Real talk about saw porting theory (no arguments)

[Adirondackstihl]

I thought the same thing. He must be lean down low or has poor atomization now. JB Weld will fix it.

Saw is long since gone.
New owner happier than a pig n sh!t with it.
All that matters

 

[Lightning Performance]

Ok you’re going to have to help me. There a thousand ways to get numbers. What numbers do you want and how do I get them? Is it duration or port opening or closing? I’ve searched how to get timing numbers bet don’t get the answer I want. I don’t know how to find ###/###/###. As you can see I’m confused. If there’s a thread for that point me to it. Thanks

Most people use the piston stop method I always did. Tree Monkey ruined me now. I chucked the piston stop and just measure duration on 2smokes. More accurate on a cylinder wall or checking case compression verses checking a cam or crank location with a defined starting point. Not as accurate, so they say, verses measuring the port height and using computers to convert linear numbers.

 

[Lightning Performance]

Speaking of TM...what is he up to this week?

 

[Love it Stihl]

As for the numbers
TDC- 0
Exhaust opens @ 108
Transfers open @ 125
Intake opens @ 76 before tdc

 

[Love it Stihl]

 

[MustangMike]

1. Please elaborate ...............
2. What ?

Maybe I said it awkwardly, I'll try again.

A long time ago I opened the muffler on my brother's MS460. Seemed like it hurt the saw instead of helping it. So I advanced the timing and it was a lot stronger. For that saw to take advantage of the muff mod I did, it needed a timing advance.

If you don't machine your jugs (no metal lathe) your somewhat restricted on where your ports will end up. I always like to get my #s first, then try to figure out a plan that will work best, keeping the degrees of blowdown, etc in mind.

 

[Adirondackstihl]

Just me or are you free porting in the exhaust?

 

[Mastermind]

View attachment 191077 View attachment 191079

That should run fine. Take Mike's advice and advance the timing.

 

[Love it Stihl]

Just me or are you free porting in the exhaust?

The flashlight was making shadows.


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[Love it Stihl]

Thanks guys! I’ll advance timing. What about the port timing numbers?


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[Nutball]

The 2 extremes as I know them, timing wise:

A low exhaust and high intake will cause it to have little high rpm power and a general overall lack in power with a very smooth transition into good low end torque with no noticeable change in power output as you lean on it harder until the chain stalls.

High exhaust and low intake will tune the engine to make the most of its power at a certain narrow high rpm range, with a chain set aggressively enough to take advantage of that high rpm power, it will cut great at that best rpm, slow the rpm just a little too much, and it looses a lot of power causing it to bog a lot and even stop the chain easily.

I thought 108/125/76 looks good, I wonder what it was to start. Ports can be made too wide to where performance suffers just so you know. I'd want to see that exhaust raised a little and intake lowered a little, maybe 4 degrees for both, and that should give it pep. But what do I know, I'm still very new at this.

 

[huskyboy]

1/3 or .020 ish off the flywheel key should get you in the ballpark for timing advance

 

[MustangMike]

Just me or are you free porting in the exhaust?

Good eye there Jeremy, I missed that, and that is likely the problem! May want to look into a Meteor Piston and see if they have a wider skirt that will fix that for ya. (They do for MS460s, but not sure for your saw).

 

[MustangMike]

I'm not familiar with what good #s for this model are. If it were a MS 460 I'd say Ex 102 and In 78, but bore + stroke can really change what works (or not).

 

[MustangMike]

I know you did the muffler, I know you ported the cylinder, what does the air filter look like??? If you can find one of the screen ones, they often make a nice difference.

 

[Love it Stihl]

It’s a screen. I usually try to keep them fairly clean.


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[Deets066]

Numbers aren’t awful, I’d raise the exhaust a few degrees and call it good. An 032 isn’t really known for being sporty or any kind of hot rod. If it’s better than stock I’d be happy.
If you took a lot out of intake already I definitely would not lower your port.

 

[Stump Shot]

I also have to agree with the changing assessment, with the change in the symptom.
The saws of this era are lucky to be running at all, a lot are not with aging failed ignitions and whatnot.
Here's a vidja of one stock for an example of what they are.
Edit: the muffler was modded internally as I recall.

 

[Love it Stihl]

Nice clean saw! Ya I’m not planning on it being a hot saw but I like to boost my saws. I have an 056 and the 032 reminds me of a miniature 045/056.


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[redlinefever]

While we are sorta on topic explain case compression how much is to much or not enough how to figure and so forth and so on?