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Tannin
Can't remember
Joined: 06 Aug 2006 Location: Huon Valley Tasmania
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Post subject: Why? | |
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Yesterday I spent the afternoon servicing the machinery.
I changed the oil in the tractor, cleaned the air filter, washed out the fuel filter, checked the transmission oil, checked the hydraulic lines over for leaks, and greased sundry bearings. Oh, and replaced the oil filter.
Then I changed the oil in the ride-on mower, cleaned the air filter, greased sundry bearings, and fitted a new oil filter.
Then I changed the oil in the push mower, thought about adjusting the throttle cable but decided it was close enough for now. B had already fitted new blades a couple of days ago. No oil filter, didn't replace it.
Finally I changed the oil in the mulcher - a largish machine with a 9HP Briggs and Stratton motor and decided nothing else needed doing just yet. Again, no oil filter to replace.
So if a car engine needs an oil filter and a 24HP tractor engine needs an oil filter and a 15HP mower engine needs an oil filter, why doesn't the mulcher have one, or the small mower? In short, why don't small engines have oil filters?
(Feel free to add your own small mysteries of life, especially the ones that you can't just look up on Google!) _________________ �Let's eat Grandma.� Commas save lives! |
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stui magpie
Prepare for the worst, hope for the best.
Joined: 03 May 2005 Location: In flagrante delicto
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Wild shot, were the small engines 2 stroke? _________________ Every dead body on Mt Everest was once a highly motivated person, so maybe just calm the **** down. |
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Tannin
Can't remember
Joined: 06 Aug 2006 Location: Huon Valley Tasmania
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Nope, all four strokes. Most of the other engines are two-strokes (chain saws, brush cutter). There is a four-stroke fire pump, it doesn't have an oil filter either. That's just back from being serviced by a pump man, so I didn't need to touch that one.
As a matter of interest, one of the chain saws is actually a four-stroke which acts like a two-stroke. It runs the usual two-stroke fuel/oil mix and sounds odd for a chain saw, but for all practical purposes you can treat it as a two-stroke. Stihl have a blub about them here: http://www.stihl.com.au/4-mix-engine-lightweight-and-with-good-lugging-power.aspx _________________ �Let's eat Grandma.� Commas save lives! |
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luvdids
Joined: 22 Mar 2008 Location: work
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I have machinery that needs servicing.
Oh wait.
This isn't the Bored Board. |
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David
to wish impossible things
Joined: 27 Jul 2003 Location: the edge of the deep green sea
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You know that thing I went to on Friday night? Apparently there's another one in three months.
Er... right. Tannin. Mowers. Please carry on! _________________ "Every time we witness an injustice and do not act, we train our character to be passive in its presence." – Julian Assange |
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3.14159
Joined: 12 Sep 2009
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Post subject: Re: Why? | |
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Tannin wrote: | Yesterday I spent the afternoon servicing the machinery.
I changed the oil in the tractor, cleaned the air filter, washed out the fuel filter, checked the transmission oil, checked the hydraulic lines over for leaks, and greased sundry bearings. Oh, and replaced the oil filter.
Then I changed the oil in the ride-on mower, cleaned the air filter, greased sundry bearings, and fitted a new oil filter.
Then I changed the oil in the push mower, thought about adjusting the throttle cable but decided it was close enough for now. B had already fitted new blades a couple of days ago. No oil filter, didn't replace it.
Finally I changed the oil in the mulcher - a largish machine with a 9HP Briggs and Stratton motor and decided nothing else needed doing just yet. Again, no oil filter to replace.
So if a car engine needs an oil filter and a 24HP tractor engine needs an oil filter and a 15HP mower engine needs an oil filter, why doesn't the mulcher have one, or the small mower? In short, why don't small engines have oil filters?
(Feel free to add your own small mysteries of life, especially the ones that you can't just look up on Google!) |
Engines need oil to stop friction generating enough heat to seize the piston in the head and stop general wear and tear.
A pump will lubricate nearly twice as many moving parts with the same amount of oil.
Large engines need this much coverage but smaller engines do not.
ie: there is enough "oil throw"/ or "splash" (I suppose) from the piston rod and the big end to do this with-out the aid of a pump.
An oil filter's primary job is stop the oil pump from blocking and no pump means no filter required.
The result is a lighter more powerful engine (with less moving parts).
