Flywheel ballance?

[BROSS]

After I lighten the flywheel is it a must to balance it? With the crank snout in the laith it was at 0, and everything was taken of evenly. :question:

 

[#ZERO]

Just make sure when lightening your flywheels to install the snout of your crank with the flywheel attached and bolted on, snug in your jaw fixture. Then push it in with a dead centering tool till it makes contact with the flywheel hub, that will ensure that it's accurate before tightening the jaw fixture completely around.

A friend of mine built a real cool looking balance machine copying one that he saw SBT use on their propellers. He went to the trouble of finding sealed, no contact, special bearings without grease and hours of machine work, only to find out that all my flywheels were balance perfectly statically.

This however does not mean that they are balanced dynamically and it's very expensive to purchase that equipment to do the job.

I've been removing most of the material from the outer edges of the flywheel front and back with only a very light cut on the front surface. If you take to much metal off the front area it will crack around the hub rivets for sure. So far I've been able to take the flywheels from 3.75 ~ 3.80 pounds in stock form, to 3.30 ~ 3.20 lbs without any problems.

 

[SuperJETT]

Yes, balance it.

My old engine builder George Grabowski had a low tech but effective method. He had machined a piece of bar stock with the proper tapers for multiple flywheels, he'd put the flywheel on it and lay it across 2 level pieces of metal on his mill and roll it. If it rolled smoothly and slowly stopped, all set. If not, it would stop with the heaviest part down so he'd drill a small amount off that side and test again. Took maybe 3 minutes to do my flywheel like that and it was almost perfect.

 

[BROSS]

Thanks for the info fellas, my dad has no way to ballance it at his work and he has been building nascar motors for years and said he would trust it, I was just wondering if anyone ever ran into a problem w/o ballancing one. #.0, we took off about the same as you, so hopefully wont have any prob.

 

[BROSS]

The finished product

 

[Scraggly]

The finished product

thats nice!! so when do you want mine?

 

[Mark44]

d

The finished product

looks good and you will be fine run it. Balance would be nice but no one does it.


Mark44

 

[WILDBILLHD]

Gentlemen,I agree with all of the above :smile:.Sometimes I don't trust the center of the crank,espically the one I used on Billys flywheel.Although I agree on using a live or dead center so long as the tailstock is dead nuts aligned with the lathe head.Instead I took a new JE wrist pin and put it in the lathe an put an indicator on it.It ran out .0001(one tenth of one thousandth),so I know the lathe is accurate,espically for fixed chucks.The old snout I put in it ran out .0001(one tenth of one thousandth) also,so from that point I lightened the flywheel.The outer thickness varies.001(one thousandth),the face varies .001(one thousandth).In my opinion it will be fine,if it was mine,i'd run it in my engine! :icon16:We have a HINES balancer here,but the flywheel arbor is a bit too big! LOL. I still may try to machine an arbor if I have time.But ,I think it will be fine as is. As you can tell by the photo Billy took,I machined the face comming close to the hub but not touching it, using a 1/32 radius carbide bit.After the face was done I radiused the 2 openings in the front,smoothed and deburred all machined surfaces.I wanted to magnaflux the flywheel for cracks afterwords,but wasn't sure how the solution would react with the magnets,besides,the solution has very fine metal particles in it.Would of been a pain in the ass cleaning the magnets,it was bad enough removing the machining chips from them :crying: Well,i've rambled on long enough,hope nobody fell asleep reading this,time to get back to work!Ya'll have a nice day!:wave:

 

[BROSS]

Well my father made a jig to balance the flywheel, it was a gram off, now its perfect:bananapowerslide: