So when my 306 was built it was internally balanced with the stock flywheel on it. Now I want to upgrade to a 10.5 inch clutch so I have to use the bigger flywheel. Am I going to have to have the engine completely rebalanced with this flywheel?
Changing flywheel on internally balanced engine
- Thread starter Dean85GT
- Start date
Vipersix
Founding Member
Unfortunately yes. You also have the option of balancing the flywheel to the specs of your crank, which is probably your best option.
Well, what if I was to get a better 10" clutch? Would this be able to hold a HCI car on slicks? Then I could just use my old flywheel still
Vipersix
Founding Member
There's always that option. You can find good clutches rated in excess of 600 ft/lbs of torque for a few hundred bucks. I'm a big fan of SPEC personally.
1991vert
10 Year Member
that doesn't make any sense. a stock flywheel is 50oz imbalance. when you interally balance, a 0 balance flywheel should have been used along with a 0 balance harmonic balancer, which would leave all the balance up to the crank.
Vipersix
Founding Member
That's true to an extent and really depends on how reliable you prefer to have your engine. I suppose he could get away with simply replacing his current flywheel with a larger zero balance flywheel but I wouldn't really recommend it.
When performing an internal balance, the pistons are first weighed and corrected in order to achieve uniformity. The connecting rods need to be weighed in order to determine the rotating weight versus the reciprocating weight. The crankshaft is put in a machine that determines imbalance and then drilled in order to balance to the rods and pistons. This internal balance will still have slight imperfections and will be countered by the flywheel which is added last (normally with the dampener) in order to get a complete rotating assembly balance.
I suppose if RPMs are kept relatively low and the torque figures aren't terribly high you could just replace it with a new zero balance unit. However, many shops keep the specs of the balance. If this is the case, the new flywheel can be drilled as necessary without tearing apart the engine.
When performing an internal balance, the pistons are first weighed and corrected in order to achieve uniformity. The connecting rods need to be weighed in order to determine the rotating weight versus the reciprocating weight. The crankshaft is put in a machine that determines imbalance and then drilled in order to balance to the rods and pistons. This internal balance will still have slight imperfections and will be countered by the flywheel which is added last (normally with the dampener) in order to get a complete rotating assembly balance.
I suppose if RPMs are kept relatively low and the torque figures aren't terribly high you could just replace it with a new zero balance unit. However, many shops keep the specs of the balance. If this is the case, the new flywheel can be drilled as necessary without tearing apart the engine.
Well my engine was balanced with my stock damper and that flywheel. So how was it done then? Dont mind my stupidity cause im confused on this one.
1991vert
10 Year Member
okay so it was externally balanced to 50oz. if that's the case, i dont see the harm in switching keeping the balance(s) at 50oz. have to talked to rick91gt?people at hardcore5.0 would probably give you a definate answer
