take the new flex plate and the old flex plate to a good engine builder and they should be able to match the balance.
When the time came for my engine builder to balance my new crank, for my Cleveland, he asked me to bring him my flywheel. He balanced the crank with my freshly re-surfaced flywheel and a new dampner all bolted together as a single unit. Can you balance a seperate piece like a flex plate by itself?
Ummm, yes you can. Any compentent machinist that does engine balancing can do this job. All he does is remove weight from the counterweight area. I've had two done.
I don't feel so bad now. Glad I labeled this thread Confusing Imbalance Issue. Right now the car is parked, and the project is on hold until January or February when I have a house/garage. At that point the car will more than likely get stripped of everything, and I'll be scrapping it in favor of a less destroyed body.
from what i have read and understood, the crank itself doesnt interfere with the balance of the engine. the balancer and flexplate/flywheel will determine the engine's balance/im-balance. i may be wrong, but i have always read and understood it to be this way. a friend built up a '56 Vic and used a '75 truck engine with his T5, and used a 50 oz balancer and stock 5.0 mustang flywheel with his crank and everything works perfect. he's been running it for about 5 yrs now
I saw you were putting that up for sale. Unfortunately my cash flow will be fairly limited until after the holidays. If you've still got it then though, a trip down may be in order.
Machine off ? All they do is drill spots out of the counterweight. It takes all of 20-30 minutes to do one. If your machinist can't handle this, I wouldn't be giving him work to start with. The guy I use hasn't charged me a dime to do those two flywheels.
You read wrong. The crank determines which flywheel/flexplate and harmonic balancer it needs. The 50 oz cranks have much smaller counterweights than the 28's.
That's why I just let the speed shop do their thing with balancing my new stroker crank as a single unit with the dampner and the flywheel. Sure, it cost me some money but once they told me "it took very little to get it balanced", the piece of mind that I have now is priceless. Now someone that just buys parts and assembles their own engine, at home, would be missing that "little bit of balancing".
i completely agree. i have taht problem now. i have 85 gt crank and rods in my 73 motor. had to change flexplate and damper. but the assembly was previously balanced with 30 over dome tops. i put 60 over flat tops on the rods and now i have a vibrstion. which means tearin it back down.
it seems to me that some people here dont understand what balancing a motor is. its takeing the rods and pistons and weighing them. then grinding them to where they all weigh the same. next they take the crank wich should have an imblance of 50 oz or 28 oz, the balance and flex plate of flywheel both of wich will be made specificly for the imbalance of the crank, and bolt it all togther and put it on a balancing machine. now they have what is called bob weights. these are weights that they bolt onto the rod journals of the crank. the weights are adjusted to the weight of the rod, wrist pin, piston, and ring combination. now the machine spins the assembly and detects how much out of balance it is. it will tell you where the heavyest point of the imbalance is. now the machinest will either remove weight or add weight to the crank or sometimes the fly wheel/flexplate to achive a nutrual balance. when a motor is internaly balanced the flexplate/flywheel and balancer will have 0 imblance built into them. all the balancing is done on the crank and is usually pretty expensive because it requires use of malory metal wich is very heavy and expencive.
