RE: SAP 180 (Syssa Performance)
 

I received my new engine a couple days ago. Todd did some optimization to Hall sensor position to take advantage of piped operation.

So far, operating the old engine in the Extrra, it seems that the 18x12 hybrid prop is ever so slightly too much load. The SNL flight is no problem...it does this all day long and doesn't miss a beat. Extended vertical however, especially after the engine warms up, seems to be a problem with sagging from very little to severe.

So far, I've richened the HS needle to 2 1/4 turns open and richened the low end to 1 1/2 open. At 2/3 throttle the engine sags...at full throttle it picks ups again (1/2 to 2/3 is a must for cruising in pattern). This makes me think that the LS needle could use even more richening but then the idle suffers and most importantly the transition. I have the pipe stretched to 27 3/4" to the baffle and this may not be enough. Problem is I am out of room in the Extra's tunnel and to stretch it to 29" or longer will require some surgery. I'll probably do that...I need to know what my options are for the pattern plane.

Lack of Cooling was suggested by Ed. I am in process of ducting around the engine to cool more efficiently.

The engine never had issues turning an 18.1x10 apc and maybe that's what I'll do in the interim until I figure stuff out. I guess I don't understand why a 2" pitch difference would cause such a dramatic shift in performance

RE: SAP 180 (Syssa Performance)
 

I am getting close, I need to program the 9303 and cut the cowl and it is ready. The throttle with the pipe is not linear so I will do some throttle expo. After this run, it did 9600 RPM. I think when it is full broken in and tuned better, it will do almost 10K.<div><span style="font-family: Arial, Helvetica, sans-serif; white-space: pre; ">
http://www.youtube.com/watch?v=9TrtUNFWyhk</span></div><div><font face="Arial, Helvetica, sans-serif"><span style="white-space: pre;">
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RE: SAP 180 (Syssa Performance)
 

Hi, Matt:

Likewise, my experience with the props always leads me back to the 18.1x10.

I got in 6 long-ish (11 minute plus) flights today and really flew the crap out of it, trying to learn how to deal with the verticals with a pretty strong cross-wind. For the last 2 flights I switched to the 17x12 pattern prop, and although it was significantly quieter (and lower RPM, of course) it also wasn't quite as good with the verticals. Very good extended verticals, but slowing down somewhat after several seconds. Not so with the 18.1x10 - unlimited vertical with mucho gusto.

The new coupler looks like a real winner! I did not remove it yet to inspect the innards, but it held tight with zero slippage. While the JB Weld lip on the pipe (or your button-head screws) is a must, there was nothing at all done with the header pipe, and the two zip ties did the job with no signs of distress.

RE: SAP 180 (Syssa Performance)
 

Excellent...two straight forward couplers at least, the turbo hose and the teflon tube. Straight silicone hose that Dan is using appears to be a thrird option

It does appear that anything above 10" pitch bogs the engine down too much with the current set-ups. There's gotta be a better set-up to drive higher pitched props.

RE: SAP 180 (Syssa Performance)
 

Hmm... the thought occurred to me today that it might be helpful to try a 16x12. However, the effect of that exercise would be to get the RPM's up, and it seems that RPM's are what this engine likes. I think you speculated earlier somewhere that FAI sequences would probably demand a 40cc version.

I don't know enough about tuned pipes and engine variables to extract any better performace than I'm getting now, which is actually quite good. The only real issue is noise. My "Fogasser" is quiet by gasser standards, but noisy by pattern standards.

RE: SAP 180 (Syssa Performance)
 

Bob,

That's what we found out in all of our earlier testing...with an exhaust duration of 170 degrees, the engine will unwind like crazy with light loads.

Back it the days of the 60 sized planes, we stretched the pipes a lot to get the engines to haul the bigger props. Where the engines of the day were turning 11x7s at 14500-15000 with shorter pipe settings, we stretched them as much as 2" to get rpm down to 10000 turning 12x11 props. Decent pop on verticals too.

That will probably be next for me...stretching the pipe to 30" to baffle and try again. Nice to have the extra as a test bed to play around. I am setting up the new SAP in the extra right now so that's how this one will be run

RE: SAP 180 (Syssa Performance)
 

Wow - 30 inches??!! Well in that case I'm glad I got the Focus because it won't be too difficult to lengthen the pipe channel if the increased baffle distance works out.

RE: SAP 180 (Syssa Performance)
 

Call me crazy but the most of the noise of this engine set up is comming from the carb. I am running ES30G pipe with 18.1x10 and hear most of the noise comming from the carb. Next is prop noise and if I get real close I think I can hear some sort of exhaust note.
I am currently mounting the motor in the old Evo. OS160 out and Syssa in. My son has a lot of flights on this airframe and we should be able to draw a real good comparison of the 2 engines.
Guys... Thanks for sharing all your info. It alows us to keep moving along. Inevitably we will all draw our own conclusions as to the ultimate set up but all this sharing will make the path more fun.

