What Balance?????????
 

I am building a 331 and have the rotating assembly and block ready to go. Now I need to have everything balanced but I dont know whether to get a 28 or 50oz balancer. The company who makes the crank said it can be balanced to either 28 or 50. Which balancer and flexplate do I need. If someone could help me out that would be great. Thanks, John

I think this shold be a question for your machine shop or engine builder. But why not internally balance it?
andy

No one ever suggested internal balancing to me. People have told me to go with the 50oz balance but I just wanted to see what the guys on here said about it. John

you'll need to talk to the machine shop or the balance shop... they can tell you what to buy, but you should also have it internally balanced because 7 ounces of unbalance inside the engine is 212lbs at 4000 rpms... so you don't want that kind of extra stress on it if you can avoid it... depending on the type of crank you have and where you live it can cost you anywhere from 300 to 900 for a good balance job... but it is well worth it!!! since you wont loose the power of the unbalance.... hope this helps...

steve

You can have the whole assembly balanced to either 28oz or 50 oz. 81 and up 302's changed from a 28oz to 50 oz balance. Whichever you choose, you need to have the flywheel and harmonic balancer match your balance. So if you have the very common 50oz balancer, and flywheel lying around, then have the crank balanced to 50oz. Either can be used, so I guess it is a matter of preference, and $$.

What crank are you using, Notch? Is it an aftermarket steel crank, or a stock crank thats been stroked? If its stock and has flange on the end for the 2 piece rear main, it is a 28.2 oz. If it is smooth on the end, (one piece rear main) it is a 50 oz. If you go 50 you will need the Motorsport flexplate. M-6375-E302 It is the special 50 oz 157 tooth designed for C4's on late model engines.
andy

I have an aftermarked crank and the company says it can be balanced to either 50 or 28oz. Is there any difference between the two? I am going to be using an aod tranny, what flexplate is used with that? Ive heard the fms balancer are pretty good, so maybe ill run 50oz.

Of course there's a difference! The more external an engines balance is, the more load is placed on the #1 & #5 crank journals. It may or may not create a problem, but if you've got the choice, always go with less external weight when it comes to balancing an engine, ALWAYS!!

Take care,
-Chris

Ok thanks, I didnt know that. John

And the man (pekerwood) does it again! It's really nice to know we have people like you around. Knowledge is very deep! We appreciate being able to come here for knowledgeable answers. All we have to do is get on our CPU at home and we can find out almost anything!

Thanks
James
;) ;) ;)

James-

Thanks for the kind words!

Take care,
-Chris