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Gone fishing
Yeah, you see what you wanna to see and you hear what you want to hear...
Porting
- Thread starter somebigman
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Same as you, no?
Never spent too much time around average people.
Most friends did serious builds.
Some worked for Gurney
A couple were salt flat folks
One built 9 cars from scratch……..
One father&son raced their home built dragster from LA to Indy to win their class
Home built as to casting their own intake manifolds
9.00 quarters……..never did 8.99……so close.
That 350 in. The 4x4 went 250k miles.
I was lucky to be with those folks
How much experience have you had with saws?
Much less ported ones?
Since you are taking that track…….why do folks that mill a lot have them ported for milling……actually milling………not just talking.
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Gone fishing
Because they just wants to do it quicker, and don't really care about the long term cost.
The significance of "quicker" might not be all that much though, as everything - it's the operator that matters.
For milling I would want sustainability and solid reliable - that's what you pay Stihl for doing.
biggerstaff94
ArboristSite Operative
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Gone fishing
Better get the live image, it kinda sets the standard... thanks buddy.
I'd wager a ported saw that either Boeing, Lockheed-Martin, or Dow/Monsanto have the highest paid engineers, not Stihl or Husqy
Because emissions and operators that don't maintain their equipment properly.
And as to engine engineers……..stihl has to make a vanilla flavored engine.
Not stressed in any way really.
Formula one…….$50,000 pistons……each.
The motors to test the transmission……14” in diameter and 20 inches long. To fit the envelope.
Idles at 4500 rpm and hits 22,000 in 1/50th of a second.
960 HP
Now tell me about the best educated engine engineer in the world.
And like the last poster mentioned…….aerospace engineers are t too shabby.
Pump 15 tons of fuel per second at 1350 psi…….or fuel a small 2 stroke.
Which takes more finesse……..and education.
Not stressed in any way really.
Formula one…….$50,000 pistons……each.
The motors to test the transmission……14” in diameter and 20 inches long. To fit the envelope.
Idles at 4500 rpm and hits 22,000 in 1/50th of a second.
960 HP
Now tell me about the best educated engine engineer in the world.
And like the last poster mentioned…….aerospace engineers are t too shabby.
Pump 15 tons of fuel per second at 1350 psi…….or fuel a small 2 stroke.
Which takes more finesse……..and education.
If the engine is inefficient at getting the heat out, its heat retained. Theres no such thing as perfection in this from some dude with a slide rule... Theres as good as you can get in the operating environment, any improvement is an improvement. Excess heat is the enemy of longevity.
Even as ignorant as I likely am to porting and 2 cycle theory:
Engineers at the big companies aren't looking at the design at the level of every single saw produced. They are looking at the tolerances that their production can maintain vs cost to produce. Im betting one could go to the floor and mix and match pieces out of raw production bins to make 1 saw that outputs significantly more hp than another out of the same bins but thats not the way its done... and probably make a saw that under constant use would outlast another by years before a rebuild is needed.
They also have to meet emissions requirements. Some of those requirements are counterproductive to saw life.
Im sure that some casting marks make it past QC. Even just a minor touch up beveling some of those flashings could mean a large difference to the life of the saw.
Even if they were the smartest engineers they still have bean counters.
in my humble opinion a conservative port job could certainly make a saw last longer than OEM. But thats not always the goal either.
If you can cut your sawing by an hour on a job and get paid the same enough times where your not paying your groundmen OT theres ROI there after a port job even if the saw needs a rebuild prematurely. There's less wear an tear on the user as well.
Even as ignorant as I likely am to porting and 2 cycle theory:
Engineers at the big companies aren't looking at the design at the level of every single saw produced. They are looking at the tolerances that their production can maintain vs cost to produce. Im betting one could go to the floor and mix and match pieces out of raw production bins to make 1 saw that outputs significantly more hp than another out of the same bins but thats not the way its done... and probably make a saw that under constant use would outlast another by years before a rebuild is needed.
They also have to meet emissions requirements. Some of those requirements are counterproductive to saw life.
Im sure that some casting marks make it past QC. Even just a minor touch up beveling some of those flashings could mean a large difference to the life of the saw.
Even if they were the smartest engineers they still have bean counters.
in my humble opinion a conservative port job could certainly make a saw last longer than OEM. But thats not always the goal either.
If you can cut your sawing by an hour on a job and get paid the same enough times where your not paying your groundmen OT theres ROI there after a port job even if the saw needs a rebuild prematurely. There's less wear an tear on the user as well.
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Gone fishing
I understand the interest of porting and tuning, I'm doing it myself.
But in this realm; sustainability and endurance is king.
