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"Bolt-on" HORSEPOWER

Dave Calkins

Dave Calkins

Registered User
Anchorage, Alaska
I gotta know what some engine modders are doing for "bolt-on" horsepower.

I've always been limited by my dealing with certificated a/c over the length of my a/c maint. career, but am thinking of an experimental PA-18 for the next project and would love to pick the brains of you guys who've made the mistakes, and come up with some real answers.

I'd love to hear about what crank will still fit in what case....

...what cylinders, cam, carb, sump, induction tubes, can be mixed and matched. And this isn't limited to the 0-320.

I hear that some guys are doing 135 horse 0-200's that weigh less than an 0-235. But no auto gas in these. That's OK.

I've heard of some 0-320's that are dynoing over 180 hp or more.

Any of you have some comments?

I'd like to hear from guys who are doing this stuff, or maybe know someone that they can speak to about this. Please, no second guessers posting opinions.

Please, not too much ribbing from you purists. I'm interested in doing this for the best HP/Reliability for little to no weight gain.

Anyone?

Dave Calkins.
 
Dave........I just saw a dyno chart on a O-320 that had 160 pistons and polished ports.......we installed the engine in a Cherokee 140.........it's all approved....I know this isn't exactly what you're looking for.....but the owner was telling everyone that his 0-320 was now putting out 184hp........well, according to the dyno readout I saw, that's true.......but it also was at 2800rpms.........I only saw the readout for a second.so I don't remember what the hp was at 27 or 2600 rpms.........Personally I think that's stretching it a little.........I don't want to turn my engine that fast, and the cherokee we installed it in......won't ever turned it that fast, or at least shouldn't since the redline is 2700rpms........and the prop won't let you go that high.....unless you point the nose down........lot of good that extra hp does then LOL. I quess my point being........some of these guys may be getting lots of hp........but in some cases......it's just becuase they cranking them up more....heck........I believe that's basically the principal behind the borer prop. That's not to say, they're aren't other ways of getting hp........Brian
 
Thanks, Brian.

Yeah, you need to know what RPM you're shooting for if you intend to be smart with the extra "power".

Seems to me that increasing torque output at the RPM one intends to run is what I'm looking for.

I'm still WWAAAAYYY open to ideas here.

The Borer prop puts a long blade out there to bite a larger "disc", but the relatively fine pitch doesn't overload the engine. There's no question that this works.

If you could make more torque with your engine, you could load it with more prop (pitch and/or blade length) to the engines "best torque" speed....then hope that speed (best torque) is not so high (RPM-wise) as to make that prop inefficient. (Tips supersonic)

The point is, build an engine, and hope the "best torque" RPM on the dyno is low enough that the prop is still efficient.

I know I'm running a strong Cub engine when it will turn high static RPM when on the ground. This is verified by using an electronic tach, and verifying the pitch and diameter of the prop. A 160 HP 0-320 that will turn an 82-44 to good static (2450 RPM) is considered "strong" in anyones book. Anyone want to comment?

You'd be surprised how many new McMauley "Borer" props come new in the box with wildly varying pitches, even differing between blades on the same prop. I guess they put the "new-hires" on the fixed pitch production line. Mine and customers' always go to the prop shop before the new box gets opened. I've even been getting warranty payment for this, so it doesn't cost me or the customer.

Anyone else have good souped-up flat engine advice?

Dave Calkins.
 
Dave...

2 weeks ago, Lycon had an O-235 that dyno'd 151 hp @ 2800 rpm... "F" model pistons, high compression, polished ports, etc.... Sounds good, except I run auto fuel...
 
Thanks, Grasshopper.

Any idea what case ?

I've got a 235-C, 100HP on the data tag.

It's gonna need going through by the time the airframe's ready.

Anyone else out there got something to say? Home-brew ideas that have proven time on them are welcome for discussion if it's up to me.

I guess I'll have to get with LyCon.

I hope there are some more of you guys out there that will comment.

Dave Calkins.
 
Dave...

