jjscott

Anybody have any opinions on this?

I've got an excellent Super Tigre G20 .23 and a new X15 F.I. .19 ABC. Both have the same size carbs; the 19 is about one ounce lighter than the 23. The X15 is a little newer technology.

I plan to use one engine on a light Super Pacer (I may actually scale the plans down a bit - the original used a ST 23). I don't want a modern engine.

Somebody will tell me to just tach them and find out, but I wondered if there were any thoughts about how ABC power compared to ringed power.

Thanks, Jim

Dan Vincent

You have a lot more going on there than just a ringed vs ABC. The older .23 is an older loop scavenged design from around 1960 or so while the X series engines were from around 1978. The X series is a Schneurle-ported engine that has a characteristic of unloading an additional 2,000 or more RPM when it's in the air.

Your X-series should tach a bit more on the ground than the old .23 but in the air it will really come on stronger.

This is not to dismiss the .23 as it is still a nice engine with plenty of power. If your model is light the .23 may be the perfect match.

I'd try it with the .23 first and if it works OK send me the X-19 and I'll be your friend. LOL

jaka

Hi!
I would say both engines are not that well suited for the Super pacer. Had one of those 25 years ago and powered it with a Enya 25X engine.
But if I had to chose, The ST .23, as it is more suited to swing a 9x5 APC prop. The .15 engine can just swing a 6x5 or 7x5 prop.

NM2K

My Feedback: (14)

I love the ST .23, but powerful, it isn't. The .19 ABC is going to cream the .23 on props that are suited for that model.


Ed Cregger

jjscott

Thanks for your comments. Seems the X-15 .19 will be the power winner, but on a smaller prop.

I'm still undecided on what to use, though. The Ace Super Pacer plans show the ST23 as the installed engine. I'm certain that, between the new light radios and building carefully, I can cut considerable weight from the original. The ST23 may be just fine, and I can find something else for the 19.

Jim

summerwind

Jim,

i had several planes that i powered with the ST .23 running an 8x6 Rev-Up.............break-in is the key to this engine. my Flea Fli+10 was just over 3.5 lbs and went like a Banshee..........my Super Pacer was just under 3.25lbs and had a great vertical performance with the .23.
my .23 wasn't ringed though.

NM2K

My Feedback: (14)

Just think of the power it would have made if someone hadn't forgotten to install the piston ring! <G>


Ed Cregger

jjscott

These last two posts raised my curiosity about my own ST 23. I pulled the muffler, and, sure enough, someone forgot to put the ring in my engine too. They also forgot to cut the groove in the piston for the ring!

So, I get a Dumb Award for this topic. The 23 is lapped not ringed. What was I thinking.

Jim

puttputt

Jim, I built a Super Pacer back in the seventies and never flew it. Over the winter I scraped off the old epoxy and sanded her down, went back on with paper and nitrate. Pulled the 25FSR, found a good old ST.23, went down to HS-81 servos on R+E, and really teenie one for throttle, 250mah NiMH. For the first time I am about 6 oz under the published weight! I think the .23 will be fine. Don

stg61abc

Hi, the .23 is a excellent small engine. Is powerfull and has a excellent idle. Two tips: First, use ALL castor in you fuel, minimum 20 / 22%, and second, it dont "like" big props, stay with 8x6 for speed end 9x4 for general use. Atached a pic of my trusty .23 from 1970...
cheers

larry@coyotenet

My Feedback: (21)

Hi, have them both, the 23 is a much better running engine than the x15. I found a TF 9x4 or 9x5 to work well with 15%nitro in the 23.
My X15 was a big dud as far as I am concerned, didn't seem to have much more power than a std ST 15 and wasn't even in the ballpark with a Rossi or Cox15. I think the 23 would suit your plane just great, was one of Supertigre's classic motors.

Larry