Balance assembly to 28oz or 50oz

[arbailey]

I am going to have a new shortbock built by Rick, and said he prefers to balance his motors 28oz but he can balance it to 50oz so I can use my current (recently replaced) 50oz balancer, and new in the box stock replacement flywheel. Is it worth the extra $$$ of buying a billet 28oz flywheel and 28oz balancer to have it balanced to 28oz? Would I even notice the difference on a street driven car (below 6,000 rpms)? I'd ask Rick but he's away and I was wondering what you guys thought?

 

[Realmongo]

I would just stick with the common 50 oz. I had my new shortblock balanced to 50 oz along with the new Ford flywheel and balancer.

 

[86bluecobra]

the reason rick wants to balance it with 28 oz is because that would give the engine a internal balance as opposed to a extrenal balance. Internal balancing is a much better balance for a bottom end. however if you are not going to see above 6000 rpm either would be good. But i'm not a engine builder he is. I wouldn't not trust the guy. He knows his stuff.

 

[arbailey]

I'm 100% sure if it wasn't good to balance it to 50 oz he wouldn't even do it. I was just curious if others have come to this "fork in the road", and which way they went (and why).

 

[bubba-dough]

Yeah trust your engine builder. If he would do it, it is fine. If it were me I would just stick with the 50 oz and re-use my recently new parts. Now if you didn't have new parts I would consider the 28 oz.

 

[Grn92LX]

28oz.
I was going to do mine 50oz so I could be cheap and reuse my balancer/flywheel. Then I came to my senses and told him to go 28oz and he set me up with an aluminum flywheel and I bought another romac light weight balancer.

 

[302RollinHard]

There are some advantages to 28 oz vs 50 oz. But IMHO balanced is balanced is balanced. Unless you are gonna be winding it up to 8000 rpms or something crazy like that, you should be fine. Use the new parts that you already have. This isn't gonna be a race car is it??

 

[Busted07]

I had the same dilemma.. i had posted a thread asking about it, and most people said 50oz was fine.... so thats the route i went... i bought an eagle crank, eagle rods, and TFS forged slugs.. got the whole rotating assembly balanced and you can spin the motor over easily by hand now.. the only thing i didnt like was seeing the holes drilled in the counterweights of my shiny new crank... but.. its required.. i havent put the motor in yet, but everyone ive talked to said that its better to be at 50oz than to not be balanced at all

 

[R2D2]

50 on a motor that sees most street action is fine, internal is a better deal though. Some people on a budget shy away from internal as you can run into an aftermarket "ebay" crak that will take 5-10 slugs of mallory to balance it and mallory is usually 40 bucks a slug, so thats why people lean to the external 50. Which is fine for a 6k street motor

 

[vristang]

Yeah, 50oz balance is surely better than no balance.

When I made the decision to go with 28oz on my 408w, I had to make the same decision. I had a new 50oz flywheel and damper.

The flywheel can actually be rebalanced to 28oz. This is not done too often, but I have not heard of any risks, and it has worked very well for the last 13k miles.
I would by a new damper, and have the flywheel rebalanced with the rest of the rotating assy.

An aside - I didn't take the entire rotating assy in when the flywheel was originally done. They were able to balance just the flywheel to factory specs.

jason

 

[86bluecobra]

Vristang 351w are balanced to 28 oz not 50oz so your 408w should have been balance to 28 oz. Some people get them 0oz balanced at that point.

 

[2002BLGT]

Terry Walters here in Roanoke VA did my 306 using new 50oz balancer and new stock flywheel , and it revs almost as quick as my R1 ......so I would say 50 is fine unless you are turning 7K plus

 

[vristang]

Vristang 351w are balanced to 28 oz not 50oz so your 408w should have been balance to 28 oz. Some people get them 0oz balanced at that point.

I had the option of both with the rotating assy.

As I think about it now...
When I first did the 351w swap I used an old motor from a junk yard. Later on I rebuilt the motor to a 408w.

When I did the original swap (to a 351w) is when I had to make the first balance choice. The 50oz flywheel had a couple of hundred miles on it, and the damper was new on the shelf.

Sorry for any confusion.

jason

 

[arbailey]

This car is a street car (stock ported heads, stock ported intake, 3.55 gears, etc...) so the revs will be 5,000-5,500 (6K max). I'm sure once I actually talk to Rick he'll hook me up. Thanks for everyone's input/experiences.