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V8 Powered Rocket Strength

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GeeBeeFan

I'm New Here
I've seen various references to the LS1 being a suitable replacement for the 540. Geared drives makes a kit for the RV-10 for instance. So I am curious if there has ever been a v8 installed on a rocket. I am considering it for my rocket but I have concerns about the engine being too powerful for the base design of 180hp. Normally doubling (or more) the power means a total redesign so I feel my concerns are valid. If you guys have any insight to the durability of the design with a v8 I would love to hear it.

I have preview plans for the RV4 and I'll be ordering the HR3 plans soon, I am building the plane specifically for racing. I would like to have the LS engine because even in stock form it can exceed the lycos but with years of endurance racing experience it can be built to make impressive power while still being very reliable. I am working with an engineer to double check my work but if anyone has already done this installation that would save us a lot of time.
 
GBF,

It isn't the HP that will be the problem but rather the weight.

Do some research on the empty weights of planes running the LS1 engine vs. the IO-540. Then you will have to decide if the complexity, weight, resale value, etc. are worth the sound of a V8.
 
Weight and glide

As Bill noted, it is major weight concern. I'd also be concerned as to how it glides with the power off with this weight.

Not trying to be trite but history will show that you have a much better chance of becoming a glider with this type of engine combination.

Go with tried and true power.
 
RV7Guy said:
As Bill noted, it is major weight concern. I'd also be concerned as to how it glides with the power off with this weight...
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For various reasons I don't think this engine is a good idea in this airframe. Among the reasons are not the power and not the glide as glide ratio is not affected by weight. One of my pet issues I guess.

I wish everyone could have the experience of flying the same glider at 7 pounds per square foot wing loading and then at 12 pounds per square foot. Amazing difference, and much more fun at the higher weight. You will be touching the ground at a higher speed though which is why I would rather have lower wing loading for unproven engine installations.
 
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Not that I want to pick a fight with you guys but almost every race plane in history has posessed the exact qualities that you describe. Big engine, little wing, flies like a rock with the power off. I understand this is atypical of the RV mentality but so far the RV4/HR3 airframe is the most promising for the goals I have in mind. I have heard mention of v8's ripping off the firewall and overpowering the airframe to the extent of easily exceeding Vne. Basically I am curious if anyone has spent time to seriously increase the Vne of this airframe? My ideas are pretty far out there and the deeper I get into this the clearer it is becoming that I need to totally redesign the entire aircraft.

Maybe I should stick a couple RV parts under the seat just so I can keep my membership here..
 
Start from scratch

GeeBeeFan said:
My ideas are pretty far out there and the deeper I get into this the clearer it is becoming that I need to totally redesign the entire aircraft.
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I think you are on the right track with that statement. Between raising the VNE to use the power of the engine safely and designing a fuselage that will properly accommodate a liquid cooling system, you might as well start fresh. Good luck, the result could be a terrific performer.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
The airframes are designed for two people and since you are going to make this a one person aircraft then I believe the weight issues are not as significant. The main limiting factor in your quest for more speed is the wing itself. Although this wing has a lot of good things going for it I believe we are reaching a point were there are rapidly decreasing returns with the application of additional horsepower. The HRIII was a decreased span from an already shortened HRII wing and the very powerful engine that was on the Reno HRIII did not really show that much more speed.
The EVO is quite a bit faster at higher altitudes but not that much at lower race altitudes. You need a smaller wing with less frontal area. Mark Fredrick is working on one at this time and you should contact him regarding your needs.
I am fascinated by the thought of a V8 powered rocket but so far I am not convinced that we have a reliable system for that power plant. As your needs are specifically for racing then you probably have the resources that are required for a developement program. If not, then you should probably forget the V8 and the rocket and go with a Lancair legacy.
 
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I believe there are many Rockets with IO-540's on them. According to Bud Warren's website is weighs about the same. I think mine is 100lbs more than and IO-540. I have over 100 hours of flying on mine. Mine is a Vesta V-8 though. Bud did have some issues with the ECU which hopefully has been corrected. His RV-10 test bed should be up and flying again soon. It is in the paint shop. I probably have the most Chevy RV-10 time out there. Take offs are a blast! I would wait a year or two until these systems have been proven unless you enjoy experimenting like I do.
 
