Brodak .049

[Joe Ed Pederson]

Back on Feb. 21, 2017 WWWarbird posted a message on the 1/2 A forum:
Just a note here, the Brodak engine is pretty weak, even for an .049. I'd recommend going with something else.

I was wondering if he may have been referring to the Brodak .049 Mk I or the Brodak .049 Mk II.   Does anyone have experience with both the Mark I and Mark II so as to compare the earlier and present version?   

If anyone has experience with both a stock Cox Tee Dee .049 or a stock Cox Medallion .049 and the stock Brodak .049 Mk II, how would you say either Cox engine compares with the Brodak .049 Mk II for power?

Another question I've wondered about is the lifespan of the Cox Medallion and Tee Dee engines.   Can anyone comment on the lifespan of the Cox engines and the lifespan on the Brodak .049 Mk II?

I hope it's ok to post this on the Open Forum rather than the 1/2 A Forum.

Thanks,
Joe Ed Pederson

[Larry Renger]

cox ran a Tee Dee 049 for 400 hours once. Fox ran 55 gallons of fuel through a stunt 35.

I only have experience with the Mk 1 Brodak engine. It was pretty pitiful until I modified it to use Merlin glowheads. The Galbreath/Nelson conversion perked it up even more.

[Trostle]

I've never worn out a Cox TD.

Motorman

What are the most hours you have on any single Cox TD.  Just wondering.  I know, properly run with the proper fuel, Cox engines can last "a long time", but I cannot quantify "a long time".

Keith

[Gary Dowler]

What are the most hours you have on any single Cox TD.  Just wondering.  I know, properly run with the proper fuel, Cox engines can last "a long time", but I cannot quantify "a long time".

Keith

Larry's post above says that Cox claims to have put 400 hrs on a single TeeDee 049.  That's about 7500 flights

[Mike Scholtes]

Or 72,000 free flight launches, which is how a lot of TeeDee 049s are used. I still have and use the one I bought in 1963. Original parts except Galbreath head and Nelson plug. Have three of them, same setup, same results. Not a match for the Cyclon 049 but not a fair comparison.

[Trostle]

399

Impressive and credible.

Keith

[Fredvon4]

I have many Cox, Norvel, Fora, and Cyclon .049s    never had or touched a Brodak or ASP version

I never kept any log on flights or run time on any ----but in my hoard of Cox TeeDee .049 or .051s that have a lot of run time   many bought used and some I built from parts (about $109 per engine)

Cox's really do not need a bunch of break in BUT they all need a piston / rod reset when you feel the slop at TDC after a few tanks of fuel.. BUT ----after a good first Piston Rod end reset they seem to last a long time with out any more slop

I have a buddy in Romania that is a Cox engine lover and often berates the junk Norvel he has claiming that his .049 TeeDee from youth ( a prized item from behind the Iron Curtain) has well over 500 hours on it  on a wide variety of air-frames

There is no doubt the low cost Norvel's or Fora's have a lot more power ( I have them on 1/2a combat wings) that a heated up Cox .051 with Galbreath head and Nelson plug...and of course the Expensive Cyclone is another step up RPM and power wise

Again no Brodak .049 experience since I had a lot of Cox engines for various 1/2a planes... most versatile are my Medallion .049s for stunt type air-frames....as an aside my SkyRay sports a fairly HOT Cox Black widow that I had to increase line length for

For what it is worth all my .049s get 25% or 35% N and all castor 24~28%.....even knowing the Foreign ones would prefer mostly Synth oils

I am supprised Ken Cook has not chimed in...he has experience with all including the Brodak .049s

[kenneth cook]

