Here goes nuthin…June 1, 2018
I pulled my 470 and quickly sold my 470 back in November thinking I would only be down for a month or two, but after a long spring, I finally have some time on my hands, and am going to get my new motor back in the bird! We finished the O-520 PPonk last month, and Im very excited to get it installed.
I took my time in the process, and hand painted each individual part before assembly. The net result is a real pretty engine.
I took an IO-520F and used the PPonk STC to turn it into an O-520. If you are unfamiliar with the PPonk mod, it takes a IO-520D/F, pulls off the fuel injection, adds low compression pistons, changes the fwd crossover tube, and adds a carb. This mod will get you about 265HP. http://pponk.com/
I ended up buying six brand Millennium new cylinders, but was surprised at the consistency out of the box. In the end, we pulled them completely apart and got them perfect. With a little care and obsessive attention to detail, she dyno’d at just under 300hp. I’m hoping it’ll be screamer! I also made the decision to run high comp pistons (legally by DER approval) so she should perform at altitude as well.
I’ll be running a 3 blade MT up front, and to avoid the chance of kickback and broken starter adapter, decided to go with a Shower of Sparks ignition. This will retard the ignition during start and totally avoid a poor timing/kickback.
The plan will be to eventually pull out the non-impulse coupled mag and install the new Surefly electronic ignition. This is a really cool unit that unlike the clunky Electro-Air is totally self contained inside the mag. This combo (IMHO) will give the best of all worlds. Surefly is hoping to have certification done by Oshkosh. https://www.surefly.net/
I also decided to go with an old style starter adapter, and forgo a Skytec choosing an old skool energizer starter. Yes its a couple more pounds back on the bird, but the piece of mind with that time honored starter is well worth it.
She was pretty much broke in on the test stand, so it should be fun right out of the box. Big thanks to Tim at Unlimited Aero for the support. http://www.unlimitedaeroengines.com/