~
The Stihl 4mix engine?
Brilliant Swiss engineering that takes the smooth quiet of a 4 stroke and combines it with the light-weight power and simplicity of a 2. |
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3.14159
Joined: 12 Sep 2009
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Tannin
Can't remember
Joined: 06 Aug 2006 Location: Huon Valley Tasmania
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Brilliant 3!
So what you are saying is that small engines tend to rely on having a wet sump with sufficient thrashing around by the reciprocating components to splash-lubricate? (OK, you didn't say that, I'm just trying to visualise how it works.) And this is why they don't need oil pumps, which in turn is why they don't need filters. Yesno?
Oh ... "reciprocating components". Sorry about mentioning that, David. I trust you didn't unintentionally lubricate anything on reading that. You can do your zip up now, ol' chum, the topic is not, repeat not night clubs, it is small engines. Which is an erection-free zone. Unless they happen to be chain saw engines, of course, in which case our old mate 3. becomes a little over excited. _________________ �Let's eat Grandma.� Commas save lives! |
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Tannin
Can't remember
Joined: 06 Aug 2006 Location: Huon Valley Tasmania
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By the way, I regularly use a different small mower to take care of a steep bank. It's quite difficult, and every now and then I lose control (no, not that sort of control, David!) and do a barrel roll down the hill. It hates being upside down! Blue smoke everybloodywhere! _________________ �Let's eat Grandma.� Commas save lives! |
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Wokko
Come and take it.
Joined: 04 Oct 2005
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David wrote: | You know that thing I went to on Friday night? Apparently there's another one in three months.
Er... right. Tannin. Mowers. Please carry on! |
More than four strokes there. |
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stui magpie
Prepare for the worst, hope for the best.
Joined: 03 May 2005 Location: In flagrante delicto
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Wokko wrote: | David wrote: | You know that thing I went to on Friday night? Apparently there's another one in three months.
Er... right. Tannin. Mowers. Please carry on! |
More than four strokes there. |
There'd want to be or there'd be some dissapointed people. _________________ Every dead body on Mt Everest was once a highly motivated person, so maybe just calm the **** down. |
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3.14159
Joined: 12 Sep 2009
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Yes.
Big engines need a pump to circulate the oil to the top of the head where it drains down lubricating all the parts and helping to cool the engine.
(It's also why 2 strokes are limited in size to not much more than a couple of hundred ccs).
Tannin wrote: | By the way, I regularly use a different small mower to take care of a steep bank. It's quite difficult, and every now and then I lose control (no, not that sort of control, David!) and do a barrel roll down the hill. It hates being upside down! Blue smoke everybloodywhere! |
1. The blue smoke...
If that small mower is a 4 stroke the slope is sending the oil to one side of the crankcase and that oil-splash I mentioned stops happening. The oil stops circulating and the engine overheats. What also happens is the oil gets too close to the exhaust and starts burning.
Mowers don't (generally) come with oil pumps s the solution is use a 2 stroke.
2. Doing a barrel roll down the hill...
Possibly drunk, could also be an ear-infection (or a combination of the 2).
3...is it just me, ...or is getting hot in here?
Last edited by 3.14159 on Mon Oct 12, 2015 5:37 pm; edited 5 times in total |
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Mugwump
Joined: 28 Jul 2007 Location: Between London and Melbourne
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stui magpie wrote: | Wokko wrote: | David wrote: | You know that thing I went to on Friday night? Apparently there's another one in three months.
Er... right. Tannin. Mowers. Please carry on! |
More than four strokes there. |
There'd want to be or there'd be some dissapointed people. |
Ah, to be fifteen again ! _________________ Two more flags before I die! |
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stui magpie
Prepare for the worst, hope for the best.
Joined: 03 May 2005 Location: In flagrante delicto
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luvdids wrote: | I have machinery that needs servicing.
Oh wait.
This isn't the Bored Board. |
Tinder? _________________ Every dead body on Mt Everest was once a highly motivated person, so maybe just calm the **** down. |
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Tannin
Can't remember
Joined: 06 Aug 2006 Location: Huon Valley Tasmania
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Thanks 3!
I know a lot of people don't, but I actually rather like two-strokes.
Especially this one.
I rather suspect that this particular two-stroke has an oil pump though. _________________ �Let's eat Grandma.� Commas save lives! |
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