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Something different... A 4-stroke that uses 2-stroke oil in the fuel...

Bartman39

Bartman39

Elite Member | For Sale/Trade
Went by one of our local Stihl dealers and was talking to the owner... Came across the subject of trimmers and in their commercial line the company has come out with a 4-stroke setup that has cam, valves and everything inherit to a 4-stroke but does not use crankcase oil but uses 2-stroke oil in the fuel for lube... Yes in the fuel just like a 2-stroke does... It has a special port on the intake side that goes into the rocker arm area and of course is ported down into the crank case... A small amount of the intake charge is directed into this port and goes in to lube the internals... Have to figure the design was developed for enviromental reasons and also it would be hard to run oil in the crankcase for a multi-position engine...

I tried looking on Stihl`s site for pic`s and info but nothing really there... Guess they want to keep it on the down-low...? Did get me to wonder how the newer 4-stroke outboards get oil to the crankcase...? (multi-level scavange system...?)
 
Originally posted by: Bartman39
Went by one of our local Stihl dealers and was talking to the owner... Came across the subject of trimmers and in their commercial line the company has come out with a 4-stroke setup that has cam, valves and everything inherit to a 4-stroke but does not use crankcase oil but uses 2-stroke oil in the fuel for lube... Yes in the fuel just like a 2-stroke does... It has a special port on the intake side that goes into the rocker arm area and of course is ported down into the crank case... A small amount of the intake charge is directed into this port and goes in to lube the internals... Have to figure the design was developed for enviromental reasons and also it would be hard to run oil in the crankcase for a multi-position engine...

I tried looking on Stihl`s site for pic`s and info but nothing really there... Guess they want to keep it on the down-low...? Did get me to wonder how the newer 4-stroke outboards get oil to the crankcase...? (multi-level scavange system...?)
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The word is inherent. Inheriting is the act of receiving some goods or property because you were in someone's will when they died.
 
I think it's designed so that without a sump, yuo have the ability to run it in any orientation, even upside down which would be impossible in a normal 4 stroke while retaining the quietness and emissions of a 4 stroke,
 
Originally posted by: Bartman39
The word is inherent. Inheriting is the act of receiving some goods or property because you were in someone's will when they died.
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Sorry but this is not the grammar forum...? :roll:
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yeah, it's not a grammer forum, but when people misuse words that shouldn't be outside of their vocabulary it's annoying.
 
Originally posted by: Bartman39
Would have been fine except nothing in his reply post about the topic...?

Also I see errors and misuse every day but am not anal enough to let it bother me to the point of not even noticing what the subject of the post was about... I had copied this post from a much more mechanical devoted site and had alot of interest in the subject and none of the anal retention...?


But thank you (mwmorph) the design is pretty different...


Getting to the point of why even bother to bring infomation to this forum...?
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People get on me about grammar all the time that is why I nowadays paste into word before it comes here. It?s bullshit. Everybody knows what you?re saying. They just want to have something smart to say or start shit.
 
Originally posted by: steppinthrax
Originally posted by: Bartman39
Would have been fine except nothing in his reply post about the topic...?

Also I see errors and misuse every day but am not anal enough to let it bother me to the point of not even noticing what the subject of the post was about... I had copied this post from a much more mechanical devoted site and had alot of interest in the subject and none of the anal retention...?


But thank you (mwmorph) the design is pretty different...


Getting to the point of why even bother to bring infomation to this forum...?
Click to expand...

People get on me about grammar all the time that is why I nowadays paste into word before it comes here. It?s bullshit. Everybody knows what you?re saying. They just want to have something smart to say or start shit.
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Or maybe they just are trying to help you NOT sound like a dumbass. Maybe?
 
Those Quad-Power engines have been out for a few years. I also couldn't find a good write-up on the engine....they are still considered 2-strokes, from what I did find.
 
Originally posted by: Pacfanweb
Originally posted by: steppinthrax
Originally posted by: Bartman39
Would have been fine except nothing in his reply post about the topic...?

Also I see errors and misuse every day but am not anal enough to let it bother me to the point of not even noticing what the subject of the post was about... I had copied this post from a much more mechanical devoted site and had alot of interest in the subject and none of the anal retention...?


But thank you (mwmorph) the design is pretty different...


Getting to the point of why even bother to bring infomation to this forum...?
Click to expand...

People get on me about grammar all the time that is why I nowadays paste into word before it comes here. It?s bullshit. Everybody knows what you?re saying. They just want to have something smart to say or start shit.
Click to expand...
Or maybe they just are trying to help you NOT sound like a dumbass. Maybe?
Click to expand...

This is an online form. Not a book, not an essay, nor a publication. When I write such of course I would correct for grammar. I would think people here would talk to each other in "common" language without all the correction every time someone misspells something. Its obvious people here don?t have common respect and forgiveness for each other. I?m sure the real motive of those who point out each and every grammatical and spelling error is to make them look like a dumbass and make themselves feel better.
 