        I just saw this post and I have posted prior in regards to both Brodak engines. I enjoy all 1/2A engines.  The MK I was a Chinese engine. Mine had issues but without bashing it, I did what I needed to make it suitable. I for one am not a fan of 1/2A engines with glow plugs. Larry mentioned this above and this is what made the MK 1 come alive when I drilled out the threads and used a Norvel button. Larry used Merlin plugs. I remember Larry commenting on the Nelson head which Henry had for these engines. The cost of that head was nearing $30 at the time. The shaft on the MK I has a spiral oil groove ground into it in which I found out quickly when it chewed up the case. After taking it apart, new case and a good polishing off the shaft the engine was utilized. I should've taken it apart when new. I would compare it's power to a decent reed valve engine but it was a lot steadier. The recommended fuel per the instructions was to use 10% nitro. That worked, not as good as 35%. The MK 1 also came with a muffler, this robbed a lot of rpm's. I just didn't use it. Having it on there prevented easy prime starts. From memory, I believe the recommended props were 5x3-7x3 possibly 7x4. I found it liked smaller and it didn't care too much for the Cox black 5x3. For my style flying I used thin blade APC props. They offered more rpm's and drive over the traditional props that most use. I'm pretty certain if you had some decent and in good shape Top Flite white nylons, they would do well.

         The MK II was made in Moldavia with the larger.25's and .40's by the same maker. It has AAC technology which I feel is quite impressive due to typically not seeing this in engine under $150. My feelings are still the same for the standard plug which the MK II has. A big thumbs down for me. I did have a Nelson head that was made for this engine and I can't find it. That was a HUGE difference in terms of starting.  I found the crankshaft fit overly tight which I can deal with but many aren't quite certain as to what's going on. The engine has a bit of pinch TDC and having a heat gun on hand initially takes a lof of frustration out of trying to get it to run. The crankshaft timing on the MK II offers a timid run. I know this engine has a lot more potential to turn more rpm's. I really wished they made another optional shaft for higher performance. I was going to play around with a few shafts I have as they're real close. This would take some modifications to the case. I flew it on a Baby Flite Streak with the black Cox 5x3 and a APC 5x3. The engine was an improvement over the MK 1. No muffler comes with the Brodak. Both Brodak engines without mufflers are quieter than Cox engines.


           Both the above engines can run on low nitro fuel as mentioned. Cox engines generally are pretty demanding on high nitro fuel and trying less than 15% usually makes them fickle. Both Brodak engines are considerably frugal on fuel compared to the Cox Medallion and especially the TD. The TD can be a learning curve when using tanks and it works quite flawlessly on bladder. The Medallion offers better fuel draw but the power is a lot lower than the TD due to the lower compression plug different crankshaft  and single bypass cylinder. Essentially all four engines your inquiring about all have different runs. The Cox variants essentially share many similar components and can be interchanged. This is not the situation with the Brodak engines and this commits you to one supplier when in need of parts.

          As far as longevity, I no longer own the MK1 so I can't comment on it's longevity. CS the manufacturer is no longer in business making engines. Therefore parts are going to be a issue and Brodak has had them on clearance for quite a few years now. The MK II seems to be stocked in terms of parts. Finding true TD cylinders are not commonplace but the production cylinders will suffice offering decent power and seem to be plentiful. I look at parts availability as a big deciding factor which would have me leaning towards Cox.

[Joe Ed Pederson]

Thanks everyone, especially Fred and Kenneth Cook,

I found the post below from Fred in the archives which answered a lot of questions.   I have one Medallion .049 I bought new decades ago and probably has less than ten runs on it, and a Tee Dee that was given to my son 20 years ago (It runs fine). 

I'm aware that RSM Distribution sells bladder tanks for 1/2A engines, and I think I remember a post that talked about a non-pressurized bladder tank, but that sounds to me like an oxymoron.  Is it possible to have an unpressurised bladder tank?

Years ago I watched Free Flight gas guys use pressurized bladder tanks.  It seemed tricky to get the hemostats off the fuel hose before the prime ran out.  I'm not sure I would want to mess with that.

Kenneth, you mentioned a learning curve or some such to use fuel tanks for a Tee Dee .049.   Could you point me in the right direction to use a regular tank with a Tee Dee or pull up one of your previous posts on the subject?

Also, can someone tell me how to copy and paste previous posts in that little light blue box with the print size reduced?


