Hi! newbie here. I have a Bushmaster. Experiamental stretched Pacer, with big long Supercub wings. I am wondering how foolish it would be to hang an O-540. I'm not so worried about the weight, and balance, but rather the strength of the tubing and firewall area, on airplanes that were meant for 0-320's and seem to have done well with 0-360's. Any comments would be welcome. Thanks!
I would say you are not the first person to try this , this fellow had his plane on barnstormers a while back , If you could find out who he is you could get some good info from him I believe the plane is in Minnesota
www.cutbow.com/bm300/Home.html
gerry
I'm just a pilot, no expert, just finished Bushmaster with Smith wings, 0-360 and McCauley 1P235 84/43, waiting on weather for test flight. I started on J3s and owned Super Cubs and think my rig is all I'll need.
The answer to your question resides mostly in a frame perhaps 50 years old. Do you know its condition? Did you strip, blast, paint and prepare for covering? Did a knowledgeable person inspect for soft spots?
As for the 540, what's the mission: towing banners? The engine could be 200 pounds heavier than a 320, depending on the model. And the fuel consumption would strain my pocket.
0
Why aren't you worried about weight and balance? The typical O-540 is going to weigh about 100 pounds more than an O-360, which is already 25-30 pounds heavier than an O-320. In addition the typical constant speed props for the O-540 weigh about 30 pounds more than the comparable props for an O-360. You would suffer less of a penalty with fixed pitch props, but you still can't get rid of that 100+ pounds.
With 100 pounds added to the nose, are you going to have to add ballast to the tail to avoid exceeding the forward CG limit? If so you have given up a lot of useful load or structural safety margin if you just decide to bump up the gross weight. Tail ballast also contributes to some unwanted handling characteristics.
As you rightly suspect, the structure will need to be beefed up to handle the extra engine weight. Remember, you are adding 100 pounds time 6 g's.
For all this trouble, what have you gained?
Dave Prizio
TX Sport Cub N114DE
Sounds like a cool idea.... like Tim the Tool Man says...
MORE POWER...
a lot of folks will poo poo your idea.... for various reasons.
Get a good check up on the tubes... locate the battery and other
things in the tail for W&B....
are you looking at an IO-540 or the O- 540...? can use a
fixed pitch prop on the latter.....
a lot of Piper sprayers went from the 0-320 to the 0-540....
with some tube and other structure modifications.
Its been done before..... what ever floats your boat
And Welcome to a really pretty darn good site...!
Yes, I'm an Oenophilia. And I VOTE...!!
Here's one, sort of.
IO540, 3 feet longer fuselage to make up for the extra engine weight. Empty weight is approaching that of a Cessna 185. Shaved 44" tires on it.
gb
Thanks for all the replies. The reason I have not been worried about the weight and balance, is that the current power is very similiar in weight to the 0-540. Currently it has a water cooled automotive engine with prop speed reducer unit. Performs really well, but I tend not to trust it. I did not build the craft. A friend, AandP, who is deceased constructed it, so I can't ask the questions I'd like to. Like many experimentals, the airframe is an elegant creation. Actually two Bushmasters were built by the same person. The other one with an 0-360 was impressive but underperformed compared to the one I have. I hate to go down on power in the change over. If I trusted that the current power set up was reliable, I would not change to an aviation engine. My original intent was to hang an 0-360. You know how it is. Never too much power.
sounds like it is way more weight than you should have...
go turbine
A good PT-6 should give you enough ponys to get her airborne :P
I don't know where you've been me lad, but I see you won first Prize!
Why stop at an O-540? West Texas Aviation, in Lubbock, had an STC to install an R-985 on the Super Cub!
Volunteer, in charge of Political Correctness
Just cruising through the thread, clicked on the link that Super Sportsman posted and Low and Behold up pop's the airplane my neighbor built.