LS1 on a Rocket

The LS1 in an RV-10 presents a full RV-10 cowling when everything is installed.It looks very tight to me. The shape and frontal area of a Rocket cowl might have to be modified substantially.
 
GeeBeeFan said:
... My ideas are pretty far out there and the deeper I get into this the clearer it is becoming that I need to totally redesign the entire aircraft.

Maybe I should stick a couple RV parts under the seat just so I can keep my membership here..
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What is the mission of this airplane? Once you can articulate this and then define the individual requirements of the mission, you then find (or design) the airplane to match. Don't find the airplane first then try "back into" the requirements.
 
Toobuilder said:
What is the mission of this airplane? Once you can articulate this and then define the individual requirements of the mission, you then find (or design) the airplane to match. Don't find the airplane first then try "back into" the requirements.
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The primary mission is to race at this plane at Reno. Secondarily I would like to participate in some cross country races IF I can work in enough fuel capacity. I would like to think I can build an all metal airplane to keep up with the NXT but those have been turning some incredibly impressive numbers lately.

Honestly this has been a pet project of mine for many years and as you can tell its been very slow progress, real life keeps getting in the way. I am an experimenter and tinkerer in my spare time so just building it will be reward enough, if it actually wins something that will be icing on the cake.

I've been looking into the RV line because if I can share parts it will save me some work but if I have to start from scratch then so be it. I dont know if you guys are interested but here is a dreaming sketch I did based on the 3-view in the preview plans. It should be easy to see how far out I am thinking with this one. The canopy is too small but the RV cues are still there, the fin, wing, seat placement and length are all stock -4
100_3784.jpg


Thanks for the help guys. I'll still be lingering around here for a while, perhaps you'll spot this thing at airventure sometime soon.
 
That looks awesome--kinda like a mini P-51 with the scoop.

Keep us posted, lots of people said it wouldn't work to Orville and Wilbur too:)
 
Good idea, keep going.

Try reasearching the NACA 2300 series airfoil most of the RV's use. I have heard they hit an aerodynamic brick wall around 200 mph. This could be true or total BS, I don't really know.

Free of the RV wing profile, you can still use the Spars, and other parts for your project.

One other challange you will have in the P-51RV you penned is getting the water and oil lines to the cooling doghouse without risking the life of the pilot. If I were to fly a plane (Other than a real war bird) with that type of radiator set up, I would want to make sure I don't get boiled if a line broke in flight or after a hard landing.

Keep drawing, soon it will be time to pound aluminum.

BTW, Lycoming makes an IO-720 400 HP eight cylinder engine. That might be a good starting point.
 
GeeBeeFan said:
The primary mission is to race at this plane at Reno. Secondarily I would like to participate in some cross country races IF I can work in enough fuel capacity...
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OK, if you want to win against the fast glass, you are going to have one heck of a time with the surface finish that a riveted aluminum structure provides. RV's are built the way they are because it is inexpensive, easy, and forgiving of mistakes. The fact that they are relatively fast is icing on the cake, but their mission is to be a sport airplane, not a racer.

I was very much in the same boat as you not too long ago, but my mission was not to race (but high speed was a key). I wanted to use some RV components to save time, but in the end, if you want a thoroughbred, you are going to have to optimize everything. Keep in mind that the HR is an adaptation of the RV-4, which is from the RV-3, which in turn came from a modified Stitts Playboy. The point is, hanging a V8 on the nose of a Rocket might make it go faster, but at what expense, and will it be fast enough? BTW, a pumped up 540 could make 400+ HP pretty easily also, and be a whole lot easier.

The point of writing all this is not to discourage, but to point out that the HR is just about as fast as it's going to go right now. Without some serious aero work, even 1000 HP will not help a lot. BTW, just as a point of reference, I once read that 1000 HP is the figure that would be required to drag a Cessna 172 to 200 MPH in level flight.