Contact Steve at Lycon, steve@lycon.com, to get the straight scoop... Mine's a -C1, 115 hp (until I take it to Lycon)...
 
The best HP gain I can do is to go on a diet. This also increases the usefull load. It is early, I think I fix up some bacon, egs and spuds :).pak
 
If you want horsepower, go to the guys that race at Reno. They can make little engines do some quick times. The balance between power and longevity will be the tough issue.
 
Stewart, I've heard those 0-200's on the midgets are doing 4 grand on the tach.

They're running little tiny props with very coarse pitch.

That's not the formula for the Holeshot performance I want.

...and I'm not giving up my heavy breakfast, though I intend to lose about 15 pounds by next summer, PAK.

TJ, I'm sure the venturi detail work is worth somethin', but not likely the kind of power increases I hope to gain by creative compression ratio, cam timing, and intake volumes that the pro-rodders are achieving.

Grasshopper Dave, thanks for the link to LyCon.

Anyone else?

I've just barely been exposed to this stuff.

Any of Jerry Burr's buddies out there running those smokin' 135HP 0-200's that want to let us in on the goods??

Thanks in advance, Dave Calkins.
 
Prop Tips.

Just a thought on prop tips going supersonic. As far as being quiet in the neighborhood, keeping the tips subsonic is a great idea. It has nothing to do with pulling power however. We are spinning a 91" way past supersonic and it just keeps pulling harder. Jerry.
 
I stand corrected, as I have before, by Jerry.

Jerry, what's the deal with those 0-200's on the Coyote?

Dave.
 
...And Jerry, is that a 91" prop on a Cub? And what's it made of, and anything else you can say about it?

Dave.
 
Prop speeds ect.

The 91" is on a O-360 in a Exerimental Cub owned by Denny Martel. If you were at Gulkana or have seen videos of the last year, (1995) then you have seen this Cub. It is a pawnee prop that has been flattened far enough that it looks broken in the middle of each blade. The engine has custom exhaust, much shaved cylinders, flow/ported, Ellis F/I body, 180hp Nitrus system, and much more. No starter , 4 amp gelcell to run the Nitrus and gages. Wayne Mackey slat system. Denny made a 18 foot takeoff and the announcer mentioned that it was probably just a fluke. Denny backed it up on the second run with another 18 foot takeoff. It was no fluke. And that was without the slat. It is a daily work airplane by the way. Used to haul well drilling supplies. I am not at liberty to say much about the Dakota Coyote engines. Please contact Wayne at stolmaster@earthlink.net. If he can't give you an answer he can give you a name and number. Jerry
 
WOW............that's amazing.....18 feet...sure that's not a 91 inch rotor blade he has ??? LOL
Brian
 
What I think is even more amazing than Denny Martel taking off in 18 ft. in an experimental Cub is the fact that Jerry Burr was able to take-off in just a few more feet and land a bit shorter in his certified normal catgory Cub. Now that Jerry has added taller tires and added wing area with the Crosswinds Concept Wing Tips he may be very well able to take-off shorter than Denny. Jerry does more with aerodynamics than brute horespower, that says alot.
 
New Engine

Has anyone out there heard of the I0-390 that Lycoming is coming out with or it might be out now? It is supposed to put out 210 hp is fuel injected and weighs about the same as the 0-360. This would qualify as bolt on HP. Crash
 
I recall several years ago Firmin and I were at the Lake Hood strip talking to the Avid flyer demo pilot. This guy had just flown to Ak. their answer to the supercub. This one had a O-320-160hp in it. There was about a 12 mph wind straight down 33. Anyway the Avid guy was blowing about how great this plane was. I told him to go to Gulkana which was in a few days. Mum was the word about that. About this time a cub on big tires rolls out for an intersection North. We all watch this and he gets off in about 150 ft or so. Firmin turns to the Avid pilot and says 'Will this plane do that?' The Avid guy says a weak 'no.' Firmin says 'That is what the people want.'