Bob... I have only run the 18.1x10 as that is the prop that I feel is a good benchmark. I see it run on everything from OS140 to the YS170 DZ. There is something special about the prop in that it works well with many set ups.
I see you have run the 18x10PN so I gave it a try on my OS140RX powered 10# Temptation and was pleasantly surprised. Can you give a comprison of the props on the Syssa?
Thanks,
RC

RE: SAP 180 (Syssa Performance)
 

Definitely try the 16x12 and see how it does.

A 40cc gas engine might work a little better at the lower rpm we want (crusing at half throttle) but it still would need to be set-up correctly. The SAP has terrific raw power at full throttle, but if we want to turn big props at mid rpms, mid range torque seems to be the issue. That's been said before too.

I'm taking time off tomorrow to work on this longer pipe set-up. The fact that tomorrow is supposed to be a stellar day weather-wise is not lost to working the day job (vbg)

Matt

RE: SAP 180 (Syssa Performance)
 

Rick,

Ed Skorepa thinks the same as you do. I think we should be able to control intake noise by installing a foam donut around the carb. The soft mount should make this fairly straight forward. It may require that we also open a hole in the firewall.

I like the 18.1x10 also. It works fine with the current set-up on the extra including extended verticals. It is a good benchmark prop and if I absolutely must go back to it, I will. In the meantime, I am trying to push the engine's envelope as far as I know how. There's a lot of raw power out of this thing....just want to see if I can modify the curve to suit my taste.

RE: SAP 180 (Syssa Performance)
 

My other hobby is racing karts. On our Yamaha 100cc piston port motors, intake noise is a major concern at the noise regulated tracks we race. We run have to run an air box design that is purpose built for noise reduction. It is basically a plastic tube that is attaches to the carb like a air filter, and the opposite end is completely closed in. Air enters through 2-3 tubes that are flush with the outside of the tube, and extend down into approximately 1/2 the diameter into the main tube. There is no power loss at all, and it really shuts them up. You might be able to make something similar out of light weight materials. It also traps any fuel that gets spit back out of the carb.

RE: SAP 180 (Syssa Performance)
 

Wow!
Another strange and intriguing thought???? Combo mount and intake filter/silencer???

Just something to keep you up at night!

RC

RE: SAP 180 (Syssa Performance)
 

It's going to have to be something pretty clever if the current choke plate is going to work with it.

RE: SAP 180 (Syssa Performance)
 

You would have to make a choke plate that would cover the holes in the air box. We choke our kart motors by placing our hand over them. In fact, on direct drive karts we reach over and choke them slightly going into corners so they are just a bit fat when we get back to the throttle. You get a little extra torque for the drive off.

RE: SAP 180 (Syssa Performance)
 

Rick, interesting you should mention this, because I went back and forth with the 18x10PN and the other props (17x12 pattern, 17x12W and 18.1x12) before getting the 18.1x10. If anything, the 18x10PN might be a teensy bit better than the 18.1x10 simply because the blades are narrower and lighter, which lets the engine spool up that much more.

Now that the needle settings are pretty much where I like them and the coupler issues are resolved, some RPM comparisons are in order. Might even check it with some other flavors of 18x10, perhaps Xoar beech, etc.

RE: SAP 180 (Syssa Performance)
 

Yes . . a kart racer for 16 years, I can attest to that. Images below are of a typical air box and adaptor. I am not sure, but with an adaptor like the one pictured, I think you could still leave the choke baffle in place ??

I can hear intake noise on my DL1OO and was thinking about making an "air box" out of an old film container. Remember those? :eek: . . Maybe not enough volume, but you get the idea?

PS . . Yeah, choking the kart by hand at the end of straight sections . . keep throttle open as you hit the brake marker, hand over airbox as you brake with throttle still wide open . . hand off airbox and power thru apex of corner while 'tapping' other karts :D. Almost makes the F3A-P11 integrated half roll in the figure 'M' seem easy ! ;) We did this mainly with aircooled engines to bring the cylinder temp down (sudden large dose of fuel) . . rarely choked a water cooled.

JB

RE: SAP 180 (Syssa Performance)
 

I like the film canister idea! I think it might be enough volume for a 30cc. I think you could bore a hole in the lid the same dia. as the venturi, the attach it with the two carb through bolts. The modified container would the be able to snap on and off. If I can figure out the choke situation I may have a go at that.

RE: SAP 180 (Syssa Performance)
 

I cut the bottom off a 1 oz mixing cup and fitted that over the two carb hold down studs. The round cup needed to be flattened a little to form an oval shape. Small holes in the cup near the studs and small tie wraps secured the cup to the studs. Then I fitted an oval shaped piece of 3/4" urethane open cell foam into the cup. The baffle spring crosses the gap between the two studs so it is a convenient way to hold the foam from getting ingested....I think this will work but maybe not. I'll try it tomorrow

Matt

RE: SAP 180 (Syssa Performance)
 

Bob,

The mixing cup was fitted such that the baffle could easily slide under the lip. It isn't supposed to be that simple I guess, but maybe it is. I'll find out tomorrow. I didn't open a hole in the firewall and maybe I should have. The cup inlet has 1/4" clearance all around. It should be enough but not sure.

