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#Post#: 35477--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Stoker Date: February 13, 2021, 2:01 pm
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Next oddity that I noticed on this engine is on the underside of
the cylinder casting, at about 7 o'clock if looking from the
rear, and right up near the packing gland end. It is a rather
large diameter plug with a lot of exposed thread, but must
logically be drilled and tapped into the inner cylinder as well.
As seen here:
[attachimg=1]
What the purpose for this plug could possibly be, totally
escapes me, unless if functions in some way to hold an end plate
into that end of the cylinder bore, which would be a very
strange setup if you ask me?
Certainly having a valve in this position would make some sense,
for draining off condensate from in front of the piston to
prevent hydraulic lock situations from occurring at startup,
until the cylinder gets warm enough to obviate this issue. But
this plug can in no way be used in this manner!
Weird ...
From this point, I started "feeling" the engine to see how it
turned through its full revolutions and instantly found that it
had a noticeable bind/drag when the crank pin was near 12:00
o'clock, continuing around to almost 9:00, and my first though
was ... Oh No, a bent crankshaft.
But the crankshaft on this beast is truly substantial, so I
didn't quite buy into that being the issue just yet.
Thus I started to take down the various motion parts on the
engine, starting with the valve linkage, and immediately found
some rather discouraging evidence of bad/sloppy machining ... as
seen here:
[attachimg=2]
Note that the valve linkage toggle arm bearing shaft hole in
both the fixed mount bracket and the boss of the toggle arm
itself, are noticeably off center in roughly opposite
directions, and the hole in the latter has been wallowed out
oversize to facilitate a fit. Also note that the hole in the
valve cam linkage arm head is also nowhere near centered as any
good machinist would have striven to make it!
Interestingly, this is only true of the holes on the mating
surfaces of the toggle arm and mount bracket, while the axle
bolt head and nut, or opposite ends of those same bores (outside
exposures) are both reasonably well centered.
This all leads me to believe that this engine was bought as a
set of castings, probably pre-machined for the most critical
work, and then finished up by an amateur likely using hand tools
rather than machine tools.
These issues could be remedied with a lot of work, but it is
actually a fairly non-critical situation, such that as long as
these parts are all free to move through the required range of
motion, they should do their job just fine as is. But it does
look shabby, so maybe someday I'll get around to over-boring
more centrally, and then sleeving those bores to obtain a proper
fit.
#Post#: 35517--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: St Paul Steam Date: February 13, 2021, 6:16 pm
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Thanks for the update Daniel , I've had engines that looked
absolutely horrendous but ran beautifully , And engines that
were showroom gorgeous and ran very poorly (if at all). I
haven't a clue what that plug could be for other than it might
be an access port for the connecting rod/piston somehow ?
#Post#: 35519--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Jim Date: February 13, 2021, 6:24 pm
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Daniel that's so off center....I wonder how it could be THAT off
center by accident? Could the builder have meant to drill it
like that for some reason ??? ???
[attachimg=1]
#Post#: 35523--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: St Paul Steam Date: February 13, 2021, 6:36 pm
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[quote author=Jim link=topic=3787.msg35519#msg35519
date=1613262251]
Daniel that's so off center....I wonder how it could be THAT off
center by accident? Could the builder have meant to drill it
like that for some reason ??? ???
[attachimg=1]
[/quote]
Kinda of my thought as well, maybe he was adjusting for other
issue's.
#Post#: 35525--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Stoker Date: February 13, 2021, 6:46 pm
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[quote author=St Paul Steam link=topic=3787.msg35523#msg35523
date=1613262965]
[quote author=Jim link=topic=3787.msg35519#msg35519
date=1613262251]
Daniel that's so off center....I wonder how it could be THAT off
center by accident? Could the builder have meant to drill it
like that for some reason ??? ???
[attachimg=1]
[/quote]
Kinda of my thought as well, maybe he was adjusting for other
issue's.
[/quote]
No real reason why it needed to be like that, as there is plenty
of built in adjustment along the valve linkage train. This is
just reflective of the level of quality of this build I'm
afraid. Actually worse is the hole you see on the left, which is
wallowed out about 15-20% bigger that its bearing shaft
requires, is also well off center, and in the opposite direction
of the mating shaft hole (the middle one) which is well off
center to the lower left. Oddly perhaps, both of these latter
two holes are very nicely sized and centered at the other end of
their respective bores, so that is obviously (maybe) where he
started drilling from?!?! The off center condition of these
bores at their mating interface results in the two boss faces
being offset from each other, which in the long term would wear
poorly, but in the short term makes for an offset that looks
poorly.
