[Steam-engine] [SEL] O/T Steam lead lag

James Mackessy jmackess at twcny.rr.com
Fri Oct 5 22:52:16 PDT 2007


Rick;
     Yes, but not that much. When you have her on dead center, the amount
open is the "lead", in general terms it should be about 1/32" per foot of
stroke.
     I have to travel early tomorrow, so I am going to refer you again to
that link for the on-line version of "Steam Engine Principles and Practice",
Division 4, page 84, for the chapter on slide valve setting. In particular,
read article162 on page 113, and article 159 with the chart. This is the
best explanation I have seen anywheres, and the instructions should put you
dead on.

http://books.google.com/books?id=uzoJbLVkUHUC&pg=PA1&dq=Steam+Engine+Principles+and+Practice#PPP20,M1
     I hope you have a fast enough connection to download or view it, if not
it may be worth the trouble to start a download and go watch TV or something
until you get it downloaded. That being said, what is the dimension across
the steam edges of the valve ( top to bottom), and what is the dimension
between the outside edges of the ports (again, top of the top port, to
bottom of the bottom port), and what is the total travel of the rod carrying
the valve? Try to get this to the nearest 32nd ". These dimensions were
altered to suit the design of the engine, and it's possible those of us at a
distance are missing something that would be obvious were we to examine the
engine in person. I think it might help the guys and myself to get a better
picture of the valve situation to have these dimensions.
     I think you've done a great job on this engine, and I think when it's
all "tuned up" it will really make an impression on both the knowledgeable
person and the neophyte as to how quiet and beautiful steam engines in
motion really are. I'm glad to see each and every engine that makes it back
to steam contribute to keeping the hobby alive, but it's especially good to
see a job so well done. Congratulations!
Jim Mackessy
----- Original Message ----- 
From: "Richard Strobel" <Richard_Strobel7 at msn.com>
To: "The SEL email discussion list" <sel at lists.stationary-engine.com>;
"Steam-engine mailing list" <steam-engine at lists.stationary-engine.com>
Sent: Friday, October 05, 2007 11:25 AM
Subject: Re: [Steam-engine] [SEL] O/T Steam lead lag


> Ok Jim and Joe, anyone.  Please click on the below link and see if the
> statement is correct.
>
> I've cross posted to steam list and hopefully will get this off the SEL.
>
> http://home-and-garden.webshots.com/photo/2733541280039077051PEuqSi
>
> Regards,
> RickinMt.
> PS: Joe to answer your questions.  The knocks seem to get weaker with
speed
> increse and we haven't loaded the engine yet.
>
>
> ----- Original Message ----- 
> From: "James Mackessy" <jmackess at twcny.rr.com>
> To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
> Sent: Friday, October 05, 2007 8:34 AM
> Subject: Re: [SEL] O/T Steam main bearing babbitt
>
>
> > Hi Rick;
> >      Joe raises a good point. Does the knock lessen or go away during
> > acceleration? Have you tried loading the engine? The little Leffel
center
> > crank we have will do the valve slapping thing if we close the throttle
> > too
> > fast, and even the big Corliss gets noisy if the throttle is closed too
> > fast
> > and the engine is pushing enough to lift the valves a little. Water
stuck
> > in
> > the cylinder also causes knocking, but from what you've said so far, I
> > doubt
> > that's the problem.
> >      As for the SEL, that's what it's there for! You even got a few of
us
> > lurkers to let go the throttle and type a little!
> > Happy Steaming!
> > Best Regards;
> > Jim M.
> > ----- Original Message ----- 
> > From: "Joe Prindle" <joe_prindle2001 at yahoo.com>
> > To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
> > Sent: Thursday, October 04, 2007 11:08 PM
> > Subject: Re: [SEL] O/T Steam main bearing babbitt
> >
> >
> > > Hi Rick,
> > > Is the knock when you are running the engine, or turning it over by
> > > hand.
> > > Are you running it on air or steam? An engine needs to be timed so
that
> > > it
> > > goes into compression on each end of the stroke, to cushion it as
> > > everything comes to a stop and reverses direction. An engine timed
wrong
> > > will really, really knock.
> > > Another thing that can cause a knock is if the engine is running
without
> > > load and the governor has the steam throttled back so far that the
> > > pressure in the steam chest is so low that when the engine goes into
> > > compression, it lifts the slide valve off the seat, then as the piston
> > > goes back down the cylinder, the valve slams back against its seat.
> > > The bearings, as you describe them, don't sound all that bad. Are you
> > > sure
> > > the knock isn't somewhere else? Steam engines are usually a lot more
> > > forgiving than a gas engine, things have to be really worn to be a
> > > problem.
> > > Do you have a book with the details of setting a slide valve? A slide
> > > valve is a lot harder to set than a poppet or corliss valve since you
> > > can't get everything perfect, just a series of compromises. Ha, sounds
> > > like being married.
> > > Good Luck,
> > > Joe
> > >
> > >
> > >
> > > --- Richard Strobel <Richard_Strobel7 at msn.com> wrote:
> > >
> > > >
> > > >   G'day all;
> > > >     Friend Corky and I are at our wits end trying to find a very
> > > > obnoxious
> > > > knock(s) on both dead centers of our vertical Wachs engine.  This
list
> > > > has
> > > > such great experience with main bearing babbitt, I wanted to ask
here.
> > > >
> > > >   Here's the engine and as you all probably know a "Single Simple"
> > > > fires??
> > > > on both sides of the piston;
> > > >
> > > > http://home-and-garden.webshots.com/photo/2308067910039077051Ronfyj
> > > >
> > > >   Dial indicator on end of cs shows .003 slop.  This may indicate a
> > > > bend
> > > >
> > > > crank or just out of round..I would think this would be tolerable.
> > > >
> > > >   M/B babbitt looks new and shows no sign of ever being
scrapped...one
> > > > can
> > > > still see some ripples.  There is some side to side/axial slop in
both
> > > > main
> > > > bearings.  Yes, this would have showed up on the dial indicator had
we
> > > > loaded one side.
> > > >
> > > >   Now the big question as the crank is going to the crank doc and he
> > > > can
> > > >
> > > > flux weld and machine to any diameter.
> > > >
> > > >   Do I have him flux weld and machine to a diameter so there is no
> > > > side
> > > > to
> > > > side/axial slop and if so, how do I determine what diameter to use?
> > > >
> > > >   Also, the rod inserts show wear on one side towards the solid
> > > > flywheel.
> > > > How do I assure this crank is level?  This has been mentioned
> > > > before..eh,
> > > > Curt.. somewhile back.
> > > >
> > > >   I really don't want to pour new babbitt.
> > > >
> > > >
> > > >   Thanks much...after this endeavor, I'll be headed back to the
4.5hp
> > > > New
> > > > Way in which I'm always looking for a mixer.
> > > >
> > > > Best Regards,
> > > > RickinMt.
> > > >
> > > > _______________________________________________
> > > > SEL mailing list
> > > > SEL at lists.stationary-engine.com
> > > > http://www.stationary-engine.com/mailman/listinfo/sel
> > > >
> > >
> > >
> > > Joe Prindle
> > > Baraboo, WI USA
> > > "All I ask is the chance to prove that money can't make me happy."
Spike
> > Milligan
> > >
> > >
> > >
> > >
> >
____________________________________________________________________________
> > ________
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story.
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