Liney "Halo-5"... Engine Morph

[BronxFigs]

Love the Liney, "Halo-5"....but want to do a single cylinder, and a V-Twin version, but on a larger scale....maybe with a bore, about 1 inch. Also, instead of the push-rods working off a cam, I will use exposed eccentrics to work the rocker arms after slightly modifying the rocker-arm mountings.

Can you suggest what angle I should use for the V-Twin....90 degrees, 60 degrees, 72 degrees between cylinders? Is there a preferred angle for getting the best balance?

Thanks for any help.


Frank

 

[stevehuckss396]

The angle wont mean much other than "looks". Do it the way you think it looks best.

 

[enfieldbullet]

for best balance the angle would depend on the crankshaft's 'throwing style'

i don't know if you can balance a v twin properly, but consider this idea:

if you have the cylinders offset by 90º, and offset the throw of the pistons by 90º, they should go up and down at the same time, thus minimizing torque vibration (rocking of the engine forward and backward). they wouldn't minimize up and down vibration though, but that may be easier to deal with.

it would probably fire better as well because the power stroke would be evenly spaced. (should go pop..pop..pop, instead of pop-pop..pop-pop..)

you can do that with any angle though, no need for 90º. but the cylinders must be offset to the side a quite a little bit so this style of crankshaft would fit.

 

[BronxFigs]

Thank you for the help and suggestions.

I was going to make a crankshaft and connect the big ends of the con-rod on the same throw, using a con-rod style like the Howell V-Twin where the big end of the con rod fits into the other con rod like a fork. Then, the cylinders could be mounted on the crankcase in the same plane, and not have to be staggered, one behind the other.

I'm in over my head at this point, but I don't see why I should not try at least the single-cylinder version.

Steve: thanks for the information. I thought it was VERY important. I think 60 or, 72 degrees of separation. 90 degrees, too air compressor-ish.

Enfieldbullet: I have to take some time to visualize the set-up you describe, where both pistons reach TDC at the same time. Any diagrams to help this dense brain see the whole enchilada?

Frank

 

[enfieldbullet]

i had to risk a stroke myself to visualize it too. if you try to see the whole thing at first it wont work.

you have to try to see them reaching TDC at same time, and then work backwards to see where the conrods are.

i put together a sketch for you, but i'm a paper guy, so i took a picture of it.

getting out of you confort zone is where engineering gets interesting. nothing wrong with it. failure is also an option in this line of work. 90% of my ideas crash and burn terribly. so i say go for it.

i like the 'conrod octopus' idea that i see on some radials, you don't have to offset the cylinders.

the angle thing depends more on fit issues, 90º can be a bit wide for some engines so they make the angle narrower. or looks as steve said.

good luck on the project.

 

[Art K]

Frank,
Don't throw out the 90 degree twin yet unless you don't think a Ducati sounds and looks cool. There's my two cents worth.
Art

 

[jwcnc1911]

will they both be bdc at exactly the same time? if so just machine a little relief in that area... some one's tag line is "a little clearance never got in the way of anything."

 

[enfieldbullet]

will they both be bdc at exactly the same time? if so just machine a little relief in that area... some one's tag line is "a little clearance never got in the way of anything."

yes.

the drawing is a little exagerated, no way to know if that interference exists without the engine's plans.

but we think rather alike.

 

[123RWO]

This is an interesting animation of the varying unbalance forces in v-twins of different configurations. http://www.sense.net/~blaine/twin/twin.html scroll down.

RWO

 

[BronxFigs]

enfieldbullet...Thanks. That picture was worth a thousand words. Okay.... now I savvy.

Thanks for the encouragements from all the readers. You can't fail if you don't try. So, now I order the Liney-"Halo-5" plans...unless someone wants to trade for any of these other plans:

"Plunket Jr".
Howell's "V-Twin",
"Gade" H and M engine,
"Powerhouse"
"Robinson-Chippie"
Verticle Hit and Miss by Luke Tonneberger Bar-stock construction, air cooled

Frank
([email protected])

 

[BronxFigs]

RWO....

Watching the animations of the various engine cylinder configurations is fascinating. But, I haven't the experience, or knowledge to know what they mean, and how to translate and use that information when building a model engine. I literally, can't do the math. I have no clue how to analyze forces, vectors, angles, balance, etc. Wish I knew what it all meant.

Frank

 

[enfieldbullet]

Frank, it wouldn't take much learning to understand. if you are interested there's a nice physics section in the Machinery's Handbook.

and basically they don't mean much in a model engine. in a full size they can do some damage. imagine a 302 v8 trying to rotate when you hit the throttle and all that torque cracking the chassis. it is not that rare to happen.

the animations show why i like the boxer configuration though, near perfect balance.

 

[BronxFigs]

enfield ammo,

Thanks. So can I basically pick my poison, and then go from there? Some of the animated, V-twin configurations look interesting.

Frank

 

[enfieldbullet]

i say go for it.