I think you need to decide what your specific goals are, then decide what kind of equipment will meet that need. If you want to beat Jon Sharp within the Supersport rules, you will quickly see that a metal airplane like the HR is not going to do it. I’d suggest doing some research on the Arnold AR-5 as an example of near aerodynamic perfection. It’s a good lesson in what makes stuff go fast - then go from there.

Best of luck
 
V8 power for V8 fun!

Gee Bee Fan,

I recall there are kit mustangs about 1/3 scale that use the V8 engines. If using a V8 is your goal these kits or plans might have much of the design work for engine mounting and under fusealage radiator worked out.

I believe when the newest F1 rocket kits are available its higher VNE and new wing could give you the other half of parts you need to build an Airplane that would make Henry Ford sit up and take notice.

Yeah that is it! use the modified P-51 fueslage and new F1 wings and empanage.

Go for it!
 
N941WR said:
Larry, I have always wondered why the left the doghouse on the bottom of that plane. After all, the engine doesn't need it.
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Bill,
The Legend was originally designed around a liquid cooled V8, hence the radiator scoop. IIRC, there were problems with the V8...don't remember exactly if they were cooling issues or reliability issues...that led to the installation of the turbine. Most Legend builders have either reduced the size of the scoop, faired it over or removed it entirely as it is no longer needed.

Best,
 
GBF,
In the relentless quest for speed I have toyed with many ideas to make the HR3 even faster than it is already.
The wing is the limiting factor and so I have put my name on Mark Fredericks list to be one of the first to purchase his new F1 kit with the composite wing to satisfy my need for a 2-place aircraft.
Meanwhile, I still look at ways of increasing the speed and have looked into re-winging the HR3.
You can go here and see that this gentleman used a Mustang II kit for his project with some impressive numbers coming from an O-360.
http://www.nexusmustang.com/
I'm looking into using this same wing for the HR3, with some mods of course.

 
Yes, to a point..

GBF:

Yes, the structure is strong enough to take the added power and weight...IF...you agree to lower G limits. While this step is not quite as large as putting the 540 on an -8, the stock airframe with a heavier engine will be good for some percentage of design load. Don't forget propeller loads in your calculations!

As for Reno racing, you would want to check the rules 1st. Super Sport does not require that 5 kits be produced and sold to make your plane eligible to race, but as of the 09 season, this was the case for Sport class racing. So, you would be restricted to Super Sport, unless your plan is also to produce your plane as a kit.

I do not know what equipment you are flying now, but if you need to beg borrow or steal something that could be used to attend the PRS this June, I would recommend you do that to get a feel for what Reno racing requires in terms of skill and equipment.

Cooling lines/aft radiator: run 'em in a sealed tunnel to protect the pilot, or build a secondary containment duct; reduce that calculated risk as much as you can.

Kevin Eldredge is building his next NXT with V8 power (Trace Engines), so your idea is not that far out. If he pulls it off, he is gonna be very hard to catch!

Your drawing looks great -- good luck!
Mark
 
Cubic dollars...

..are the rest of the equation.

The few years I helped with my boss's -51 showed me early on that it was the really deep pockets/sponsorships that made the most speed, as in motorports. If you have a waaaaay larger than average money source, go for it, otherwise it could be nothing more than an idea....and there are many of those out there that failed.

Best,
 
Michael White said:
Bill,
The Legend was originally designed around a liquid cooled V8, hence the radiator scoop. IIRC, there were problems with the V8...don't remember exactly if they were cooling issues or reliability issues...that led to the installation of the turbine. Most Legend builders have either reduced the size of the scoop, faired it over or removed it entirely as it is no longer needed.

Best,
Click to expand...

At the time the legend was designed and kit production started the cost of the V8/PSRU skyrocketed well beyond projections. At the same time the Walter Turbines were plentiful and cheap by comparison.

The molds were already made and several kits produced when the decision was made which is why the scoop stayed.
 
Sport class

Yes, cubic dollars availability is a factor, but it is a much smaller factor when you participate in the Sport Class venue. The years I raced, I flew there, raced, and flew home with no worries. Heck, I'd bet at least 75% of the Sport class racers do this, or at least expect to. The course is at 5000'MSL, so without forced induction, you can't even get to 100% power. As I recall, I saw 26"MP while turning 2600RPM, ~21GPH, and the ASI showed ~195KIAS; this was good enough for 4th in the Bronze race. Temps/pressures stayed in the green the whole time, so I wasn't worried about the engine. In fact, Doug R is still flying that engine, and I don't think it's had more than oil & plug changes since then.

