Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

A fine deal you struck there in my opinion Ben.
The 85 is a WAY better engine than the D3!

No steamline, the steamchest is screwed directly onto the boiler.
But it is very easy to ad a control, as the single exhaustport exits opposite to the cylinder rear end.
Not much magic needed, to ad a valve there restricting exhaust.

My head was not going in that direction, but now I see your photo and ideas, I like it! Thanks Jan.
  In my trade we use a ton of air cylinders to move things, we put "flow controls" on the cyl to control speed and prevent violent slam at high pressure. The flow controls meter in one direction, you can meter incoming air OR exhaust air, we Always select meter exhaust air as the cyl will move Much smoother! The piston is seeing full power and we are just slowing it down by making it harder to exhaust. Metering the incoming air can give less smooth motion. A steam cyl is pretty much an air cyl made to take the heat of steam.

Also if I tap a line into the exhaust port, it might be nice to run it down to a tiny bucket or chuff pot to keep condensate from running down boiler.
  Thanks for helping me get my head straightened out Jan.

Jan is correct , a Jensen #85 a much superior plant than the Wilesco #3 , a control valve can (& has) been done to an #85 as shown in the video , Nick now owns this plant.

Remember that one well Bruce, that sure was some cool mods you did there! 

However, the steam control on it appears to be a relatively advanced build, compared to inserting a simple premade exhaust valve, which would demand no more than a bit of soldering?

My thoughts on restricting the exhaust on an osyilator type engine would be the pent up pressure might make it escape from between the cylinder assembly and the steam chest.

My thoughts on restricting the exhaust on an osyilator type engine would be the pent up pressure might make it escape from between the cylinder assembly and the steam chest.

Doesn´t happen on Mamods.
Assume it merely is a matter of having a trunnion spring matching that of your safety valve.

I have a Jensen #35 and have wondered why there is no
exhaust choke.  The Burnac Vulcan, along with the Mamod SE2,
use a 'choke' as a throttle.  The throttle/choke on the
Burnac seems to have a better range than that on the SE2.
The exhaust port exits toward the boiler and the other
side was tapped for the thumbscrew.  Screw in to slow
down and out to speed up.  I added an end-of-post photo
and YouTube video demonstrating it.  Maybe you can mod your
engine and add a choke. You just have cogitate on it a bit.
That's what I tell my wife I'm doing when daydreaming.



Good Luck,
Wayne