PROFI RAMBLER .049
 

I was on the Delphi speed forum and noticed something very interesting! a new Profi 049!! this ones a little more "regular".

Just thought id pass on the news!

"on 10% nitro fuel and a 4 x 3 3/4" prop ( 35000 rpm)" - Alberto.

You can e-mail Alberto at domingoe (AT) msn (DOT) com for info and pricing!

RE: PROFI RAMBLER .049
 

Awesome! Looks like it's a plain bearing motor so it will be eligeable for 1/2A pylon etc.

RE: PROFI RAMBLER .049
 

Between Fora, Profi and Cyclon I would love to know how many engines they sell worldwide...?

Next question..out of all the engines they sell, how many ever get used for something besides a decoration..?

RE: PROFI RAMBLER .049
 

I cant imagine a plain bearing engine getting up to those RPMS, but perhaps.

Its the Proto speed guys that I think will like this engine.

My guess is, north america isnt the real market for these hot engines.

RE: PROFI RAMBLER .049
 

more likely to have top specc'ed ceramic bearings than a plain bearing..................

ChrisM
'ffkiwi'

RE: PROFI RAMBLER .049
 

Great looking engine. I would want to know what the word is about them before buying one, though.
Last I heard, Jim Booker was importing them.

RE: PROFI RAMBLER .049
 

I believe its a really new engine and there is a tuned pipe version in the works. Pretty sure it will cost a pretty penny too.

So far my profi is the nicest running and looking engine i've owned. I havent flown it yet (been too chicken) because I really didnt have a good flying season. I think I went out 4 times since the snow melted, not enough flying this year.

BUT next year, because I'll be done with school I will fly more!

RE: PROFI RAMBLER .049
 

I've put a few flights on my .061 powered sport racer - it's a monster engine, and I found it quite easy to handle. I never knew something that small could pull a 1/2A model so [expletive deleted] fast. 25" span, 10.5 ounces, thin wing.

This configuration would be much easier to cowl into a pure RC speed design.. I hope there is a 1cc version.

RE: PROFI RAMBLER .049
 

There would have to be a 1 cc version for FAI events.
Notice this model mounts just like a TD or a Norvel.
This would make the engine a little bit wider than the backplate mount version, but the difference would hardly be noticeable.
I don't know why the engine spec given for rpm used a 4 x 3.75 prop...? Unless you're running a 4 pitch in a speed application, you're just wasting your time.
It has been ages since I logged on to the MACA or NASS forums to see what is up these days. These places are fun to visit to see the extreme ends of the model plane hobby.

RE: PROFI RAMBLER .049
 

1/2A proto speed is popular I think? That prop seems reasonable for models with a bit more drag and acceleration from launch being important.

35k on that prop sounds like - wildass guess here - maybe 32k potential on a 4.2x4 APC?

My .061 spun a 4-1/4 x 4-3/4 E5 Eliminator at about 32k as I recall (I keep getting the prop specs wrong so I looked it up this time) which is stupid pitch speed for a 1/2A (A really, but I still rank them as 1/2A for sport). Should check that rpm again next time I'm at it. After one insane test flight I dropped a combat prop on the thing to slow it down, then flew an APC 4.2x4 which was also crazy fast.

One problem I found on my .061 is that the prop shaft is short - great for combat and FF props, but up the pitch and fatten the hub and the aluminum prop nut has very little to hold onto. I stripped mine which halted further flying this season, and am whining at a certain RCU speed junkie/machinist buddy to make me a nice stepped nut, so I can counterbore the front of the props a bit.

RE: PROFI RAMBLER .049
 

On another post on this forum someone is making a fan unit for a TD .049. Hypothetically only, would this be a good engine candidate for that type of application? (yes, I know electric would be easier and no, I don't care) [8D]

Tim

RE: PROFI RAMBLER .049
 

A stepped nut that fit APC props would be really handy. That sounds like a good excuse to fire up the lathe.
Steve Wilk also published this design for a simple C/L racer. It's good for his business to get guys involved. I think I'll make time this winter to build one. If you build one of these with a 1.5 inch line spacing at the bellcrank I think you also want a 1.5 inch [or less] spacing at the handle.?
The guys over at NASS will be able to get me straightened out on that stuff......

RE: PROFI RAMBLER .049
 

These competition engines would give you a pretty good chance for success if the load is kept in check. They need to be able to rev to run efficiently...or just to run at all.

