Vacman

My Feedback: (14)

Beave,
I sent my older SP-5 back to Germany for the mandatory $2K Gearbox upgrade :-(, now lost in the mail and I fear gone forever I fear (never ship USPS; lesson learned).

So I'm now considering the SP-10 or the K-100 by KingTech as suitable replacements. I fly at 6,000 ft MSL, so the SP-5 (with the additional huge chunk of lead up front for CG in the Tucano) was marginal power, at best. Any operation less than "full power" was pretty sorry (tail would drop, awful vertical, etc.). High Density Altitude operations knock off 25% of the rated performance and it only gets worse on warmer days (Denver, CO). The SP-5 would likely work fine enough at Sea Level, where I rarely operate anyway. The argument above for NOT going with the bigger engine is pure non-sense and couldn't be a more conservative view. No thanks, LOL. One can always pull the throttle back on the larger power-plants! The Tucano needs addition weight up front anyway, so why not go to more HP? As we all know, C-ARF builds an extremely strong airframe (I'm a big fan of anything C-ARF frankly), so absolutely no worries there! "JetCat", on the other hand, is currently experiencing Dealership & Servicing issues in the US, hence the K-100 consideration now (and I'm an old time, 15 year loyal JetCat fan :-( ). Bummer, but then, that would be a whole different thread, wouldn't it?

I can use a little assistance with the current upgrade I am considering (perhaps PMs would be better suited for our discussions?). No matter. All input is welcome.

Beave, were you able to use the stock C-ARF CF engine mount basically (mine is all black CF)? What did you encounter hogging it out to refit the SP-10?
Did your SP-10 shoehorn in with just a little effort or was it a major re-design required, in other words?
Are you currently using the 3-blade prop mentioned? That would be a plus, since I'd rather not have to buy another spinner for a 4-blade. You are using the 24/14 3-blade, holding the prop RPM to 7750 in flight? Is all of that still working out nicely? Is that the Biela? Have you landed on a suitable 4-blade yet? OR are you thinking that's not a huge concern now? Where did you find that 4-blade beauty?
Nuff for now, thanks...…….

LKL

Dave Wilshere

The stock carbon mount takes the SPT-10.
You can use a 3 blade Biela 25 x 12 TP version if you want to keep three blades.
The Four blade is a 24 x 12 Biela (24 x 14 is available but the 24 x 12 will suit the Tucano more)
Other than heat protection there is much else that will cause you a problem.

Dave

scoeroo

My Feedback: (9)

What rpm's will the SPT-10 gear box handle ?

Dave Wilshere

scrogerio

Dave Wilshere

Vacman

My Feedback: (14)

Fellas, I received my newly purchased JetCat SPT-10 engine and it dropped right into the C-ARF Tucano's CF Engine mount just beautifully. Very few mods were required to fit it and best of all, the measured weight of the earlier SPT-5 engine and the SPT-10 were exactly the difference in Lead Weight I had to add to the smaller SPT-5 engine set-up :-) . (I absolutely hate adding ballast weight to any airplane, LOL).
I was pleased to find that the forward engine mount (off the gearbox) was the exact same fit as the smaller SPT-5 engine. That helps! Exhaust fits beautifully too, (was the very same dimensions, offset, etc.). Great stuff.

I'm sure fuel consumption will be somewhat higher, but I don't intend to bomb around at full wick all the time, with this engine. I HAD to keep the hammer down on the smaller SPT-5 engine in the Tucano through-out every flight, since it's power seemed lack-luster here. I'm sure that didn't help the gearbox much either (clanky sucker anyway, LOL). So lowering the throttle during each flight with the SPT-10 ought to help in all regards. Might have to bump the fuel capacity up. We'll see. I know I'm going to have to bump the Smoke Oil capacity up a bunch. Andy Kane reports that he loads a gallon up when he's running smoke. OMG that's a lot of smoke oil! LOL But Andy walks on water in my opinion. So I'll have to look for a way to pack more Smoke Oil into the old Tucano!

Our friend Gerhard at AI, LLC kindly provided me with two beautiful Biela 3-blades (26/14 & 26/16), so I need not change spinners from my original 3-blade C-ARF CF spinner! That's a plus :-)

I did not receive any sort of operator's or installation manual with the SPT-10 Engine, so I'm in the dark on it's operating limits, etc. I'd like to set the prop limit and I'm assuming 8,500 (their default?) is OK? The SPT-5 was set to 7K, but that gearbox was NFG from the start.

As mentioned in my earlier forum notes: I operate at 6,000 ft MSL and the SPT-10 engine ought to provide way better performance on the Tucano now, especially on those warmer days where the density altitude is way up there near 11,000 ft.

So performance and GSU settings feedback are all welcome my friends. Heck, all feedback is welcome, right? You know, turbo-props are unique and their performance at the events have not always gone well, making for a sketchy reputation in general. I expect the newer line of TP engines & gearboxes are performing much better anymore. It would be fun to compare notes here though.

Thanks all

LKL

Dave Wilshere

You won't get anywhere near the max RPM with that much prop, I would say its too much actually.
A 25 x 12 three blade Biela will give you good performance at your altitude.

Dave

Vacman

My Feedback: (14)

Thanks Dave. I am still very unclear as to exact what Max RPM I should be aiming for now anyway. 8,500 is the number, from what I gather above, but what do I know?

I've been all over the map trying to pin down the correct prop for this SPT-10 too.
I was told that the previous three-blade I was running on the SPT-5 was way too small and would over-rev the gearbox. I still have those props (Mejzlik 25x12S). I also have one that I was told would be too much for the SPT-5 (an Air Models 27x12, 3-blade), but hell, that might work as well on this SPT-10 engine.

I was trying to narrow down the "trial & error" hassle a bit more, but that hasn't worked out so well, LOL. The props available for this engine appear to be a wide range: 3, 4 & 5 blade types :-(
So indeed, I'd love to hear from you and all running these engines and exactly what props are working best, etc.

I DID want to stay with my 3-blade spinner, so any of the props I own currently may work fine as well. Its just a matter of what Max RPM I'm looking for, performance, heating the gearbox, etc.

Barry at KingTech even told me that their engine (K-100 TP) HAS to run the five blade to load the gearbox correctly (I don't really buy that so much), but KingTech has no prop governor or tack (which I why I stuck with JetCat mostly).

So heck! Trail & Error? I hate being the beta tester on this stuff! LOL
The data is out there! I just have to turn over rocks and beg for more information all around.

Thanks my RC brothers,

LKL

Dave Wilshere