1200SportsterRider

Thanks, I have a Sig Four Star 54 for it, it has been mounted, set up and then removed to break in.

Mine is the pre-cowl version, even with the new style, small JR receiver it is tight in there.

Glowgeek

Should be a fun combo Dave.

1200SportsterRider

I should find out this coming week, of course I'll run the 50 with a Turbo-Header.

Jesse Open

Are you going to run it with both the Saito stock system and the TH exhaust?

Glowgeek

It would be interesting to see difference in performance between the two on a smaller engine like a 50.

1200SportsterRider

I have numbers for a then new 56:
10% fuel with 18% syn. lube.
Xoar 12 x 7.
Stock long muffler, rpm===9,080
TurboHeader, rpm=======9,210

Glowgeek

Good gains with the Turbo muffler on the 56. Likely even higher gains using a 12x6, 11x7 or 11x6. Truly, most folks never see the full potential of these smaller 4 bangers when running them below 11K static.

I'm not proposing everyone should run them at 11K static, just pointing out that the rpm is there if needed/wanted.




Note the very narrow power band of the 72. This one I would prop for 9000-9500 on the ground, prop dependent.

Jesse Open

200 RPM is about right.
(RC Specialtiies muffler)

1200SportsterRider

Saito 56 Xoar 12 x 6 10% full syn 9,830


Saito .56 Graupner G-Sonic 12 x 6 Wildcat 2/4. 10%, full syn. 10,970 Idle 2,200

1200SportsterRider

The home made .66 is coming along, the piston is in the cylinder, the cylinder fits comfortably into the crankcase, I have a used 80 ring on the piston. It has surprisingly good compression, the used ring is apparently still good. An RMJ ring will arrive in a day or two, the current assembly is for,(proof of concept only), until the new ring arrives. Having fun the name of the game.

FlyerInOKC

My Feedback: (6)

I can't wait to hear how she runs!

1200SportsterRider

Thanks, me too.

Jesse Open

Are you using the FG-11 piston?

FlyerInOKC

My Feedback: (6)

RCU strikes again! Triple post.

acdii

At least is wasn't


Are we there yet?

FlyerInOKC

My Feedback: (6)

No kidding!

Jesse Open

Well......

.......Are we?

FlyerInOKC

My Feedback: (6)

Another mile and a 1/8.

Glowgeek

I've already been there, not going back.

Jesse Open

Me too, forty years ago. Got the smelly shirt and tossed it out.

No way going back.

1200SportsterRider

Yes sir, I am. https://www.horizonhobby.com/product...AIG33R306.html

It comes mighty close to the glow plug hole, but does not hit anything.

Jesse Open

Nice! Basically you have a FG-11 on glow then (?) Should be a real fine combo

acdii

Does that make it a FAG-11?

1200SportsterRider

The FG 11 piston is exactly 1 mm taller than the 62 piston, the ring grooves line up exactly, the used 80 piston ring has a loose 3 mm gap.

The wrist pin is lining them up.

The 80 ring is used, maybe well used.

the Wasp

My Feedback: (1)

EDITED below.
I noticed the 91 and 100 Piston Top's are the same way, the 100's top is much thinker of course. I would guess they are from the same casting. so most like you can mill /turn down the Piston top if needed to achieve the correct C-Ratio. even on your lathe with care.

back when I was porting G23s for my boats. I found that one company was using the G23 but their rings gaps were about 1.5mm farther apart than Zenoah's were. that piston allowed me to widen the exhaust port a good 1mm more ; ) they were both Zenoah engines, so I supposed they were made in different places.

here is a pic of my lower Jig I had made to mount the cylinders to my Mill Table. made from Tool Steel. it hasn't been used or touched for some 30 years. I can't find the upper support brackets I had. (pic is of the bottom side)



Jim