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Author Topic: Brodak 40  (Read 2876 times)

Offline Motorman

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Brodak 40
« on: December 24, 2012, 03:09:21 PM »
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« Last Edit: September 05, 2021, 09:28:54 PM by Motorman »
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Offline Bootlegger

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Re: Brodak 40
« Reply #1 on: December 24, 2012, 03:40:18 PM »
How much oil do you have in the fuel?  Sometime the factory doesn't get enough oil in the fuel even though it says on the container there is "X" amount of oil there.

  Some years ago I had some "run away" problems at a contest, and Dee Rice said the oil content might be low.
 I started running some fuel that we know the amount of oil in it and "WOW" the engine ran like it always had.
  I added oil to the fuel when I returned home and all was well.
  P.S I added equal amounts of castor and synthetic to a total amount of 5 % and the fuel was ok...

  Hope that this helps, and Merry CHRISTmas...
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Offline Bill Hummel

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Re: Brodak 40
« Reply #2 on: December 24, 2012, 04:17:41 PM »
Try a 10" or 10.5" prop. The overheating will stop but you'll still have
a nice run.  With more time on the engine you might get back to
11" props.
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Offline Balsa Butcher

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Re: Brodak 40
« Reply #3 on: December 24, 2012, 05:02:13 PM »
Try an APC 10.5 x 4.5 prop. It will run in a fast 4 stroke (10,200 rpm plus). Go to 10% nitro in the fuel. 10/22 is a good blend. If the engine is still being broke in add an additional 2.6 ounces of castor. It will raise the lubrication percentage approximately 2% and cure the run-away tendency. After the engine is broken in you will not need to add additional castor. Stay with the original muffler, they work well and are not all that heavy. The smaller prop will help ground clearance as well which can be an issue with the Vector 40.  8)
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Pete Cunha
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steven yampolsky

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Re: Brodak 40
« Reply #4 on: December 26, 2012, 06:33:01 AM »
Quote from: Motorman on December 24, 2012, 03:09:21 PM
What kind of run should I be trying for with a Brodak 40? it's on a Vector 40, uniflow tank, full factory muffler which I have to use, 11-4 MAS and stock venturi on 5% fuel. It's got enough power I've been running it in a dead 4 stroke through the beginner pattern but sometimes it goes too slow. If I lean it out to try and get it to 2 stroke under load it just runs away and never cools off again. Thanks for any help.

MM

Did you break it in? Mine run "funny" for the first 10 flights or so.

11-4 is perfectly fine size-wise but you need to make sure it's balanced. Plain bushing motors misbehave when prop is oob and MAS are always guaranteed to be OOB.

Can you check your fuel line or NVA for any particles.

As a starting point, B40 should to be setup like a classic stunt engine: it needs to keep switching between 2 and 4 cycle. About 1 second in 2, 1 second in 4. When the model is released for take off, the motor will go into 2 cycle for about a lap or two until the model gets up to flying speed.

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steven yampolsky

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Re: Brodak 40
« Reply #5 on: December 26, 2012, 07:39:29 PM »
Quote from: Motorman on December 26, 2012, 06:16:21 PM
The olde 2-4 break, ok thanks.

B40's are among the most user friendly motors you can have. It may not be the most powerful motor on the block but it more than makes up for it in the ease of use. The motor has all the right characteristics of a good 4-2-4 motor. Too bad the latest issue of Model Aviation announced that IC engines are dead.
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Offline Steve Helmick

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Re: Brodak 40
« Reply #6 on: December 30, 2012, 12:24:59 AM »
I would suggest a better propeller, and if Pete Cunha says the 10.5 x 4.5 APC will work, I'd certainly give it a try. With a thorough break-in, the stock venturi and 10% nitro, the 11 x 4.5 TT Cyclone works very well, but it is borderline on too much. Might well be too much prop for higher altitude density, or a substandard engine. The 10.6 x 4.5 Mejzlik "Phelps Copy" from Randy Aero will work well, but then you may also need more $ and a pitch gauge.  H^^ Steve
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Offline Lyle Spiegel

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Re: Brodak 40
« Reply #7 on: December 30, 2012, 06:34:15 PM »
 My B40's are very happy with the Thundertigre  11x4.5  grey color prop running Powermaster 10-22,:and  sonictronic rc plug or the thunderbolt. Uniflow tank. Have also found extra head gasket helps. Over the stock venturing I use sof womans  pantyhose held on with black O ring. When using stock muffler need to drill a few 1/8" holes ear rear tail one to help reduce back pressure and helps to reduce overheating when engine is cowled.
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steven yampolsky

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Re: Brodak 40
« Reply #8 on: December 31, 2012, 02:58:29 PM »
Quote from: Steve Helmick on December 30, 2012, 12:24:59 AM
I would suggest a better propeller, and if Pete Cunha says the 10.5 x 4.5 APC will work, I'd certainly give it a try. With a thorough break-in, the stock venturi and 10% nitro, the 11 x 4.5 TT Cyclone works very well, but it is borderline on too much. Might well be too much prop for higher altitude density, or a substandard engine.

