Is it all over for 1/2As???

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    What is the current situation for 1/2A engines? …I’m really depressed! I’ve got my students finishing up some planes and would like them to be able to buy some engines off the shelf. Sure, they can try their hand at used stuff off of eBay, but you never know what you’re going to get. Some really nice folks have offered up to share older goods, but there again, these older engines often need a little work, and then they’re relying on me again. Here’s a copy of some emails that I just exchanged with Eric Clutton, the deisel guy. Any tips from the forum would be greatly appreciated.

    Hi Eric,
    Thanks for the info. Have you noticed how dire the 1/2A situation is? Norvel has stopped production. Doug Martin, the Fox engine guy that picked up the line from Randall Hopkins says he has a two month backlog (I suspect he’s waiting for a large chunk of orders before he tries to put some engines together), the Cox TDs are rarely available (and if they are, they’re almost $80) and Brodak has a nice CS clone but it’s power output seems a bit low from what I’ve read. Cyclons seem available from Doug Galbreath (and they are NICE engines) but they’re going for $200. What do I tell my students that are putting together a Starduster X or Geef 250? Is this it? Is it game over? Are the PAW diesels a truly viable option for 1/2A competition without a lot of expert input? You mentioned that a pinch-off doesn’t work well (bummer, I just bought a bunch of the micros from Hank Nystrom) but what is a plunger shut-off, can it be adapted to a Starduster X? Are the PAW diesels available for a reasonable amount of money? The Norvels were in the $40.00 range. The Brodak and Fox 1/2As are around $50.
    Where do we go from here? I know a lot of folks are pushing electric, but I’ll be honest with you, a lot of the kids (and me too) still like the noise, thrill, and even smell of real engines! I’ve got a hunch you do too. Any help would be greatly appreciated.
    Think Thermals!

    — Eric Clutton wrote:

    > Glows are good at producing noise. Diesels are good
    > at producing thrust.
    > Now which one do you think flies better ? Because
    > of their frugal
    > thirst, diesels are hard to stop by just squeezing
    > the fuel tube and a
    > positive plunger type stop is preferred if you need
    > to time the engine
    > run accurately. The PAW .03 diesel is equivalent in
    > flying ability to a
    > Cox .049 reed valve glow and this superiority
    > continues on up with all
    > sizes. I have also found that diesels are much
    > tougher than the Cox
    > engines in particular and will withstand the odd
    > crash much better ! ERIC.
    > Rocco Ferrario wrote:
    > > Dear Mr. Clutton,
    > > Thanks for helping us out. My students and I are
    > > making up some 1/2As (Space Rods and Bounty
    > Hunters)
    > > and would like to see if a diesel might be a good
    > > choice. What are your thoughts? I have not run a
    > > diesel before but would love an alternative to the
    > TDs
    > > that are so hard to come by now.
    > > Thanks, and
    > > Think Thermals!
    > >
    > > Rocco Ferrario
    > > Harvest Middle School
    > > Napa, CA
    > >
    > >


    > You mentioned that a pinch-off doesn’t work well

    It works fine, though better as close to the jet as possible of course. Bear in mind that AMA rules do not include ‘rundown’ time as part of the engine run.


    There are a couple of more affordable high-performance .049 egnines for free flight application than the Cyclon.

    The GRS-FORA from glideTek at $149 is near the performance of a Cyclon.

    There is also the new Profi from Jim Booker at

    Keep in mind that “fast” is not inexpensive – there are no free rides. The COX TD was a $100 engine when it was dropped and only turned 19,000 RPM. The engines like the Profi/FORA/Cyclon turn in the 33,000 to 37,000 RPM range.


    I understand that there are no free rides in the high performance dept, but when it comes to an off the shelf 1/2A engine for a Starduster X or Sloworm 300 where does a newcomer turn? How do the Brodak engines work? I have a email in with the company but have not heard back from them yet. Do they run OK on pressure? Are they comparable to a TD? Has anyone tried them on a FF yet?
    Just wondering.


    Hi Rocco

    1/2A is not dead, just changing direction but that is not the answer you want.

    Practicalities first; of the 4 engine options mensioned sofar the Brodak 049 Mk2 with a Galbreath head and Nelson plug on nitro will give you the performance you seek within fiscal limits (compatible to a Cox 049), next, the FORA 049 is a bit more expensive but you can run on FAI fuel and have performance well above the Cox.
    If you want to “sport fly” then consider the PAW 049 and despite the warm words from Eric, they are not on the same level as a Cox 049 in either power or weight (been there done that).

    The last engine mentioned is the Profi 049 and while I have no experience with this engine I believe they are being used in 1/2A free flight but on cost and handling grounds fall outside the the “beginners” level.

    You could consider any of the reed valve Cox 049’s as a viable alternative and I think there is a version that utilizes TD parts to go a bit faster.



    I really appreciate all the tips.
    I just received an email from John Brodak. The stock engine offered at their website is a lower performing engine, while for an additional $10, they have a much faster turning copy (their Mkll) from Russia. He also said that he’s not sure if it would run on pressure (I’m sure it would) and he did not offer any other performace data.

