Well I dont want to cut any corners with this BBC build. Alot of people say get it balanced. I know what they basically do to balance everything but im not sure what kind of pros and cons there are in getting it done, the basic works of engine balancing is new to me. Its a couple hundred extra to do this, if I didnt have to it would be nice tongue.gif darn money problems

As far as I know (and it seems we're kind of in the same boat as we're starting a 454 build at about the same time, mine just went to the machine shop yesterday), the only con is the money you pay for. Pros it just helps increase the longevity of the engine as well as just making things 'quieter' as I would think...if something isn't balanced I'm sure you'd hear some annoying sounds every once and a while. I think it is just good to do to keep everything together and solid.

Phil,

If you plan on taking it anywhere near the 5K mark or above, get it balanced. This is especially true when you start talking BBC.

Fred.

Sounds about right. Its up in the air, i think i'll have it done. What are they doing to yours? I just had mine tanked, magna fluxed and a 30 over bore. I forgot to get cam bearings put it so I had to bring it back, Monday I bring it home smile.gif Ive got some harmonic balancer issues, if anyone has a sec check my post ;)

The stuff im shopping for and the way I think im going will probably def. be above 5k

Hey Phil,

Not to change the subject, but I have to fly into Sacramento tomorrow. Then I have to travel down to Stockton for a week or so. Do you know if there is any shows, etc down in that area?

Thanks,
Fred.

What they're doing to mine is cleaning and magnafluxing right now...my crank might need turned a bit. Then probably cam bearings and any other type of machining needed, if he needs to align bor or anything, clean up the deck, etc. Then I'll get it bored some, and then once I get in the town where the engine is (I'm at school right now), I'll be able to talk to the machinist personally about what I'm really wanting to do. My combo is a few threads down if you're interested.

Has anyone built an engine without having it balanced? And had something go to crap because of it? Or better yet, gone without and had no problems?

Like they say.... if ya want it to last and run well... get it balanced. If you want it to run... don't.

I have built balanced motors, built motors without balancing them. The balanced ones always run better and last longer.

I would spend the $$ and get it balanced.

Yes, my junk 301 that I built way back when was made out of the following parts;

'55, 265 crank.
Who know's what thicker 283 rods.

A junk -097 solid cam that I coffeee canned the lifters on and it ran fine!!

A worn out, small journal, 327 block that I installed el-cheapo, W/JCWhitney, 1/8th over, 1/8th inch tall, half round domed 283 pistons in along with the '55, 265's small valved heads with Z- springs on it that I ground h-ll outta!!

The rest was my stock, L-48's Q-Jet intake and exhaust manifolds.

It wasn't balanced AND I ran it above 7,000 rpm just ta clean the plugs every time I got the chance!!

It had about three harmonics that it used to go through before it got above 7,000rpm and I could tell my rpm by it's vibration, believe it or not!!

Yes, balance the sucker AND it will run a whole lot smoother and last a lot longer...

pdq67

PS., and my old 301 had a nasty habit of throwing it's damper going down the road at like 55 mph a couple a times!! It made a heck of a racket as it went out under the front of the car at speed !!

Last time it happened, I didn't find it so I just went to the Boneyard that following Sturday I had worked at in the summer while going back to school and took a RR track bar and beat another one off a junk motor and installed it AND kept right on going!!

lets put it in simple terms for you balance the motor to the .01 of a gram look at it like this if you was on a uni cycle thats a one wheel bicycle and you was travling down hill at say 80 mph and your only rim was wobbeling how long do you thing you would last./ ? now picture the same event with a true wheel that didnt wobble . the bent rim you,d be breakin your neck and gettin all banged up . the straight wheel and you would make it to the bottom and suffer no damage. thats a lame explanation but i think it makes a clear point as to why get the best balance job you can afford. really your spending your money and you want your motor to last and run smooth a long time and make good power right.

I've built quite a few motors and NOT balanced. Some of these were 6000+ rpm BBC's...

However, they used relatively stock parts, as in stock rods, stock replacement pistons, etc.. No stroker motors, non-OEM rods, etc.

If you change any component that would change the weight significantly, the factory "balance" is no longer good.

The factory balance is not anywhere near what a machine shop would do anyway, but in the car you'll never know the difference.

However,
I will say that if you ever watch a crankshaft spin up on a balance machine you will want to balance every motor you ever do after that...

Even a set of replacement pistons can weigh significantly different. Replaced the old GM forgings in my 427 with TRW L2268's, which were the stock replacement piston.
30 grams lighter even though they were a larger bore size...

Since the motor was previously balanced I did some trick work to the rods to get it all back close without rebalancing the crank.

If you are gonna run it hard I'd definately balance it...

Definately going to balance, I think the way you put it about the bike and the wheels... etc. Made it easier to understand. Being a daily driver and something I want to last a long time I'll definately be getting it balanced this week.

If you do have it done I would suggest one thing...make sure you get a balance sheet that shows what it was and what it is now. It should be balanced to at least within a gram.

And have it internally/nuetral balanced, that way if you need to change the balancer or flywheel/flexplate down the road it will be simple rather than rely on matching the balance to what's on there when it was originally balanced. The engine will rev much nicer/faster/smoother if it's balanced. And get the balance sheet as previously mentioned- handy if you need to order replacement parts down the road and have to match the weight of a component.

Parts all back in the shop getting balanced! The crank needed a "crank kit" Which was quite pricey, the journals had seen some hell, but everythings getting gone this week. Boy do things ad up ;) Merry Christmas to me....