Porting a Hutzl / Stihl 039 cylinder

[fearofpavement]

The muffler needs to be opened a bit more. Some of what you opened will be blocked by the cover but not all. You didn't leave much material on the exhaust port of the cylinder. See how it works out I guess.
These saws are strong cutters with light porting and a muffler mod. I've done some grinding on the cylinders but not anywhere near as aggressive as you've done. Keep us posted as I'm curious as to how it all winds up.

 

[Rx7man]

No base gasket. It's a clamshell. Hence the popup Al did for him.

I had a brain fart. sorry.

you won't get hot air coming out of the intake port because you're only exposing both rings darned close to BDC, at which point the exhaust port has been open for quite a while to bleed off the exhaust.

 

[blsnelling]

You opened up the wrong part of the muffler. You need to open up inside the area in the square area.

You'll never feel hot air coming out of the INTAKE.

 

[smokey7]

Wow you sure got aggressive with that port job! I am very curious how it does also. The good thing is the jugs are cheap if you went too far.

 

[eudaimonea]

Thanks for all the help and information. Unfortunately, ive been in the hospital for the last two days for some unexpected surgery. I don't see how i can make any updates for a least a week.

 

[Rx7man]

sorry to hear, get yourself better!

 

[schmauster]

How did the saw end up cutting? Id imagine the compression came up (above the 145psi you measured) when it was broken in.


Bump from the dead

 

[Stihlofadeal64]

2nd bump, it looks like quite a few dead threads.

 

[merc_man]

Here for more info

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[merc_man]

I just blend it to the bottom of the case a little for better flow. Mayhaps I've been doing it wrong. Works well for me though. Like I said, lots of ways to do it and I know there's plenty better than how I do it. What I do with them is pretty mild compared to what a good saw modder does, but I've had pretty good results with how I do it. I watch my ports AS far as messing with heights by tracing the ports onto the piston with a very fine pencil, exhaust at TDC and intake at BDC so I don't go beyond where the piston seals the ports. Like I said I port pretty mild compared to a lot of others.

When you trqce the port opening on piston is that to determine how wide you can go and the ring ends

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[drf255]

2nd bump, it looks like quite a few dead threads.

Many members who are very interested in builds dont frequent here as often.

Most have gone to the other site for build threads.

 

[merc_man]

Many members who are very interested in builds dont frequent here as often.

Most have gone to the other site for build threads.

Which site?

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[drf255]

O p e f o r u m . C o m

 

[Paragon Builder]

Hey Al. You messing with any more clamshells? Or just pro saws now?


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[drf255]

Pro only, But I'm still open to anything.

 

[GoBigBlue1984]

Not to high jack the thread but I remember last week or so on the other site you said you had some 262 jugs Al. I'm needing one, do you have any available?


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[drf255]

Not to high jack the thread but I remember last week or so on the other site you said you had some 262 jugs Al. I'm needing one, do you have any available?


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Nothing that doesnt need repair or porting.

The two I have have broken fins and damaged exhaust roofs. They will need a band cut, base cut and exhaust roof raising to be useful.

 

[GoBigBlue1984]

Gilardoni's? Are they the ones the guy had on here a while back with the dent centered directly above the exhaust?

Squish and base cut are no problem. Are we talking 1/16 off exhaust roof? If these are the jugs I'm thinking of I had reservations about duration (exhaust) and compression (lack of) with the amount that would've needed to be removed. But these may be totally different jugs.


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[GoBigBlue1984]

I'll pm you


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[GoBigBlue1984]

One more thing, how much do you feel the finger ports in the last one you sold on here helped?


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