So, Sport class racing can be done without spending your $$$ by the shoebox full. SARL racing, done at generally lower altitudes, is probably more stress on the normally aspirated engines than Reno, tho we have seen no racing related engine problems to date.

I expect that for the Super Sport participants, the cubic dollar factor is a few steps higher, tho the scale could be logarithmic, kinda like the earthquake scale. I don't think I will ever get far enough into the program to find that answer!

Unlimited? Not in my future, or my wallet, but they sure are a kick to watch, as are the other classes.

Carry on!
Mark
 
The Legend...

What I see in your drawing looks alot like the "Legend". The Legend used to be powered by a 572ci Rodeck big block, about 580 crank HP if I remember right. It was clean as an ice pick, and SUPER nice to fly. I was a bit saddened to see the Rodeck get replaced by the Walter M601 turbine, even though the Walter is more powerful, etc its just not the same as flying behind that huge V8.

Painted.jpg


If you can get your hands on one of these, it can be flown with the Walter or you could probably refit it with the V8. I think the plane was designed to take 1000HP in the nose. Lots and lots of carbon in that airframe. www.turbinelegend.com
 
Bugatti Veyron W16

I'm surprised someone hasn't mentioned the Bugatti Veyron W16 engine. With 1000 hp and four turbochargers, who cares how much it costs or how much it weighs? It'd definitely turn heads at the run-up pad!
 
Its all about: Kerosene!

I just passed 1000 reliable hours in my Rocket with a standard aircraft engine with plenty of power producing stellar performance. If you're going to bolt a non-standard engine in a Rocket why not go with modern technology: JET power! A turboprop generates 4 times more HP per pound than a piston engine and is far superior in reliability.

Having spent alot of time over very cold water and bad guy land on one engine I can tell you what I would go with...:)

Smokey
HR2

http://www.youtube.com/watch?v=swhSLbQHL74&feature=related
 
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'Cause reno doesn't like turboprops. I understand where this is coming from, but from someone else that's done Reno (and probably will be 're'building something in the next 5 years to race...) it's WAY more than one guy can tackle. To do it right you need an airframe (easy part), money (sponsors? don't count on it, unless you can find a private one), and a crew that is as knowledgeable about the airplane as the builder.

And an engine guy

And money

Oh yeah, and two weeks of vacation in September for the whole crew...
 
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GBF:

The artist's concept sure looks great...it'll be purty, that's for sure!

I saw Tom's recommendation to look at Mark's newest F1 design, and was thinking the same thing. If Mark feels it could handle the V8, then it may be worth considering...very sleek and strong airframe starting point! And I don't think the ever-humble Boss mentioned in this thread that it may have an option for retractable gear...so that might catch your eye as well.

Fitting the engine might be a hurdle, as you alluded to in the first post. Mark's thought that it's not as far a leap as putting a 540 in an 8 (or in my case in a 6 [bought flying with the big motor]), is encouraging. I have a buddy in Vegas that is building a Thorp, redesigned to be a single seater for racing. His initial plan was to go with the LS1, but due to physical size limitations, he's opting for a souped-up V6. Don't have more specifics, but he's talking pretty big HP...short of an LS1, but pretty impressive. The Thorp is an interesting starting point for the project in terms of clean racing lines, but he built and flies a T-18 and likes the airframe. I think starting with a Rocket will put you out in front from the git go!

I like Smokey's TP idea too...if you could make it fit, a PT-6 or Walter-powered F1 would purr like a kitten and eat up sky like a lion! But as Steve said, it puts you out of the standard RARA classes.

Of course there's always the Thunder Mustang with it's Falconer 12-banger. John Parker down the street at American Air Racing has a stocker for sale for just $675 large! Cool, but yikes!

Good luck, it'll be fun to watch your racer's development!

Cheers,
Bob
 
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