance Mods ....Ozbourn Park ....Perth ....WA .

Just a row of little dimples so no worries mates'

I also use Brisbane Engine Balancing at Capalaba.
Can supply their phone number if you need.
Graeme

Ps that's very pretty hobot

Martin,

If you wish to check the balance factor, Dave Blisset in Sydney could do this. You could google Blisset Engineering Sydney. You would need to supply the complete rods, piston & rings etc. But then I would love to ask, what are you trying to achieve? Are you concerned about engine vibration, or do you want to try and improve smooth running? If the crank has already been dismantled, to clean out the sludge trap, it should have marks to ensure the parts are correctly reassembled. Otherwise it is possible they could be put back reversed?

Cheers Richard

Read 'Tuning For Speed' by Phil Irving, and do it yourself. It is not rocket science and it is not critical. If you are going to race , try to get the balance factor over 70% without drilling holes which weaken the flywheel. A threaded steel plug which fills the hole opposite the journals gets the balance almost right for racing.

I'm in asia, the problem is crankshaft balancer in here don't understand balance factor like you guys talking about 60% 70% and so on..
they only can balance the crankshaft to full balance till it reach zero thats what they called it.. i actually don't really understand what 60% or 50% balance factor means..

I'm building an offset cranks 90deg and people are suggesting me to go with 45-55% balance factor.. for smooth running offset cranks.


@Hobot that is a really tempting sprocket housing.... where did you get that from???

'Tuning for speed' is downloadable...

MARTIN.K said:

I'm in Indonesia, the problem is crankshaft balancer in here don't understand balance factor like you guys talking about 60% 70% and so on..
they only can balance the crankshaft to full balance till it reach zero thats what they called it.. i actually don't really understand what 60% or 50% balance factor means..

I'm building an offset cranks 90deg and people are suggesting me to go with 45-55% balance factor.. for smooth running offset cranks.

Click to expand...

If the reciprocating weight is (say approx) 1 lbs of pistons and upper rods, and the balance factor is 50%, then the flywheel is unweighted by 1/2 lb.
So is heavier on the non-crankpin side by 1/2 lb, to counteract it.

Ask them how many lbs and ounces is 100% ?
May give an idea of where they are coming from...

if this is the setup, and if the
conrod+piston+rings= 2lbs total on both cylinder and the balance factor 50%
than the counter sink weight is 1lbs/side or 1lbs of total both side / or the flywheel+countersink weight 1lbs

and if 60% balance factor should the counter sink weight more or less?

Jim Schmidt raced at power and rpm levels few of us will ever see over 3 decades ago on just his DIY static balancing which is detailed in his Race Manual. Cutting down some of the cast iron flywheel lowers its tendency to crack apart. With iso BF is a non issue as long as mid 50's and above. Solids need very strong frame or BF in the upper 70's and above. OZ is full of hopped up Vinetage racers, surely one could contact some of them for guidance off the standard path.

A balance factor of 72% means that after you have weighed the pistons, gudgeons, rings and circlips, you have hung 72 % of that mass on the end of the rods, and run the crank on level straight edges, and adjusted the weight of the crank to achieve perfect balance. If you tap the hole in the commando crank, and fill it with a steel plug, you will achieve that figure, which is enough to smooth out a standard 850 crank at 7,500 revs when the motor is rigidly mounted. In 650cc Triumph motors, I've always used a 79% factor, but the revs are higher. I've never used an offset crank, I don't see the necessity for the complication of altering the camshaft (loss of interchangeability). My bike rocks back and forward when idling, but as soon as you start riding it and give it a squirt, it is as smooth as silk. You need to make the decision as to whether your motor is to become 'top end' (big ports and hot cam and high revs and a crank etc that will cop it) or 'bottom end' ( conservative revs , small tapered ports, squish band head and cams designed to make the motor pull - less overlap ). I opted for the latter, and for me it is enough - and I am still able to ride a fast motorbike very well. If you make a 'botton end' motor which pulls hard, gearing it to race can be a problem, I think a 'top end' motor could be easier.