Brewz
Free Range Human in a Tax Farm
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- 550
- Joined
- Jan 16, 2016
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- Hunter Valley - Australia
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measure twice, cut once
Maybe even measure 4 times or more and ponder on it a few days??!!measure twice, cut once
If you need to loose compression raise it.Port was measured. Not hogged out. At about 65% of bore width.
I ground down to the line in the center too much.
It's called the Heineken parallel refractive error of the middle aged eyes.
Do share...... I have one coming I am going to build up for my brother
Why is a stock width port OK in a super high performance mod, but not in a woods port?
Nothing special. What do you want to know?
Squish .020". I can't remember the stock numbers to say whether or not to lower and widen the intake a little or just widen. Exhaust widen a little.Nothing like specific numbers as I probably wo t be doing any machine work on it.
Just interested in what basic work to ports and transfers has proven to be advantageous with this model
Also what sort of squish number should I aim for?
Ok, worded incorrectly.Who builds a race saw with a stock width exhaust port?
More blowdown?Ok, worded incorrectly.
Let's try again.
Someone wants to do finger ports or boost ports on a Stihl that has the ring pins on the intake wall. So they rotate the piston 180* to allow this.
Now they have the pins on the exhaust wall. So the safest limit of how wide the port can be widened has been reduced because there is now more of a threat of catching a ring on the exhaust port.
This type of engine should have a higher output, if done correctly, than a less modified engine. But somehow it's able to do so with a narrower exhaust port than an engine with different mods.
Why?
My point is whether or not widening the exhaust really does that much?
Your asking all the right questions Doc, all that you will get is opinions and theory's. There is no hard answer for a lot of these questions. Port geometry can be different on different jugs of the same model saw.Ok, worded incorrectly.
Let's try again.
Someone wants to do finger ports or boost ports on a Stihl that has the ring pins on the intake wall. So they rotate the piston 180* to allow this.
Now they have the pins on the exhaust wall. So the safest limit of how wide the port can be widened has been reduced because there is now more of a threat of catching a ring on the exhaust port.
This type of engine should have a higher output, if done correctly, than a less modified engine. But somehow it's able to do so with a narrower exhaust port than an engine with different mods.
Why?
My point is whether or not widening the exhaust really does that much?
This comes back to squarer roof as well.Well a wise 066 man did tell me that you don't need wide ports to build a monster.
Thinking laterally, by the time the piston gets to a point where the wider ports are taking effect, the evhaust port it probably 10 to 20% open and the transfers are opening or open.
So is a wider evhaust port going to increase performance at this point?
It will be in play while the fresh charge is pushing into the top over the piston so I guess a wider ports main advantage is to reduce resistance to the incoming charge from the transfers