Are you using the 5.2 inch version of the engine? What did you do to soft mount to mod it? what prop is being used?

Looking at a 140rx replacement?

Randy

Please give some rpm numbers with pattern props or were those so low that you are not going to publish those

What I have read from gas engines forums, Syssa is not that much stronger thatn MVVS/Evolution 26 gasser. I dont care about Vess 18x6 numbers since they dont mean a crap for F3A performance.

Hi MTK!

Just somting that come into my mind re the Syssa eng. testing. Some want to restroke it, but is this the right way to power-up this engine? Ihavent a clue of the innards and porting of this engine so I just speculates if an increase in BMEP (brake mean effective pressure)would be beneficial for the purpose of comparison to an YS 4c???? To make it equal powerful to an YS 170 cdi the Syssas pumping/charging of cylinder must incrase i guess? The problem is that the userfriendlines of the engine may dissaper. The disadvantage of gas engines are that they need a air/fuel ratio of 12-18 : 1 and methanol mix engine may have very low air/fuel mix as little as 4-5-6 something : 1 but then burns methanol mix 2-3 times the volumes of gas.
You were running on 87 octane, this indicates it is a trapped compression 7:1???

Iam looking foreward to follow your testing and results for future use in pattern!

Regards

What is the length of the engine being tested?

Well, it is a gasser, and if the desired pattern performance can be achieved, does it really matter what prop ends up working best?

Just asking, because I was seriously thinking about getting the 2M Vanquish (when it finally arrives!) with e-power in order to migrate away from glow... and glow fuel costs and hassles. It seemed that no viable gasser option existed, but if this engine works for pattern I will seriously consider it.

5.2" version ??? Don't know what that is. It's the standard engine version. There are no revisions yet or other engine offerings. Todd Syssa is not YS

MattK

Use the MVVS Evolution, I don't care one way or the other. I have no business interest in this. I am only reporting my experience with THIS particular engine.

The engine's performance (bench running NOB) is being reported in an article by Ed Alt in the KFactor. After the report comes out I will post numbers here. I will not steal my partner's thunder; be patient

MattK

You will not be disappointed. Don't forget that it needs the ESC40G pipe also which is about half the cost of the engine. But then again pipes are a fact of life for 2 strokes. If you purchse one, ask Todd NOT to include his standard muffler...you might shave a few bucks from the price. He is fully aware that Ed and I are testing it in piped set-ups

MattK

Thanks, Matt, and yes I fully expected the need for the pipe.

Someone asked before, but which soft mount is that in the photos of your Enigma, and which prop and header are you using?

No rush, so I will wait and read about it in K-Factor if you don't want to divulge more at this time. I was disappointed when reading about the less-than-ideal results with the ZDZ 40 and am very excited that I might have a reasonably-priced 2M that doesn't gulp $30/gal fuel![8D]

Bob,

The header is a Mcas (for a Webra 145/160) with mounting holes enlarged to 5 mm and brought in to center approx 1mm on each side. Ed Alt brought his Macs (for an OS) to Todd Syssa's place during the first bench runs about a month ago, and after enlarging the holes, centering was dead on. So which ever header you have, it can be worked with

The soft mount is my own design.... Similar to a Hyde, it isolates using the rubber bands. These are extremely simple to make and I highly recommend learning the skill. I have a tutorial on a similar build for the ZDZ40 RE here on RCU. If you did a search, you would find it. It's plywood and balsa with rubber band isolators. Been using this design for many years after reading about something similar on Pastorello's site. Isolation is at least as good as any Hyde. I have original servos in my Temptress for at least 1500 flights and they have never been serviced. Neither has the mount. I've used the same design on engines as large as 2.1 Moki.

The interesting thing is the weight of the mount for the rear mounting of this type engine. No bearers are necessary therefore weight usually comes in at around 2-2.5 ozs complete ready to install.

The prop I had handy in the flight trials was the 18.1x10 apc std blade. I have 19x8E and 19x10E Xoar wood props coming. I like the shape of the E props better. I re-carve the blades to reduce thickness even further and then carbon laminate them. Extermely strong and stiffer than about anything else I've seen, including pure carbon. Plus the biggest benefit is the very thin blades and the extremely light weight. The props come in at around 65-70 grams ready to install. Compare with apc

As far as the reasonable price...yes absolutely. As I mentioned before, we were privy to Todd's design philosophy and materials, which we can't divulge. Suffice it to say that the proof of the pudding is .....

Go for it. You will not be disappointed even if your plane came in at 11 lbs. Forget about waiting for some imaginary re-stroked offering. The engine is damn good as is.

MattK

We need to fly it more and see what enhancements might be useful and provide that feedback. Based on only one flight so far, the results were very encouraging. If things continue to progress this way as we get back into the warmer months, it may be that most applications won't need any change. And then it's up to Todd Syssa to decide on what kind of investment may make sense. It's going to be based on a realistic assessment of the potential market.

It already looks like it is an OS RX / FX beater before it's even broken in.

For the Nay Sayers and the merely impatient, RPM figures from our static tests. Remember, this had an ES pipe on it. The SAP 180 was brand new, right off the production line:

APC 17x12 Std blade: 8200 RPM 19.5 lbs static thrust
APC 18.1x10 Std blade: 7700 RPM 20.5 lbs static thrust
APC 18.1x10 wide: 7400 RPM 20.4 lbs static thrust
APC 19x11 Std blade: 6400 RPM 19 lbs static thrust (Proved what we expected -way too much prop!)
APC 15.75x10 3 blade 8200 RPM 21 lbs static thrust (Prop is a re-pitched "Lockhart special")
APC 17x10 Std blade 8900 RPM 22.3 lbs static thrust (Not enough prop, obviously)
Vess 18x6 wood prop 9300 RPM 26 lbs static thrust (Yep, not a pattern prop)

Thanks for the information, Matt!

