A

Antoine.S

Member
Hi every one,
I would like to know if any of you, got the metal sensenich 70cm7 81" propeller on a O-320 160hp RV-6.

My actual set up is O-320D1A with the metal sensenich 70cm7 79" on a rv6 with old wheel fairings. Total use of all 200H
I do only fighter aerobatics (use the energy!!!) sometimes and most of the time speed cruise.
I never goes over 8500ft
My plane weight 465kg or 1025lb so my climb is around 1500ft/min at 100kt
1325ft/min loaded at max.
So A little cut in the climb perf is acceptable (no mountain flying)

At 7000ft full open my engine run's betwen 2700-2800RPM. (Depend's of density alt but anyway Never under)
So i always reduce rpm..
This prop as limation to 2600RPM so impossible to use the motor over 50-60% of power during cruise.
At 2400RPM the true speed is around 145kt +/- 5kt (21-22 inches mercury)
At 2500RPM the true speed is around 155kt +/- 5kt (22-23 inches mercury)

Around 2000ft wide open gives more than 2800-2850RPM.. again i need to reduce throttle 50 open to get 2400-2500RPM
I would like to use the same RPM range with trottle around 75%

160-165kt around 2500 2550RPM

(Plan to get the new wheels fairings)


I've read that +1" on pitch give -40RPM on level flight

So 79" to 81" pitch will give: +2" -80RPM

Transfer all my actual RPM numbers down of 80RPM for the same trottle position

In that way it will be possible to increse the usable power without overspeed the RPM, and increse my cruise speed.


Am i right?

What is better: kip it like that?
Add 1" so use a 80" pitch?
Add 2" so use a 81" pitch?

With or without new wheel fairings?

Is someone with one this set up can give me numbers?

Thank you all

Antoine
 
I have a 15 year old RV-6 with the pressure recovery (new style) wheel pants and Rocket gear and intersection fairings. Engine is O-320, carb, and the prop is the metal fixed-pitch Sensenich. It was repitched many years ago by a local shop from 77" to about 80" pitch. I say 'about' because it turns out the shop had never worked on this prop and there was some question of exactly how it ended up.

2400 map and 2400 rpm yields 152kts TAS below 5000' DAS. It still has a little throttle left at the 2600 rpm limit and sees 162kts TAS.

I think you will find 80" to be an excellent compromise between climb and cruise. And by all means install the pressure recovery pants and clean gear and intersection fairings, they will be worth a few knots and make the plane look a lot faster. ;)

My prop story:

http://thervjournal.com/fairings.htm#repitch

Installing the wheel pants:

http://thervjournal.com/fairings.htm
 
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RV6 70cm 79

I have a Rv6 with the 70cm 79 sensenich prop.. I have the old style wheel pants and cruise at 180mp always and that's at 4000ft .. and climb 1500fpm half tank .. Very pleased with my performance.. Everyone ask me what prop I have .. As far as I'm concerned it's the perfect match with my 0-320 160hp.
 
You could also spend the big money and buy their ground adjustable carbon fiber prop and be able to adjust it :D Mine is a great performer, my bank account is still hurting from the purchase though. :p
 
If you have the Sensenich prop with the 2500 RPM limit, I am not sure I'd be going past that limit. Sensenich has pretty serious warnings about even making sure your tach was properly calibrated at the 2500 RPM limit. I had some insight to the engineering aspects of the prop stresses and they seriously escalate above the 2500 RPM. Potentially shortened the fatigue life of the prop to something under 1000 hrs.

I'd hate to see you loose a blade. Gets kind of nasty.
 
Great to get all these numbers! Thank you guys!:)

I think that the best thing i can do is make a little video and it will be perfect for you all to tell if yes or no, a modification is needed.

If you expect that the difference of cruise speed will be under 10kt, with the new fairings and new pitch i think it will stay as it is actualy. ;)

(Excuse my english i eat frogs ;) ):D

A little surprise about headset will be include in the video... :cool:

My be the 79" / old fairings will appears a good combo for you. :eek:

I'm only frustred to led the throttle handle so down during cuise to not exeed normal cruise rpms. :eek:
 
RVDan said:
If you have the Sensenich prop with the 2500 RPM limit, I am not sure I'd be going past that limit. Sensenich has pretty serious warnings about even making sure your tach was properly calibrated at the 2500 RPM limit. I had some insight to the engineering aspects of the prop stresses and they seriously escalate above the 2500 RPM. Potentially shortened the fatigue life of the prop to something under 1000 hrs.

I'd hate to see you loose a blade. Gets kind of nasty.
Click to expand...

The prop limit is 2600 rpm and yes, I too believe it should be absolutely observed. Antoine, there is no need for you to exceed 2600 rpm in your video. :)
 
Back from the sky and after 1h30 of testing (never over 2600 :) )
i can tell you that i was victim of a "psyhsich fixation" betwen my last flight after the one i've opened this thread and the flight of today..
Some times a flight feel's different than the others and you fix on it... :p

Today at 8000-8500ft my gaz throttle was wide open and the rpm were exactly 2600RPM with a 165kt TAS confimed by the gps... My climb rate on take off is around 1700ft/min solo with half tanks and parachute on me.
At 6500ft it was still 1500ft/min without trow it hard:)

And as jordanrv6 i got exactly the same 180mph or 155kt at 4000ft.

I need to thank you all for the numbers you give me, and advices.
This confimed me that my set up give me normal performance for a 6 with 320hp and some aerobatics during airshows..
New pant's seem's to me useless after studies cause i need big clearance on my wheels due to use on lot of french grass strips with unplane surfaces... (Afraid to crash those new lower fairings)

Thank's to: sam, dan, jordan, Neal. So nice from you to answer so rapidly.

So as my decision is to keep it like that,

i will not boring you with a useless instrument video, BUT don't sharing a video i've promised is not cool :D

So here is a short in-flight video of a very special headset.. ;)
 
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