Hmm... not sure how well your concept would work. Because the vibration force is rotational, seems that the round shape absorbs the vibrations more evenly.

If you're in a hurry, my suggestion would be just to make a good, solid firewall and hard mount it. I think this is what most of the guys are doing with the EF Extra. The SAP-180 seems to have a very well balanced crankshaft and has very low vibration levels compared to other engines in the class.

The main reason I am using a soft mount is that my engine is in a pattern plane, where noise is more of a concern. Also using the tuned pipe for quietness and a bit more torque for a higher-pitched prop.

After I posted it I wondered if the forces were rotational.  I got the firewall cut and I am ready to mount the new one soon as I do some fitting of the carb in the wall.

Question? Has anyone tried to use a starter on the motor without choking it for the initial start of the day?

Dave Ruminski and I used a starter on his initially but never tried to start it without choking it. If it will start without being choked, it could eliminate some complexity and weight.

Just another crazy thought...
Rick

Rick,

I had a problem with my first engine's original carb not drawing. I occasionally resorted to using the meat grinder on my polished spinner. Worked okay but damned near ruined the spinner. Just kidding!!

A starter works fine...throttle up a little to about mid throttle and spool it up for a second before turning ignition on. Return to just above idle and spin it. It should start

Matt,
I don't like using a starter at all but sometimes its better to swallow the pride and fly. I really like to have things adjusted properly and use the backflip. So when I resort to the starter I hear about it from my fan club. Pete Cosky always comes over and inspects my spinner to look for telltale starter marks so I polish my spinners on a regular basis to keep him shut up. Then he shows off hand starting his YS140.

Are you using a choke servo or just a rod? Have you considered using a starter and doing away with the choke all together?
Could there be any potential damage done to the motor using a starter? Any shortening of life of the motor?

Thanks for the help,
Rick

It is so easy to pull my canopy on and off I might just use a thumb choke and not worry a linkage to the choke. I have the Great Planes angled mouth velocity stack that is going on should I decide not you use the choke plate. The air box that gets installed on these carbs has the choke built into it... thats why he has it setup that way. Actually have a airbox in my garage that would mount right up and it maybe reduce the carb noise that you guys were talking about. You could probably guess what the airbox is currently installed on.

Rick,

I can't stand to use a starter. I've had to resort to it too, but I can't stand it when I do. Old school I guess.

I have been using the choke manually but do have my new model set-up for servo actuation.

I am in the finishing stages of retro -fitting the SAP in my old Temptress. I'll post some photos

I am not sure it will show up in the picture. I wanted to show the soft mount

The SAP looks like a snug fit but it wasn't bad at all. It requires one stand off to be installed after inserting the engine into its slot

Considering all the angles of carbs and exhausts of other engines making a fit into pattern models difficult, the SAP was tailor made for narrow pattern fuses. Fat fuses are bonus

I think I described how the choke is worked before. One of the photos shows a nyrod with a piece of nitrile tubing on it, cut to correct length. The hole in the chin cowl is a sort of keyhole.....pull the nyrod to the end of the rubber tube, and engage the plastic nyrod into the key.

The frontal shot clearly shows a snug fitting chin cowl that will aid engine cooling. Would you believe that Webra heads actually grazed the chin cowl, hence the relief hole shown. They are much larger than the SAP head

And one final set of shots that show the pipe mount and the Teflon PTFE coupler. A simple O-ring is fitted around the ears of the U and over and around the the pipe. The U is mounted on a Lord type soft mount. The set-up has proven ultra reliable, over many many seasons of flying. Inspired by the Hush Clamp that Dave Von Linsowe designed 20 years ago or more

If you look closely you can see the 4-40 button head screw under the Teflon, as suggested by Ed Skorepa

Through the magic of Photoshop...

Very neat installation - hard to believe there was more space with the SAP than with a glow engine!

Did you paint the mount black? Nose ring? Static nipple for the carb plate? My engine simply will not run during negative maneuvers without it.

Very interested to hear how the OS header works out. I looked on the Tower website and noticed that it uses 2 O-rings at the exhaust flange.

Very nice install!
There would be no damage to the engine using a starter....no worries.

Those "Webra" and "Cool Power" decals are going to have a lot of guys scratching their heads.

Two O-Rings?? No, no, you want the Macs header for the OS 140, not the hatori header for the OS. The Macs is flanged conventionally. I had a hatori header for the OS 140 and I didn't care for it.

The Webra's head is huge comparatively speaking.

