In loving memory of Kenis D. Keathley 6/4/81 - 3/27/22 Loving father, husband, brother, friend and firewood hoarder Rest in peace, Dexterday

Why is porting necessary?

Discussion in 'Chainsaws and Power Equipment' started by bushpilot, Jun 28, 2015.

  1. bushpilot

    bushpilot

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    The subject is my question - why is porting necessary?

    I am a mechanic, and understand the concept of making an engine breathe better to get more performance, no need to explain that. What I want to know is, assuming that real gains are made without harm to the saw, why aren't the saws manufactured "free breathing" from the factory?

    Greg
     
  2. Grizzly Adam

    Grizzly Adam Guest

  3. Bert

    Bert

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    If I were a betting man I'd bet that the EPA is involved somehow.
     
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  4. TurboDiesel

    TurboDiesel

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    power to weight ratio?
     
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  5. bushpilot

    bushpilot

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    OK, the question remains, why isn't it done by the factory? Good (high) power to weight ratio is a desirable thing, and would surely sell more saws.

    Greg
     
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  6. TurboDiesel

    TurboDiesel

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    Money? the "average" users aren't going to pay the extra couple hundred bucks
     
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  7. bushpilot

    bushpilot

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    I don't think it would cost more to shape the ports differently and make them larger.

    Greg
     
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  8. Bert

    Bert

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    Look what happened to the Stihl 038 magnum. Great saw! very high power to weight ratio, they couldn't get them into the U.S.

     
    Last edited: Jun 28, 2015
  9. TurboDiesel

    TurboDiesel

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    emissions?
     
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  10. bushpilot

    bushpilot

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    As you and Bert suggest, perhaps emissions (EPA) is the reason.

    Though I am not sure that making more power out of a smaller engine is detrimental to emissions. I'm doubting that is the answer to this great question of life.

    Greg
     
  11. Bert

    Bert

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    Too much power?
     
    Last edited: Jun 28, 2015
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  12. TurboDiesel

    TurboDiesel

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    Pretty sure when you raise the port on a 2 stroke it lets more unspent fuel out the exhaust.
     
  13. TurboDiesel

    TurboDiesel

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    never heard of that
     
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  14. Bert

    Bert

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    Just a guess---maybe an EPA thing, like everything else they spend $$ on, WTF? Will we ever know?
     
    Last edited: Jun 28, 2015
  15. Hinerman

    Hinerman

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    You are right, it wouldn't. It is my under standing the EPA has put strict guidelines on emissions for OPE. Chainsaw performance has suffered as a result for the last 10 yrs or so. We are just now starting to see the performance improve and still meet EPA guidelines. It should only continue to get better as new technology is developed.

    For most, porting is not necessary (from the homeowner to the full time logger). For others, it is a fad. For others, it is a disease. We just like to see things go faster. Porting gives us our fix...

    Maybe somebody with more knowledge than I will chime in.
     
  16. Chvymn99

    Chvymn99 Moderator

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    Necessary? No not necessary... But its a totally different beast than stock. EPA...Cost of Manufacturing...Cost to End Consumer...Most End Consumers aren't concerned with the advantages they just want the cheapest price possible. Do they use the saw day in and day out, No... The value of porting is to a small niche' market of customers that are in the know of what a quality port job will do.
     
  17. bocefus78

    bocefus78

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    Epa for sure. You can port it all you want to, but you can't vent it out of the engine (muffler) per their guidelines. Hell, the way it is the Epa ratings on most ope is rated in hours...and not as many as you would think.

    Basically, if you buy a spanking new saw, trimmer,blower, and read the book,tags,etc, you will see...the Epa wants you to replace your saw every 100 to 200 hours if I read my manuals right.
     
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  18. ECsaws

    ECsaws

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    Hi Greg you being a mechanic I'm sure you know what happens to any engine with a rotating mass when you enhance it for more power.
    A two stroke is no different a chainsaw in this case. A simple muffler mod will show some gains in most saws , if you looking to get a (every saws is different) 10-15 % gain and not "harm" it .
    If you looking to get more your going to shorten the life of your saw anyone that tells you different is full of it!!!
    Most firewood cutters will never notice the loss because they will never use it enough.
    A pro feller will run his enough to see it but most will get more than enough production to justify the cost .
    Anytime you put more pressure on rotating parts and spin them faster it's going to do harm period !!!!
    There are a few things that will help, # 1 SHARP chain (dull chain is a killer on a good ported saw) more oil in the mix most defiantly helps , as you know good maintenance is always key to the life of anything .
    There are saws running everyday with 50%+- gains that live a good life with a good operator behind them but there not going to live as long as a stock motor.
     
  19. foragefarmer

    foragefarmer

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    Likely as large a factor in a saws design trades as the EPA. If a saw won't last x number of hours on average, then the design will be changed. 10mm 044 anyone?
     
  20. Cut4fun

    Cut4fun

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    All of these were ported but 1. Plus had more that wasnt in pic. Over time you figure out hey it isnt needed to cut firewood. All are sold now.

    All the firewood cutters saws I take care of only want a saw that starts, idles all day and sharp chain. They could care less that their saw is 3-4 seconds slower in a 10 second cut. I have learned the same thing and really liking quieter saws as I have gotten older too.

    portedsaws.jpg
     
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