It is stretched. The battery is way back there to keep it in balance. The wings are built from 4 Pacer wings with 4 18 gallon tanks. There is a tube welded from the upper engine mount cluster angled down to the front gear fitting to reinforce the firewall for the engine weight. If memory serves me right it is a 5/8 diameter .032 wall tube. It is heavy. Performs similar to a 185 and would probably due better with a long 2 blade prop. That 3 blade one is custom built out of cut down helio blades. The guy that built it is a machinist / fabricator and did exceptional workmanship, sold it so that he could build up an 0-470 powered Cessna 175 on its tail.
My Maule with the 540 was a good aircraft. It was not unruly. Throttled back, it consumed about like the 0-360. Admittedly, a big six on a pacer firewall, may be a questionable idea. I think the guys at Cubcrafters had some sort of an overgrown Cub with a Lyc. 540, maybe even a 720, hanging around, for sale a while back. I saw it, but wasn't interested at the time. They are not too far away. I may stop by and talk to them one day. They may want to laugh me out of the place too. I enjoy the comments. Per your suggestions, I will surely get to work on the round engine idea right away. He He. Prop clearance is gonna be an issue.
I would think the parallel version of the 540 would be a good choice for weight vs the heavy angle valve version, granted the hp is a bit less but if you stick some 10:1 pistons in you can make some of that up it would probably be around a honest 280hp just guessing,(not like the guys that claim 200 plus out of a 320). check with the fuselage builder and see what tubing thickness and size and run some tube column formulas for buckling and see what you come up with you will also need to know the thrust out of the prop engine combination. There is plenty of good literature out there to figure this sort of stuff out. When in question overbuild. sounds like a cool project. I wonder what the weight of the 540 parallel valve vs the heavy 390 angle valve. There is plenty of these 540s around so finding a core to build up should be easy. I believe the engine you want is a 540A1A-5. Best of luck and building i would sure like to see the progress of this project. right on.
Brian, that is a gorgeous aircraft. Thanks for the info on strengthening of the firewall area. I'd love to come into contact with the person who did that elegant work.
here check this out there are more videos if you search it , also can you post pics of your bushmaster
http://www.youtube.com/watch?v=ZD1oz...eature=related
http://www.youtube.com/watch?v=ZD1oz...eature=related
The one in the picture IS the one Cubcrafters had for sale for a couple of years. An acquaintance of mine now owns it. It was de-registered when he bought it. It was disassembled and transported to an undisclosed location in the NW where it was re-assembled and is now waiting in a hangar for FAA blessing to fly again. He plans to use it for high altitude off airport landing areas while hauling heavy loads of mining equipment. We'll see.
gb
I think an IO-390 would be a better choice. There's an outfit working on an STC for PA-18's at this time. Says it really rips....
http://www.hoaircraft.com/PA-18-IO-390-STC.html
Crash
"The fear of God is the beginning of wisdom". Psalm 111:10
In reading this very interesting thread my mind wandered back a few years, it seemed I had read that the guy(s) who built the Sherpa had put a 540 on a Cub, couldn't begin to remember who he is or when I read it or even where I read it, so I googled it....two clicks and there was the article about the Sherpa and the reference to the 540 on the Cub.
If you're interested here's the link http://www.airbum.com/pireps/PirepSherpa.html
I would never throw cold water on someone's idea to upgrade the motor or any other part of the cub, I'm pretty sure that's how the Bushwheel Tires came about, someone saw a need and went from there to where the company is today. Fun Stuff
db
My dad built up a Cub with a parallel valved IO-540 back in '99. I was a helper on that project, so was Nate. he and I both served as ferry pilots on it for several years, in fact Nate still does. It was purpose built for skywriting and night time pyro acts at airshows. Originally sponsored by Pepsi, and now by Oregon Aero. Promotional info here:
http://www.skywriter.info/magazine_a...ters.pdf&pli=1
http://www.skywriter.info/skywrit_gallery.htm
It excels at the skywriting, lots of heat made by that big engine to help produce the smoke, and lots of reserve power up in the teens where they do most of their work.
