Buretting a very small volume.
Tim Wescott
more than a fraction of a CC of volume.
Anyone know how to do this when the volume to be measured isn't that
much larger than the volume in a drop of light oil? I'm thinking maybe
a small syringe, complete with needle, filled with mineral spirits,
really really light oil, or rubbing alcohol.
But I'm open to suggestions.
--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
Ecnerwal
Tim Wescott <t...@seemywebsite.now> wrote:
> I want to CC a few Cox 049 heads, but none of them are going to contain
> more than a fraction of a CC of volume.
>
> Anyone know how to do this when the volume to be measured isn't that
> much larger than the volume in a drop of light oil? I'm thinking maybe
> a small syringe, complete with needle, filled with mineral spirits,
> really really light oil, or rubbing alcohol.
>
> But I'm open to suggestions.
Probably cost too much, but the biology/microbiology types have
"micropipettes" (the tip that holds the fluid is cheap, the thing that
controls how many microliters are dispensed is not, I think) - I've seen
them, never bought one.
Without much shopping effort, 2-20 uL for $99 (but they don't seem to
have tips to fit that one?)
http://www.enasco.com/product/SB39111M
Fixed volume 5 or 10uL is only $20, 250 tips for 11.30 from the same
place, but you should no doubt shop more before buying, if buying.
--
Cats, coffee, chocolate...vices to live by
Ed Huntress
"Tim Wescott" <t...@seemywebsite.now> wrote in message
news:_NGdnemny9vuSgjW...@web-ster.com...
As a diabetic who uses plastic syringes for many things, I think you'll do
best with rubbing alcohol. The rubbery plunger material doesn't stand up to
petroleum oils for very long (maybe hours -- that's how I lube the bearings
in my furnace blower fan, using South Bend spindle oil), and, if you get the
98% isopropyl that they probably have behind the pharmacy counter, you won't
find many common materials that have lower surface tension. You want as
little water in it as you can get for lowest surface tension; it appears to
be related by a rule of mixtures. Water and alcohol don't cause the plunger
to stick until they've been in the syringe for a few days. With oil, leaving
it in the syringe will make the plunger stick and it will be almost
impossible to dispense smoothly after a few hours.
Straight isopropyl has a surface tension of around 22 mN/m; water is 75;
gasoline is around 20. So mineral spirits probably is in the same
neighborhood as gasoline, and probably, again, offers no advantage over the
alcohol.
Good luck. CC-ing an .049 engine has to be pretty tedious. I had enough
hassle doing it with a 1300 cc Alfa Romeo.
--
Ed Huntress
Ed Huntress
"Tim Wescott" <t...@seemywebsite.now> wrote in message
news:_NGdnemny9vuSgjW...@web-ster.com...
BTW, I'm curious about why you'd CC a single-cylinder engine, unless you're
experimenting with compression. Or are you using them in a multi-cylinder
configuration?
--
Ed Huntress
Tim Wescott
I'm going to fabricate some heads, and experiment with compression and
combustion chamber shape (within the limits imposed by using a glow
plug, which is relatively huge compared to the 049's cylinder diameter).
T.Alan Kraus
> I want to CC a few Cox 049 heads, but none of them are going to contain
> more than a fraction of a CC of volume.
>
> Anyone know how to do this when the volume to be measured isn't that
> much larger than the volume in a drop of light oil? I'm thinking maybe
> a small syringe, complete with needle, filled with mineral spirits,
> really really light oil, or rubbing alcohol.
>
> But I'm open to suggestions.
>
it with a apothecary or reloading scale?
Jim Wilkins
> I want to CC a few Cox 049 heads, but none of them are going to contain
> more than a fraction of a CC of volume.
> Tim Wescott
I'd try a brazing rod piston and a cylinder of telescoping brass
tubing, with a blob of RTV to seal the piston. Neck down the end of
the piston so the RTV will stay in place while you suck the fluid into
the cylinder. Determine the volume from the length the piston extends
out the back.
How will you know that the compressed volume is filled accurately
without the glow plug in place?
If it's worth the effort you might turn a dummy glow plug with a hole
through the middle. Then among other ways you could compress a drop of
expanding foam to make an accurate chamber casting. If you use Wood's
metal you could weigh it.
jsw
Mike Henry
"Tim Wescott" <t...@seemywebsite.now> wrote in message
news:_NGdnemny9vuSgjW...@web-ster.com...