Best flying cub like plane I've ever seen was the Thompson cub. Build your plane like that and the story is over, very tough to beat that one.pak
 
Pak, Thompson Cub? Maybe I've been in the hangar too long and need to get out a bit more often? Where may I find info.?

Crash...It hurts to even think about the outright purchase of an IO-390. And then there's the weight issue.

Jerry Burr recommended the souped up 0-200 and some wing mods and ....."...you'll never need any more power..." in one of his numerous interesting, educational, and very helpful e-mails.

The point is, with a light airplane and suitable power, what more do you need?

..Like the preacher said, "...enough is never enough".

..."...the ability to acquire more eliminates the ability to realize what is sufficient."

Thanks you guys.

Dave Calkins.
 
The plane is parked West lot across the street from the North terminal. It is white with orange trim. It was built by a couple of brothers and was billed as the most highly modified SC. The wings are longer and the cord lenght is wider. It has fowler flaps, slats and spoilers. Powered by a 0-360. I haven't seen it move for years. I can't say that it is any better than Denny's cub. Jerry and his buddies are on the cutting edge of the performance envelope. I saw some video of Denny's plane and....wow. Jerry's cub is also ...wow. Go by and take a look at this plane all of the mods are listed on the plane.pak
 
"bolt on" horsepower

I think Jerry Burr's cub is the best example of low weight and it flys on the wing and not on the prop. I have been trying to emulate Jerry's cub in the building of my exp. catagory bastard cub. I like lots of power but I think 5 gal. an hour with bush capability is a hot deal. I have looked at Jerry's cub and it is "more is less"
 
Real Cub

The test of a real Cub is to throw two people in it with a week's worth of gear and full tanks then get off safely and fly to a short rough strip and get it on the ground right side up. I haven't seen any J-3's or PA-11's that are up to this with a 800lb + load. Otherwise all the Alaska guides would be using them. I know a number of guides that swear by the O-360 conversion. I'm still toying with the idea on this current progect. Crash
 
Thanks Pak, I know the a/c.. My guess would be that the thing HAS to be heavy. I've seen it sitting for a long time, have you EVER seen it fly?

Crash, I agree with you, but only to a point. I'm not going to be offended by what your description of the test of a "real" Cub is. But..I'm putting together an -11, which I intend to keep light. I'm not going to stuff it full of goodies for a week and then go off. But if I were, I'd like to maybe haul a couple of lighter loads in, and with my intended end-product, I could get a couple of lighter loads into and out of an even shorter and rougher area, if I wanted, because the thing is light and strong. The "real" Cubs of the Alaska days-gone-by were operated into the roughest and shortest areas by use of the "shuttleing" method. (Several light loads VS. One load of full fuel and full cabin). You know this, so why are you mentioning full fuel and stuffed cabin? I agree with you to a point, but I think it might be OK to call my a/c a CUB.

But that's not what this is about. I just enjoy getting more for less.

One way is to always be fiddling with stuff and finding a better way, and some people like to spend their time fiddling.

Crash, did you talk to John G. about that 180 horse?

Some guys are running the LyCon souped-up 160's and have all the power, but none of the roughness or additional wieght of the 0-360.

That may be a great option.

Dave Calkins.
 
"bolt on" Horsepower

For those interested, I have saved a few pounds on using a titanium firewall, it was easier to drill and fabricate than stainless and lighter than both stainless and galvanized. For those that choose to go into the exp. catagory there is many ways to lighten a cub. I have built many components out of .028 wall tubing when it is safe to do so,Piper used .035 and up in the early cubs and their other rag wing models because they bought tubing by the traincar loads. Although Dakota cub ribs are the best Piper ribs are the lightest, it makes a 7 pound difference in the a/c . I have been told that 125 honest horsepower is available out of the O-235 with gapless piston rings. This was done here in Indiana on a homebuilt cub by Bud Williams. I know to get the performance that crash describes will take a tougher cub than Im building but for now I will just be looking for bragging rights at local sunday pancake breakfasts.
 
