Welcome to Club SAITO !
Senior Member
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Thanks, I have a Sig Four Star 54 for it, it has been mounted, set up and then removed to break in.
![](https://cimg1.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/536x536/sigrc44egarfy_a0_cw8749m0_5e86c6223872edbaa8f52ec71203c14dd3524d57.jpeg)
Mine is the pre-cowl version, even with the new style, small JR receiver it is tight in there.
![](https://cimg1.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/536x536/sigrc44egarfy_a0_cw8749m0_5e86c6223872edbaa8f52ec71203c14dd3524d57.jpeg)
Mine is the pre-cowl version, even with the new style, small JR receiver it is tight in there.
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Senior Member
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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
10% fuel with 18% syn. lube.
Xoar 12 x 7.
Stock long muffler, rpm===9,080
TurboHeader, rpm=======9,210
![](https://cimg8.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/620x465/saito_56_nib_403a5c0c4d0b13888f43f671adb6c580a5e6a8d4.jpeg)
Last edited by 1200SportsterRider; 09-19-2022 at 01:28 AM. Reason: Add picture- make correction
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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.
![](https://cimg8.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/1460x2000/fa_56cl_62cl_975fd521d31c1328b83ed7d11b7b7c0aad01792e.jpg)
![](https://cimg5.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/1460x2000/fa_72cl_e8a2c9030681603e2a90480ef19129e1c6aaca2c.jpg)
Note the very narrow power band of the 72. This one I would prop for 9000-9500 on the ground, prop dependent.
I'm not proposing everyone should run them at 11K static, just pointing out that the rpm is there if needed/wanted.
![](https://cimg8.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/1460x2000/fa_56cl_62cl_975fd521d31c1328b83ed7d11b7b7c0aad01792e.jpg)
![](https://cimg5.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/1460x2000/fa_72cl_e8a2c9030681603e2a90480ef19129e1c6aaca2c.jpg)
Note the very narrow power band of the 72. This one I would prop for 9000-9500 on the ground, prop dependent.
Last edited by Glowgeek; 09-18-2022 at 09:56 AM.
Senior Member
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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.
![](https://cimg1.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/260x535/saito_66_1_2a52cfb5475c553b40752f73813643e0a264d948.jpeg)
![](https://cimg7.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/260x535/saito_66_2_f4723801cee840651f63e7ddf86a7d8ad2e1c024.jpeg)
![](https://cimg1.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/260x535/saito_66_1_2a52cfb5475c553b40752f73813643e0a264d948.jpeg)
![](https://cimg7.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/260x535/saito_66_2_f4723801cee840651f63e7ddf86a7d8ad2e1c024.jpeg)
Last edited by 1200SportsterRider; 09-19-2022 at 04:49 AM. Reason: Add picture
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Senior Member
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Yes sir, I am. https://www.horizonhobby.com/product...AIG33R306.html
![](https://cimg0.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/1600x1600/fg11_piston_070056027c12e53f9d0823819f1edd7a41c268d9.jpg)
It comes mighty close to the glow plug hole, but does not hit anything.
Last edited by 1200SportsterRider; 09-20-2022 at 02:14 AM. Reason: Add picture and content
Senior Member
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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.
![](https://cimg6.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/620x465/saito_66_piston_1mm_taller_601864698cce59cc432e4c5eeec409bc5b298cf0.jpeg)
The wrist pin is lining them up.
![](https://cimg2.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/620x465/saito_66_piston_ring_gap_ddca74af49bfff25e5728eedf46be9d993bd3c32.jpeg)
The 80 ring is used, maybe well used.
![](https://cimg6.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/620x465/saito_66_piston_1mm_taller_601864698cce59cc432e4c5eeec409bc5b298cf0.jpeg)
The wrist pin is lining them up.
![](https://cimg2.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/620x465/saito_66_piston_ring_gap_ddca74af49bfff25e5728eedf46be9d993bd3c32.jpeg)
The 80 ring is used, maybe well used.
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My Feedback: (1)
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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)
![](https://cimg9.ibsrv.net/gimg/www.rcuniverse.com-vbulletin/2000x1504/20220920_165712_resized_26d5f5284af79d7fb4376c6e4be8b2b4ddb86e3c.jpg)
Jim
Last edited by the Wasp; 09-20-2022 at 01:15 PM.