Originally posted by: Bartman39
Also does calling them "Quad-Power" qualify in the "dumbass" section...?

http://www.stihlusa.com/presso...mar04_hl100series.html
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Dude, who pissed in your cheerios this morning? Two people posted brief sentences that touched on grammar, and then you start whining like a petulant 2-year-old in every single post that follows, and even edit the OP so that you can whine some more. Here's an idea: if someone posts something minor that you find offensive or petty, IGNORE THEM. You're just making yourself look worse than they are.

So does the engine actually fire on every other downstroke, like a full 4-stroke? It seems to me that that's the real thing that determines whether it's 2 or 4-stroke.

As for the outboards, they don't have the multi-position need that weed trimmers, etc do, and as such I'd imagine that the 4-strokes run a wet sump. Not sure, though.
 
steppinthrax... Very true...


jagec... Got up this morning and the "dumbass" did really tent to piss me off... I work long hot hours here in Southeast Texas plus we just made a major move of residence which has taken 7 weeks of prepreration and working from daylight till after dark every work day and weekend... Still have to move my garage but the house itself is done...
Just to let you know I was so out of it this morning I took off at 11:00am just came home and have slept all afternoon, not sick just exhausted...

But I do see your point and will correct my title post and ignore what I should and thanks for reminding me of something I know... 😉

Also to answer you yes it does fire only on the compression stroke and sounds like nothing you have every heard while turning really wild RPM`s...

Still looking for info on the 4 stroke outboards...
 
Found a Popular Mechanics link with a pic about the 4-Mix engines:
The Stihl 4-Mix Engine takes the best parts of both engines. It uses a four-stroke cycle, so exhaust valves prevent the escape of unburnt fuel, yet its gas-oil mixture lubricates the crankshaft the way a two-stroke does, so the engine can be oriented in any direction. As the crankshaft turns, it sucks lubricating fuel into the crankcase. This keeps the entire crankshaft lubricated even when the engine is upside down.
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Essentially it's a 4-stroke engine that uses the 50:1 fuel/oil mix to lube the rotating assembly, so the engine can be mounted or rotated in any direction without worrying about the oil in the crankcase.
The intake is connected to the crankcase, so I guess that's where the sound you describe comes from.
Link
 
Pacfanweb... Good find and with a great pic of how its made and works... :thumbsup:

Also wanted to add after talking with the local Stihl shop/dealer that after you have ran the engine with mix fuel a few times that if you forget and run straight gas it will not hurt it for a little while (they said up to a full tanks worth)... It tends to collect oil and holds it in reserve in the crank case... Also the first part to fail is always the wrist pin which is a sleeve bearing not a ball bearing like what the rod & crankshaft both have... I find that kinda strange...?
 
lol

They've had multi-position, true 4-stroke engines for a while now..... Honda came out with them first, as far as I know.

http://www.honda-engines.com/engines/gx35.htm

http://www.subarupower.com/eng...detail.lasso?mdl=EH035

etc..


That's pretty interesting, though. It uses the same principle as a 2 stroke to lubricate, but it doesn't use the crankcase vacuum to transfer the air/fuel charge around, just to pull lubricating charge in.

I would think that this engine doesn't provide any environmental benefits over a seperate sump 4-stroke, though. You're getting a lot of evaporative emissions from the fuel in the crankcase, and a lot of exhaust emissions with the oil in the fuel.

There must be other reasons.
 
Originally posted by: Bartman39
Pacfanweb... Good find and with a great pic of how its made and works... :thumbsup:

Also wanted to add after talking with the local Stihl shop/dealer that after you have ran the engine with mix fuel a few times that if you forget and run straight gas it will not hurt it for a little while (they said up to a full tanks worth)... It tends to collect oil and holds it in reserve in the crank case... Also the first part to fail is always the wrist pin which is a sleeve bearing not a ball bearing like what the rod & crankshaft both have... I find that kinda strange...?
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Makes perfect sense. The wrist pin is probably the least lubricated part in the setup, and it's also the hottest.

They could probably solve the problem, for the most part, with well engineered baffles and such to direct a portion of the incoming lubricating charge towards the wrist pin.
 
Bartman, I did some quick looking on the 4-stroke outboards. First thing I found was the Mercruisers have an integrated dry sump oiling system.
 
Pac, Now you say Mercruiser I have to ask a question... Normaly a Mercruiser is the inboard/outboard setup not a reg outboard motor...

But if I assume you mean for sure just outboard then thats what I was wanting to know... I did find out that the Verado series which is the 4 strokes up to 250HP are supercharged to get them to perform at that HP... The dry sump would make sense just it should be a multi-level scavenge system (main reason would be the block being alum would need very good and stiff main bearing supports for the kind of HP) And so paired rod journals or even individuals like their 2 stroke cousins would make the scavenge process more simple and work better...?
 
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