pecojets

any body has try the irvine .46 ducted fan ? since the os its going to be out of stock for some time im looking for other choices
the specs in sig web page state 1.9 hp and i think it way far from
os .46 and kb .48( also out of stock)2.6 hp

pecojets

MiragePilot

My Feedback: (6)

In the long run, you are better off waiting for the OS 46 VXDF. The performance improvement between the OS and the Irvine are significant enough to justify the delay in delivery.

Peter

MMallory

My Feedback: (1)

Pecojets,

From what I hear the Irvine is more in line with the older OS .46 VRDF. I would post a wanted here on RCU and acquire a VXDF or a K&B .48. With that said, the Irvine will get you in the air (just not as quickly).

Mark M.

1930wl

My Feedback: (1)

Look at the FAN-JET .50 at http://www.jettengineering.com/
I have one to use in the BAE Hawk (under construction). It reportedly turns a Turbax I fan at 25K.

MiragePilot

My Feedback: (6)

Re: Jett 50: "It reportedly turns a Turbax I fan at 25K."

I doubt it. I have seen the Jett 50 in action and it could barely make 23.5k rpm in a Turbax I. Nope, if you want a high performance .46 sized fan engine, the OS 46 VXDF is the only game in town.

Peter

1930wl

My Feedback: (1)

Peter,
We may be talking about two different engines. I'm talking about the FAN-JETT .50.

The Jett RR.50 has the same configuration but is specifically timed for lower RPM.

MiragePilot

My Feedback: (6)

Nope, I'm talking about the Jett 50 designed for DF applications.

Peter

1930wl

My Feedback: (1)

Fair enough. I'm having a Turbax mount modified for the Jett. When I get it, I'll mount the Fan-Jett .50, break it in and take some RPM readings.

Will post here.

Crash-RCU

I have a F-J 50 mounted on a Turbax 1 and I am turning 24 K. This engine took over 1 gallon of fuel to break in all the while the RPM's got better. Not to knock the OS as I know they are good engines but if you can't get them as was the case when I got the F J 50 it seemed like a good alturnitive.

F900

My Feedback: (2)

On the wish list for the JHH hawk engine is.....

K&B .48DF
OS.46vxdf

As far as the K&B.48D/F , better chance on winning lottery than buying a brand new D/F engine from K&B

OS.46vxdf when the next batch come out my advice is get them while you can or else you will be waiting another 1+years for the next stock

FAN-JET .50 is the only engine that you can buy now. I think JHH was working on a better d/f engine with jettengineering but that was late last year and have not heard anything since. Its a pitty it does not produce more thrust, giving more speed with the hawk.

KCFlyBoy

My Feedback: (12)

Wait for the OS.

MiragePilot

My Feedback: (6)

I don't know how much longer the Jett DF engines will be available either. I spoke to Larry Wolfe a few weeks ago and he told me that Jett had quit all work on developing an updated engine for the Turbax fan and it was not certain if they would even continue producing their current fan engine....

Peter

1930wl

My Feedback: (1)

There is a difference of opinion on who is reluctant to develop what with reference to the Fan-Jett .50 and the Turbax I.

Larry has his engine mounts in stock waiting on K&B and the OS .46. I've corresponded with his extensively on this problem. He has not been successful in getting Jett to modify their crankcase to fit his mounts - nor has he bought a Jett .50 engine to test. Jett will not "give" him one.

Dennis of Jett has a bunch of .50 crankcase castings on his shelf. He doesn't see the demand that would pay him to trash these castings and develop a new one.

It's simple economics for both Jett and JHH. The best way to insure a supply of engines is for the DF community to get off their duffs and BUY SOME!

Money talks while BS walks.

Re the Irvine .46 DF which SIG controls, it costs the same as a Jett .50 ($275.00) and is only ADVERTISED to turn 23K.

