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Cranking Engine to Check Spinner Alignment

C

Chris Engler

Active Member
I'm in the process of adapting a Whirlwind 15 inch spinner to a Sensenich ground adjustable composite prop and would like to check spinner runout (I'm using the Showplanes cowl that requires a 15 inch spinner). Are there any issues with spinning the engine (Superior XP 400) using the starter without the prop blades attached? If this is feasible, should I remove one set of plugs from each cylinder to reduce compression and allow the engine to spin faster?
 
Spinner

By hand , easy to move before you drill . A cheap dial indicator is really handy for this .
 
Chris Engler said:
Are there any issues with spinning the engine (Superior XP 400) using the starter without the prop blades attached?
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JonJay said:
Turn it by hand. It will be easier to see the runout anyway.
Click to expand...

No blades attached---------how U gonna turn by hand???

If the engine has been "pickled", you need to consider what spinning it will do to the long term preservative coating.
 
Mike S said:
No blades attached---------how U gonna turn by hand???
Click to expand...

Easy!

If no prop is installed, then he must be using a spacer to simulate the prop hub
This can be risky BTW if you don't yet have the prop on the premises to confirm the dimension and you use the spacer while fitting the cowl).

What ever is used as a spacer can have holes in it for a piece of pipe to be used as a turning handle.

I agree with Mikes comment regarding the engine preservation though. Turning a pickled engine should be avoided as long as possible.
 
Thanks for the responses. I have the hub, prop blades, and spinner components....just thought it would be safer to rotate the engine without the blades if using the starter to spin. If turning by hand is the consensus, I can install the blades in the hub to rotate. Mainly looking to ensure the spinner rotates concentrically...sounds like using a dial indicator similar to the link below and rotating by had would be the best bet. The engine has been pickled but planning for a first start in the spring so thinking of adding the break in oil and rotating by hand won't be a problem at this point but let me know if this isn't correct.

http://www.harborfreight.com/clamping-dial-indicator-93051.html
 
Don't need dial indicator.

We simply clamped a pencil to an A-frame ladder and moved it 'til the point of the pencil was extremely close to the spinner point and we could easily see which way we needed to bump the spinner.

Best,
 
What a great tip. I would have never thought of that. And so simple.

pierre smith said:
We simply clamped a pencil to an A-frame ladder and moved it 'til the point of the pencil was extremely close to the spinner point and we could easily see which way we needed to bump the spinner.

Best,
Click to expand...
 
I used the pencil method and my spinner had to be offset slightly. This worried me after most the posts about the subject said the spinners usually are pretty close from the factory. I had my wife crank mine without the plugs so I could watch before I was truly satisfied. I had already cranked it before testing my oil lines and oil pressure on my used engine.
 
I used the pencil method today (thanks Pierre!) and was able to reduce the runout from a quarter inch to less than a 16th. Planning to pull the plugs and spin with the starter soon to confirm. I'm using the long acro spinner from Whirlwind so the slightest change at the flange has a noticeable impact on runout.

While on the subject of spinners, is it advisable to balance the spinner independently or just have the spinner/prop combo dynamically balanced once the engine is running?
 
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