O/T 2 CYCLE AIR COOL mtrs.
five...@webtv.net
that never get exposed to the mix ?"
And does the 2-cycle oil have an additive that aids the lubrication
factor?
just curious
ps - weedeaters, chainsaws, lawnmowers, blowers, and the like.
mho
vƒe
>double dog dare you, sound familiar?
>to reduce your driving by - 10%.
John S.
There are very few parts, but it's all here:
http://en.wikipedia.org/wiki/2_cycle_engine
Steve W.
mix to them. That is why the shaft seals on them are so important. Lube
wise there is the crank bearings, rod bearing and wrist pin. They are
all usually roller bearings and all are lubed by the premix. Rings get
lubed the same way as any other engine. What's left?
--
Steve W.
Life is not like a box of chocolates
it's more like a jar of jalapenos-
what you do today could burn your ass tomorrow!
<five...@webtv.net> wrote in message
news:10976-444...@storefull-3317.bay.webtv.net...
How do 2 cycle engines with only a fuel/oil mix lubricate internal parts
that never get exposed to the mix ?"
And does the 2-cycle oil have an additive that aids the lubrication
factor?
just curious
ps - weedeaters, chainsaws, lawnmowers, blowers, and the like.
mho
vfe
>double dog dare you, sound familiar?
>to reduce your driving by - 10%.
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Steve
> How do 2 cycle engines with only a fuel/oil mix lubricate internal parts
> that never get exposed to the mix ?"
I can't think of an internal part that DOESN'T get exposed to the mix,
so I don't understand your question.
>
> And does the 2-cycle oil have an additive that aids the lubrication
> factor?
Uhhh. yeah. Its called "oil." The additive package for 2-cycle oil is
more concerned with using additives that reduce smoking and carbon deposits.
no_name
> How do 2 cycle engines with only a fuel/oil mix lubricate internal parts
> that never get exposed to the mix ?"
>
> And does the 2-cycle oil have an additive that aids the lubrication
> factor?
>
> just curious
>
> ps - weedeaters, chainsaws, lawnmowers, blowers, and the like.
>
Chainsaws have a separate place where you put in lubricating oil.
five...@webtv.net
====
>Chainsaws have a separate place where >you put in lubricating oil.
is this for the chain?
======
Thought I would toss this in for those who are concerned, a mechanic
told me one
time that these air-cooled 2-cycle engines operate better when they are
run at high R P M S occasionally during each use. Helps keep the ports
open. Makes sense.
mho
vƒe
John S.
Chain oil.
patrick mitchel
stihl- it uses premix. How the heck they lube the cam/rockers/ whatever they
have for valve operation? The stihl fs110... Pat
John S.
Good question, why don't you look into it and report back.
corning_d3
http://www.stihl.ca/4mix/english/stihl4mix/default1.htm#
--
corning_d3
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John S.
Interesting link on the 4-Mix, thanks for posting it. Two questions
come to mind.
1. I wonder if carbon build-up will be an issue on a valved motor that
burns oil as a part of the combustion cycle.
2. Are seals a long term potential problem since the crankcase and and
overhead areas have to be well sealed to permit alternating pressure
and vacuum.
Steve
For the CHAIN, not for the engine.
Steve
> corning_d3 wrote:
>
>>http://www.stihl.ca/4mix/english/stihl4mix/default1.htm#
>>
>>
My reaction is, "That's the STUPIDEST thing I've ever seen!"
The WHOLE POINT of switching to 4-strokes in these applications is to
reduce emissions. Sure, a 4-stroke burning premix is marginally cleaner
than a 2-stroke, but its still burning premix and emitting tons of HC
and carbon from the oil. It defeats 90% of the purpose.
John S.
Yeah, I'm not sure which emissions standards were omitted in getting
this engine certified for CARB but they must have dropped hydrocarbon.
Also, to my uneducated eye it doesn't seem like an inherently efficient
design since the fuel/oil mix has to be pumped around and through so
many orofices for proper lubrication. I wonder how the fuel
consumption and power output is compared to a conventional 4 stroke
engine of comparable size.
I suspect that carboned-up valves and leaky seals will be long-term
problems with this design.
Still it is an improvement over the outdated 2 cycle engine.
Scott Dorsey
I would think the advantage of a 4-stroke engine is that the power
curve is a little better... you have a wider range of engine speeds
at which you can get good power.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Steve
> Steve wrote:
>
>>John S. wrote:
>>
>>
>>>corning_d3 wrote:
>>>
>>>
>>>>http://www.stihl.ca/4mix/english/stihl4mix/default1.htm#
>>>>
>>>>
>>
>>My reaction is, "That's the STUPIDEST thing I've ever seen!"
