Due an update here. Teal has made a few upgrades to the original design, to include a larger oil reservoir, an oil level sight guage, and helical gears. And bigger news (for anyone that has missed it) is that Edge Performance is working with Teal on a full zero timed Apex with beefed up internals and their fully automated aviation grade Turbo. Edge should be testing a prototype here within the next two months and Steve Henry is planning to be the launch customer. HP in testing will be in the 250-300 range. Production units are planned to go out in a detuned range of 180-230 or so. For reference, the Apex is run up to 600 HP in the snowmobile drag racing world. Basically, Edge is planning to do all the internal upgrades (as seen in the pic below and website link) that are used for the 600 HP race sleds, but send it out to only run it in the 180-230 range for aircraft use. http://www.powerbygns.com/Products.html Follow the Edge Performance build in the FB post here (click the "veiw on facebook" link)
Reference post above, here is Thomas H's (Edge Performance) comments on the project: It’s Yamaha time. I’ll try and keep this post alive as we progress. Step one is to tear down the engine and inspect and measure the internals. Ultrasonic clean and bead blast all parts. Send off all steel parts for tumbling and cadmium/zinc plating. Next, install forged pistons and rods, new bearings, ARP studs and MLS head gasket. Make a mil-spec Raychem DR-25 motorsport harness and adapt the Apex engine to our ECU. Make a 4-into-1, S321 turbo manifold and fit a Garrett turbo. Thinking either GT2860R or GT3071R. We’ll see how bald we dare to be. Fit Teal’s Sky-Trax PSRU Run it like we stole it on the test bench and dyno. Gain data and numbers. * Maybe do a full head job with full radius cut valve seats, grind the valves, and possibly a 5-axis CNC porting job. Needed, NO! Would it be cool, YES !
Looks like Teal answered your question, but I wanted to add that with Steve Henry on your side you have a totally unfair advantage over the rest of us if you end up going Yamaha! If his headers, motor mount, and other fabricated parts would have bolted up and fit my KF like they would on a Just firewall I woulda bought them in a second!
Also FYI below is Steve Henry's weight worksheet for his new plane with this Skytrax Apex adapter (note the weight includes the radiator)
My deal with Roman direct went well too. Long wait but good deal. Those props are a work of art. And I shoulda hired Fred to come over to do my engine swap with the same method used in the video above.
I sure can't solve the mystery. I've owned twelve 2stroke Rotaxes and have been lucky... only had 6 of them fail. 4 in sleds and 2 in aircraft. "Lucky" is because I was driving for all the sled fails but on the ground watching someone else for the 2 airplane fails (my KF2 and a PPC I just went for a ride in). So now I'm in the 4 stroke camp (trying for better luck there ) but watching this reminded me that "keepin 'er low" when you can on departure puts you in a better position to handle something like this: better speed and pitch angle to work with and also not as far to fall! Sometimes you gotta climb at Vx but if they woulda held it at 5 ft for awhile here I think the outcome would have been better. So my takeaway is a reminder not to "put myself there" whenever I can.
Good looking option one of the guys in the Yamaha group found: totally premade with shroud, fan, fittings for $70! (Just run a plastic hose off one of the duct outlets up for winshield defrost like in my pic earlier) https://www.ebay.com/itm/Universal-Under-dash-Heater-12V-Heat-w-Speed-Switch-for-Car-or-Truck-6-port/192343135303?epid=23007808432&hash=item2cc88b5447
John, with the RX-1 you might want to consider using an oil cooler as a heater. It might give a better amount of heat than the coolant on really cold days. In the little amount of testing I've done, the engine Tstat modulates pretty far to the closed side when running cold (15 deg oat) with prop blast going past everything. My heater core temp was noticably cooler because I think the tstat was barely opening as more cold wind was generated. If I were installating a new one now I might experiment routing hot engine oil output to a core in the cockpit with a fan, then off to the oil tank. The oil temp is said to run about 20 deg higher than coolant and, with addtional cooloing (cabin heating) I would think that "more and cooler" oil in the system could only be a good thing. Since I'm invested in my coolant heater I might experiment with a second thermostat in the line prior to the main radiator input. Then when the engine tstat opens nearly all the coolant will be routed through my heater core and when it gets hot enough or when the heater core is valved off by me then the temp will increase and the radiator tstat will open to do the big cooling. Id plan the radiator tstat will have to be opening a few degrees cooler than the engine one to keep things moving early enough.
Here is a video of me testing ignition sources and fuel delivery: https://youtu.be/wLrP70CLfi8 And below are tools that make life a zillion times better when doing carb work. The long hex wrench reaches way in to get to the inner airbox screws and the upgraded carb float bowl screws, the jets are available in many sizes and come in pairs... so only order 2:
Gates has a good selection of tees and reducers as well. My system simply has a tee right before the hot goes in the radiator, and another right after the cold comes out. Run those up to the core. Pretty simple. I have a SOV by the core but I don't think you'd necessarily need it.
Maybe consider a heater core type cabin heat? A lot safer and also gives you additional cooling capacity if you ever needed it. Couple extra pounds of course. (Firewall is on left, white tube going up to windshield, fans ziptied on top that blow down through it)
As far as clamps, I am sold on oetiker clamps. Nothing squeezes as tight, is as 100% secure, grips all the way around the hose (zipties and worm gear clamps always have a slack spot under the tab) Just gotta be careful not to put the oetiker in a location where you cant remove them easily (to remove I cut the compression tab with a dremel cutoff disk)
These puppies need to breath right or you will miss out on a ton of HP that they are capable of. Header design is well beyond my knowledge and experience so I went with advice from others, but here's a quote from a performance shop that sheds basic light on the topic: "Header primary tube tuning has two basic parameters: airflow requirement and exhaust pulse tuning. Tubing diameter is dictated by flow requirement, which in itself is determined by engine displacement and rpm... Header primary length has to do with timing the exhaust pulses so that the exhaust from one primary helps to suck the gases from an adjacent cylinder."
It gets real deep. Bore, stroke, valve duration, and other factors change design parameters. But in a basic sense if the header isn't done right it will have the effect of putting a potato in your tailpipe!
Nice write up. And nice that the hardy disk fails in a propeller turning mode like that. Additionally, for anyone that missed it, in the Yamaha group we saw two Cbox's with damaged bearings because the pinion shaft bolt (bolt #19 in the first diagram above) came loose. The Rotax service center recommend (whenever servicing the gearbox) to make sure to clean up and dry the threads (male and female) - use plenty of red loctite - get it torqued right (212 in-lbs) - and let the loctite cure before refilling the oil. Also a pinion shaft axial clearance check is a good idea.