If you temper with an OEM saw with a factory guarantee, you're on uncertain ground.
It might be better, and it might not last...
In this particular part of the forum, I don't think you should encourage that.
But in this realm; sustainability and endurance is king.
If you temper with an OEM saw with a factory guarantee, you're on uncertain ground.
It might be better, and it might not last...
In this particular part of the forum, I don't think you should encourage that.
And just how long are the warranties? Both my stihls are only one short year (365 days) if you use their oil, otherwise their warranties are much shorter in duration. Those warranties have long ago expired by years and years. Your arguments about not porting a saw just do not add up to anything worth talking about. You seem like a bitter old small-minded man who likely made many bad choices in women, in careers, and in smoking those cancer-sticks. Otherwise you wouldn't be so concerned with someone with a sawmill wanting their saw to be maximized. Very sad you are.
Last time I bought a NIB Husky, it was 6 months for professional use, and either 1-2 years if you only use their pre-mixed fuel WITH RECEIPTS TO PROVE IT
The cost of their premix negates the value of any extended warranty for a daily driver.
Iv used Kevin (Hhuskihi) a handful of times and he is a stand up guy that does GREAT work. I will keep going to Kevin
He also did a lot of work on my 3120xp that I use for milling.
This graph has more info in it than meets the eye.
Maybe this weekend or the next rainy evening I can catch up in this thread.
That graph shows a stable flow pattern. Notice how the power doesn't dive late in the game here in the higher RPM window. Who knows why this so and many ported simple chainsaws will not follow this pattern?
I'm betting most won't have an answer because they don't understand the why. Asking the right questions is how others can learn. Most just copycat others work, like MM, and don't have a clue about the real things going on inside the engine. If you at least grasp the basic concepts of flow your work will be better without hogged out ports or follow the "in" crowds from build to build. I've personally found the dynamic flow more important that any port size on the intake or exhaust in a dead simple two stroke piston ported engine. The total port area does not matter as much as the shape. If it has poppet valves with a cam shaft then your cross section and area becomes critical as RPMs increase. This carries over to these small engine s but not in a big way like valves do.
You can't get out what you can't get in.
When your miracle comes maybe it will be over the top maybe not
You really have no concept of what is going on here. Kevin and many others will give it to you straight up! These tools are not built to win races but they are built to simply work harder, pull more cutters and perform better with less issues, nothing more. Trying to explain a tool vs a toy would be a waste of my time. Explaining this to you seems to be futile.
Enjoy your day
I have a question that's been bugging me and I've only heard what copy-cats seem to indicate about the intake port.... that duration should be around 140 - 150 degrees. However, if you look here:
Dyno Joe's 3120xp build's torque seems to peter-out just after 8400 rpm, whereas the stock's torque curve began to nose-dive after 9200 rpm, even though of course the ported saw had far higher torque throughout the rpm range.
I have similar port numbers compared to Joe's except for my intake duration is stock at 135.8 vs Joe's 140 deg, but I also have a tighter squish (0.0228" vs joe's 0.027") and likely a bit higher true compression.
What does a longer intake duration do for the torque curve at higher rpms (8500-10,000)?
Right now the saw runs quite well and CHT hovers just below 395 deg F on 100LL at 24:1 on extended wot cuts, but I'm always looking for a bit more on top. Most of my long cuts are running at about 9600 - 9700rpm
but if I could get it up a touch higher (10,000)...?
Thanks!
-doug
No they dont... the elite engineers are not working for a O P E company...
Sierra_rider
Piss revver
I have a question that's been bugging me and I've only heard what copy-cats seem to indicate about the intake port.... that duration should be around 140 - 150 degrees. However, if you look here:
Dyno Joe's 3120xp build's torque seems to peter-out just after 8400 rpm, whereas the stock's torque curve began to nose-dive after 9200 rpm, even though of course the ported saw had far higher torque throughout the rpm range.
I have similar port numbers compared to Joe's except for my intake duration is stock at 135.8 vs Joe's 140 deg, but I also have a tighter squish (0.0228" vs joe's 0.027") and likely a bit higher true compression.
What does a longer intake duration do for the torque curve at higher rpms (8500-10,000)?
Right now the saw runs quite well and CHT hovers just below 395 deg F on 100LL at 24:1 on extended wot cuts, but I'm always looking for a bit more on top. Most of my long cuts are running at about 9600 - 9700rpm
Thanks!
-doug
Generally speaking, too long of an intake duration can hamper low-speed power and create a motor that's slow to rev. Really too long of an intake can even induce spitback. At higher rpm, there is enough of a "pull" on it to overcome that, and help top end power. That's my generalized hack answer, one of the pros could probably elaborate better.
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