#Post#: 35527--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Jim Date: February 13, 2021, 6:55 pm
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Very roughly approximately this is where it would have been
centre marked for drilling -
[attachimg=1]
#Post#: 35528--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Jim Date: February 13, 2021, 6:56 pm
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I think you will have some trials and tribulations getting this
to where you want it, but the end effort will be rewarded with a
fantastic engine.
#Post#: 35529--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Stoker Date: February 13, 2021, 7:13 pm
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I'd guess he just put a drill bit up against the piece and let
it walk to wherever it started actually cutting, which is where
the hole is now!
Trust me ..... there is much more like this to come. 8<O
#Post#: 35532--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: St Paul Steam Date: February 13, 2021, 7:55 pm
---------------------------------------------------------
[quote author=Stoker link=topic=3787.msg35529#msg35529
date=1613265229]
I'd guess he just put a drill bit up against the piece and let
it walk to wherever it started actually cutting, which is where
the hole is now!
Trust me ..... there is much more like this to come. 8<O
[/quote]
Oh oh...
#Post#: 35604--------------------------------------------------
Re: Bargain 1/2 hp G. Sipp .... the good, the bad & the ugly
By: Stoker Date: February 14, 2021, 4:56 pm
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So now to continue this tale of woe (sorry Tommy), I'll follow
the valve linkage back into the steam chest and see what there
is to see in that locale.
I should add here that with the steam valve linkage fully
disconnected from the eccentric, and free from the crankshaft
and flywheel, the bind/drag/stiff spot in the rotation is still
there, so its source must be elsewhere, which is good
information even if not immediately helpful to resolution.
It was with some trepidation that I removed the six nuts from
the steam chest studs, as I really didn't know what I would
find, having had the air I tried to run the engine on just blow
straight through and out the exhaust, suggesting that the
D-valve was not seating. Certainly relieved to find that things
actually looked reasonably okay in the steam chest. Did note
that the top center stud was loose, so I'll be fixing that one
with a bit of shim material to tighten it back up. Both the
D-valve and port face seem acceptably flat, and only a bit
scored, so some judicious lapping should be all they need, but
only after a little file work to dress the actual steam ports,
which though not too bad, could certainly use a bit of squaring
up and deburring.
[attachimg=1]
[attachimg=2]
I must confess to being very glad to see some actual liquid oil
upon opening the steam chest, as up to this point all the
lubricant that I'd come across was either gummy or solid
varnish, so seeing some that could actually perform the proper
function, especially in such a critical place, was encouraging
and even a bit reassuring. At the same time I'll have to say
that upon opening up the valve linkage packing gland I found no
solid substance at all, where there should be a few winds of
graphite yarn or a Teflon O-ring or something of the kind, all I
did find was the most sticky, jet black, get on everything and
impossible to wash off, tar like compound. Alcohol doesn't touch
it, Acetone does little better, Gasoline sort of works it with a
lot of mechanical action and any soap short of Lava is hopeless!
Even GoJo had a tough time with it!!!
A bit of a mystery, this engine has plenty of them, is the two
holes in the top flange of the steam chest cover that are on
either side of the center stud. They do also appear in the
cylinder casting, so I suspect that they were used with pins to
properly locate the steam chest cover on the side of the
cylinder casting for properly locating and drilling the steam
chest studs. Can't really think what other purpose they would
have?
One other issue noted was that the end faces of ears and channel
that surround the valve linkage rod have a slight taper that
might be why the D-valve wouldn't seat for me, as the jam nuts
on either side of the D-valve to locate and traverse it may be
just a little too close together such that if the D-valve falls
away from the port face it could get wedged between the nuts
instead of "floating" between them, so perhaps I'll chuck that
up in my mill and square those two faces to be parallel, even
though they are only tapering by a bit more than .006".
[attachimg=3]
[attachimg=4]
I'm glad to report that although still showing evidence of a
poor build, at least the steam chest seems to be readily
redeemable, and not requiring any too much work.
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