Author Topic: Longboy's "BRATZ" Model Gas Engine.  (Read 11052 times)

Offline cfellows

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #30 on: September 21, 2017, 05:03:32 PM »
Very nice engine.  Lots of innovation, very well done!

Chuck
So many projects, so little time...

Offline Longboy

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #31 on: September 22, 2017, 05:00:10 AM »
Congratulations to this really nice running engine!  :ThumbsUp: :ThumbsUp: :ThumbsUp:
And the O rings on the pistons seem to work well too. Did you check them yet?

Plani
Engine runs well so they are holding compression. 5% WD40 mix with fuel.      Dave.
Wadda you mean, "It don't run"???

Offline rudydubya

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #32 on: September 22, 2017, 07:09:52 AM »
Well done, Dave.  Beautifully crafted.  I like its slow idle.

Regards,
Rudy

Offline Longboy

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #33 on: September 22, 2017, 05:50:33 PM »
The heavy brass flywheel and its 3 1/2 in.  diameter give BRATZ that low rev industrial idle.  For a hand start, it is about the max diameter I can get a flip grip upon.  I believe a 3 in. dia. flywheel to be more ideal in this scale for similar RPM idle speeds plus keep a low crankshaft center of gravity profile.  A 3 1/2 dia is used on my FOREMAN 4 cyl , made the same speed reduction. I'm sure the extra cylinder contributed to the smoothness too. Thanks to a senior modeler who brought up the benefits of large dia flywheels and idle quality during FOREMAN's build.  :D     Dave.
Wadda you mean, "It don't run"???

Offline Roger B

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #34 on: September 22, 2017, 06:15:32 PM »
Excellent  :praise2:  :praise2: I've only just caught up on this thread. I have always liked the sound of a three cylinder engine  :ThumbsUp:  :wine1:
Best regards

Roger

Offline Longboy

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #35 on: November 21, 2017, 06:33:40 AM »
Does sound unique to me.
Wadda you mean, "It don't run"???

Offline ThomasM

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #36 on: November 22, 2017, 08:16:51 AM »
Hello Dave,

Your design is perfect for relaxing while just watching and listening to the engine.
Everything is visible and the low idle is perfect.
Maybe with a larger flywheel and smaller carb it would be possible to idle it even slower.
The o-rings in the cylinders should provide enough compression at even lower rpm.

This or something similar has just became part of my to do list.

Best regards,
Thomas

Offline Longboy

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Re: Longboy's "BRATZ" Model Gas Engine.
« Reply #37 on: December 19, 2017, 04:54:16 AM »
You are welcome Thomas. Inspiration from model engine videos activates the soul of desire! Good luck in your designs. :ThumbsUp:
Wadda you mean, "It don't run"???

 

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