[bigwildgrin]

I see alot of balanced lower ends for sbc, especially the 383 stroker. the price of them seems so reasonable that I'm thinking they are the way to go. the only thing I've noticed is all the ones I've found come with a flex plate. if I use a flywheel is it still balanced? I'm thinking not or else they wouldn't include the flex plate. any options here? I would never give up my m-22 for an auto, so what's left?

[poncho62]

Generally 400 Small Blocks are externally balanced. Get your lower end components and your flywheel all balanced at the same time. That way you can be sure it is right

.Don't forget about your harmonic balancer.

[mikeweyman]

what rpm can you hit with a well balanced setup??

[Dubz]

Originally posted by mikeweyman
what rpm can you hit with a well balanced setup??

depends on the components, and valvetrain

[tm454]

OK, I'll ask, best case senerio what kind of RPM is a sbc capable of? I understand the 302 is very high strung, capable of sustaned high rpm runs. Just how high, anyone have any experience here???


Todd


Rat Rods Rule!

[lluciano77]

Originally posted by tm454
OK, I'll ask, best case senerio what kind of RPM is a sbc capable of? I understand the 302 is very high strung, capable of sustande high rpm runs. Just how high, anyone have any experience here???


Todd


Rat Rods Rule!

I think a stock SBC's RPM limit is it's valvesprings capability to maintain valve stability.

Originally posted by bigwildgrin
I see alot of balanced lower ends for sbc, especially the 383 stroker. the price of them seems so reasonable that I'm thinking they are the way to go. the only thing I've noticed is all the ones I've found come with a flex plate. if I use a flywheel is it still balanced? I'm thinking not or else they wouldn't include the flex plate. any options here? I would never give up my m-22 for an auto, so what's left?

There are two ways to consider an engine "balanced". One is external or internal balance. The other is rotating balancing where the crank, rods, pistons, and rings are balanced.

[camaroman7d]

lluciano, is correct. There are 383 kits that are internally balanced and externally balanced. The externally balanced 383 needs a dampner and flexplate/flywheel off of a 400SBC (they are counter balanced).

An internally balanced 383 kit uses neutral balanced flexplate/flywheel and dampner.

If you want your rotating assembly 100% balanced the only way to get that is to use the same parts to balance it that will be used on the actual car (even a balanced engine is not 100% in balance, there is a cushion or error factor involved +/- X%). Technically assuming your flywheel is neutral balanced and you were to buy a internally balanced kit ti should not throw off the balance. It would be a much bigger issue if you were using external balanced parts, in that case they should be balanced together due to variances in the external weights.

[redcamaro4spd]

okay, what about this? my scenario right now is that I have the stock roads and crank, with a new flywheel and forged pistons. I am not planning to balance this...Is this going to be a problem? Thanks for any help...

[camaroman7d]

What kind of engine are we talking about? In either case balancing is money well spent. I wouldn't even think about building a performance engine without balancing it.

[lluciano77]

Originally posted by redcamaro4spd
okay, what about this? my scenario right now is that I have the stock roads and crank, with a new flywheel and forged pistons. I am not planning to balance this...Is this going to be a problem? Thanks for any help...

You don't have to balance it. It is just an option such as honing with a torque plate, referencing the crank centerline to the deck surface, or align honing the mains. They are all good for the engine, but it is up to you if whether you want to spend the money. I think balancing adds 20 hp along with longer engine life.

[redcamaro4spd]

sorry for the delay guys, the motor is a 355 with a mild/modrate top/end and cam. I was planning on turning it too about 5500rpm. As stated before, stock bottom end with Sealed Power forged coated skirt pistons...thanks for any help...

[Dubz]

you shouldn't NEED a balancing to be bale to get that high, cause that' not really all that high

good valvetrain and you should be set

[woodz428]

TM454, I don't know about the 350 and upward but the 302/Z28's used to hit 7000 easily and regularly.

[camaroman7d]

A non balanced engine will have no problem getting to your RPM range, that is not the reason you balance an engine. If you want a smooth running engine that won't eat up bearings, you should have it balanced. When you start changing parts (pistons and rings) you change the balance (unless they weigh the same as the ones you are replacing). Balancing is by no means a MUST, it is just recommended. SBCs were all internally balanced (except the 400). They are balanced/engineered to work with the components they came with. Once you start swapping parts you are changing the balance. I as well as others have built engines that were not balanced and yes they will run. A few ounces becomes really heavy at 5000+ RPM.

You can mount a tire on the rim and drive just fine too but, how many of us buy tires and tell the guy "nevermind on the balance"?
It will cost you about $125 for a 350 to get balanced, in my opinion that is money well spent.

[Deuce]

http://hotrodders.com/showthread.php?s=&threadid=30142

Go read this previous thread and look at the balance sheets.

BEFORE and AFTER