Too much exhaust steam.

[Corrado]

Hi guys,
Built my first slide valve engine...it's a single cylinder with 5/8 bore & 3/4 inch stroke. Was a big learning process for me.....however it runs weakly & has way too much exhaust steam. It seems the steam is by-passing the cylinder.
How can I fix this problem?
Cheers.....Corrado.

 

[gbritnell]

It sound like your valve is not sealing properly. If you pull the cover off the steam box and then just secure the box with the studs or bolts then move the valve on it's stem and see if it sits flat or rotates around the stem.
gbritnell

 

[velocette]

Hi As already been advised that valve seating is critical also the valve timing in relationship with Top Dead Centre and the width of the ports in relationship with the slide valve faces.

Eric

 

[kvom]

Steam pressure should press the valve flat against the cylinder port face. First thing to do is make sure the valve and port faces are flat and smooth. The valve rod should not prevent the valve from sealing.

Also check the dimensions of the valve pocket vs. the port spacing. Ensure that the cylinder steam ports fully open on each end.

 

[Corrado]

Thanks for your good advice gentlemen....I played around with the slide valve & hey presto...magic happened. The difference in performance is outstanding.
I love this forum!
Corrado.

 

[Corrado]

Now...that's what I'm talking about!

 

[Cogsy]

Looks good. Got video?