Thank you and AZK35525 cheaper too. Can't always find everything with google search. having trouble right now getting on catto propellers site at the moment.
Help Support Homebuilt Aircraft & Kit Plane Forum:
Well, I think a 1750 lbs airplane can handle that
Since you're building a Cozy, you're probably well aware of the Cozy Girrrls. If you need to fab a motor mount, might be worth at least talking to them. They do speak rotary.
Charlie
I personally would not put the Renesis on the Cozy without turbocharging it, and since the Reny has some issues being turbocharged I would stick with a 4-port 13B-T or 13B-REW. Brand new REW engines are currently available from Mazda. Not cheap" but 100% brand new OEM assembled engines, not rebuilt or reman. If I were not me that is the route I would go. Alternatively I have a friend in East Tennessee that has been mentioned here before that I would 100% trust to build a flight engine.
I am in Middle Tennessee, about 1 mile north of KMBT. Swing by anytime. Currently I am working on my Dragonfly with Corvair power, but the 13B Turbo is about to go on a Long EZ false firewall to start mocking up all the cool stuff, including a motor mount. I have one the TIG welders and *some* of the fab tools from my race shop still, so if you need help along those lines I am happy to teach and/or help.
I feel like the Cosmos did you a favor by removing the temptation of using a carburetor. I have my own personal path I am taking with my EFI system, but I recommend a call to Ross at SDS, he posts on this forum pretty regularly as well. I very much recommend against Haltech, Microtech, Fuel Tech, Megasquirt, and many other EFI systems as they are not very well supported, buggy, and simply not reliable enough. Yes, I am aware of the "rotary community" fondness for some of those, especially Haltech, but their support is from a financial, not a reliability perspective.
Ahhh at murfreesboro,my daughter went to college at MTSU. Will definitely make a road trip to you after the holidays. Currently with the FWF package I just need to modify the engine mount to set on the cozy firewall. Changing the angle of some tubing and having it welded again and powder coated. I have a miller MIG 185 but am not confident in my welding skills to attempt that plus I heard it is better to TIG weld it. Am looking at a Miller Syncowave 210 that does both and can also run on 110 current if needed when 220 not available. I also have to redo/build the cooling system as it was set up as a tractor prop and of course the cozy is a pusher so as it is set up will not work the way the rads are now. Then a new prop not sure I can use the Catto brand one that came with it, still doing research on that. I am semi-retired work Tuesday thru Thursdays at the moment.
Thank you Charlie.I am familiar with their site. I hope I can modify the one currently on the FWF package I got without redesigning/purchasing one. Hopefully can just rearrange some tubing angle to fit the Cozy firewall and clear things, and then onto a new prop and modify the cooling rads to fit the pusher set up.
Hello again ..
I just ordered the skf seal, partnumber is 9862 btw.
The RD-1C manual suggests to drill a hole in the housing of the gearbox and put a bolt in it to pry it off the adapter plate. Are there any other methods you guys prefer ?
I have a magnetic oil drain plug on the oilpan of the engine. It collects very fine metallic particles which are almost as fine as graphite powder. Is that acceptable ? Maybe this is from the spacer between the two bearings ? I have not opened the gearbox yet.
My engine is a 6port stockport engine that I run with a weber dcoe and DLIDFIS. Premix 1:125. Max rpm at WOT (static and flying) is 6000 and I need 5500rpm for cruise with a 68x60 cattoprop. Although my Breezy is very draggy and heavy (1750lbs MTOW) I am very happy with the performance of the engine setup. Takeoff roll is about 700ft with immediate climb of 800ft/min which is comparable with a O-360 powered Breezy.
My split is currently fixed at 10° with 20° total advance. During cruise I adjust the mixture slightly on the rich side giving an egt of 1650°F. Fuel flow with this setting is 9.3 gal/h. Any Ideas regarding these numbers?
I know these values are on the safe side but maybe I could improve mileage and power output without taking any risk.
Sorry for bothering you, but I am a lonesome aviation rotary wolf here on this side of the pond
Last edited:
I can't offer any direct experience, but if you ask that question over on the Flyrotary list, I'm pretty sure that several guys will tell you that they fly all the time well lean of peak. The two big risks with piston engines are the exhaust valves and detonation. No worries about exhaust valves here, and all the research I've done indicates that destructive detonation is almost impossible in an unboosted rotary.
Going lean of peak should allow you to lower the EGT a bit, or if you're keeping it down by running rich now, keep it at the same level with much lower fuel burn. One guy on Flyrotary who is a research scientist in his other life tests/quantifies everything he does, and IIRC, his best BSFC was at somewhere in the 50-75 degrees F lean of peak.
