Needs over 40lbs. to run?

[bigal2749]

Just got my newest ebay purchase of a treadle or stepple-type steam engine model. I thought when I won it that it was machinst built but now wonder if China or others make repro steam engine.

sorry about different sie pics-got learn how to fix that

2" stroke and 1 1/2 bore with a working governor and a beauty, BUT on air it does not turn over under 40lbs. Starts to get smooth at 60 and have gone to 90 before air hose popped off.

Seems like alot of air needed for such a small engine. Stands 10 1/2 with 7" flywheel.

What's wrong?

adjustments needed
poorly make
needs alot of running-in
learn to live with it

any help and suggestions greatly appreciated

al

 

[Tin Falcon]

Nice looking engine

adjustments needed

I would check the packing back off the nuts see if it will turn easier.

needs alot of running-in

That should help

learn to live with it

Unless the engine is going to sit on a shelf and sit idle no. an engine with 1 1/2 inch bore should not need 40 psi to run. Most of my little wobblers will run on ten or so. 40 psi applying almost 70 pounds of force on the piston it should not take that much something is way to tight.
you may want to to treat this like a pre assembled kit ie take it apart check and debur all parts and reassemble.
Tin

 

[cfellows]

If the engine is hard to turn over by hand, then something is probably out of alignment or too tight.

If there is a lot of sound of escaping air when the engine isn't turning over, then something isn't sealed right.

If there is little or no sound of escaping air and the engine turns over easily by hand, then the problem is probably with valve timing.

And, it could be a any or all of the above :'(

Chuck

 

[bigal2749]

With info from the top two posts I can see that first problem is something is very tight and a dismantle is in order.

Disappointed that this engine requires any work on my part since seller said it runs well on air. But I love the design so much that it will just have to become my next project.

Guys, thanks for your help--I'll be back.

 

[Cedge]

Bigal
I'd be inclined to go easy on the seller. Shipping these engines quite often means having to work the kinks back out of them. It's not unusual to have to loosen things and realign them after several days of bouncing around in various means of transit. I've got one here that needs to be taken down and realigned, for the same reasons.

Steve

 

[bigal2749]

Well no air leaking , so started to loosen the nuts (although I didn't take off the cylinder cover). With most nuts loosened I was happy to see that the engine would then turn over very slowly at 16#. I then tightened the nuts and could tell that some seemed to interfire with the engine speed when tightened.
Not quite sure what I should do next to improve it.

I know it should run better than that but certainly better than 40#

 

[Philjoe5]

BigAl,
What you're experiencing sounds a lot like what happened when I built my first few barstock engines. If I tightened the bearing blocks to the base, the crankshaft had a little binding in it. If I tightened the crosshead guide, the piston movement got sticky. So I backed the screws off to get free movement but not so much as to have noticeably loose attachment. Now I have almost 100 hours on that engine and over time I gradually tightened all the fasteners up. Now it runs on just a few psi quite smoothly.

Cheers,
Phil

 

[compound driver 2]

while its apart check the valve timing and the valve to port face fit. Id be inclined to lap the two to be safe.
A poor seal on the slide valve will make the engine air/steam hungry.
Any engine should turn over free with one finger in the flywheel.