Tim Wescott
I'm going to clamp the head to a piece of acrylic sheet with an itty
bitty hole in it, and measure the volume of the cavity complete with
glow plug. This is absolutely necessary with the Cox heads, because
they _are_ the glow plug, and just about absolutely necessary with a
glow plug adapter head, because with a displacement that small the
volume of the cavity in the glow plug cannot be ignored.
I expect that brand and model of glow plug will be important, and hope
that manufacturing differences between different glow plugs of the same
make & model won't be too severe.
Karl Townsend
"Mike Henry" <Michae...@msn.com> wrote in message
news:hn5n1...@news4.newsguy.com...
> Insulin syringe? They run < $20 for a box of 100.
Free from me, if going to a good use.
Karl
axolotl
> I want to CC a few Cox 049 heads, but none of them are going to contain
> more than a fraction of a CC of volume.
>
> Anyone know how to do this when the volume to be measured isn't that
> much larger than the volume in a drop of light oil? I'm thinking maybe a
> small syringe, complete with needle, filled with mineral spirits, really
> really light oil, or rubbing alcohol.
>
> But I'm open to suggestions.
>
Micropipettors use disposable glass tubing as the cylinder, with a
stainless wire (.00225" on the ones in front of me) on the micropipettor
acting as the piston. The one with the 3" long piston (wire) can be set
to pull up 10-50 ul.
How much volume do you need to measure?
Kevin Gallimore
Tim Wescott
Good question -- probably somewhere between 0.1 and 0.5 ml -- which
sounds pretty big compared to your micropipette.
I'm going to try doing it by weight -- weigh it empty, fill it any old
way, weigh it full, do some math...
Steve Lusardi
Steve
"Tim Wescott" <t...@seemywebsite.now> wrote in message news:_NGdnemny9vuSgjW...@web-ster.com...
Pete Snell
> I want to CC a few Cox 049 heads, but none of them are going to contain
> more than a fraction of a CC of volume.
>
> Anyone know how to do this when the volume to be measured isn't that
> much larger than the volume in a drop of light oil? I'm thinking maybe
> a small syringe, complete with needle, filled with mineral spirits,
> really really light oil, or rubbing alcohol.
>
> But I'm open to suggestions.
>
I've done this many times with larger engines, but nothing that
small. I think the suggestion to carefully weigh the head empty and full
with a good scale is a good one. Alternatively, maybe you could 'cast'
something into the chamber, cut it off flush, pull out the plug and
weigh it? Jello? Everybody likes Jello!
As another suggestion, can you fill the combustion chamber with the
engine assembled and with the piston at TDC? This is the standard way of
doing it with a smaller engine, and it reduces the number of
measurements and calculations needed to find the true combustion chamber
volume, which results in better accuracy when calculating compression
ratios.
Pete
--
Pete Snell
Department of Physics
Royal Military College
Kingston, Ontario,
Canada
-----------------------------------------------------------------------
For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled.
Richard Feynman.(1918-1988)
Personal Observations on the Reliability of the (Space) Shuttle.
Tim Wescott
> Tim Wescott wrote:
>> I want to CC a few Cox 049 heads, but none of them are going to
>> contain more than a fraction of a CC of volume.
>>
>> Anyone know how to do this when the volume to be measured isn't that
>> much larger than the volume in a drop of light oil? I'm thinking
>> maybe a small syringe, complete with needle, filled with mineral
>> spirits, really really light oil, or rubbing alcohol.
>>
>> But I'm open to suggestions.
>>
>
> I've done this many times with larger engines, but nothing that
> small. I think the suggestion to carefully weigh the head empty and full
> with a good scale is a good one. Alternatively, maybe you could 'cast'
> something into the chamber, cut it off flush, pull out the plug and
> weigh it? Jello? Everybody likes Jello!
>
> As another suggestion, can you fill the combustion chamber with the
> engine assembled and with the piston at TDC? This is the standard way of
> doing it with a smaller engine, and it reduces the number of
> measurements and calculations needed to find the true combustion chamber
> volume, which results in better accuracy when calculating compression
> ratios.
Good suggestions, but --
It's a two-stroke glow engine and the stock heads have a built-in glow
element, rather than a separate glow plug.