Going lean of peak should allow you to lower the EGT a bit, or if you're keeping it down by running rich now, keep it at the same level with much lower fuel burn. One guy on Flyrotary who is a research scientist in his other life tests/quantifies everything he does, and IIRC, his best BSFC was at somewhere in the 50-75 degrees F lean of peak.
Thank you, will do that. I often heard and read of running excessively lean but never got first hand information about a similar setup and never dared to do that
.
Last edited:
If you're running a 2.85:1 ratio drive, 6000 rpm WOT in level flight sounds like you're over-propped by quite a bit. Finn, are you still listening? What do you think? Might be reasonable to limit power on something like a Breezy that will never go fast anyway, but it sounds like you're leaving a lot of climb performance on the table. IIRC, Tracy updated to the 2.85 on his 13B before he switched to the Renesis, so either engine should be fine at higher rpm, and with a 68" prop, efficiency may be suffering a bit if running at 2100 in climb (even lower in cruise). Fixed pitch Lycs with 68" dia props typically turn 2300-2400 in climb on RVs, and they fly at roughly the same weight range as you. They turn 2700 at WOT both down low and at altitude. For perspective, I do local flying in my 180 HP RV6 with a 72" dia fixed pitch prop at around 21" MAP & 2100 rpm, 1500-2000 feet altitude. Admittedly much lower drag, but fuel burn is ~5.3-5.5 gph going ~120-125 kts. The engine has 'traditional' Lyc fuel injection and one electronic (automatic advance) ignition, and is running well lean of peak at that setting. (Lean of peak works fine on Lycs, too.)
Given the low speeds of a Breezy, if you could swing a larger dia prop I'd bet on fuel burn going down due to improved mass flow through the prop at the low speeds. On a previously owned RV4, I flew props from 68" to 76" dia, and the larger dia props were Waaaay more efficient at speeds under 90-100 mph. Idea is basically to go as large in dia as can safely be used on the airframe, and set the pitch to match the combination of speed of the airframe and rpm needs of the engine.
Given the low speeds of a Breezy, if you could swing a larger dia prop I'd bet on fuel burn going down due to improved mass flow through the prop at the low speeds. On a previously owned RV4, I flew props from 68" to 76" dia, and the larger dia props were Waaaay more efficient at speeds under 90-100 mph. Idea is basically to go as large in dia as can safely be used on the airframe, and set the pitch to match the combination of speed of the airframe and rpm needs of the engine.
As you might know a Breezy is very loud due to the pusher configuation. I do like aircraft noise, but we have tough noise restrictions for airplanes in germany - there would have been no chance for me to get my project certified as experimental using a conventional aircraft engine. Also a rotax 912 was out of choice - I wanted power ...
So I was looking for a engine that could swing a 3 bladed prop at a rather low rpm, which lead me to the 13B. I found a guy in switzerland who passed the strict noise certification in switzerland with his Breezy, using the same setup as me, with Tracy's engine controller.
I decided to go the same way and asked Craig Catto to calculate and build a prop for my Breezy. The numbers regarding max prop diameter, Vx, Vcruise, max rpm and cruise rpm I gave him (except cruise rpm, I aimed for 4500-5000, but that was a unrealistic desire as I know now) are matched by the prop he made for me. Of course this is a compromise, but I just did not dare to choose a higher prop rpm because of said noise problem.
Long story short : you are absolutely right, but I am restricted
.
Last edited:
Ah, yes; I forgot about the strict noise regs in Europe.
Carl, I watch with interest, where are you in Germany, I was over there in 2019 Friedrichshafen (Bondensee). I would like to look you up on the map. Good on you using the Rotary I agree with Charlie in regards prop size- 72" would be a good size.
George (Australia)
George (Australia)
Well first flight after being away for 6 weeks doing a house renovation. Still running the RV-3B 74x80 prop. Need to get the 76x88 prop back on and balanced.
6,300 on take-off 100-120 mph climb on this 67F OAT morning.
Will be interesting to compare to the 76x88 prop.
Finn
George, I live in Reutlingen near Stuttgart. My airplane is in EDTM. If Corona permits, my Breezy will be on display at AERO EXPO next sprig.
Carl, Here is the T-shirts I had made for the Airshow in 2019.