And boy will she haul one heck of a load. All of the tubing was sized up one size in the fuse. The tail feathers are double braced all the way around too. This airplane is, I believe, for sale.
Was looking at a Pacer fuselage today and realized I was wrong on the location of that tube. It is welded at the top engine mount cluster, then it angles down to the top of the SEAT cross tube through the front door tube. You can see it in the pic's of the airplane as the angled tube at the bottom of the door.Originally Posted by Steve's Aircraft (Brian)
Brian.
Thanks guys, so much for all the tips and help. Iv'e gotten a little distracted by work lately so will make attempt to post some pics and study thru what everyone has offered a little better this weekend.
I've not thought this through, but what about redoing the tubing in the boot cowl area and the boot cowl and firewall to allow moving the O-540 aft about 6 inches? If feasible, that should help a bit with the cg problem.
JimC
JimC
Leg room. The rudder pedals are already against the inside of the firewall and if you are a tall guy like me, shortening that area is not a good thing.
Brian.
The Blue Cub pictured above had the engine mount shortened as much as possible, to the point that I had to go to Gall's Sporting Goods in Lexington late one night to find two stainless steel camp dinner plates that we riveted and RTV'd to the firewall to allow clearance for the mags and their associated harness. The dishes ended up allowing a recess of about 1.25 inches.
Still though, weight on the nose was a definite issue. We ended up mounting the largest battery that Concorde offered as far back in the fuselage as dimensionally possible. Ran the extended baggage back to about two feet forward of the empennage, and mounted a huge ass oil cooler to the back side of the baggage compartment as well.
Clay
How much does the lead weight "stinger" on the T/W weigh?
Lou
Right at 15lbs. When we switched from the 90" EXP Mac, to the 210cm 3-blade MT, it added some weight to the nose. At the same time we switched the RG35 battery to an RG25 for fleet maintnance reasons; loosing a few pounds on the tail.
To give you an idea of firewall space....
nkh
I just don't get it. Why not an IO720? I'm just being a smart ass. That big Cub has a purpose and it's not landing on river bars and other remote sites. Not exactly a machine a guide would need.
Well, we don't want to be ostentatious.
But if we were to do it again.... a Walter Turbine would be a better choice.
nkh
Thought this may be of interest to big motor fans!
300hp Cub.
www.dougronan.com
hi all - been lurking a while but thought i'd add my 2 cents here. I have a bushmaster with an 0-470, great airplane 3000 lb gross weight 1501 empty. Built mine after flying another bushmaster with an 0-540 thought it was great too
IMG_6007.JPG
Van Wagner 250hp Super Cub with 90" McCauley Prop
supplane.jpg
The Super Plane
I thank Tim Tepper at shadey cove oregon built more than one 540 cubs and I believe he still has one. I thank he built the frames for all the 540 that Byron Root built an the frame and alot of the parts fore the Sherpa.I have friend that is building one now that Tim made the frame.Ron
Ron,
Tim and John still fly the original "Bruitimus" 0-540 Cub and it is still based in Shady Cove..... In fact, post #6 on this thread looks a lot like it, wrong prop though...... Tim was involved with the Sherpa group for a long time still does stuff for a few of them.
Brian.
Brian I thank Tims Hanger at shade Cove is Byrons old Hanger from Portland thank tim and John moved it toShady Cove. Tim done frame and some of the hard to parts. Thanks fore the heads up. Ron.
This is a GREAT thread and I hope that we see some of these things flying around. With respect to weight and balance, I seem to remember sitting in the back seat during my first hours of dual in a J-3 in 1955!!??
HI all 540 cub fans I thank that Byrons old 540 Cub Brutis is fore sale if some one is enterestedand if it hasent sold. Its the one Krueger got from Byron. I can get the phone if someone is looking for a 540. Ron
Clay, how did the trim work?
Like a Cessna.
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