Waiting on the OS .46 MAY be as futile as waiting on the much touted K&B .48. My guess is that OS will put the .46 on the shelf along with the .25.

I'm betting on Jett if anyone will support them. After all, a lousy 24K is better than nothing.

1930wl

My Feedback: (1)

There is a difference of opinion on who is reluctant to develop what with reference to the Fan-Jett .50 and the Turbax I.

Larry has his engine mounts in stock waiting on K&B and the OS .46. I've corresponded with his extensively on this problem. He has not been successful in getting Jett to modify their crankcase to fit his mounts - nor has he bought a Jett .50 engine to test. Jett will not "give" him one.

Dennis of Jett has a bunch of .50 crankcase castings on his shelf. He doesn't see the demand that would pay him to trash these castings and develop a new one.

It's simple economics for both Jett and JHH. The best way to insure a supply of engines is for the DF community to get off their duffs and BUY SOME!

Money talks while BS walks.

Re the Irvine .46 DF which SIG controls, it costs the same as a Jett .50 ($275.00) and is only ADVERTISED to turn 23K.

Waiting on the OS .46 MAY be as futile as waiting on the much touted K&B .48. My guess is that OS will put the .46 on the shelf along with the .25.

I'm betting on Jett if anyone will support them.
After all, a lousy 24K is better than nothing.

MiragePilot

My Feedback: (6)

I am somewhat more (cautiously!) optimistic when it comes to the future of the OS 46 VXDF, simply because it is a spin off of their successful 46 VX-M marine engine (which appears to have a much larger demand than the DF sector...just compare the prices of the 2 engines and the virtual 100% availability of the -M engine). The only difference between the -DF and -M engines is a thrust washer and cylinderhead. The OS 91, 77 and 25 DF engines did not have that commonality, so they are/were a lot more vulnerable to the bean-counter's axe.

Your summarry of the JHH/Jett dilema hit the nail on the head. Tough problem for both parties, with the modellers and hobby losing as a result. The sad truth is that the DF hobby is vaporizing before our eyes and the writing is on the wall.... If OS cannot justify another production run of the OS 91 VRDF, which is the most popular DF engine in the world by far, what hope is there for the DF hobby, let alone .45 DF??

Time to start saving for a turbine... :-(

Peter

F900

My Feedback: (2)

MiragePilot,

Some very good points made, I been told by towerhobbies that the OS.91VRDF (small head, byron) have been discontinued, and lady who i spoke too stated that the OS.91 large head will probably be discontinued too as there is no mention of it on there website nor OS's website. If i rememeber a few weeks ago it was back ordered until the end of the year. But that does not look like the case now, looks to me like there will not be another production run of the OS.91 VRDF.

P.s whos R/C mirage kit do you fly ?

Jackjet

My Feedback: (1)

[QUOTE]Originally posted by F900
[B]MiragePilot,

Some very good points made, I been told by towerhobbies that the OS.91VRDF (small head, byron) have been discontinued



Can you use the OS.91 marine engine parts ? (piston/sleeve/ con.rod)


Jackjet

motorhead-RCU

I have a newly aquired turbax 46. I was hoping to get a OS for it but it looks like I will have to start looking at the jet. What is the possibility of just running a maring engine?
Mike

MiragePilot

My Feedback: (6)

Mike,

The 46 VX-M has a (blue) water-cooled cylinder head. The 46 VX-DF has a (purple) air-cooled cylinder head. In addition, the -M does not have the thrust washer on the crankshaft (forward of the front bearing) that butts up against the Turbax 46 rotor+spacer assembly.
The thrust washer is the same part that was used on the older 46 VRDF, so if you have one of those lying around, you can vulch the part off of it. Then all that's left is finding a cylinder head. I was able to get one from Irvine in the UK (since GP was not listing it as a spare part at the time).
Another option is ordering the 46 VX-DF from a source overseas. I have done that successfully to (from a shop in Singapore). The price (for a 4-engine order) was cheaper that what Tower was selling the engine for in the US.

