I think you have to send it all in together so than can assemble it put it n the computer and spin it to see if it's balanced and where to add/remove material if not.

When I was having my externally counterbalanced bike motor balanced by Crankworks in Tempe I sent in crank rod, piston and all the little pieces to assemble it. Sending the counterbalancer apparently wasn't necessary. I believe they had some dynamic process to determine what to do but I don't know any details. Bottom line is I got it all back assembled and welded, and there was a big holedrilled in the crank weights on each side.

 

if your going internal balanced the flexplate/balancer does not need to be present.internal balance requires the crank to be spun/balanced to X amount and may need some heavy metal to complete the balance.the rods ends and pistons are weighed and matched.then use a neutral/318 flex/harmonic/damper.we internal balance all sbm strokers.

 

Really? Any particular reason? I would think that if it started out as an external balance, remaining so would be easier? Although, I don't have a clue where the crank comes from, I assume its a custom piece (not simply something from another motor reground.)

Would you be so kind as to enlighten me?

 

performance cranks come unbalanced so it up to the end user which way to go.internal the balance is in the center within the throws/counter weights.external theres a huge weight hanging on the end for balance.this can pose an issue at higher rpms putting stress on the crank and could damage bearings.turbo/supercharged/nitrous this poses a bigger problem so we just internal all.

 

That makes good sense. Thanks.

 

glad you were enlightened....thinking the reason your builder went with those kb356 piston is there very light.taking material of the the quench dome will lighten more.lighter parts quicker reving motor.with the comp height of the pistons and a .010 clean up of the deck given stock length rods puts the piston in the hole .0009..........basic zero deck quencher if running compressed .040 gasket pending rods used.thats a nice tight squish and will help when tuning.quencher motors can typically run alittle more compression and timing.i still would of went forged pistons for alittle more.gives options later down the road.nitrous/turbo/supercharger.

 

when it was previously assembled the domes were out of the hole .010, not below the deck .009. whered you get .009?

i realize your saying to set quench at .040, my machinist says .060, why?

 

Your machinist might be trying to reduce compression ratio.

Quench is one of the biggest controllable factors in engine building to control spark knock. There have been books written on the subject......

 

o yea just doing some research, theres ALOT of oppinions. it seems that .060 is right on the border of acceptable quench.

ill ask him tomorrow exactly why they went to .o60 instead of .040

 

first we need some static numbers to use in order to find deck clearance.

mag block deck height.....9.599-.010 cleaning=9.589
kb-356 compression height(not including dome or dish).....1.465
stroke...4.000
rod length....6.123(stock length)

(stroke / 2) + rod length + piston compression height = deck/piston face height of combo

(4.00 / 2 ) + 6.123 + 1.465 = 9.588

9.589 - 9.588 = -.001 or -.000999999(neg # is in the hole)........deck clearance

none of this caculating includes any dome or dish.piston compression height is measured from centerline of the wrist pin to the top of the piston face not from the dome or dish.per kb the dome is .050 ABOVE compression height.this puts the dome .049 out of the hole.this dome should be widdled down to the top of the piston head/compression height of the piston then you can run a .040 or .054 gasket.....possitive DC limits the gaskets you can use and the thicker they must be.if he wants the dome to be .010 out then running a off the shelf fel pro .39 would be to tight for a street motor.would need to jump up to a fel pro .054 which is still in the .04x range.if he wants a quench of .060 and the dome is out .010 you would need a .070 head gasket....to thick imo...just remember the more dome(cc's)there is less volume=higher compression once you get this figured and set in stone you can calculate compression.