    Who knows, maybe there’s a need for a “clearing house” type set-up where folks just trying out 1/2A power can be partnered up with someone who has an engine ready to mount and go. Might be a fun project.



    It can’t be THAT hard to get a TD 049 can it?
    Even a used one shouldn’t be so scarce , nor pricey.

    Rocco, I assume that you are reflecting a need for an entry level gas plane for a youngster without unlimited funds and quite possibly no help from an interested dad figure. $150-200 for an engine, $35-50 for a timer, $35-50 for a kit ( which isn’t available for the $200 engine). That’s a lot of cabbage for a beginner who doesn’t know if he really wants to come play.

    There must be boxes of TDs laying around in some you guy’s shops. Why not unload some of them?

    George Reinhart

    C’mon fellas!
    Cox Corp. web site is still listing the #8901 .049 Sure Start for $6.99 plus shipping. It sure ain’t a Cyclon but it sure is C H E A P !!!! Build an appropriate size airplane and you could have a very nice flying free flight half A. A Mini Pearl at 216 sq. inches comes to mind, use an eye dropper tank and a home made silly putty D.T. timer and it couldn’t get any cheaper. Slightly less power might let the kids get it trimmed without crashing. Bounty Hunter might be another choice.


    …here are a few questions about that Cox Surestart.

    – That eyedropper tank is not going to cut it for true competition. I need to be able to run the line through Hank’s Micro timer and get a fairly clean 4.8 second run. Here at Waegell, we’re running 5 second runs with a 90 second max.

    – Can a reed valve engine handle a very small amount of pressure? It takes a bit to get used to, but once the newcomers that I’ve worked with go with pressure, they never want to see a tank again. If I use two little ballons, one inside the other, and try to get away with just a bit of positive pressure, would it work? Has anybody come up with a system that gives a consistant feed with those Cox production engines.

    – Are those Cox engines still Nostalgia legal? The guys really like the idea of flying the same plane in multiple events. Would they still be OK on a T-Bird, or Geef 250? Of course, the more events they’re planning on flying a plane in at a contest, the faster they crash it at the beginning of the day on a test flight.

    – I’m just still bummed that I can’t give the kid’s folks a URL for some company, and have them buy a nice engine for Christmas. Where did that Norvel guy go? Why can’t the new Fox guy get a working engine out?

    Oh well.

    Seriously! I really do appreciate the comments and help.

    George Reinhart

    You were looking for a cheap engine.
    $6.99 is as cheap as it’s gonna get if you can’t find a sugar daddy to buy Cyclons for you.
    I bought 6 for the glow heads.
    Who knows?
    Nosta;gia legal? who knows?
    Timers cost more than eydroppers.
    You need to define your requirements and develop a budget to meet them.
    If the budget is too steep , revise the requirements.
    What’s important ?
    Getting a flying Half A or building the next generation world beater?
    You weren’t very specific when you asked about engines.


    “You weren’t very specific when you asked about engines. “

    OK, I’ll try to keep it simple. I’m not trying to outfit the next F1P Junior Team flying in Poland 2008. I’m also not interested in some goofy little sport job.

    If someone built a BMJR Bounty Hunter, what engine could they purchase, run it with a TT pinch-off, Badge timer for the DT, and have fun as a viable FF competitor? I’ll help them, but I don’t want to make it for them. I realize that the used engines kindly donated or bought on eBay are a great start, but the minute something doesn’t work, they have to turn to a veteran…and they’re not always available.

    Right now it looks there are two alternatives: the Brodak Mkll and the Cox Surestart. (The Brodak engine has a business standing behind it, and the Cox is cheap enough to buy multiples for spare parts.)

    If we went with the Cox, used a Tornado 6-3 prop and SIG 35% fuel, what would be the best fuel system? Can I run a balloon under pressure with the reed valve?

    Thanks for the help.


    You mght try the 5.25×3 TF prop on the sure start. Pressure works fine on the reed valve–you don’t need much and the pennt balloons will work. Just remove them be for storing the plane.

    The Bounty Hunter isn’t Nostalgia legal. Word has it that it will get plenty high with a TD.

    The eye dropper obviously isn’t an option for your purpose.

    Other than smacking it into pavement, what’s gonna go wrong with the TD that would require the help of an old pro?


    I read this thread and got a kick out of it. To be viable contest performer cheap is not the way to go. For entry level the Cox offering for $6.99 is the way to go. If you go to RC swap meets, Meca collectos, mecoa web site etc you will find reasomable priced TD engines. The Cyclon/Fora/Profi will cost you but they are the best made screamers. The CS line I wouldn’t pay a dime for one. Anyway my point is any gas powered model airplane is going to have cost envolved. Best od luck,Dan


    Hi Dan,

    Thanks for the tips.

    Those SureStarts are looking better and better. I’m going to put together an example of what a super simple yet competitive Bounty Hunter 245 might look like. I might even consider rubber banding the engine on ala Cox PT-19; might help prevent wing damage on a rough landing.

    Thanks again,


    I use a VA MK11 o49. No longer produced. I have a TD or two. Rocco’s guys have a limited budget and some desire. Ultimate performance is not their goal, I believe. They are , however, looking for better performance than a Dakota with a sick Cub.

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