Wolfgang Tepperr two pistons and three con rods engine.

[brickyParticipant @bricky]

Having restarted to build this engine I tried the pistons at tdc to see what gap I had between the two opposed pistons.This is 1.5 and the designer specified .4mm.The only thing to do to achieve .4 is to make two new con rods 1mm longer or will 1.5 mm be allright.

Frank

[JasonBModerator @jasonb]

Is it the top piston that is too high ? If not would a single conrod to the lower piston have the same effect.

As they are not hitting you could just try it with the larger gap and if it does not run make alterations. Have you worke dout why you have a larger gap and what is the cause? were the rods shorter than drawing?

[brickyParticipant @bricky]

Thanks for your reply Jason.The top piston pulled down by two con rods is the highest one and the  lower single con rod piston is slightly high in the cylinder head.I will check the con rods are correct or not and reply.It has been a difficult engine to build as there are few dimensions in the ME series but the con rods do have dimensions.I have had to scale from the images and a lot of guess work.

Frank

[brickyParticipant @bricky]

I checked the con rods and they are correct.I think the error is in the upper piston as one has to to reduce the length given on the drawing by finding a figure by comparison means to divide it by.This has been the problem all the way through the construction,so it has to be my miscalculation that the 1mm discrepancy has occured .I will take your advice and to finish the engine and see if it will run.Thanks again.

Frank

[duncan webster 1Participant @duncanwebster1]

Looks like opposed piston engines are making a comeback

https://mart.cummins.com/imagelibrary/data/assetfiles/0058689.pdf

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