How many of you get your clutch and pressure plate balanced?

[Sagaris]

Just wondering how common this is. I plan on doing it because im flat out OCD. Does anyone else have this done?

[whodwho]

Typically the flywheel is balanced and then the PP is balanced on the flywheel and it's position marked. Not common to do when not rebuilding the engine but not a bad idea as it is a massive chunck of rotating metal :)

[jlevie]

A stock flywheel will be balanced. If you modify it, it will need to be re-balanced. In a like manner a new unmodified pressure plate should be already balanced.

On a street car engine I use the parts without having them balanced. But on a race engine the entire rotating assembly (harmonic balancer, crankshaft, flywheel, and pressure plate) is balanced as an assembly.

[bastianshaw]

A stock flywheel will be balanced. If you modify it, it will need to be re-balanced. In a like manner a new unmodified pressure plate should be already balanced.

On a street car engine I use the parts without having them balanced. But on a race engine the entire rotating assembly (harmonic balancer, crankshaft, flywheel, and pressure plate) is balanced as an assembly.

How is balancing the entire assembly achieved? I don't even see how that is possible?

[xwill112x]

How is balancing the entire assembly achieved? I don't even see how that is possible?

Weighing everything very precisly and removing material when needed.

[jlevie]

How is balancing the entire assembly achieved? I don't even see how that is possible?

You put the assembly on a balance machine and have at it. Obviously this is only done while the engine is being built (or rebuilt).

It may seem that you'd run into problems later when the clutch needs to be replaced, but on a NA M20B25 in a race application you'll be rebuilding the engine before the clutch needs to be replaced.

[bastianshaw]

You put the assembly on a balance machine and have at it. Obviously this is only done while the engine is being built (or rebuilt).

It may seem that you'd run into problems later when the clutch needs to be replaced, but on a NA M20B25 in a race application you'll be rebuilding the engine before the clutch needs to be replaced.

let me get this straight, the crank is pulled from the block? flywheel, and driveshaft and pressure plate are all balanced together, marked then reinstalled?

[MR 325]

let me get this straight, the crank is pulled from the block? flywheel, and driveshaft and pressure plate are all balanced together, marked then reinstalled?

No, the flywheel and pressure plate are balanced as a unit. (No clutch disc)

It's common when building a performance based engine but TOTALLY unnecessary to do during a clutch replacement.

[jlevie]

let me get this straight, the crank is pulled from the block? flywheel, and driveshaft and pressure plate are all balanced together, marked then reinstalled?

Correct!

The balancing is a part of a race engine build. During the build extreme care is taken with respect to bearing and piston clearances, rods and pistons are weight matched, ring gaps adjusted, and pistons and rods are juggled to get uniform deck height. We also tweak a new oil pump & OPR for higher oil pressure. Since the head is where the power is made that gets a lot of attention. The cam (new or used) will be blueprinted, rockers polished to eliminate stress risers, valve springs matched, three angle valve grind, etc.