912 Big Bore

[WWhunter]

Thank you sir! I wasn't able to tear into the carbs yesterday since I had other jobs that needed to be finished. Hopefully I can get to it this weekend.

I seem to recall I put the clip on the 3rd notch but now I am trying to remember if it was the 3rd counting from the tip or from the blunt end. Dang it sucks getting old.

[trentp]

Hey guys, I thought I should key in here. I just flew out to Elko and had Hal Stockman install a high compression Zipper kit and slipper clutch on my series 5 kitfox. I had the Xtra high compression pistons in my 80hp motor before this and already had pretty decent performance. But since I fly at high density altitudes and am playing around with some short backcountry strips, I felt the extra power was needed.

I am still in the first break in hours but I could instantly tell the difference. Tail comes up much quicker and my ground roll is shorter. My climb went from around 500fpm to right around 1000fpm with two guys and a density altitude of 7800ft With the extra power we had to add 2 degrees of pitch to my prop so I got about 12-15mph out of the top end in cruise. I have to keep an eye out on my altitude now, the plane loves to climb so I find I will be cruising along and look down to see that I am still climbing around 400fpm still while indicating 85mph (about 100mph on the ground). One other big note is how smooth the engine runs! I don't know if it is mainly due to the slipper clutch but it definitely idles a lot smoother and seems to run smoother overall.

My air master prop with the STOL blades just came in so that will be going on this week, it should compliment the big bore perfectly!

[AirFox]

Super info Trent. I'm very interested in the results with your Airmaster at DAlt.

[Paul Z]

I've read through these postings on the Big Bore Kits, everyone talks about using MoGas. Here in Texas I know of only 2 places to get MoGas. I would say that 99.99999% of the time I have to burn 100LL, or I don't get to fly. When it was pushing $6 a gallon I had driven 25 to 30 miles east of the Dallas Metroplex to get Regular No Lead auto fuel from the only station I know of that has gas without alcohol. The guy sells to farmers in East Texas. It is very difficult to find in Texas.

[KFfan]

Web sites to check for non-alcohol gasoline retailers

http://www.pure-gas.org/
http://www.flyunleaded.com/airports.php
http://www.buyrealgas.com/

I'm confident there are many more.
I do not vouch for the accuracy or timeliness of any reference.

[TahoeTim]

You can run premium pump gas with up to 10% ethanol. If you have the fuel return line, I would be fine with it.

On a side note, the stick and rudder school planes run 100LL in the 912is engine.

[teamkitfox7788]

I am not seeing posts on big bore conversion experience since Oct 2015.
Am I looking in wrong place or ??

[Av8r3400]

Speaking for my Zipper big bore, it's running great.

I'm waiting on a prop for it but until I took the prop off, it was running as expected.

[avidflyer]

Is the prince prop not working out for you Larry? Jim Chuk

[trentp]

I have a little over 80hrs on my high compression zipper kit, still running smooth and strong! Still very happy with it.