Anybody here run a wood sensenitch on their cub?

The cub in question is a standard a/w cert, and 160hp.
I know the all time gold standard is the Borer, and I have had several over the years.
I also know which flavor (pitch) in a Borer works best in this airplane for what I do (82/41).
But in light of what I, aktahoe, and several others, have recently learned with our 180's,
sometimes the gold standard leaves a little to be desired. Specially if your mission isn't
exactly where that gold standard shines.

The woodie Sen appears to be as much as 30# lighter than a Borer. My experience has been
that when I am stuck on something really, really short, my Borer isn't making full RPM until I
am well into my roll. And if it is that short, the roll at that point is usually on water, which is
OK, but if there is something else ending the useable take off area, then it may not be OK.

In my mind a quicker spooling prop, is frequently better than a prop that ultimately
pulls harder, This is certainly the case with the 401 vs the MT, and if the woodie Sen comes
close to the Borer, then it just may be the same there.

I am aware that metal will take a better hit than wood, but with 6" extended gear and 35"
tires, sucking up rocks isn't much of a concern. And in the event of a much larger hit, the
wood will probably save the day for the engine. 6 bolts and a couple of screws later and a
guy could be ferrying the airplane home, where a metal propped airplane just mights had
a twisted crank, busted cam / mag gears, etc...

Anyways, just wondering... I know Jim Drometer has sold a bunch with his STC, but just
recently realised that when you buy the STC from CC to hang a 160hp engine on a cub, the
wood Sens is covered on that STC. So in otherwords a guy in my position is a log book entry
deal.

Any thoughts out there?

Take care, Rob

If spool up is a concern and hittin rocks is not, could you just hold brakes until your engine is making max rpm?

The metal props also tend to be more efficient so your extra 30lbs is not only more durable it also tends to make moire thrust for a given rpm.

soyAnarchisto wrote:If spool up is a concern and hittin rocks is not, could you just hold brakes until your engine is making max rpm?

The metal props also tend to be more efficient so your extra 30lbs is not only more durable it also tends to make moire thrust for a given rpm.

Appreciate the input...

A couple thoughts tho...1) Rocks are not a concern because I dont do things like lock the brakes and pour the coals to it.

And 2) being bound by a standard A/W means I have to abide by the STC which spells out a max static RPM. Max Static and max engine RPM (where you are producing max rated horse power) are not the same thing, so even locking the brakes and pouring the power to it isn't getting you where I want to be.

Thanks anyways tho

Take care, Rob

If I am in a really tight strip I add full power while doing a 180 to rwy heading to give time for spool-up so by the time I am a round i am at static RPM. So that eliminates spool-up on take off.

Rob wrote:
The woodie Sen appears to be as much as 30# lighter than a Borer. My experience has been
that when I am stuck on something really, really short, my Borer isn't making full RPM until I
am well into my roll. And if it is that short, the roll at that point is usually on water, which is
OK, but if there is something else ending the useable take off area, then it may not be OK.



Anyways, just wondering... I know Jim Drometer has sold a bunch with his STC, but just
recently realised that when you buy the STC from CC to hang a 160hp engine on a cub, the
wood Sens is covered on that STC. So in otherwords a guy in my position is a log book entry
deal.

Any thoughts out there?

Take care, Rob

From what I've read, there is only about a 17 pound difference between the woodie(18 lbs with stainless LE) and the Borer (35 lbs). Not that 17 pounds off the end of the nose isn't significant...I also think there are more benefits than just lighter weight, although not necessarily benefitting the takeoff performance.

I think the only way YOU will ever know for sure is to try one!! I would like to hear what you have say about the wood prop, as I am thinking about going that way myself....though I'm only at the beginning stages of learning what the supercub can do, and also what I can do, so my performance report wouldn't be as valuable as yours!!

While I totally appreciate the input so far it seems the only one who can really answer the question is someone who has run a Borer and the woodie sen back to back.

Just for clarification;
I am making rated static RPM. I am also easily making max engine RPM (and beyond) once airborne. What I would like to shrink up is the time it takes to get to static, as well as the time it takes to get to max engine RPM once I am rolling.

I have run this combo with the prop twisted to 40, 41, and 42. At 40 it zips right up and will make you smile, although it's stuck in first gear once airborne. However 40 is below the STC criteria, it was just how I bought the prop... SO I twisted it up to 41 (the minimum pitch allowable by the STC). 41 was still good, but that 1 " cost at least 50' in a real life take off scenario. Worse than that, at 41 it would static 2475, which is above the STC criteria (Minimum static-2350 ; Maximum static -2450, BTW,this is quite a bit short of max engine RPM and consequently max available horsepower) So I twisted it another inch, and at 42 it takes another 50 +/- feet (now 100' penalty) and is a slug.....

Now I know several folks running 82/39s on their 160 hp cubs, and they rip right off the ground and nothing disastrous happens... and in the event of an all out FAA shake down, it would be hard to imagine anyone noticing the prop is twisted just a touch flat, but.... I just want to know if there's a better way because while the airfoil of the metal prop may indeed be a more efficient shape, the weight alone will allow a steeper pitched but lighter prop to wind up faster, and yet keep providing increase after the flat metal signs off.... The MT on 180's is a great example, the Cattos and Whirlwinds on EX cubs is yet another....

cstol... your tip serves well if you have the room. The places I am concerned with are tight enough that a point and shoot, make it stick departure is the concern...

So.... any woodies out there?

Rob

Get on Supercub.org and send a PM to John Brietenger. He ran a sensinich prop on a 160 powered wide body cub.

MTV

mtv wrote:Rob

Get on Supercub.org and send a PM to John Brietenger. He ran a sensinich prop on a 160 powered wide body cub.

MTV

Thanks Mike,

I actually know the gent who bought that cub and chatted with him some in hopes of learning a bit about it. Since then I have talked with Craig Catto about the rumors of his prop getting certified, and he is indeed persueing that. Right know a Catto sounds far more interesting to me so I will stick with the Borer until then!

Tanks again, Rob