Right at 25hrs, with the weather getting hotter 98 Today, I changed to the 170 Main Jets, dropped the climb out fuel consumption down to 8.3 from 9.5. With cruise and leaning under 4 gph. EGT's high 1400's to low 1500's once cruise established settled in mid 1400's, will stay with these jets for further flights and will probably settle in for the summer, Hope to do some prop testing next week.
Engine running great.
We changed the 105hp engine to 165jets and seemed to have positive effects with the higher temperatures today and expected as summer is here.
BigJohn Kitfox 5 Outback Rotax 912ULS With 1622cc Big Torque Zipper Conversion
Hackman is a leaning unit that allows for manual leaning on the Rotax Engins, even though the bing carbs are altitude compensating they are limited and the Hackman allows for manual additional leaning, it works off of manifold pressure to the float bowl. I find between 20 - 25% decrease in fuel consumption at cruise.
They are sold by greenskyadventures.com
BigJohn Kitfox 5 Outback Rotax 912ULS With 1622cc Big Torque Zipper Conversion
Did more flight testing with the 170 Jets and was just seeing higher EGT temps than I like to have in the low 1500's, upon further checking the what I thought was a 176 jet that had been bored out by local machine shop had really been bored out to 190 ( no wonder it was a little to rich). So put in factory 180 and temps are down in mid 1400's, good climb temps and cruise temps. Climb fuel burn at 8.9gph. cruise with leaning still around 4.0gph. Added another 1/2 degree pitch in Warp prop and still able to get 5600rpm on climb and increased cruise slightly. Plan to try another prop next week.
BigJohn Kitfox 5 Outback Rotax 912ULS With 1622cc Big Torque Zipper Conversion
28hrs, 8oz oil in past 20hrs of flying, and this has been hard test flying, Tested the prop with the extra 1/2 degree pitch, take off distance was increased due to cavitation on Innitial roll with full throttle, required to use the first 100' to add power to full power to keep from cavitating, The climb was decreased by Bout 200' min top speed was increased by approx 8mph but not worth the loss of climb and takeoff. Rep itching back to where it was for more testing. Next other prop testing.
BigJohn Kitfox 5 Outback Rotax 912ULS With 1622cc Big Torque Zipper Conversion
Now just over 35hrs, Still no additional Prop Testing as my prop contacts have been unavailable to get my hands on them, hope that changes this next week.
We did change Jets once again to 185's, fine tuning to see what works best and these have a great balance between fuel flow 8.9 on hard climb and EGT's at under1500 in all settings, Cruise with Hackman Leaner still at or below 4GPH. We will also be trying a newly designed Cam for the 1622 conversion, Once all the testing is done we will have this conversion as dialed in as the two 1484 Zipper conversions already on the market.
BigJohn Kitfox 5 Outback Rotax 912ULS With 1622cc Big Torque Zipper Conversion
No website developed but they are advertised on Barnstormers and you could contact Wayne Flemmington at Southland Rotax 951-255-9144 in S.CA Or Jay Stewart in Nv 775-388-2046.
The Zipper BigBore's 1484cc 105hp and 114hp are truly perfected and performing great in many aircraft now, the 1622cc is coming along and is truly a great performer, Hal and Wayne just want more testing with some additional modifications like a special Cam, Exhaust and possibly additional Carb mods, That is not to say it is lacking, The 1622 has been performing excellently with only modifying the Jet size changes but if it can be made even better Hal and Wayne want to do it, If you would be satisfied with either the 105hp or 114hp Zippers they are ready for prime time and available with minimal installation necessary.
BigJohn Kitfox 5 Outback Rotax 912ULS With 1622cc Big Torque Zipper Conversion
Hello to everyone from Jay, Hal, Wayne, and the ZIPPER.
To let you know we are working on a Web presence. Been busy though working on satisified flyers. There are a number of ZIPPER flyers out there now and we've been letting the ZIPPER track record speak for its own. Thank you Big John for all of your very valuable ongoing information you have posted. Hal installed another 1484 High Torque 9.7:1 Kit on a Rans S7S last Wednesday morning with a 100HP that has a little over 1400 hours. He stated to me today that right off he had quicker take off, felt more torque, was smoother, cooler, and can now use Regular Gasoline. I am shipping our second 1484 11:1 HP Kit Tuesday to Norway for install on the Dynali Helicopter. ZIPPER has gone World Wide. We just received some more stock. Let me know when you're ready to GO OUT AND FEEL THE ZIP.
I ran into this guy today. Has a 140HP 912ULS. Didn't ask him how many hours he had on the engine but he told me he has been flying it over a year trouble free.
All the work was done by Rotech in British Columbia.
Re: 912 Big Bore
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