I have this set-up on the new engine and maybe I should not have done that, especially if the beastie swallows the foam somehow

RE: SAP 180 (Syssa Performance)
 

Ouch, that would not be a pretty sight.:(

To be honest, I was a bit dubious in the past about claims that the carb makes so much noise, but it appears to be a well-documented and substantial noise factor.

OK, so if there were a velocity stack that extended past the soft mount and the motor box, with the area behind the motor box (in front of the firewall... for those of us with the Focus II with soft mount) somehow muffled, it seems that would help with the noise. I have heard (and also seen) that the carb spits out a bit of fuel without the stack, therefore recovering that bit of fuel on each cycle should also improve the power at least a little.

RE: SAP 180 (Syssa Performance)
 

I believe your correct. A velocity stack would do exactly that or atleast it does on side carb engines. I have a Zenoah 26cc in a super cub kit bashed into a military version and it spit fuel every where until I added the stack. That really cleaned up the fuel issue. Before adding thestack fuel randown the side of the cowl and plane.Obviously the overall system's fuel economy is better but hard to say if that fuel actuallygets used by the engine on the intake part of the cycle.I guess it all depends on whenand how fuelwas exiting the carb. I'm sure some knows the technical timing and engineering behind this. I presume therear exhaust reed is going to do something similar as the reed seals on each stroke?

RE: SAP 180 (Syssa Performance)
 

Bob . . having used velocity stacks before, it does little (on it's own) to improve intake noise. The inlet track needs to be baffled. i.e. the air gets in, but the sound bounces off the baffled 'bends and twists' . . or at least that's what appears to happen :eek:

We have even found a 'baffled', unfiltered air box to be much quieter than just an air filter on it's own.

Cheers, JB

RE: SAP 180 (Syssa Performance)
 

The piston port type engines spit more fuel than a reed valve. Our reed valves seal at very low pressure differentials for quite a few reasons. Bottom line is our engine, like many reed engines, will not spit nearly the same amount of fuel as a piston port engine. The stack helps because some of the fuel gets pulled back in eventually in the air flow. Without the stack it just goes right out and is lost.

RE: SAP 180 (Syssa Performance)
 

I tried a bunch of things today:
A brand new SAP 180 in the extra. Stretched pipe to 30" to the baffle. Teflon coupler. Mixing cup over the carb, with foam insert. 18.1x10 apc, 19x10 Hybrid, 18x12 Hybrid props.

The first flight was uneventful (less than 10 min on purpose) for the most part using the 18.1x10 apc. RPM was very slightly down by sound compared to no 1 engine with the shorter pipe. HS needle open 2 1/8 turns; LS needle at 1 1/2. Plane had good speed for a 10" pitch. Keep in mind this is a large draggy platform. Sound quality was really very nice...the carb's noise suppressor appeared to be working. The long pipe possibly helped.

I attempted no vertical stuff until the next run and the 18.1x10 was turned with authority anywhere in the flight envelope

Then, after a couple flights with the 18.1x10, I tried the 18x12 hybrid. Opened the HS needle to 2 1/4 for the heavier load and kept it there for the remainder of the flying. The engine is just too new for any vertical stuff with this much load. It sagged badly when I attempted it, confirming that this prop is definitely more load than the others, even though the horizontal stuff was fine. Cut this flight short, maybe 5 minutes.

I decided to shorten the pipe about 1" and try the 19x10 hybrid. Also decided to remove the foam insert from the carb's noise filter. The top end rpm (I had some early experience with this prop before on no. 1 engine), was slightly lower than earlier testing on no 1 engine. Noise was slightly higher. The biggest noticeable change was the slow plane speed...slower than the apc. I suspect that this may not be a true 10" pitch. The engine had no problem with verticals turning the 19x10

Then I took a couple more flights with the 18.1x10 without the foam insert and shortened pipe and 2 1/4 needle. Not much difference was noted except for noise; it increased. It didn't seem that the foam intake insert was terribly restrictive after all because there was hardly any change to the pull of the powerplant.

I think I will re-insert the foam filter into the cup for tomorrow's flying.

Bottom line is that the engine and the 18.1x10 apc are a good match right now. Even in today's windy flying, the combo worked well. Pipe set-up appears to be not terribly critical in terms of length. Pipe lengths from 27" to 30" results in very small differences. The foam insert appears to help reduce noise. More testing is needed to make sure, but the early results are positive. And BTW, the engine ran great, as expected....

RE: SAP 180 (Syssa Performance)
 

Thanks, Jeff.

That was my understanding, hence my little doodle in the photo showing the stack extending back into the motor box, which I am assuming (incorrectly maybe) would act as a noise-reducing baffle if the back of the moror box were enclosed.