I painted the mount black. I also opened a hole in the firewall that I'll line with very open foam. No nose ring as yet but I have the stand offs on the fuse to accomodate one. I will fly the engine as is and see how high G maneuvers behave, then I'll decide whether to go through the trouble of making one

HA HA!! Yup true enough. Can you imagine a day where we would have "Petrol-87 Octane" and "Amsoil" decals??

Todd, you need to provide "SAP180" decals

Oops, my bad... I thought you had mentioned somewhere that you would use the OS-brand header made for the OS 1.40. Tower does indeed have such a beast.

I am thinking of ordering another Macs header as a back-up, which I will need eventually anyway when I get another engine.

Not sure how well the O-rings will stand up to the higher exhaust gas temps in a gas application. They don't last very long on that header when running glow, and I suspect you might be changing them very frequently when running gas. However, if you replace them with Viton O-rings it might work out.

One other thing about the OS header - if I remember right, it's got a fairly restrictive opening to it. Might not work as well as the Macs header in the SAP-180 application.

Now Rick, in all fairness, you have seen me use a starter to run my YS dry....

I have to admit I am looking forward to seeing this engine fly tomorrow. As much as I love my YS engines, I really want to see this engine succeed. More alternatives can only mean better things for pattern.

Pete

Bob,

I've had no problems at all with inverted stuff or high negative G stuff.
The only problem I have now is that the 18x12 hybrid is ever so slightly too much on extended verticals. I will break the new engine in on the 18.1x10 and then play with the hybrid again, even if I have to cut it down a little.

Ed, that was my thinking as well concerning the O-rings. Just sounds like something that wouldn't last long with a gasser.

I didn't know about the smaller opening... also not good.

Sent my registration info to Rick W for the Jackson event. Hope to see you and Matt there.

Bob:
I will be there for sure. Most likely stopping down on Friday for warmup too. See you then!

Inverted is fine for me - problematic only with negative G. Airflow inside the cowl perhaps a bit fluky.

Got a couple more props to try. Xoar 18x10 standard gas/glow beech (85 grams![sm=thumbup.gif]) and an APC 15.5x12W pattern (105 grams). GravesRC did not have a 16x12 APC. Time before last when I flew, the 17x12 was a bit too much, so this 15.5x12W is the next step down. Also got an APC 18x10 sport prop to try just for the hell of it.

Really got my fingers crossed that the Xoar works out. I admire the work and thought you've put into the hybrid featherweights, but it'd be nice to have an off-the-rack prop that is fairly lightweight. However, already I suspect that the APC 18.1x10 airfoil is better.

Bob,

Thanks! The XOAR standard beech has a pretty thick hub...Does it fit okay? I agree that if this gives us what we need, then it's a clear path for most.

We will finally get the chance to play in warm, muggy weather Saturday and Sunday, assuming Sunday holds. This will be the first time we run the big props on the SAP on pipe in this kind of weather. We will learn something.

After conversation with Ed, I want to find a source for 100 LL Avgas. There may be some real benefit in mid range

Matt,

Yes, the hub is a lot more voluminous overall, but it fits. Had to open up the spinner slots yet again.

The blades are thicker and wider than the APC, LE and TE not as sharp, especially TE. Probably will end up stripping the varnish and sanding it to see if it can be improved, but wanted to try it straight-up first.

Interesting mention of Avgas. Any benefit to 93 Octane pump gas. At WRAMS, Ed had a very interesting idea for a hybrid blend of glow/gas. I'm leaving that to you guys. Just running 89 octane for now.

I'm flying tomorrow, work Saturday and maybe fly Sunday if the weather holds out for us.

Interesting prop stuff

First the bad news: The Xoar 18x10 was mediocre. Not horrible but not nearly as good as the APC 18.1x10. Maybe better with some re-working, however I'm looking for right-out-the-box good.

Up until today, the top contender has been the APC 18.1x10.

That might've changed today after running the APC 15.5x12W. I had little confidence when ordering it - and even less when bolting it on - that it would be suitable for the SAP-180 and a pattern model. When the model took off, it appeared to lack speed and zip, seemingly confirming the low expectations. But after flying through several elements of the Intermediate sequence, I began to realize just how incredibly right it was!

Vertical was unlimited, with authority, and did not lose momentum even with multiple rolling maneuvers. The vertical speed was not as fast as with the 18.1x10, but it had a more "torque-y" feel to it, like a good 2C glow engine on a pipe, and the speed was a lot steadier through all maneuvers at 45 deg and SNL. It actually helped me fly the sequence much better than I've flown it before.

On top of all that, it was MUCH QUIETER than the 18.1x10.

I hope one of you longtime pattern guys could give this prop a try. I realize the diameter sounds as if it is not adequate, but for whatever reasons it was an excellent performer for me today.