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Engine basics => Engine set up tips => Topic started by: John Skukalek on June 26, 2021, 12:15:39 PM
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Is the Brodak 15 that is currently available a good motor?
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Depends on what you are going to do with it. For all round sport flying it is great. Broken in correctly is is a decent stunt engine. Not a power house for speed or racing or even carrier. D>K
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Thanks for your replies john and Motorman. I think i'll give it a try in a trainer for my 6 yr old grandson.
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The Brodak 15 is a very nice all-around stunt/sport engine.
When I wrote the operating instructions, I made an error in the fuel requirements.
I mentioned 5 to 15% nitro - you can, in fact, go as high as 25% nitro without any issues.
Do not run straight castor - a good oil blend is 50/50 castor/synthetic but the engine seems happier with less castor and more synthetic. 30/70 is fine.
Don't look for a 2/4 break - it won't happen unless you lower the compression with an extra head shim or two. That will cost you some power.
Keep in mind however that the engine was designed to run on the lean side and in the tests I've run, that's where it performs best.
Experiment with different props in the 7 to 8 inch diameter range and different pitches to see what works best for you.
I've had very good results with the 8-6 Top-Flite wood.
The break-in time varies. After around 20 minutes total time, slowly lean it out until it stops. If it stops abruptly (like seizing), it needs more time. If it just leans out and dies, it's ready to fly.
Bob Z.
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Thank you for that information Bob. What total % of oil do you recommend?
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Hi, John.
22 to 23 % total oil will do just fine.
I've used the Brodak 10-23, 50/50 since the engine was new.
Powermaster is excellent also.
Bob Z.
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I recently purchased a Brodak 15 CL engine. Can someone tell me if a long glow plug such as a SIG GP003 RC long with idle bar can be used or does it require a short glow plug?
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Long reach.
I have never needed an idle bar plug so I cannot comment on the performance.
If you do use one, make sure there is no interference at top dead center.
Bob Z.
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Thanks Bob. To confirm, you are saying that a long plug will work but you're not sure if one with an idle bar will interfere with the piston?
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I take it the instructions have not been read. mw~ S?P H^^
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I recently purchased a Brodak 15 CL engine. Can someone tell me if a long glow plug such as a SIG GP003 RC long with idle bar can be used or does it require a short glow plug?
Easy way to check is to take the head off and run a plug with gasket washer into the hole and see what it looks like. The end of the the threads should be flush with the surface in side the head. If the threads are too long it will, of course protrude below that. if too short you will see female threads.
Type at you later,
Dan McEntee
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Thanks for the help everyone.