Hope that "helps".


F900: I used to fly a scratch built Philip Noel Mirage 2000C (the one featured in the 2-issues article in RCJI a few years ago). After 175 odd flights, I retired the jet and it is now a hangar queen/gate guard in my shop. Busy working on a JHH Mirage 5F and a coouple Mirage F1 projects...

motorhead-RCU

Can anyone give me a line on a os 46 vx-df source. I had better order one now while I can get one.
Mike

DaFatha

I spoke with Great Planes yesterday and they have received a very limited number of OS .46VX engines. From that limited number, we will receive only 4. The better news is that they expect to receive more of them in about 2 weeks.

On the subject of the Jett .50 DF engine, when I spoke with Dennis at Jett Engineering about 2 weeks ago, he that "there was a disconnect" and indicated they are no longer making the ducted fan engine "due to lack of interest." In large part, the problem has been their lack of effective marketing of this engine. At no time did they offer to have us even RUN a Jett .50! At no time did they send us anymore than a casting so we could see what would be required to make some turbine bodies to accept their engine. Somehow the process seems to have worked backwards; afterall, if a fan exists that will accept an engine you might be able to make, would it not be logical to find out what it takes to make the engine work with the fan BEFORE making the engine?!! Then wouldn't it seem logical to have the fan manufacturer run, fly, and promote your engine? Wouldn't this stand to benefit both parties involved and the hobby at large? Contrary to one statement, the issue has never been whether or not we were willing to pay for a Jett .50; in fact, that was never discussed! The issue has been that somehow the folks at Jett Engineering were content to keep the real performance of their product a secret. I guess that is how they do it in Texas!

Unfortunately, when products are single-sourced (be it engines, retracts, kits, etc.), they also tend to become scarce--and the "source" controls the supply. This has led to what we see today: since D/F engines of any size and description don't sell like .15 car engines, the supplier makes the decision to neither make nor carry them based on the overall bottom line; afterall, volume and money are the only things that matter!

Of course, all of this has reduced prices and profit margins to the lowest possible denominator for the consumer, dealer, and the manufacturer. The end result is that the outlook for our hobby industry is one of less rather than more--and this is largely attributable to the breakdown of the distribution network to a few, giant, front-door/back-door operations that control both WHAT we can buy and what PRICE we will pay.

As someone else said, "money talks, B/S walks." Well--there you have it!

Best regards,
larry Wolfe
[email protected]

1930wl

My Feedback: (1)

DAFATHA has outlined the problem authoritatively.

HOWEVER - I'd be willing to bet that Jett Engineering would respond to any order placed for a FAN-JETT .50. Compared to OS Engines, JETT is a relatively small operation with a lot of flexibility. CASH TALKS GUYS!!!!!! Crying in your beer while lamenting the lack of engines only dilutes your beer.

If we let him shut off production, inertia says it will be hard to crank it up again.

Re converting the OS .46 Marine to DF, apparently this is feasible since most parts are the same (according to the parts list on OS Engines.com). Look at the pictures on the OS web site and check their parts lists. http://www.osengines.com/engines

MiragePilot

My Feedback: (6)

Me262,

There is nothing "apparent" about converting the 46 VX-M to a VX-DF. It is fact, and I have done it.

Peter

1930wl

My Feedback: (1)

Good to know, Peter.

Since I don't have the hands on experience, "apparent" was the only appropriate word.

The other interesting fact is that the VX-M sells for $40.00 less than the VX-DF. My guess is that you could buy a purple head for that difference.

MiragePilot

My Feedback: (6)

Me262,

"The other interesting fact is that the VX-M sells for $40.00 less than the VX-DF. My guess is that you could buy a purple head for that difference."

Not from Great Planes...they are smart enought to price the cylinder head and thrust washer high enough to make a conversion of the -M more expensive than the OEM -DF engine...:-(

Peter