dynamic balancing and chasing your tail

[RLCarter]

50 minutes ago, Cyril Gibb said:

I’d view it as 2 1/2 types.  For massives, there are also BY plugs with an extended nose designed originally for oil fouling on the bottom plugs. An additional advantage is the same price as other massives.  Also the theoretical advantage of firing more within the cylinder fuel mixture rather sparking at the edge of the cylinder head which, again theoretically, should give the effect of more spark advance.

Works for me.

I would use caution installing protruded electrode plugs, might end up with a smashed plug and a damaged piston crown 

[Cyril Gibb]

1 hour ago, RLCarter said:

I would use caution installing protruded electrode plugs, might end up with a smashed plug and a damaged piston crown 

Incorrect.  They are appproved for our engines and have bags of clearance.  We aren’t dealing with high compression pistons in a high performance engine.

[jaylw314]

9 hours ago, Dan at FUL said:

What was the time frame for this "quiet" change to the Champion design?

I don't know.  I remember hearing it listening to one of Mike Busch's old EAA webinars, so I don't have a reference or anything.

[kortopates]

What was the time frame for this "quiet" change to the Champion design?

Over a year ago. Their new design is just like Tempest with an integral resistor which should make it easy to tell what kind they are.


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[Cody Stallings]

On 10/19/2018 at 2:20 PM, jaylw314 said:

I've got a hard time imagining you could balance at two different RPM's.  Not an A&P, but the guy who did the balancing just wanted one RPM.

In terms of plugs, people seem to prefer Tempest over Champion by reputation.  People seem to think fine-wire plugs are worth it, but it's a cost/benefit problem.

If you have plugs bad enough to affect ignition, that should have been apparent on either the runup or an in-flight mag check with a 4-cylinder engine monitor.  Not clear if you have an engine monitor.

I personally like to balance at two different RPM’s.

Reason being, you can aquire a clock angle on the Prop at say 1300rpms then raise to 1800rpms an Check that the clock angle is in roughly the same place.

Im most cases it will be, but the few times it swings 180 degrees, that means you have a blade tracking issue. When that happens you need to have that Repaired before you go any further.

Also, when Balancing a propeller, you want to be aware an have the guy at the controls to do his part to make things as smooth as possible.

That comes by way of the Mixture knob.

Some folks are reluctant to lean when on the ground, but trust me an engine that says IO an has a Bendix RSA-5 servo will make you pull your hair out.

They are extremely Rich an rough on the ground full rich.

I have also had great success Balance Propellers not on the Governor. Just a spinning Propeller.

After it’s balanced, running it up to say 2200-2300 to verify the balance doesn’t change is okay. 

If you Balance say at 2400 “ where it’s run at” an it’s rough at every other RPM, then there is an underlying problem.

Little food for thought:

What if I was to say your not really Balancing your Propeller, while your Balancing your Propeller...:)

[Shadrach]

2 hours ago, Cody Stallings said:

Little food for thought:

What if I was to say your not really Balancing your Propeller, while your Balancing your Propeller...:)

I would say I agree. A dynamic “propellor balance” balances the reciprocating mass and the aerodynamic forces. If these forces weren’t in play, a quick static balance would be adequate.