View Full Version : Just started my rocket!!!!!
12-17-2010, 07:31 PM
I just started my rocket, RV4 tail is out in the garage, plans will be here Tuesday.
I have some really interesting questions as well as ideas. I plan on going to Reno with mine, yes Reno so I will be tweaking every MPH I can out of mine, so I look forward to talking with all of you.
12-17-2010, 08:09 PM
If you're serious about Sport Class racing at Reno, now is the time to consider a different aircraft. Here's the 2010 Sport Class results (here (http://reports.airrace.org/2010/Sport.ResultOverview.Report.html)). As you can see, to be a contender in the Silver it takes 275+ mph and a Harmon Rocket with 500hp won't get there.
12-18-2010, 10:46 AM
A few Rockets have run at Reno (John Harmon, Mark Frederick, Greg Nelson), and Tom Martin's fast Rocket would do well in the Silver mix! Unfortunately that is harvest season for him at the farm (I volunteered to fly it for him...didn't get past "Hey Tom, I'd...) :p
A few of us are considering PRS (Pylon Racing School) next summer, just for the fun of it. An -8, two -6s (a turbo-rotary and my super) and an F-1 or two. For PRS, who knows, maybe we can have a heat to ourselves. I don't see an RV class coming, but there was a Sport racer in the 220s at Reno this year, so its not out of the realm of the possible to run for fun. Sure, we won't win Sport Gold...but the fun is in the racing itself, me-thinks. If you want to win Sport Gold, that's another story...Ernies right...ya gotta be in the 300's to play with those boyz (and have deep pockets! IMHO)
If you want to go fast...Tom and Mark (F1 Boss) are the guys to talk to! Don't forget Bob Axsom and the gang at Mike Thompson's SARL. Lots of shmart fellers over there (and there are mucho important safety considerations to build in when planning to go that fast!).
Don't forget to polish those formation skills....FAST card required (that training is also part of PRS, but good to come in with experience, which you may already have).
Have fun, and keep us posted (and we will shamelessly steal all good ideas! ;))
12-18-2010, 03:04 PM
I live for a chalange. I took a beat up old 1984 Mazda RX and ran for the national championship to prove I could do it.
After talking with my EAA chapters engine guru, I settled on the Algie Engine packege, at least for now, it can easily put out 500+ HP at 13.5 GPH and is lighter that a IO 540. Now all I have to do is work out the whole stuffing a V8 into a rocket thing and I am on my way.
Anyone have a cutting torch and a good set of sheares?
12-19-2010, 06:58 AM
you sound like a serious competitor and if so then you should consider using another wing for your aircraft. This wing is running up against a 250 mph wall and increases in HP are giving marginal increases in speed.
To be competitive you are going to need to be in the 275 to 300 range and if that is that case then you should be looking at a different tail and some consideration should be given to beefing up the aft fuselage.
I would be very interested in seeing your data regarding a V8 engine installation being lighter then a parallel valve 540. Most alternate engine installations are heavier. I would be interested in a lighter installation if you can provide some data.
12-19-2010, 09:44 AM
The Rocket is a Sport plane pure and simple. A great, highly utilitarian one, but sport plane nonetheless. Like Tom stated, the (RV4) wing was designed as a compromise for both ends of the spectrum, fast and slow, to a point. I use the low end every landing on my 1400 foot strip. The high end is an amazingly efficient 180 knots cruise at 10 GPH, 210 Knots in a full gallop, big tires, caked mud and all. Near vertical takeoffs, anything you can stuff into it loads, great aerobatics and landing off-pavement with a 62 Knot approach; but a sport plane pure and simple. As you already know, really fast airplanes have different airfoils with a single mission in mind, speed.
I recently escorted a P-40 fighter (one of six flying) flown by a former F-16 squadron mate to a memorial fly-by for a friend. (Former flying tiger) We did a formation takeoff (section go for you Navy guys) and My HR2 was airborne and throttled way back waiting for the P-40 to get off the ground. However comma, as soon as both wheels retracted and the big Allison got on the step, I was at 29 inches 2700 RPM barely hanging on. Hollywood throttled back to 50% so I could stay aboard. Simple math: Retractable gear airplanes are faster. Alot of ponies under the hood helps too.:)
I applaud your courage and tenacity, be ready for a challenge.
How a V8 powered Rocket will look?
PS:Glasair 3's with equal HP are easily 40 knots faster than the HR2, Jeff LaVelle breaking the sport class record this year at 362 mph.
12-20-2010, 08:55 AM
"it can easily put out 500+ HP at 13.5 GPH and is lighter that a IO 540."
Power output rule of thumb: 1GPH = 10HP @ FT (full rich). I have seen this formula work on 65HP A-65s up to Wright R2600s and everything inbetween. I think turbo'ed motors might be a bit thirstier at FT?
Others can correct me, but I recall 1GPH can equal as much as 14HP at LOP cruise settings...which sure aren't race settings. So, it looks like you might be a bit short on power, unless you are quoting a cruise fuel flow alongside a full power rating, which only serves to confuse.
I did run at Reno, and managed ~250MPH in Ole 84 with Evo wings; 235 with the Sport wings. ~21GPH was my fuel flow @ 250, so I would estimate I was getting about 210HP (cold air equipped 540). I think this might be fast enough for 8th place in the Sport Silver class these days, unless attrition keep taking out the really fast movers, and you get to move up.
Now, figuring that the fast movers are generating about 600-700HP, you can do the math on the fuel flow.
But, you would be well advised to pick a different airframe for your experiment - the wing on the Rocket is not the solution for racing, but it is absolutely the best for its particular intended mission profile. The Evo wing is a bit better for a Reno-type application, but there are better platforms available for a Reno-specific application.
Research what John Harmon ran in his last year of racing -- that was the HR3 with a very healthy engine and a wing specific for Reno. Unless you know a shortcut, or modify the aircraft so it is hardly recognizable as a Rocket-based platform, I would not think you could do any better than John did.
Best of luck to you, however you plan to attack the problem. Be aware of the racing 'bug' - once you get a tiny bite, you are infected for life.
12-20-2010, 01:55 PM
Catch him before his tail kit is too far along, and perhaps he's another player for your newest iteration of the F1 (the one with the carbon spar, and retractable gear!...ooops, did I say that with my outside voice? :o)
12-20-2010, 02:43 PM
I too am hoping that Mark can pull off another F1 kit, retrac, plastic wing or cont 550, I don't care. I just love the looks an the HR2 just isn't quite the same. Ron
12-20-2010, 06:51 PM
Rocket RG... I'd be all over that.
Chris M RACE34
ps. as long as I didn't have to glue or bond anything.
12-21-2010, 03:05 PM
Smokey, once again you hit the nail on the head, I got to meet you one day, to bad your Air Force, the Navy needs pilots like you!!!
Mark, your going to be my go to guy, and I hope your not afraid to hear me scream for help, your expierience will be pricless!
Thank you for all of your input guys. I do value your opinion about this stuff. I do have the air racing bug, I crewed and transported an Unlimited Class plane for a few years and have to admit, there is nothing and I mean nothing that compares to Reno at race time and the call of you have a race.
I am an engineer by trade, electrical, so I look to the mechanical pros when facing issues such as these. In my talks wit belted air solutions, there might be a window of opportunity to give it a try, so I will keep at it in some way or form.
The problems are many, so you will probably hear from me many, many more times as I take on this build.
Thank you once again.