Certainly Crash's criteria is a test for a real cub I'm not sure it is the test. I have flow my cub in the configuration Crash describes(who hasn't) and I don't favor it much. The plane is heavy and flies heavy. It is more work than fun. Most guys I know have their own cubs and I think the SC is a great one place plane. If I'm going to leave the plane and be gone any lenght of time I charter in. No baby sittin'n the plane in the wind or bear country. My observation, in the Wrangells is the guys live real close to where they fly and they don't haul much gas or extra stuff. I know guys that consistantly fly heavy, never over gross of course, and for them I think the 0-360 is justified. When hauling weight there is no substitute for HP.pak
 
Dave reply

Dave: Sorry, I didn't mean to offend you with my post. I've just seen over the last 40 years, that one needs to go out further and further out to get the kind of hunting we used to get within 50 miles of the valley. My moose camp is 450 miles out from my house, there in no shuttling back and forth with small loads. I guess I shouldn't paint the picture with such a broad brush. The perfect plane just depends on how you intend to use it.

Yes, I Know John well. The 180 hp Cub that you speak of was in my hanger for a week last winter while John worked on it. It was (John sold it) a P.O.S., that stands for "piece of ###". Had the old four fuel tank set up, 135hp 13 rib wings converted to 16 rib wings, toe brakes, from 100' it just looked heavy. No, what I am talking about is building up a 180 hp Cub with "light weight" formost in mind. It can be done, just don't know if I did the same thing with an 0-320 how much better it would fly. Still pondering the question...weight vs power. The Bushwheels are some a guy is trying to get me to take as part payment for my fuselage. They are a pass through as far as I am concerned. Take care. Crash
 
Cub Junkie. Titanium was easier to drill than SS or Galvandized? I'm surprised. You ever weld titanium tube? I've got a few ideas for titanium tube that don't involve Cubs. I've not worked with it, yet.

Diggler, thanks for the heads-up on BJ's. I intend to go chat with them, but haven't gotten out there yet.

No question that more power is a good thing, as long as it doesn't come with diminshed returns due to extra weight. Or peripheral weight due to needing more fuel, etc.

And Crash, I wasn't offended, that's what I was saying.

My use for this PA-11 will never be 450 mile trip legs with a load of moose in-between, so I hadn't even thought like you were thinking.

Sound like John's 180 Cub wouldn't have been a candidate for your 160/180 HP question anyway. I'm sure there's another 180 Cub guy around, but it seems like everyone overloads them with "modifications", and they get kindo piggy.

Still looking for an answer to the "bolt-on HP" question.

Dave Calkins.
 
Crash,
I spent of couple of hours with Atlee yesterday, and came away 95% convinced to scrap the 180 horse idea in my 12. He says I'll be chasing loose screws and stabilizer cracks forever. He admits they perform better when you're heavy, but it comes at a cost. He was welding up a tailfeather that came off a 180 horse cub that literally was held together by the fabric when brought in. He says to go watch a 180 horse cub take-off and specifically watch the tail, it'll shake violently. (I don't remember Billy's cub being rough.) I talked to Charly this morning who gave me the unfiltered version of why I'd be crazy not to do 180 horses, or the 20 reasons it's better than a 160, depending on your perspective. I'm confused again.
SB
 
"bolt on" horsepower

I dont have any 180 hp cub experience to talk about but I do know that 180 engine cores are spendy$$. All of them get snapped up by the RV-6 and 8 builders, but O-320s are almost laying on the side of the road. An O-360 crankshaft is 6 grand. I know if you want to play you gotta pay but I would almost think there is diminishing returns when comparing 160hp to 180 hp (stock vs. stock). Dave it is true that the titanium is easier on tooling, one #30 bit drilled the whole outer flange opposed to four or five on my stainless fire wall I built for my Pitts. As far as welding it I have never done it but I know that when it is welded it is in a environment controlled chamber. I think the post about Atlee Dodge's opinion on the 180 has a lot of merit, I dont think Atlee is guessing on much with the experience he has.
 
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