So casting with jello is out, because it'll stick in the element,
there's no way to access the top of the cylinder without drilling holes
in a stock head (no way!) etc., etc. That's me. Tim The Naysayer.
At this point I'm most interested in duplicating the volume of the
original head; slight errors in the absolute compression ratio that I
calculate as long as I get the _actual_ compression ratio close enough
for things to work.
axolotl
> At this point I'm most interested in duplicating the volume of the
> original head; slight errors in the absolute compression ratio that I
> calculate as long as I get the _actual_ compression ratio close enough
> for things to work.
>
If what you want is compression, why not build a manometer and measure that?
Kevin Gallimore
Gunner Asch
wrote:
You could always cast a slug in the head using cerocast and then melt it
back out. Wont hurt the glow plugs.
Measure the CCs or MMs of the cerocast
Gunner
"First Law of Leftist Debate
The more you present a leftist with factual evidence
that is counter to his preconceived world view and the
more difficult it becomes for him to refute it without
losing face the chance of him calling you a racist, bigot,
homophobe approaches infinity.
This is despite the thread you are in having not mentioned
race or sexual preference in any way that is relevant to
the subject." Grey Ghost
whit3rd
> axolotl wrote:
> > On 3/9/2010 12:06 AM, Tim Wescott wrote:
> >> I want to CC a few Cox 049 heads, but none of them are going to contain
> >> more than a fraction of a CC of volume.
> I'm going to try doing it by weight -- weigh it empty, fill it any old
> way, weigh it full, do some math...
You can replace the head gasket with an acrylic sheet, bore it
accurately, and fill through a transverse hole in the sheet. Several
fill-from-bottle/squirt-into-hole cycles with a small (hypodermic)
syringe will get you to a filled cavity. If the syringe is well-
enough
calibrated, that's enough.
The sheet will be thicker than the real gasket, but you can measure
and correct for that. The transverse hole has to be UP, of course,
during fill, to let air escape.
Tim Wescott
Not on a Cox 049 you can't! The head screws on, into a cavity about 1/8
inch deep.
I'll be clamping the head to a bit of acrylic sheet, with a small hole
drilled into it.
Martin H. Eastburn
Hypodermic needle - you can - perhaps go to the VET and get some large needle
and a metal or glass (ok) barrel.
I have machine Hypodermic needle - flat end - 6". Brass three hole finger control.
What is CC...
Martin
Tim Wescott
(top posting fixed)
> Tim Wescott wrote:
>> I want to CC a few Cox 049 heads, but none of them are going to
>> contain more than a fraction of a CC of volume.
>>
>> Anyone know how to do this when the volume to be measured isn't that
>> much larger than the volume in a drop of light oil? I'm thinking
>> maybe a small syringe, complete with needle, filled with mineral
>> spirits, really really light oil, or rubbing alcohol.
>>
>> But I'm open to suggestions.
>>
>
> Hypodermic needle - you can - perhaps go to the VET and get some large
> needle
> and a metal or glass (ok) barrel.
> I have machine Hypodermic needle - flat end - 6". Brass three hole
> finger control.
>
> What is CC...
To CC a head is to measure its volume. This is usually done when you're
building a performance engine to ensure that each cylinder delivers
equal power. In my case I'll be doing it to make sure that the
replacement heads I'm planning on building have a known volume, so that
I'll be in control of the compression ratio.
Existential Angst
news:_NGdnemny9vuSgjW...@web-ster.com...
>more than a fraction of a CC of volume.
>
> Anyone know how to do this when the volume to be measured isn't that much
> larger than the volume in a drop of light oil? I'm thinking maybe a small
> syringe, complete with needle, filled with mineral spirits, really really
> light oil, or rubbing alcohol.
>
> But I'm open to suggestions.
Someone mentioned micropipettes. They come in a variety of ranges, from 1
uL to 1cc. Very accurate, very reproducible. Not very cheap, tho.
Another way might be to take the engine apart, and stuff the various
cavities with a clay or sumpn of known density -- which you can determine
very accurately yourself without super-precision equipment.
Then you can weigh the clay on a milligram scale.
OR, then form the clay into an accurate rectangle (not difficult), and
measure with calipers. No need to weigh, no equipment nec other than
calipers and some small machinist squares or the equiv.
