Prop Hub Bolt: How to hold crank while tightening?

[Gunther]

Hello to all. I'm ready to assemble my AeroVee with the factory-installed hub. Step 10 in the manual calls for torquing the bolt to 80 ft-lbs. How does one hold the crank while torquing? I'm tempted to try clamping the crank to a table but there must be a better way. I doubt if even my mother-in-law could hold it.

I'm looking forward to assembling this engine. The packaging, labelling, instructions and support are all first class.

Thanks,
Gunther

[SonexN76ET]

Hi Gunther,

If you purchased the option of the pre-assembled crankshaft and hub, the factory has already torqued it to the proper torque.

Please check your Aerovee manual, I believe it says to skip that step if you have the preassembled crankshaft and hub. However, DO NOT TAKE MY WORD FOR IT. Check your manual!

This came up for discussion awhile back as well and I believe that was the concensus. I will look up the previous posts.

Jake

[Bryan Cotton]

What I have done on other motors for a similar situation is to turn back from TDC and feed a length of closeline in through a spark plug hole. It does not compress and you can tighten or loosen the nut. Not sure if this will work here as I have not built my aerovee yet.

[mike.smith]

What I have done on other motors for a similar situation is to turn back from TDC and feed a length of closeline in through a spark plug hole. It does not compress and you can tighten or loosen the nut. Not sure if this will work here as I have not built my aerovee yet.

The step he is talking about is the bare crank, before being assembled in the engine. I just rebuilt my engine last week and I have to admit I couldn't come up with a good way to hold the crank without damaging any metal (I originally bought the pre-assembled prop hub). So I just tightened it down with my air-powered impact driver. No torque value; just whatever the driver gave me. The bolt is important insurance, but I'm pretty sure the shrink fit and woodruff key are going to keep it from going anywhere.

[vwglenn]

I'd get an old VW flywheel (easy for me I have a couple in the garage) secure the crank to the flywheel and temporarily screw/bolt the flywheel to a bench and apply my torque.

[Arjay]

Can't you just put the crank in a vise to hold it while you tighten down the bolt?

[mike.smith]

Can't you just put the crank in a vise to hold it while you tighten down the bolt?

Most surfaces of the crank are critical wearing surfaces. Would not be a good idea to use a vice. Besides, half the weight of the engine is in the crank. It's heavy! Tough to hold such an animal in the average work bench vice.

[Gripdana]

I did mine when the flywheel was installed and secured the flywheel.

[mike.smith]

I did mine when the flywheel was installed and secured the flywheel.

That has to fall into the "why didn't I think of that" category! No reason the bolt has to be set before installing the crank. It can be done after the engine is built. :-)

[Rynoth]

Can't you just put the crank in a vise to hold it while you tighten down the bolt?

Most surfaces of the crank are critical wearing surfaces. Would not be a good idea to use a vice. Besides, half the weight of the engine is in the crank. It's heavy! Tough to hold such an animal in the average work bench vice.

With a big enough vice you could do this with blocks of wood to protect the crank. This is how I did it, but my vice was barely big enough and the crank still wanted to twist as I approached proper torque, had to be careful.