Kissing the belt-driven alternator goodbye forever-

[Hartstoc]

I thought some of you might take interest in the process of complete removal of the belt-driven alternator from my RV-7A, including the drive pulley cast into the Lycoming flywheel. This link will take you to a photo album with detailed captions illustrating that process and discussing some of the many advantages.

https://public.fotki.com/Hartstoc/go...ven/?view=roll

I now have about 20 trouble-free hours on the installation above, and about 45 hours on the awesome B&C BC462-H spline-driven alternator with custom cooling shroud that made this all possible. That earlier story can be found here:

http://www.vansairforce.com/communit...hlight=Bc462-h

[Gash]

I enjoyed reading your write ups and seeing the photos. Very interesting stuff here Otis. Thanks for sharing!

[Hartstoc]

Originally Posted by Gash

I enjoyed reading your write ups and seeing the photos. Very interesting stuff here Otis. Thanks for sharing!

Thanks for the kind words! I?m certainly grateful for all the experience shared by others on VAF, and the feedback and questions generated in response to my own posts here can be priceless and completely worth the effort. What a great venue!

[MConner]

I like this idea for moving some weight aft on my nose-heavy RV-10. Do you have any weights for the pulley and belt. Is there much diffence in weight from a PP to the pad mounted unit?

Mark
40# ballast when solo.

[Toobuilder]

Considering the heft and location of the brackets and hardware for the belt driven version, going to the pad mounted example is probably a noticable moment change on the 540.

[MConner]

Agreed, the length of the motor moves the heavy alternator a long way forward. I saw the weight totals in the article. The process would be very simple if one left the pulley as is. No prop to pull and no mill work. I wonder what the pulley weighs?

Mark

[Hartstoc]

Originally Posted by MConner

I like this idea for moving some weight aft on my nose-heavy RV-10. Do you have any weights for the pulley and belt. Is there much diffence in weight from a PP to the pad mounted unit?

Mark
40# ballast when solo.

The pulley and belt amount to about 1.5#, but as someone noted the brackets, not to mention the heavy guage cable to the nose, and the alternator itself adds up. My brackets were aluminum, but many are heavy steel. Btw this IS covered in the captions under the photos, so if you mised those there is a lot of info there. My total removed was about 11.5#, whereas the pad-mount BC462-H weighs about 7.5 and is almost 24” further aft. If an honest 42 Amp alternator(45max) will serve your needs, then I recommend it highly. The custom cooling shroud that I built adds about 1/2 pound, but well worth it for the peace of mind of KNOWING that it is always operating in a super-benign environment. Please do go to that thread if you are considering conversion to the pad mount.

Sublty shifting my empty weight CG aft a bit is actually an intentional part of my overall plan. I’ll be starting a thread on this topic at some point- but if you want the most nimble RV possible, one that handles like a mid-engine sports car, you should bethinking about reducing polar mass AND dialing in your empty weight CG for a mid-aerobatic-envelope when flying solo with a light fuel load. The lightweight composite prop blades and the Alternator swap both provided me with these benefits, and my 7A handles like an Acura NSX as a result. For those interested, I reverse-engineered my EW CG to 80.5”. This still allows an aerobatic instructor and half tanks in the aerobatic envelope, or for me, my wife, 100# of baggage, and full-to-empty tanks to be wilthin the normal category envelope. Too-forward CG’s make for boring airplanes.- Otis

[Hartstoc]

Originally Posted by RV8JD

Just to be accurate, if that is within the Van's recommended GW of 1800 pounds, it would be in the Utility category.

Nice job on the alternator mod!

I stand corrected, utility category! It wasn’t necessary, but I’d have been willing to accept as low as an 85# baggage limit to achieve my “nimbleness” goals, but fortunately my wife and I combine to less than 300#, so thanks to Van’s incredible design, no sacrifices were required! An added advantage for the “A’s” is that moving to a slightly more aft EW CG target reduces nose wheel weight in all loading configurations. It DOES mean that you have to be slightly more on the ball as a pilot, and I would never consider violating Van’s published CG envelope in any loading configuration, not even by a little bit.

[dwranda]

Has anyone done this on an IO360 with the 90 degree oil filter adapter? I'm wondering if there is room for the alternator next to the filter.
[IMG][/IMG]

[airguy]

Like this?

IO360, 90-degree filter, 9A, B&C 410-H alternator. This is my backup to my belt-driven, since I'm electrically dependent for power and nav. It's close, but it works without any mods.