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Author Topic: Brodak 40 questions  (Read 3548 times)

Offline Jim Svitko

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Brodak 40 questions
« on: September 09, 2016, 03:36:39 PM »
I have one of the most recent batch.  I bought it about two months ago.  For those who have mounted this engine sideways, either in a profile or sideways in a full fuselage, are there any issues when side mounted?

That is, anything like the Fox burp on outside maneuvers?  I would be using a metal GRW type uniflow rectangular tank.  What about tank height?  With 5% nitro is 4 ounces enough?  Any other tips and advice are appreciated.
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Offline Motorman

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Re: Brodak 40 questions
« Reply #1 on: September 09, 2016, 04:17:27 PM »
The B40 was designed with very little crankcase volume to avoid the Fox burp problem. If you use a 2005 Wizard plug I can't see you having any problems if you're running a 4-2-4 set up which is what it was designed to do.

I think the recommended fuel is 10% nitro 22% oil with a 50/50 blend of castor and synthetic.

I've heard that a 4oz tank will get you through the pattern with a well broken in engine. I'd rather have a bigger tank and not need it so, I'm going 5oz. I would start out with the tank center line 1/8" above the center line of the engine.

The APC 10.5x4.5 seems to be a magic prop for that engine.

MM
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Online Clint Ormosen

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Re: Brodak 40 questions
« Reply #2 on: September 09, 2016, 09:20:18 PM »
You won't have any problem with a sideways mounted Brodak 40. Any good idle bar plug seems to be fine. I use the Thunderbolt plug in mine. They seem to like the 22% oil on 10-15 nitro fuel. I use Powermaster. A 4oz tank might be a little small. I use a 4.5 and seems to be the right amount. Might depend on where you fly. The Bolly Clubman 10.5x5 is THE prop for them, but they're out of production. The APC 10.5x4.5 is a decent substitute. No burps or hiccups ever.
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Offline Steve Helmick

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Re: Brodak 40 questions
« Reply #3 on: November 02, 2016, 07:54:13 PM »
IF you are willing to use the stock (~.305" bore) venturi and 10% Vitamin N, the TT 11 x 4.5 is an excellent prop for the B.40. ZZProp says he'll have a CF replica next Spring (2017).  #^ Steve
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"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Paul Smith

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Re: Brodak 40 questions
« Reply #4 on: November 02, 2016, 08:14:19 PM »
1944 - be a man and pick up women.
2015 - become a woman.
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Paul Smith

Offline Fredvon4

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Re: Brodak 40 questions
« Reply #5 on: November 03, 2016, 08:54:39 AM »
Paul I admit to being greatly confused ...UNTIL I noticed Steve's bottom part of his signature

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Online Brad LaPointe

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Re: Brodak 40 questions
« Reply #6 on: November 03, 2016, 09:06:18 AM »
The last time my very small light Brodak powered profile was flown it wouldn't make the pattern on 4 oz . It was cool (8c) and I had to open the needle to get things right. The 6oz. tank looks like overkill for this small profile but from past experiences putting the big tank on in the first place saves a lot of grief.

Brad
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Online Gerald Arana

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Re: Brodak 40 questions
« Reply #7 on: November 03, 2016, 10:40:29 AM »
Quote from: Paul Smith on November 02, 2016, 08:14:19 PM
1944 - be a man and pick up women.
2015 - become a woman.


If I were a woman, I wouldn't be able to stop fondling myself!  LL~ LL~ LL~

Jerry
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Offline Chris Belcher

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Re: Brodak 40 questions
« Reply #8 on: November 03, 2016, 02:25:08 PM »
Jim,
I'll second the TT 11 x 4.5 prop with stock venturi like Steve said. But he is right, 10% is the right nitro. I tried with 5 and it just doesn't seem to work. With 10 on a 46 oz Gieseke Nobler I do the pattern plus 7-8 laps on 4.5 ozs.  Motor comes on and off just right and i adjust for temps by adding or removing a head gasket as required to soften or harden the break. I think your engine is just not fully broken in yet like we talked about. Bender told me they take forever and he is right about that! How did the rest of your experimentation go after i left Sunday?
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Offline Steve Helmick

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Re: Brodak 40 questions
« Reply #9 on: November 04, 2016, 01:50:11 PM »
Quote from: Brad LaPointe on November 03, 2016, 09:06:18 AM
The last time my very small light Brodak powered profile was flown it wouldn't make the pattern on 4 oz . It was cool (8c) and I had to open the needle to get things right. The 6oz. tank looks like overkill for this small profile but from past experiences putting the big tank on in the first place saves a lot of grief.

Brad

Try mixing up a small sample batch of fuel with 2% or 3% Coleman stove fuel and stick with the 4 oz tank.  y1 Steve
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"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

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