Prop extension cost

[GAHco]

I believe Sensinich will also provide you with the proper bolts.

They may look like AN bolts, but they are not.

The thread length is extended to work with the bushings that go in the crankshaft flange. AN Bolts have a shorter thread made to work with full height locknuts or shorter nuts depending on your application.

If you are buying an extension kit or even a new FP prop, make sure it comes with the proper fasteners. They are NOT cheap or easily obtainable.

BTW I do not sell 'Prop Bolts" those should be obtained from the propeller manufacturer.

I do sell AN bolts that will hold props on, but you would have to use locknuts and special bushings for the Crank Flange from Lycoming that have NO THREADS.

[frankh]

Originally Posted by java

...and even if you could get the FI components to fit, you'd have to get very creative with the intake, since it would be tough to do via snorkel from the round cowl holes.

The reason I ask long vs. short is because I like the combination of FI, the speedier cowl and ability to do aerobatics, but I've also read that aero is somewhat of a no-no with the prop extension. Is this urban myth or real (i.e. I can have any two of the three, but not all three)?

Urban Myth!...Remember the recent airplane with an 8"...Yes that 8 inch prop extension, C/S prop and rated to +16G's......Wow!

Yes I researched this at length and came to the conclusion it was fine.

Remember the RV is not a Pitts, the guyroscpic forces are simply not going to be like on a hard aerobatic machine, the RV is for sport aerobatics. Not an issue.

Eh? snorkel?....There is a ram air intake, no connection to the cooling inlet holes and would be impossible to do i think.

Frank

[Jaknjoan]

I recently installed a short SJ cowl on a -7 with a Hartzell C/S for someone else.

The only thing I can add is that the SJ cowl is really made for the 4 inch extension, by Sam James' own admission. It does work with both 2 1/4 and 4 , but the 4 inch extension will provide you with a better transition from the plenum to the intake rings on the cowl. The longer cowl will give you a better appearance IMO. This also applies to the transition of the air intake for carbureted engines to the small intake ring. The more flexibility in the take transition tube makes cowl installation easier.

JT

[pierre smith]

Hi Chad,
Your signature says E6 Subaru. If that is what you're putting in the 7, then the openings may well be too small for the two radiators that sit behind them. Be careful with this issue. A friend has the 4 cyl Sube in his 7 and it runs hot.

Are the radiators still behind the cowl openings on the E6?

Regards,

[frankh]

with the c/s prop...its 2 and 5/8ths....The 4" was for FP props I believe.

With the 2.25" extension I only had about 1/2" or so to trim off the back edge.

The cowl was designed to fit the Hartzell extended hub with no extension...The differenece between the extended (M hub) and compact (C hub) is 2 aand 5/8ths

Frank