stunthanger.com
General control line discussion => Open Forum => Topic started by: steven yampolsky on October 15, 2010, 01:36:31 PM
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I just happen to swing by www.brodak.com and they listed Brodak 40's in stock so I gave them a call. Sure enough, they have them in stock!
If you are looking for more power than OS35S or Fox 35 and excellent stunt run characteristics, this is the engine to have!
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Just like Fox's, they have to have proper breakin. Mine is going into the King Sweep. H^^
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I picked up a brand new B40 from Ebay some time ago but I believe there were a number of changes made to them as they were developed. Does anyone know what to look for to determine if it's a first, second, third, whatever, version?
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Just like Fox's, they have to have proper breakin. Mine is going into the King Sweep. H^^
I ran six tankfuls(4oz) on a stand and plunked in in the plane. The engine kept getting better for the next 30 or so flights. It's been excellent since then(3 seasons).
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I picked up a brand new B40 from Ebay some time ago but I believe there were a number of changes made to them as they were developed. Does anyone know what to look for to determine if it's a first, second, third, whatever, version?
The first batch of B40's had the timing that was not as designed by the engine designer and ran poorly. One way(unscientific one) to determine if it's batch 1 is to try and use it. They were extremely underpowered and finicky.
The second batch came with a muffler that had a small diameter stinger.
All batches after the first two had the correct timing and the right muffler.
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I picked up a brand new B40 from Ebay some time ago but I believe there were a number of changes made to them as they were developed. Does anyone know what to look for to determine if it's a first, second, third, whatever, version?
Nothing external, most changes were minor tweaks and it really doesn't matter they all will run fine.
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THE first runs have issues. The front bushing goes very quickly. Mine went in 100 runs or =$1 per run.
The later engines are a good engine with all good results. I'm not here to bash any engine. HOWEVER, as with any new development there mat be some unforeseen issues..remember the Corvair LL~
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The first batch of B40's had the timing that was not as designed by the engine designer and ran poorly. One way(unscientific one) to determine if it's batch 1 is to try and use it. They were extremely underpowered and finicky.
The second batch came with a muffler that had a small diameter stinger.
All batches after the first two had the correct timing and the right muffler.
I got mine around late 02 early 03??? I can't remember exactly when. I believe I've run a barrel or more of fuel through it, maybe three glow plugs, one muffler, one crash and only the "god of control line stunt" knows how many flights. "She's takin a lickin and kept right on ticken." IMHO...it always has and still does...have plenty of power. The "coolest" thing about my .40? It starts and stops the same way, every time I run it...same steady "4/2 growl" through out the run. One of the best engines, RC included, I've ever owned.
Norm
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Thanks for the answers guys. It would seem I have one of the later engines then going by the fact the exhaust stinger is 9mm diameter which is more than large enough for a 40. The timing is exhaust 70 BBDC, transfer 62 BBDC, boost 60 BBDC, crank opens 43 ABDC and closes 48 ATDC. Compression (geometric) is 9.9:1 with .0145" squish clearance with the .2mm shim. I'll most likely end up taking out the shim to get a compression of 10.8:1 and .0067" squish because I don't use nitro.