IS having machine shop balancing a stroker assembly necessary?

[rjrobin2002]

Thinking of stroking a 5.0 and reading on some mustang sites where they talk about balancing is a must. Is this cause they are drag racing and spinning 6-7000 RPM?

Or do 99% of people just assemble them like a stock rotating assembly and rock on down the road?

 

[904Bronco]

Thinking of stroking a 5.0 and reading on some mustang sites where they talk about balancing is a must. Is this cause they are drag racing and spinning 6-7000 RPM?

Or do 99% of people just assemble them like a stock rotating assembly and rock on down the road?

I don't build a motor these days without doing a balance of the rotating assembly. The cost here is not that much in comparison to the overall cost of the rebuild. Call it piece of mind or a left over mind set when I used to open track a Fox body Mustangs ;D

Doug

 

[bronkenn]

I always have them balanced. I just did a 331 with a Scat crank and rods and Wiesco pistons and they were pretty far off. As 904 said it is well worth the piece of mind. I think it was around 125 bucks to have done. Ken

 

[NicksTrix]

If you don't want them to shake...
For sure do it. Don't forget to send in flexplate or flywheel

 

[Master Chief]

I bought this balanced Eagle kit through Jegs. For options I chose Mahle forged pistons and Clevite bearings. Engine runs strong with no issues.

https://www.jegs.com/i/Eagle/356/B16006LA030/10002/-1

 

[Broncobowsher]

Most of the kits come already balanced.

A stock build you are dealing with stock specs and they generally come close. A stroker is a mix of parts. So much stuff far from stock. Get it balanced.

Watch the old YouTube videos on the flat head V8 and those were even balanced when new

Will never do another engine I care about without balancing. It does make a difference

 

[blubuckaroo]

I've noticed a confusion about engine balancing.
There's both the static balance and dynamic balance.
The static makes sure the piston/rod assemblies are the same.
The dynamic balance makes sure the crank, flywheel, clutch/torque converter, and harmonic balancer are balanced.
Most new cranks, flywheels, and harmonic balancers are already balanced. But how they behave together may be imbalanced.
If you plan to run over 5K RPM, have it checked.

 

[rjrobin2002]

I was referring to dynamic balanced, though I didnt know it's real name.
The kits that include the harmonic balancer and flywheel and are advertised as balanced are dynamic balanced I assume.

 

[sykanr0ng]

The original question goes to the point often made that a stroker should be built as an internally balanced engine, meaning zero imbalance and using a harmonic balancer and flywheel with no imbalance weights.
The arguments I have seen for that are well made.

 

[bmc69]

I rarely build any engine without having it balanced. I take care of weight-matching the rods and pistons in my own shop so that I only have to send one rod/piston/rings assembly to the balance shop.

As automotive machine shops closed up one by one in our area, a buddy of mine and I bought up various equipment as it became available and a good balance machine is about the only thing left on our "want list".

There are some corners that I never cut when building a new engine:

1. Do final bore hone with torque plates installed.
2. Line bore/hone the mains journals.
3. Square deck to the crank centerline.
4. Balance the rotating assembly.
5. Recondition/resize the rods (if used rods)

 

[blubuckaroo]

I was referring to dynamic balanced, though I didnt know it's real name.
The kits that include the harmonic balancer and flywheel and are advertised as balanced are dynamic balanced I assume.

If these come as a kit, and are advertised as a balanced assembly, I'd use it as-is.
As far as I know, there aren't any other rotating parts involved.

 

[bmc69]

I was referring to dynamic balanced, though I didnt know it's real name.
The kits that include the harmonic balancer and flywheel and are advertised as balanced are dynamic balanced I assume.

Yes..that's the only kind of balancing that matters actually. If they are selling the entire rotating assy as having been balanced then it should be ready to install.

 

[Broncobowsher]

If the kit is already balanced, the local machine shop doesn't need to do it again.