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Skye Racer post Mojave Update

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Schmleff

Well-Known Member
Joined
Jan 2, 2006
Messages
2,714
Location
Waupaca, WI / USA
I have not really done much to update my blog or post anything all summer so here is a brief update ; )

Revised the seat pan to clear the torque tube by using piano hinges and a sheet of aluminum to make a sling seat. However, that torqued the tube that is connected to the rear torque tube pillow block enough to cause slight binding at 1G. Had to build a bunch of brackets to transfer the load elsewhere.

Converted a $69 Harbor Freight aluminum air tank into a 7 gallon aux tank that sits behind the seat rather than my head like the old one.

Revised the main fuel tank mounting and connections to make it very easy to remove. There is so much stuff going on under their that it will save me a lot of time in the long run.

Revised a fundamental flaw in my fuel system, specifically the return line from the carb. More on this latter...

Modified the taper pins to make it easy to get the wings on and off. As Tim can tell you, it was a 5 hour job because of the aux fuel tank that sits under the main. It was nearly impossible to get the nuts off of the back or put them on. I 90 degree cross drilled the pins and made combination nut and shoulder washers and JB welded them to the back of the spar box. To get them in or out, I use a punch and spin them out from the cockpit side. Takes about 30 min each way now.

Verified the accuracy of the digital timing and made modifications to the timing curve near idle. A car will idle fine at 15 degrees, an airplane will not ; )

Made a rack and pinion system for the mixture control. The carb has a thumb screw for adjustment but I wanted to keep the push pull mixture cable.

Finished the rigging of the new control system.

Re-finished the prop and static balanced it using a model airplane prop balancer. $25 bucks and its the most accurate balancer I have used to date.

Made a box for the secondary coil and lots of heat shields for pipes in critical areas.

Lots of little detail stuff as well. Check, check and check again.

Still to finish:

-Dynamic prop balance. Hoping to get that finished today if the weather holds
-Finish the baffle that goes around the exhaust collector and ejects the hot air right in front of the cooling outlet
-Finish the right side baffle
-Baffle seals
-Final test runs and carb tuning
-About 45 pages of log entries

After 26 months of work, its almost ready!!! Baring some strange setback, it should be back in the air in the next couple of weeks ; )

Picts and details to follow after its flying...
 
Thanks for the update, Jeff….Could you provide that update on the Affordable Air Racing Site as well?….That site is in need of contributions…..Ed
 
Very cool!
Seeing everybody get there projects completed and test flying my friends SIIL has got me chomping at the bit to get mine done. So close and yet not lol
 
I forgot a bunch of stuff like re setting the valve train geometry and new pushrods. Of cours after getting it all set up properly, the valve adjusters were hitting the valve covers ; )

A miracle happened today in the sense that something actually went my way for once. I hooked up the dynamic balancer and fired it up for the first test run and it said .06 IPS. That is a good level even after spending a couple of hours of balancing. Shut her down, smiled and headed home to see the family ; )
 
Jeff, when you make your site updates, can you show some detail of the rack and pinion for the mixture control?

thanks.
 
Your rack and pinion mixture control looks like an idea I can use on my zenith carb mixture control.

One concern I have with the Zenith, which may or may not be true for the Mikuni, is that the main mixture needle is a very fine pitch, small diameter, brass screw. And, it has a "packing gland" to stop leakage around the screw threads. I typically go about three turns from lean setting to rich.

If similar on the Mikuni, do you have any concerns about wearing out the thread or packing?

Thanks,
Tom H
 
Jeff,

How is that Mikuni carb working out? Looking to use one myself on a 2276, thinking maybe the 46mm.

I like your idea for the ring and pinion but how about another idea that may be a little easier and lighter. What do you think of using a sprocket on the mixture screw with a small chain or cog belt going to an idler sprocket. You attach the mixture cable to the chain-belt and you can set stops to limit the rotation.

I also like what you had talked about on your blog on tuned intake and exhaust. How hard would it be to pry some of that information out of you.

Thanks,

Bryan
 
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