>>
>>The WHOLE POINT of switching to 4-strokes in these applications is to
>>reduce emissions. Sure, a 4-stroke burning premix is marginally cleaner
>>than a 2-stroke, but its still burning premix and emitting tons of HC
>>and carbon from the oil. It defeats 90% of the purpose.
>
>
> Yeah, I'm not sure which emissions standards were omitted in getting
> this engine certified for CARB but they must have dropped hydrocarbon.
> Also, to my uneducated eye it doesn't seem like an inherently efficient
> design since the fuel/oil mix has to be pumped around and through so
> many orofices for proper lubrication. I wonder how the fuel
> consumption and power output is compared to a conventional 4 stroke
> engine of comparable size.
>
I could see it having comparable power in spite of all the monkey
business- its the emissions that seem silly.
> I suspect that carboned-up valves and leaky seals will be long-term
> problems with this design.
>
> Still it is an improvement over the outdated 2 cycle engine.
In what way?!? Its more complicated, heavier, and still emits just as
much crud. The only real problem with the 2-stroke is emissions- they're
very light and more powerful per pound of weight than a 4-stroke in
those small sizes.
John S.
If it emits less emissions including partially burnt fuel than a 2
stroke then it is an improvement. How much of an improvement I can't
determine. Perhaps you've found comparative data, because I haven't.
The increased number of parts isn't an issue per se because the basic
design of the 4 stroke motor is well established. Using the piston to
pump of fuel/air mixture up, down and through numerous orifices for
lubrication makes me think a fair amount of energy is used in the
process however.
Two strokes put out a good deal of power for their physical size, but
they use a good amount of fuel in the process and are not very
efficient at converting fuel to power - some fuel goes partly or
completely uncombusted. They are a cheap to manufacture compact power
source that had until recently could claim to be the only design that
could be run in any position.
An honest comparison of comparably sized 2 stroke, 4 mix and 4 stroke
motors is what is needed. All I found were glittering and general
comments in the online Pop Science and Pop Mechanics.
corning_d3
It does seem silly to pump fuel/oil in and out of the crankcase, but
isn't this almost like a PCV system on a normal 4-cycle? The PCV
system removes vapors of unburnt fuel that slips past the rings, and
other bad stuff. Plus using valves instead of reeds and ports allows
you to control emmisions better. I think this is where it's more
efficient than a 2-cycle..
Steve
>
> Two strokes put out a good deal of power for their physical size, but
> they use a good amount of fuel in the process and are not very
> efficient at converting fuel to power - some fuel goes partly or
> completely uncombusted. They are a cheap to manufacture compact power
> source that had until recently could claim to be the only design that
> could be run in any position.
If its something I've got to carry for a couple of hours like a
weed-whacker/brush trimmer, then WEIGHT is a huge deal. Its really hard
for a 4-stroke to win on weight. And also, I don't know about other
people but I'm not willing to spend much maintenance effort on a little
convenience like a weed-whacker. My mower is a necessity so I'll
change the oil and filters and take care of it like I do my car. My
weed-whacker and leaf blower are luxuries- and if I've got to dick
around with it, it goes out the door in a hurry. Two-strokes are just
about zero-maintenance (at least the GOOD ones- I've had some that were
terrible... note the PAST TENSE there! :-) I don't think I've even
changed the spark plug in my Echo weed-whacker in about 4 years. Just
add fuel mix and go.
> An honest comparison of comparably sized 2 stroke, 4 mix and 4 stroke
> motors is what is needed. All I found were glittering and general
> comments in the online Pop Science and Pop Mechanics.
>
I agree 100%. That's nowhere to be found- its just my gut feeling that
the "4-mix" is the worst of both worlds. One other benefit it might have
is that Stihl sells a lot to big lawn-care companies, probably more than
they do t to individuals. The 4-mix would fit nicely in with a buch of
2-strokes in that it doesn't require a different fuel than the other
weed-whackers. Switching to 4-strokes from 2-strokes might mean that a
lot of employees mistakenly put mix fuel in the 4-strokes- not fatal
probably, but it would sure cause starting and plug-fouling problems.
But the reverse- putting straight gasoline in the 2-strokes- WOULD be
fatal to them.
John S.
Good points.