From Fredvon
 Re: .049 for Stunt

« Reply #6 on: March 13, 2017, 01:27:44 PM »


Quote

 

My Sig Sky Ray has Black Widow and is a pain to get a good full tank run....and I know what I am doing with Tanked Reed engines..

All my combat planes use NV, Fora, Pico, TeeDee power--- all on bladder

All my 1/2a balsa stunt planes; Black Hawk PT 19, Baby Clown, Lil Jumpin Bean, and Baby Ring master Bi-Plane are powered by Cox .049 Medallions and balloon tank

The Medallion has several reasons for being a good choice...
1. Easy starting on a standard or balloon tank
2. Run time easy adjusted by tank size
3. More power than any of the typical reed engines
4. Beam OR radial mount ( with a Texas Timers screw in back-plate)
5. Likes anything from 15% to 35% N
6. Wide range of usable propellers
7. Can be made a tad hotter with a .051 P/C set
8. Galbraith and others make a good head that adds power if needed ( I run Galbraith heads and Nelson Plugs)
9. Also uses (as I do) the currently available TeeDee P/C assy from Cox International

NOTE...The Medallion Crank inlet is round hole Vs the TeeDee square inlet and has a slightly different timing...So just putting a Medallion Venturi plastic part does not really Tame the TeeDee

Note2 ...Do use a very good polish of the Medallion crank nose bearing areas...this adds a noticeably fair amount of RPM

Note3...Follow Paul Gibeault's Mouse Race engine hints of P/C fit
 


 

[Fredvon4]

Joe
Pressurized bladder tubing, pacifier, or fountain pen bladder are a bit different from just a simple party balloon. With the party balloon tank you need a fuel feed pipe inside with holes cut in it so the collapsing balloon can still feed the fuel until empty. We do not fill these for pressure just size it to the length needed for a decent flight time. First sucking the air out the adding the fuel.  Hope this makes sense.

Ken notes and I can attest the TeeDee is a PITA to get a hard tank set up and is sort of why Cox added a pressure tap on right side under NVA. But as shipped this tap is NOT complete...One must drill a small hole through the crank case nose...Biggest problem is the molded nipple is with OUT a barb and keeping the tubing on to the tank is a effort in frustration

There are many of techniques to run Bladder with Pressure that do NOT need Hemostats.... Many guys route the fuel feed line on an area of Fuselage you can pinch off while starting on prime then release pressure to get fuel flow while fine tuning the NVA... I personally use a line clip adapted to pinch of the full bladder fuel line and the prime run is just long enough to get it open....Yes initially it is very fiddly but you soon get the routine down....just like all combat pilots do

Ken can add advice on what has worked for him with a TeeDee on hard tank...I never had any luck so just went bladder

OH BTW I think Phil Cartier of Core house is my favorite pressure bladder supplier while I do get a fair amount of fittings from Texas Timers

http://www.texastimers.com/

http://home.earthlink.net/~philcartier/index.html

 

[kenneth cook]

           Joe, the main problem with a TD on a hard tank is this. The TD has a fairly large intake. Many have drilled them out for more performance. Ascertaining the correct size is important here. Just a note, a TD can use the Medallion body on it and this will promote better fuel draw but it will not be as powerful. I'm going to say it's marginal as to how much power your really needing. When mounted profile, the centerline of venturi is quite close to the fuse. When using a tank such as a wedge, the pickup in the tank is now very outboard. The large venturi and the outboard pickup compounds the TD's ability to deliver fuel adequately in different positions. Level flight is usually not bad but in the maneuvers, it begins to lean out and this can result in the engine just quitting.

        If building a full bodied plane such as the Pinto, the tank is directly behind the engine. This assist fuel delivery and the problems that arise with profiles are non existent other than tank height issues. You can either design the tank to be set into the fuse or inboard or one can shim the engine off of the beams. I wouldn't recommend shimming it too far off of the plane, but 1/8" - 1/4" can be done successfully if the proper shimming is used.

         The TD can be run with backplate pressure if you have the proper nipple backplate. I don't care for backplate pressure because it does nothing more than flood the engine when I use it. It's more difficult to use it for me vs a bladder but the same starting procedures are required. As soon as you turn the prop your essentially pumping pressure into the tank therefore a pinch off device is needed to avoid the case flooding out.

