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Prop Governor Installation

Rob Erdos

Well Known Member
All,

My RV-6 project has a Mattituck TMX-IO-320 engine, and I'm installing a Hartzell prop governor for my new Hartzell C/S prop. I'm confused as to the fasteners required to install the governor.

See pictures of the governor drive at the following Photobucket site:

http://s1106.beta.photobucket.com/user/RVRob/library/governor_mount

The back of the engine has a prop governor drive pad, currently sealed with four mounting bolts. My best guess is that they are 5/16"x18TPI bolts. The problem is as follows:

1. The existing bolts are not long enough to go through the base plate on the governor (about 1" thick) and into the threads on the drive pad;
2. Three of the mounting holes are threaded through the drive pad (one hole is visible in the pics via mirror), but the top hole is a threaded blind hole. What was Mattituck thinking here? Is this Lycoming-standard?
3. The bolts do not appear to be an AN standard, so I doubt that they would be available with a drilled head. What provisions exist to safety the installation?

In short: confused. What hardware is to be used to install the governor? Do I simply find longer bolts? Are there supposed to be studs installed?

Thanks in advance,

Rob Erdos
Ottawa, Canada
 
studs, lock washers and nuts

Rob,
I have a PCU 5000X governor that was installed by AeroSport on a 360. It is attached by 4 studs into the prop governor mount, with nuts, washers and internal lockwashers. The mount is attached to the engine case with studs and washers/lockwashers as well. The distance from the face of the mount to the end of the stud that attaches the governor is 1 1/4 inch. The PCU flange that fits on the mount and through which the studs go is about 3/4 inch. The stud length you need will depend upon the flange thickness you have.
There is a gasket between the governor and the mount. Your pictures show bolts through a ribbed cover on the mount - I would think that this cover is unbolted and removed, proper length studs are installed, gasket, then governor with nuts, locknuts, and nuts.
Hopefully someone with the same governor you have will be able to describe exactly.
Also, you may want to ensure that the control cable bracket is clocked correctly before final install of the governor, it is easier to change and safety wire on the bench that on the aircraft. It probably is if it was supplied by Vans, but worth checking.
Bill Brooks
Ottawa, Canada,
RV-6A finishing kit
 
Hey Rob, I'll reinforce Bill's comments - you should mount some studs in the adapter. Both my Mattituck engines came with the studs in the parts bag - you might check to see if they are rattling around with the rest of the extra stuff they give you.

Paul
 
Also, the gasket

is kinda special. It includes an inlet screen section IIRC. Be sure to get the correct part number.
 
More on The Governor Installation

Thanks All,

My parts bag from Mattituck contained two studs, which I presumed were spares for the exhaust. To be fair, I told them that I wanted the engine configured for a C/S prop, but that I had planned on a F/P prop, so maybe they didn't think I would need the studs.

Now that I know that I need studs, the next question becomes, "what kind of studs". Is there a Part Number applicable here? Does Mattituck still provide customer support in their new locale? How do you install studs? I understand that torque is critical. How are they installed?

Oh, and thanks for the warning about the gasket. I did find the Hartzell Governor Installation Manual online (http://www.hartzellprop.com/service_support.php?id=81)
and the correct orientation of the gasket is specified.

Confused, but making progress,

Rob
 
For an O-360, but may be helpful.

2vnp201.jpg


20u1f9i.jpg


Dan
 
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