I introduced this engine on the new members thread.
I had some time today and decided to do a bit of cleaning and inspection.
First off, the machinist who built this engine is very good.
The fit and detail, in my novice opinion, is outstanding.
Take a look.
The 5A is a great engine and yours is a very good example.
Very nice looking Stuart there.
I’m getting to know this beautiful work of art.
I put the linkage and Several parts in Evaporust.
Tomorrow I’ll pull everything out, I have some polishing to do on the brass.
This may take a week or two. I’m in no hurry.
What’s amazing to me is the movement feels like it’s on greased bearings
Each revolution is buttery smooth.
A mark of a true artist. IMHO
Built well and taken care of then.
There is one thing that gives me pause for thought in looking at the photo of the steam chest with the missing stud at 4 o'clock. It looks like the jam nuts are cinched down tight on the slide valve flange, and if so, then the slide valve can't "float" over the ports using the steam pressure to seat it against the port face. If in fact the slide valve can "wiggle" and is not held rigid by the jam nuts, then all is as it should be, but if there is no wiggle room available and it is clamped tight as it looks in the photo, then I don't think that is right. It needs to be able to move free, not much, but enough so that it can find its own seat against the port face when under steam pressure.
Firstly you aquire the engine for an absolute song, and now you make us wait to see it running.
What next already.
Parts are sitting in Evaporust. I'll get it back together and apply some air pressure for our viewing pleasure..
Mr. Stoker sir, I see what you mean about the jam nuts. I ran this on air just to see what happens. I oiled it first of course. It runs very smooth and quiet.
Do you think it would be different under steam? meaning the valve play.
I've heard they run different-better under steam. I'm just wondering what motivated the last owner to lock the nuts?
Air and Steam are very different things to be sure, but if it does run on air okay, then the slide valve must be seated in the correct position and maybe okay. The jam nuts are supposed to be jammed against each other, but in such a way as to allow the actual valve the slightest amount of free movement to let it "seek" its seat on the port face. At least that is how I've always understood slide valve theory. Steam admission does change temperature of the metal drastically, and could change a slip fit to an interference fit under some conditions. But if the slide can in fact "float" some, then expansion of a rigid setup should not be a problem.
the valve shoe should 'float' so the steam pressure in the valve chest can press the shoe to the face for a good seal.
If it is securely attached to the valve rod the shoe can lift as the rod moves giving a poor seal to the face.
I just watched a David Richards Youtube video. I think it was #6 or 7. He was talking about this exact thing, adjusting a bit of float in the valve.
I love his channel.
For those of you not familiar with him, he operates a 1925 environment, line shaft, full machine shop on steam.
He has some good stuff on his channel.
A nice restoration thread.
Looking forward to the next chapter. 🤠