             I can't really offer tanks because I usually make my own. Commercial made tanks for 1/2A are more than likely going to need some modification for using the TD. What I can do Joe is send you a pic via PM of a modification I used yesterday afternoon with the TD on a tank. I feel that offering the tank uniflow would be very beneficial to the overall run. I'm using standard vent which really hasn't been a tremendous issue as it becomes quite obvious when the tank is almost empty due to the engine leaning up. My advice would be thin and longer on a profile. Wedgies and thin wedge tanks can be used if the tank let into the fuse placing the pickup closer to the centerline of the venturi.

[Joe Ed Pederson]

Kenneth,

What I can do Joe is send you a pic via PM of a modification I used yesterday afternoon with the TD on a tank.


That would be great.   Thanks.

Joe Ed

[Brett Buck]

If anyone has experience with both a stock Cox Tee Dee .049 or a stock Cox Medallion .049 and the stock Brodak .049 Mk II, how would you say either Cox engine compares with the Brodak .049 Mk II for power?

Another question I've wondered about is the lifespan of the Cox Medallion and Tee Dee engines.   Can anyone comment on the lifespan of the Cox engines and the lifespan on the Brodak .049 Mk II?

  Not just apples and oranges comparison, it's apples and dinosaurs. Run stock, either the Medallion or Tee Dee is much more powerful and handle (start, adjust, break in) much better. I can't speak to the long-term durability other than I know it is very difficult to fly any Cox engine long enough to wear it out, as long as you reset the connecting rod slop every few tens of hours. Both Jim and I tried multiple copies of the Mark I engine and only got one of them to run, briefly, but we couldn't get it started again, and then same thing again with the Mark II. The Mark II feels good, loose, and good compression, but no luck. Cox break-in is <1 second for the most part, it runs well enough straight out of the box, although it will get a bit better for the first half hour or so.

    As far as which is more desirable, just based on what I have seen, get a Medallion or even a Cox tank-mount or product engine and some appropriate high-nitro fuel, keep everything scrupulously clean, and you will have enough power for any conventional trainer/beginner 1/2A airplane. I would not recommend the Tee Dee, it is not set up for easy running on suction, and you don't want to mess around with pressure tanks. If you want a larger 1/2A airplane, I know for certain (since I have done it) that a Medallion .049 with Cox Racing Fuel will fly a 12-ounce airplane with 240 square inches and a very thick wing with great authority.

  If you want something bigger than that, I would skip 1/2As completely, and go to 15-sized airplanes, which now includes up to a full-size (S-1) Ringmaster - because the engines got more powerful.

   Brett

p.s. After reading the above, with due respect to all involved, I would strongly discourage modifications, "hop-up" tips, etc. Even if they work and achieve the small improvements possible, you risk something in the disassembly and modification process, and *cox engines are built like jewels to begin with* with astonishing quality control and fits even now, much less 60 years ago. They are the only engines from the "Good Old Days" built to current high-end standards, even with old-school metallurgy. Their remarkable achievement (noted in the old engine reviews, where they marvelled over the lack of break-in required and that a glow engine could possibly outperform a diesel for goodness sake) was controlling everything so carefully that it was nearly perfect as it came. They produced millions of these things, shoved them in a box with a plastic airplane, fuel, lines, handle, and sold it for $15 as K-Mart, and they virtually ALL worked and hundreds of thousands of complete neophytes could get them started and running long enough to crash.

[Joe Ed Pederson]

Thanks Brett,

I really appreciate the input.

I had to laugh at "long enough to crash" in your last sentence.  I was one of those kids who mowed lawns until I had the $6.00 it took to buy a Cox PT 19 at a discount chain that no longer exists.  I used that Baby Bee on just about every 1/2A model Carl Goldberg made in the 60's and 70's.
 