And for the prop testing, Ed. It will be interesting to see which one you guys select. Just guessing that the Vess was noisiest and the 3-blade quietest.

Ed, the Macs/OS header you used was for the 1.40 RX? Tower has these, which is why I ask.

The web site lists different versions based on the length from the firewall to the prop hub. They list four different lengths. 5.2 inch is the shortest distance from firewall to prop hub.

Randy

The only difference is the length of the standoffs.

I am not certain of the absolute minimum length. To retro fit my existing firewall I cut the stand offs a bit to just clear the choke baffle. Choke baffle articulation is the limiting factor for length for all practical purposes.

I have approximately 1 mm clearance between the soft mount and the baffle. There is a portion of the carb that actually resides inside the central cutout of the mount. I also opened a hole in my firewall such that the engine actually breathes from the fuselage. It wasn't necessary since there is plenty of clearance around the mount central opening but I did it to help in the quietness department. It helps quiet the intake. It's a technique I will carry forward to other set-ups

MattK

The Vess was noisest by far, which was what we expected. We never for a moment considered the Vess viable for Pattern. That's not because there's anything wrong with a Vess, it was just a function of the diameter & pitch being wrong for the application. It's all we had handy in a Vess that day. We tested it and included the data because that prop is common for a sport or 3D setup, and up until our visit to Syssa Aircraft Performance a couple of weeks ago, Todd Syssa did not have any data to show what kind of power gains would result with that prop on a pipe. The RPMs picked up by over 1,000 with the pipe, which is huge. It was still good data for us, because it confirms a characteristic of this engine, which is what RPM range it is happiest in. When propped to run in the high 7K to low or mid 8K range, the SAP 180 does quite well on the pipe, with good throttle response. The Vess showed that it works well even up to low 9K. We would never run that high, but knowing how the engine behaves in that range is useful.

With the 18.1x10 STD blade APC, it was very well mannered in the air (with 1 flight under our belt) and on the test stand. I suspect that a 17x13 APC would be similar handling, just faster overall. We'll get around to trying several props, including a 17x12, which seems to be a light load for this engine. The 17x12 may be too noisy in the air, we'll see.

We did do some sound readings, but it wasn't really representative of what will happen in a model. We had the engine up several feet on a metal test stand, completely exposed, and the stand was attached to the back of a Dodge Caravan, which made for a nice noise reflector. But yes, the 3 blade seemed to be the quietest of the viable props. The 19x11 was real quiet, but it could only turn in the mid 6K range. No good!

The Macs header we used on the test stand was a standard OS 140 setup. I think Todd had to open up the holes to a slightly larger diameter. It's still usable on a 140RX, that's for sure.

I just want to clarify that when installed in a model, the noise is very low. In the air, with a good pipe like the ES Matt used, you would never know it was a gas engine by the sound.

Thanks much, guys, for the info dump. Matt, yes I found the thread on your soft mount.

I ordered the engine and header, and left a message with ES to order the 40G pipe. I am guessing a 4.8v 1000 mah NiCd for ignition.

All this happened in the nick of time because recently I had been discussing the e-power option with Anthony R and was almost ready to commit. But I prefer gas by a longshot and am really looking forward to this project.

Update: I spoke with Mr. Skorepa this afternoon and he is whipping up a new batch of 40G's if anybody else wants one. Shipping next week.

Thanks, Ed. The ES pipe is noted.

I'm not a pattern guy, still the stats help a lot with knowing where I'm going with it. I just ordered in an 18 X 6 and an 18 X 8 to start out with. I'll just be using it on a Pac Aero Monocoupe for sport flying, and your numbers indicate I'm in the ball-park at least. It's good to have a place to start at! I sort of guessed at what I'd need to get started with, this is a positive indicator for me.

Thanks again.

Jimbo

Good to hear this engine makes the same power on a pipe as the OS 160 makes on a Pitts muffler an 15% nitro spinning a 18X6 Vess which has equal load to a APC 18X6W. The power on a pipe is very similar to a Evo 26 on a pipe. In fact, if the Evo 26 was run on a 40cc pipe the power may be equal but I don't have one to try.

The Syssa on the stock exhaust and noise reducers spins the 18X6 between 8100 and 8400 based on posted reports.

Several fliers here have used the ES 26G pipe with the MVVS/Evolution 26cc gas engines with very good results. The Syssa being only 4cc larger may like the 26G pipe. It may be a good alternative in smaller planes as it is a bit smaller and lighter than the 40G pipe.

Sure sounds like this engine is going to be an all around winner. Great going Todd and very best wishes for the future with your endeavours.

Karol

The 26G pipe could be a good match. If anyone tries this, please share the performance and handling data. In the case of the tests that Matt and I have run, the ES40G was used because it's what Matt already had on hand from his ZDZ-40 project.

Just keep in mind that smaller volume pipes tend to be peaky compared to higher volume designs and will tend to run hotter. You also may get a little more power out of the 26G vs. the 40G. I will try the 40G for now, because I did like its manners during the one test flight we were able to squeeze in last weekend.

When I emailed Ed regarding pipes he recommended the 26 for the 180.