RE: PROFI RAMBLER .049
 

For reference that prop size quoted by the OP is similar to the 1/2A proto props on the Eliminator website, though I do not see the E-1 listed anymore. The proto prop I saw was 3-3/4 pitch.

RE: PROFI RAMBLER .049
 

They fly with .012" x 42 foot lines IIRC. That's a lot of steel to be hauling around. Notice the size of the tiny little tank.......bunch of "sissies"..!!:D
I say strap on a 2 oz tank and then hang on for a couple minutes.

RE: PROFI RAMBLER .049
 

But I would leave the fit loose and still center off the molded recess in the rear of the hub with inserts or a sleeve on the shaft. Those drilled through holes are sheer butchery.

RE: PROFI RAMBLER .049
 

With the props that Steve Wilk offers, it should be possible to top 150 mph with a Profi / Fora / Cyclon powered RC ship.
[without resorting to using one of those piped G&Z engines]
I've done almost no experimenting since I washed my hands of the G&Z project.
The Russian combat engines have just been so satisfying to run with standard APC props, that the motivation to seek more just hasn't been there.

RE: PROFI RAMBLER .049
 

It has to run on crankcase pressure or a bladder, so there is that to deal with, but not a big deal. I also wonder how the available commercial 1/2A impellers would tolerate the additional 10k rpm this will produce over a TD? Might be fine, dunno. But from a horsepower and rpm standpoint, why not? For $175 or so it would be easy to find out.

RE: PROFI RAMBLER .049
 

Im with you on that CP! I've already got my wilk landing gear and glen dye wheels! maybe we can do videos to prove speed and make a little "race" out of it?

RE: PROFI RAMBLER .049
 

I'm glad to hear you are going to build the Proto Racer. This would be my 1st try at it. They look really cool all painted up.
Are you going to be a real man [like me] and go with a 2 oz tank..? ;)

RE: PROFI RAMBLER .049
 

I dunno about the big tank, I get dizzy pretty quick! but I guess I could try it.


I think its supposed to be one mile for the race? how many laps is that again....(math break).... 20 laps on 42` lines. I wonder home much fuel you need on a hot 049 for that.

RE: PROFI RAMBLER .049
 

Figure it can do a mile in 30 seconds or so. The coffin tank shown in the drawing must be just enough to do that. 30 seconds at that speed would seem like a pretty long flight.

RE: PROFI RAMBLER .049
 

I think 1/2A protos fly in the 90's? 90mph = 40s/mile.

I got pricing back from Alberto on the FIRE .049, $215.00 plus $8.00 shipping. Doesn't shock me one bit, IMHO displacement is a small percentage of production cost, in fact these are limited production and probably harder to build well than an engine ten times the displacement. I'd rather own a $215 state of the art .049 than a $129.95 me-too .46.

Perfect engine for an all-out RC 1/2A (genuine 1/2A versus 1cc) speed model. It would be great fun to see how fast an .049 can go. Although, I am tempted to wait until January for the piped version - BUT - I have no idea whether I would expect to burn up p/l sets on a regular basis or if it would be not much harder to handle than the regular .061.

Ahh, some rpm and speed info from the speed forum:

"Many of us use the APC 4.4D X 4P prop. (4.2 x 4 I assume he means)

I have yet to fly under 90 mph with it in 1/2A proto. Expect 30,000 RPM+."

RE: PROFI RAMBLER .049
 

If I was to try a piped .061 again...
I'd mount it to aluminum mounts for a heat sink
Treat it like a diesel engine and start out with a compression that just barely hits the pipe during ground testing.
Start out with 25% castor, 75% methanol and work my way up from there.
Stay conservative with props...just go with the 4.2x4 until the engine has been broke in and I've had a chance to evaluate how hot it tends to get after a hard run.
Controlling heat is the biggest issue and taking your time to creep up on the killer settings.
Never let the pipe seal fail. When it fails in the middle of a run, it is just like hitting the oxygen lever on a cutting torch.
Forget about the G&Z engine, with the 4 bolt head arrangement. It allows chatter, you can see eroded aluminum after every run. The threaded head [ala Cyclon] is the only way to keep the engine nice and quiet at 42,000.
I might also clamp the upper cylinder to the firewall. To understand why, take a pair of channel locks and grip your engine there while it runs and take notice of an rpm increase.

RE: PROFI RAMBLER .049
 

I couldn't resist, I ordered one. Winter project (or three winters at my typical pace) is a mini F3Speed type model, SWR I imagine.

I can't wait until the pipe version comes out.. what's next, 22" span 1/2A RC speed models with 2x5 one blade props?