You might be right, Steve. At sea level(sub 1000ft), B40 can spin 11x4.5 no problem but above it, one may have to go up to 10% nitro.
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Offline Phil Spillman

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Re: Brodak 40
« Reply #9 on: March 01, 2013, 06:59:36 PM »
Being basically cheap, I run my B-40's on either Pro Zinger 11 X 5's or regular square tipped Zinger 11 X 5's! I use muffler pressure, 5% or 10% 22% oil 50/50  Castor synthetic. The muffler is stock on all planes. These run sweet at +/- 9200 to 9600 rpm. At least that's for me and my flying! 
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Offline Brad Smith

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Re: Brodak 40
« Reply #10 on: March 01, 2013, 07:16:21 PM »
What tank are you useing Phil?
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Offline kenneth cook

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Re: Brodak 40
« Reply #11 on: March 02, 2013, 04:14:49 PM »
           I use Randy Smith's tongue muffler which yields impeccable runs on my son's B-40. Shawn has many contributed wins using his Brodak .40 Hemstrought Pt-19. I can honestly say that I don't have a single engine that works as well as this does in regards to being predictable. One to two flip starts consistently. I drilled the existing holes in Randy's muffler to 3/32" adding no additional holes. Muffler pressure to the uniflow and all is peachy. The engine is entirely cowled in  and Shawn uses a APC 10x5. Fuel is Powermaster GMA 5% and also 10% in the heat. I didn't see any mention of the muffler and I never used the stock muffler so I can't comment on them. Traditionally I find them not to work to my liking so they get put in the box. Ken
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Offline Balsa Butcher

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Re: Brodak 40
« Reply #12 on: March 02, 2013, 04:52:14 PM »
The stock muffler works very well - can't say that about most engine/stock muffler combinations. 9000 or 10,600 rpm doesn't make any difference. Once broken in they hold a solid 4 stroke with very little break. An amazing engine IMHO. 8)
« Last Edit: March 02, 2013, 07:04:44 PM by Balsa Butcher »
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Offline Clint Ormosen

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Re: Brodak 40
« Reply #13 on: March 02, 2013, 08:30:24 PM »
Quote from: Balsa Butcher on March 02, 2013, 04:52:14 PM
The stock muffler works very well - can't say that about most engine/stock muffler combinations. 9000 or 10,600 rpm doesn't make any difference. Once broken in they hold a solid 4 stroke with very little break. An amazing engine IMHO. 8)

Exactly.

I think that those that claim the Brodak doesn't make very good power are trying to run the engine in the 9k rpm range. They work ok like that, but if you prop the motor to spin more like 10.3-10.7 you'll be surprised by the power they make. I use Brodak 40's on several models and set them all up about the same. Powermaster10/22, thunderbolt r/c long plugs and props in the 10.5" range. Bolly Clubman, APC, and Phelps all have worked well. I'd also advise tube mufflers over tounge type mufflers. The stock mufflers work good. To save weight, I use aluminum tube mufflers. I launch the models at 10,600 rpm. Yes they sound like they're screaming on the ground, but the performance in the air is great.
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Offline phil c

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Re: Brodak 40
« Reply #14 on: March 03, 2013, 08:18:09 PM »
Quote from: Motorman on December 24, 2012, 03:09:21 PM
What kind of run should I be trying for with a Brodak 40? it's on a Vector 40, uniflow tank, full factory muffler which I have to use, 11-4 MAS and stock venturi on 5% fuel. It's got enough power I've been running it in a dead 4 stroke through the beginner pattern but sometimes it goes too slow. If I lean it out to try and get it to 2 stroke under load it just runs away and never cools off again. Thanks for any help.

MM
When a motor does that it is telling you it has too much prop.  The Vector 40 is not big plane.  It really doesn't need a prop much larger than a 10/5 or 10/4 wood.  I've never been able to get a B-40 to run well any way except with a very solid 4 cycle with some mild 2cycling at the tops of maneuvers.

the first one I got had a problem with the head.  Waaay to much clearance.  It ran a very strong 4 stroke, but as soon at it leaned out it lost power.  Very strange to fly.  After fixing the head it has been fine.
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Offline Reptoid

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Re: Brodak 40
« Reply #15 on: March 08, 2013, 03:25:20 PM »
If you check your MAS 11-4 propeller on a pitch gauge you will find it is actually 11-3. For whatever reason MAS propellers are underpitched about 1" from the size marked compared to APC, Zinger, etc. APC 10.5-4.5, Zinger 11-5 pro cut to 10.5 or Zinger 11-4 pro should give you reasonable speed with a nice two four break needle setting.

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