Single Cylinder Opposed

[Flyinfool]

just a thought....
Adding weight to the flywheels will have them way out of balance when at the 3 and 9 oclock positions. What about adding weight to the lower piston to counter the weight of the upper piston and all of its linkages. And then just a small flywheel weight to counter the upper connecting rod weight in the 3 and 9 oclock positions???

 

[Tom1948]

That is still a good degree of engineering.

 

[rdean]

Thanks Chris, Thanks Tom

Jake and flyinfool I am sure there is something different going on here then just a static balance. If I made the lower piston from cast iron there would still a huge imbalance. There just isn't enough room on the lower end to add enough weight to make much of a difference. I do have a couple of ideas to try in the next couple of days and I will keep you updated on progress.


Ray

 

[tq60]

Moment of inertia.

The piston and other moving weights are possibly moving a greater distance than the flywheel weights.

Bringing Newton in, with equal weights in static balance, but one moving a greater distance in the same period will have a greater energy than the one moving the lesser distance.

The upper connecting rods should equal the weight of the lower single, both moving about same distance so equal weight helps.

If the lower piston is heavier than top one, can weight bearded to top one, maybe drill and tap for vertical bolt to add weight.

The counterweight in engine cranks are somewhat heavier than connecting rod and piston.

Maybe increase diameter of flywheel and remove material from one side of center on the backside.

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[rdean]

I was completely wrong in my thinking that I could balance this engine by adding weight to the flywheel.

The problem is that the upper piston assembly is heavier than the lower piston assembly so as it moves it creates an up and down unbalance movement. The engine trying to jump up and down.
To correct this the counter weight must also be of the same the up and down movement.
When a weight is placed on the flywheel it causes an unbalance through out it's rotation not just the up and down directions. It does overcome the weight difference between the upper and lower pistons but only for a short instant when the engine is at bottom dead center or top dead center while causing a great unbalance the rest of the time.
I was in effect building a paint mixer.

I will be looking into adding some weight to the lower piston and installing larger flywheels.

Thanks for looking
Ray

 

[tq60]

How much difference in weight?

Can the lower connecting rod be made heavier?

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[rdean]

I will make the lower piston out of cast iron. I know that will not be enough but it will help.
There may be something I can do with the connecting rod too.
Ray

 

[Just for fun]

I just read through this whole thread. Nice work!

 

[rdean]

Thanks Just for Fun and tq60 this should answer your question.

The last few days have been busy with other breakdowns and problems but I have been able to get some things done on the engine.

This is the old and new lower pistons and connecting rods.
Old is on the left.


Old piston and rod assembly = 1.7oz
New piston and rod assembly= 5.8oz
The new piston is made of cast iron and is 0.250 longer than the original.
The connecting rod is made of brass and is 1/4" wider at the base with a 1/2" long tail and is 5/16" thick instead of 1/4".

This change along with the removal of the flywheel weights has made a tremendous difference but wait I'm not done yet.
I think I can make it even better so stay tuned.

Thanks for looking
Ray

 

[tq60]

Glad to be of help, and that it was valid!

Your work is impressive, been collecting machine related stuff with machines for 45 years with intent to make little engines, only made one complete and started a V4, single cut from round crank, just never got done due to life.

Great work on your stuff.

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