I spoke to a German chap, I found on the Internet who has redesigned the Rotary for Aviation, I can't remember who he was but he was in Germany, but we had good discussion via e-mail, he was a Professor of Engineering and worked in Aviation for many years. His design was a smaller P-port and Mistral looked into his engine for their project, but they settled on the Mazda. I think it was a mistake as for Certification they needed to manufacture their own parts for the Certification Audit Trail and he had everything to start that process. I believe he's still waiting for someone finance manufacturing and yes he has prototypes running. If you find him let me know, I should have kept his information.
George
I spoke to a German chap, I found on the Internet who has redesigned the Rotary for Aviation, I can't remember who he was but he was in Germany, but we had good discussion via e-mail, he was a Professor of Engineering and worked in Aviation for many years. His design was a smaller P-port and Mistral looked into his engine for their project, but they settled on the Mazda. I think it was a mistake as for Certification they needed to manufacture their own parts for the Certification Audit Trail and he had everything to start that process. I believe he's still waiting for someone finance manufacturing and yes he has prototypes running. If you find him let me know, I should have kept his information.
George
Attachments
Nice T-shirt ! - there is more than one company in germany trying to revive the Wankel. I am looking forward to the next AERO EXPO in april, hoping it will take place. Usually all these people have their products on display.
Carl, Yes! everyone like it and wanted to know where my display stand was, maybe they wanted to buy one, you should do some T-shirts for the Breezy with Rotary,
Yes! the Rotary is a good design alright, it's had it's teething problems, nearly sending Mazda broke in the process, their integral P-port housings were best, their Al Rotor Housings with Steel liner is a very good design, I read somewhere it was another Japanese Company which came up with the process, probably absorbed by Mazda and even though the Cast Iron housings are very good, their too heavy for Aviation purposes - just my slant on things.
I got the impression no one knew anything at the show in 2019, they were all nicely dressed, but I got bugger-all info. There was one small rotary display, but I was after info on wear surfaces etc. but there was no one there with technical knowledge. Maybe I wanted to know too much!
George
Yes! the Rotary is a good design alright, it's had it's teething problems, nearly sending Mazda broke in the process, their integral P-port housings were best, their Al Rotor Housings with Steel liner is a very good design, I read somewhere it was another Japanese Company which came up with the process, probably absorbed by Mazda and even though the Cast Iron housings are very good, their too heavy for Aviation purposes - just my slant on things.
I got the impression no one knew anything at the show in 2019, they were all nicely dressed, but I got bugger-all info. There was one small rotary display, but I was after info on wear surfaces etc. but there was no one there with technical knowledge. Maybe I wanted to know too much!
George
Any one know of a factory or similar engine overhaul/rebuild manual for th 09 renesis motor? I just got the factory (blue cover workshop manual #1927-1u-08c) off Ebay almost 2" thick and I was surprised no info on engine disassembly/rebuild,torque specs, clearances etc. Can't even find a basic Haynes manual for it .Maybe not googling right.
First is no, there is very likely not a readily available engine rebuild manual. Dealerships are not encouraged to rebuild Renesis- or any other- rotary engine. there have enver to my knowledge been a coherent and more importantly- OFFICIAL- list of specifications for apex seal/side seal/ etc. clearances. Most of the information that you will find is based on either -
A- speculation and transference from earlier 13B-REW. This works for e-shaft bearing clearances, endplay, etc. Apex seal clearances *seem* to also align with the earlier engine as far as slot clearance. All torque specs line up off the top of my head. Where this falls apart is the side seal clearance. This is a fairly critical thing as the side seals are very different from earlier versions- for example they are tapered, not straight, in profile-and they are well known to break with varying reasons as to why. What Mazda did do is to give a size code stamped next to each side seal and you were to order pre-cut side seals based on that code. This does work, but my observations are that the rotors do not stay the same over thier life and while the seals order to code will work they may or may not be optimum.
or
B- The work JIm Mederer at Racing Beat did with Mazdas support and the specs he circulated, or that people measured when they tore the engine down. IIIC he used the same side seal clearance as the 13BREW as well, and it worked.
Because of this, there are MAYBE 8 or 9 people in the country that I feel can successfully rebuild a 13B Renesis engine into a reliable powerplant. You live near one, my friend Kevin landers of Rotary Resurrection in Morristown, TN. There are very few others out there, and I honestly cannot name another off the top of my head. Maybe Daryl Drummond? Bruce Turrentine? Myles Fisher in South Carolina? I am retired and in theory could, but the other fellows are still in business.
Latest posts
-
Low aspect ratio sport plane ideas- Latest: nestofdragons
-
-
-
-
