timing stwarts popcorn engine

[jonesie]

i have build stwarts popcorn engine, as my first steam or air engine.i have build 2 ic engines and have them running.i do not know how to time it, so if someone coluld help me out with a pic or easy explanition i would appreciate it.i think in some explanitions tdc is when the piston is away from the flywheel, but i am not sure how the timing should be after that, as to the excentric and the valve in the steam chamber chest . i am sure it is simple just never done one. thanks in advance jonesie

 

[rmw]

I built one double size using Brian Rupnow's inch plans. After adjusting the valve to cover (or expose) both ports identically, I set my eccentric 90 degrees ahead of the crankshaft in the direction I wanted the engine to run. This seems to work pretty well on most slide valve steam engines I have built, at least to get you started.
HTH, Greg

 

[jonesie]

thanks greg i will give it a try. jonesie

 

[SBWHART]

Hi Jonesie

The eccentric is 90 deg infront of to top dead centre.

The first thing you have to do is centralise the slide valve travel:- at top dead centre set the eccentric so the front port is just cracking open, wind it to back dead centre and note where the valve is, screw the valve stem in or out of the square cross bar in the slide valve,to equalise the travel, wind to top dead centre and adjust the eccentric so the port is cracking open again, wind to back dead centre and the adjust the valve stem to centralise, you may have to do this a few times what your'e after is for the port to be just cracking open at Forward and back Dead centres.

Hope this make sence

Stew

PS Don't forget thr video :big: :big: :big: :big:

Stew

 

[jonesie]

stew another question for you, how much air pressure did it take to get it running while you got it broke in. thanks again hope to get it timed and running soon been real busy. jonesie

 

[SBWHART]

Hi Jenesie

With mine it took about 20 psi it now runs at about 5 psi.

It took me some time to get in running any tight spot will cause problem you just have to chase them out.

Good luck

Stew

 

[jonesie]

thanks stew ,running soon i hope. jonesie