They produced millions of these things, shoved them in a box with a plastic airplane, fuel, lines, handle, and sold it for $15 as K-Mart, and they virtually ALL worked and hundreds of thousands of complete neophytes could get them started and running long enough to crash. [/i]

Joe Ed

[Fredvon4]

I actually try to follow Bret's advice a lot as pertains to new(er) modern OS  engines and such...but have to mildly disagree with his last note about the Cox Jewels

Ken and a whole host of others as well as I have have very good success tinkering with Cox engines...Hell seek out Paul Gibeaults Paper on Mouse race mods and set up

With all the support of parts from Ex Model engines and Cox international and the wide variety of combinations it is very easy to morph a mediocre engine into a pretty impressive screamer...and a lot of fun to do....yes we occasional get to far and eat a piston, con rod or crank

Almost every one of my .049/.051 Cox engines is mildly or heavily modified  some running up to 45% Vitamin N and holding together

I gravitated to the Front induction  as I was having fits with Tanked Reed valve....but each year I still fly a bunch of Sky Ray or Jumping Bean sized with hopped up Golden bees or Black Widows or Cox International specialty performance engines

Galbraith head adapter and nelson Plug...for me---Ken seem to have good luck with the Merlin set up

Good props..there are a LOT to experiment with

Good fuel...Ken and I both agree that HIGH % and ALL castor OIL is NOT that necessary

For pressure we need the more and more higher cost FINE thread NVAs.... Texas timers still has a few but now $35  mine were all $15 just a few years back and they frequently command over $50 on e-bay

Playing with venturi size both reed valve and front rotary yield some good gains until you got too far

cylinder shims to orient the exhaust ports can help or hurt depending on the cylinder ports and by passes


Micro tolerances claimed may be true back in the day but a lot of that Jewel Toleranc is killed once run...IMO

Sub Piston Induction is in MOST Cox engines but if you feeler gauge it no two engines have the same amount....hint....so some fitting and mixing and matching of piston cylinder assemblies can gain or loose power/rpm

Tinkering with Cox engines is it's own sup hobby

Hell just to tick off Brett...I use a Dremel a LOT on my Cox engines.....grin






mostly to pretty them up with Red Rouge

[paw080]

Okay everyone; here goes a bit of ancient history tempered by my failing memory.

Dave Braun and I  met with Mr Gau, Mrs Gau, another C.S. rep and possibly James

Zchou about a year before the first Brodak Mk one .049 sport engine came out.

The purpose of the meeting was to brainstorm concepts and design of a .049

sport engine. Dave and I were looking at an engine that was reliable, and produced

power similar to a Cox Medallion .049. It turned out that Mr. Gau  wanted to produce

a purely simple beginners glow head engine that was long stroked and would run and be as

simple to operate as a Mills .75cc diesel. Dave and I were pushing for a reed induction

design and couldn't influence Mr. Gau to produce a more viable product. I feel Mr. Gau

underestimated the potential modeling market.  Sure enough, James Zchou handed me

a prototype .049 engine for testing that differed from the Brodak Mk one .049 with a slightly different

head and Chinese C.S. markings on the case.  We mounted it in an old sheet wing Hobby Hideaway

model,  I'd built for a Paw .049 diesel. It flew as well as could be expected for a Cox Baby Bee equivalent

powered setup.  I then mounted the engine in a "Stork" and flew it on 35' 1/2A Combat lines. It could

fly most of the stunt pattern, but only in very calm conditions.  We decided that a lot more power could be

coaxed out of the engine, but, why bother!   

That's about all I remember, and at that;  the testing experience is thankfully fading from memory.

Tony (Tony Gallegos)

[Larry Renger]

Quote

Ken notes and I can attest the TeeDee is a PITA to get a hard tank set up and is sort of why Cox added a pressure tap on right side under NVA. But as shipped this tap is NOT complete...One must drill a small hole through the crank case nose...Biggest problem is the molded nipple is with OUT a barb and keeping the tubing on to the tank is a effort in frustration.

End quote

There is a way to keep fuel hose on the side pressure nipple. Take a 2-56 “T” nut and turn the flange down to form a hose nipple. This will screw down on the plastic nipple and is self sealing.