If you have access to a university, these scales, pipettes are plentiful in
their bio/biochem labs.
Another way would be to submerge the engine with and without fluid access to
the chamber, and then just subtract.
You need an accurate graduated cylinder, tho, and perhaps in odd geometries.
A slam, uh, dunk if you have the right flasks, proly impractical without.
--
EA
RogerN
"Tim Wescott" <t...@seemywebsite.now> wrote in message
news:_NGdnemny9vuSgjW...@web-ster.com...
My insulin syringes measure 1CC with .02CC graduations.
RogerN
Tim Wescott
Hmm. I had convinced myself that weighing would be the way to go, but
now I dunno.
I think I'll wait until it's been a few days since I've showered or
shaved, stay up all night, drink five cups of coffee, then go into my
local pharmacy and ask for some.
Wild_Bill
looks like a dial indicator about 2.5" diameter, indicating in ul
microliters.
There are likely other brands, but the particular model I'm thinking of is a
fairly simple unit, no electronics, calibrating, etc.
It has it's own chamber, so there isn't any need to calculate volume or rely
on barrel markings. I don't know the maximim volume of the chamber, but I
think it's at least several CCs and maybe as large as 10cc.
The operation is fairly simple. The chamber is filled with some arbitrary
amount of liquid and the dial indicates the amount of liquid that's
dispensed as the knob is turned.
I didn't find a picture of one to show what they look like, but there is a
dial in the center, and what looks like a micrometer thimble on the right
side.
The size is about 4x12x5" so it's not a big device.
There is a vibrating-armature-type motor in the unit for mixing, which you
won't need to use, but I mention it since the presence of the AC power cord
might be confusing.
--
WB
.........
"Tim Wescott" <t...@seemywebsite.now> wrote in message
news:_NGdnemny9vuSgjW...@web-ster.com...
Steve W.
The way we used to do this was to use plain old candle wax. Get the wax
warm, fill the entire head. Then shave the surface with a straightedge.
Now melt out the wax using a heat gun. The tiny amount left behind isn't
enough to matter.
Bore is .406, Stroke is .386, Displacement .0499 cid.
The heads depend on which head and which cylinder you have. There are 5
different heads and 4 different designs on the cylinders.
Then the cylinders themselves actually have different bores and grinds
depending on which year and model spec .049 you have.
Then add in at least 5 aftermarket heads. And there is also a true
diesel conversion.
The "normal" compression ratio is around 6.5:1 when using factory mixed
fuel.
--
Steve W.
Bill McKee
"Steve W." <csr...@NOTyahoo.com> wrote in message
news:hn7d25$3fs$1...@speranza.aioe.org...
After I left home and mom remarried, my brother moved in to the house with
his 2 kids. Only engines I ever found after that were my .049 outboard and
my .049 diesel. still beautiful pieces of metal work.
Terry
wrote:
>
>Hmm. I had convinced myself that weighing would be the way to go, but
>now I dunno.
For accuracy, you're right the first time. Weighing IS the way to
go---if you have a liquid of accurately known density. Water isn't
terribly dense but its density is very accurately known. A scale
that's good to 0.01 g can be purchased for about $25---that
corresponds to 0.01 cc of water. Or your nearby chemistry department
should have a scale that will weigh down to a milligram (0.001 cc) or
a tenth milligram.
If I understand the nature of the problem correctly: Allow engine and
distilled water to sit at room temp for at least an hour. Measure
temp. Handle engine only with tongs. Weigh engine. Fill the space
desired with water. Re-weigh engine and water. Look up density of
water at that temp. Push buttons on calculator.
Best---Terry
Mark Rand
Umm...
My current insulin syringes are .3CC with .01CC graduation, readable to half
that. 30SWGx8mm needle.
Over here, pharmacies won't sell syringes without a prescription anymore. I
guess they'd rather that the druggies don't try to control the risk of
infection...
Mark Rand
RTFM
Gerald Miller
I buy 60 ml. syringes from TSC (they do have smaller sizes) and use
them to measure concentrated laundry liquid because now that the
manufacturers have gone to 2X and 3X concentration, I don't want to
slop in even a little bit extra. Brilliant strategy on their part to
look good and increase waste of their product.
To my way of thinking, the ultimate goal of advertising is to come up
with the biggest lie that the public will thank you for.
Gerry :-)}
London, Canada