Inspired build of the Benz 1886 Engine

[Rdean33422]

TonyM your question got me to thinking that I have the perfect engine to compare different compression ratios in the same engine.
I used an online calculator and this shows my original design with the piston at TDC and being 0.500 below the end of the cylinder.

I then removed the piston and rod and shortened the rod by 0.225 so now I have a gap of 0.725 from the top of the piston to the end of the cylinder.
This is the result.

I was hoping to see a slower idle speed but I did not. The engine was harder to start and was more touchy to carb settings.
I have since reverted back to the original settings.

Thanks for looking
Ray

 

[TonyM]

Thanks Ray. I was thinking your compression ration would be around there. Your engine runs much better than the TS kit which has a very low compression ratio of just over 2:1

 

[Jasonb]

As I mentioned early on on the TS engine Torsten made the crank throw less than the original would scale to so you only get 40mm stroke not 50mm for the same scaled bore

 

[TonyM]

That's worth knowing Jason. I may remake a new yoke and new crank in future. For now, having basically machined everything before I discovered the compression ratio was a problem I reduced the free space at the head to give better compression. I have shelved the engine just now as I am working on the Gardner.