Twin spool valve engine timing

[doozer]

I new to machining. So far I have built a wobbler and Tubal Cain's spool valve.
I would like try building a twin cylinder. Haven't found any plans I like. I was going to take a single cylinder design and join them on a single crank.
Is the crank 180 degrees apart for a single action and 90 for a double acting wobbler? Would the exhaust and intake be in the same location on both cylinders?
Would a twin spool valve piston crank be 180 degrees also? I may still use an eccentric for the actual spool valve as you can adjust it.

 

[Blogwitch]

Have a look at this engine, a slightly different design to normal and made completely from barstock.

http://modelengineeringwebsite.com/2-cyl_steam_engine.html

Just click on each of the plans pictures to download.

The reason for a 90degree split is so that the engine will self start from any position.

You could also try to make this one, I designed and made it a few years ago as a training exercise for someone who has made a couple of basic engines to get them to make a more complicated one. Even if you don't make it, just by reading through it should give you a few tips on general machining. Made from bits out of the scrap box.

http://www.machinistblog.com/bogstandards-paddleduck-engine-plans/

Download the self extracting file and just double click on it.


John