14A Thunderbolt 390-EXP119 prop?

[BOHICA]

Originally Posted by lipper03

Which two blade did you go with?

Hartzel 74" 2-blade Aluminum C2YR-1BFP/F7497

[lipper03]

I ordered the MT-12-B/188-59f today after a few questions and pro/cons from Kevin in van's tech support. Excited!

[Walt]

Originally Posted by lipper03

I ordered the MT-12-B/188-59f today after a few questions and pro/cons from Kevin in van's tech support. Excited!

You may want to talk to the folks at McFarlane about your choice (plus I think they can offer a better price than Van's).
No restriction on the MTV-9, probably less maintenance due to the heavy duty hub, ok with EI and higher compression.
I personally chose the -9 to run on my IO-370.

• MTV-9 Heavy-Duty 3-blade hub is recommended over the MTV-12 series for use on engines without counter-weights,
and for engines with 'more than stock output'
• MTV-12-B/183b Medium-Duty hub is limited for use on engines with factory timing, standard compression and 6th
order dampened crankshafts - it may also require restricted RPM operation ranges.

[lipper03]

Well that’s why I was asking vans, they didn’t say there was a restriction or limitation, McFarland can confirm that?

Originally Posted by Walt

You may want to talk to the folks at McFarlane about your choice (plus I think they can offer a better price than Van's).
No restriction on the MTV-9, probably less maintenance due to the heavy duty hub, ok with EI and higher compression.
I personally chose the -9 to run on my IO-370.

• MTV-9 Heavy-Duty 3-blade hub is recommended over the MTV-12 series for use on engines without counter-weights,
and for engines with 'more than stock output'
• MTV-12-B/183b Medium-Duty hub is limited for use on engines with factory timing, standard compression and 6th
order dampened crankshafts - it may also require restricted RPM operation ranges.

[Walt]

Originally Posted by lipper03

Well that’s why I was asking vans, they didn’t say there was a restriction or limitation, McFarland can confirm that?

Suggest you reach out to McFarlane prop guys (very experienced with MT) or MT itself for more info.

Note the warning on Van's page (not approved for EI):

WARNING: Damage or excessive wear to the engine or propeller may occur if electronic ignition systems are used and timing is
set to a value other than the fixed timing stated by the manufacture (for Lycoming this is labeled on the engine dataplate).4-cylinder
engines 195hp and above must include 6th order crankshaft counterweights and operate within the engine manufacture's timing specifications if electronic ignitions are installed when using the following propellers MTV-12, MTV-15, MTV-18, MTV-20 and MT 185. Lycomings electronic ignition system (EIS) for both standard timing (matching the fixed timing used previously on Slick magnetos') and the advanced timing curve are allowed for use with the following propellers MTV-12, MTV-15, MTV-18, MTV-20 and MT 185. MTV-9-B/183-50a propeller must be used with 4-cylinder engines 195hp and above if 6th order crankshaft counterweights are not installed or electronic ignitions are installed that are operated outside the engine manufactures timing specifications.

The -9 hub was made for higher HP engines, thus handles more 'abuse' without strain (=lower mntc costs).

See this thread for discussion on this subject:
https://vansairforce.net/community/a.../t-192407.html

Type certificate data sheets for MT can be found here:
https://www.mt-propeller.com/en/entw/pro_hydr.htm

Maximum Continuous Power @2700:
-12 = 300, 44 lbs
-9 = 421, 53 lbs

[lipper03]

Thanks Walt, I'll ask McFarland, now that I'm freaking out!

[Walt]

Originally Posted by lipper03

Thanks Walt, I'll ask McFarland, now that I'm freaking out!

No need to freak out, lots of folks use the -12, the cost for the -9 is 'only' about 1k more, to me it was worth it.
If you plan on ever running Pmags or any other EI then the -12 is not recommended.

[lipper03]

Haha I’m using pmags

[MS19087]

I have an exp119 WITH accessory case. So a bit heavier than the normal-119. In fact when I’m solo I put ballast in the luggage area. Otherwise I can’t get a nice flare on landing. My CG stays within limits under all scenarios assuming gross weight is observed.

[lipper03]

I did get a change to talk to Larry at McFarland today, and both 9 and 12 are acceptable. The 12 does have a shorter recommenced TBO and may see bearing wear more then a 9, but no safety of flight or RPM or other limitations for an RV14A with a EXP119. I'm checking back with Vans to make sure I understand the color options and delivery assembly vs ordering with McFarland. Thanks Walt for the suggestion!