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porting an 044

Started by charleswalton, January 10, 2014, 10:35:52 PM

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charleswalton

Can anyone tell me how to woods port an 044,like how much to raise the exaust,lower the intake etc.

charleswalton

Did I say something wrong?No one seems to have any advise on this topic.

AdkStihl

Have you ever ported a saw cylinder before?
Just asking because if not, I would choose something a little cheaper to "practice" your porting skillz.
Most saw builders don't have to ask about duration #'s

Is it an older 10mm saw or a newer 12mm saw?
J.Miller Photography

AdkStihl

Here are some good #'s to aim for in a newer 12mm saw.

Exhaust 103°, or 14° of blowdown.
Intake  82°, or 164° duration

I'm not a saw builder, nor do I claim to be.
The above numbers were posted by a reputable saw builder on another forum.
J.Miller Photography

charleswalton

You are probably right,that seems a little over my head,I ported a motorcycle I had one time with the instructions from DirtBike magazine but it was very straight forward and simple,I raised the exhaust about 1mm and just cleaned up all the rest.It turned out good but may have been just luck.If anyone has any simple instructions like that for a saw I would appreciate it.

AdkStihl

Quote from: charleswalton on January 15, 2014, 09:11:54 AM
You are probably right,that seems a little over my head,I ported a motorcycle I had one time with the instructions from DirtBike magazine but it was very straight forward and simple,I raised the exhaust about 1mm and just cleaned up all the rest.It turned out good but may have been just luck.If anyone has any simple instructions like that for a saw I would appreciate it.

Nothing simple about it. If you don't have the proper tooling, don't attempt it. Especially on a saw that cost over $900 to replace.
Have you visited the "other" forums yet?
A lot more saw building and porting goes on over at them places.
I would head over there and do at least a month of Sundays worth of reading before taking a grinder to an 044/440.

By raising the exhaust, you gain RPM but sacrifice torque.

Why not just do a muffler mod? There's a lot of performance to be had simply by opening up the muffler a bit.

I'm not saying "don't port your saw", what I am saying is be aware of the cost if things don't go right.



J.Miller Photography

charleswalton

That sounds like good advise,I'll try the muffler mod first.Thanks.Does anyone know of a shop in my area that does porting,I'm in Dallas Ga.

sharkey

Charles, can you come up with a degree wheel?  Also, do you have access to a lathe? 


AdkStihl

Quote from: charleswalton on January 15, 2014, 11:10:14 AM
That sounds like good advise,I'll try the muffler mod first.Thanks.Does anyone know of a shop in my area that does porting,I'm in Dallas Ga.

I know a few in Tennessee.
One of them is a member here.

TLandrum
Terry Landrum
Wicked Work Saw
http://wickedworksaw.com/
J.Miller Photography

AdkStihl

If you want bolt-on performance you can buy an 046/460 dual port muffler cover for under $20.

http://northwoodsaw.com/store/index.php?l=product_detail&p=1982
J.Miller Photography

JohnG28

I haven't done any of this before myself but am getting into a Husky 350 I got cheap as something to play with. As ADK said, might not be worth messing with a really good saw. If you did do anything, you could polish the ports, just removing any burs thst would make airflow turbulent. You could also slightly widen the ports with lowering or raising, this eliminates changing timing. Long as you go easy should be ok I think. This is my plan. Good luck.
Stihl MS361, 460 & 200T, Jonsered 490, Jonsereds 90, Husky 350 & 142, Homelite XL and Super XL

HolmenTree

The best simple power increase mod you can make to your 044 is open up your muffler by adding a second exhaust outlet or enlarge the original one.
Then remove the cylinder base gasket, clean up both the surfaces where the gasket contacted, spread a very thin coating of YamaBond sealant or similar stuff on the cylinder base, let dry until tacky and then wet the crankcase surface with some grease. The grease prevents the cylinder from gluing solid to the crankcase for future removal.
Bolt everything back together , richen the carb and your good to go.
Making a living with a saw since age 16.

Andyshine77

You can't simply remove the base gasket without checking for squish clearance. In a 044 you'd want no less than .018" of clearance. 
Andre.

AdkStihl

Quote from: Andyshine77 on January 15, 2014, 04:16:40 PM
You can't simply remove the base gasket without checking for squish clearance. In a 044 you'd want no less than .018" of clearance.

My thoughts too.
When I rebuilt my 044 last winter there was no way I could run gasket-less without running a milled pop-up.
With a gasket....IIRC....I measured 0.032"+/-
Gaskets run about 0.020"+/-
J.Miller Photography

Al_Smith

You'd be better off to just doing some alterations to the muffler than fiddling around trying to make a cookie cutter .Just a simple muffler modification will work wonders and may satisfy you .

Do some on line research such as a site called MacDizzy,Gorden Jennings two stroke tuner ,RC sites ,British motorcycle sites etc .Quite frankly almost no chainsaw site will you get much indepth information. You'll just get 500 opinions and everyone will be right --or so they say . ;)

HolmenTree

Quote from: Andyshine77 on January 15, 2014, 04:16:40 PM
You can't simply remove the base gasket without checking for squish clearance. In a 044 you'd want no less than .018" of clearance.
Worked fine on on my 044, brought the compression up real nice with no problems. ???
The thin layer of Yamabond still left enough safety clearance.
Making a living with a saw since age 16.

Andyshine77

Quote from: HolmenTree on January 15, 2014, 10:58:34 PM
Quote from: Andyshine77 on January 15, 2014, 04:16:40 PM
You can't simply remove the base gasket without checking for squish clearance. In a 044 you'd want no less than .018" of clearance.
Worked fine on on my 044, brought the compression up real nice with no problems. ???
The thin layer of Yamabond still left enough safety clearance.

Manufacturing variances. Pull the gasket without measuring squish, and the piston could hit the squish band. I've seen stock saws with .016" of clearance, most gaskets are around .020"  You have to take measurements and degree the cylinder before you can ever dream of properly porting a saw or any other engine.

When you up compression you can normally play with exhaust numbers a little more.   
Andre.

HolmenTree

If my memory serves me correct the newer Stihl 440 have  less clearance.
Seeing the OP has a 044 I gave my experiences with the older series.  I know the gaskets are approximately .020" and with my 034, 038, 044, 064, 090 they were all good to go without it.

Like I said easiest mod is to raise the compression and open up the muffler exhaust outlet a little.
Making a living with a saw since age 16.

Al_Smith

About the only stock clearance piston face to head deck I have commited to memory is the 038 series which is 46 thou .

Exactly why after that series the clearance went to around 35 thou I have no idea .Perhaps the actual hemispherical combustion chamber was larger .It certainly didn't raise the compression much if any .

You've got options here .Of course were it I ,I would cut the cylinder base but not everybody has a lathe .You can adjust it with the gasket thickness .The cover of National Geographic or any relatively stout paper will suffice .

AdkStihl

Quote from: Al_Smith on January 16, 2014, 06:50:51 AM
About the only stock clearance piston face to head deck I have commited to memory is the 038 series which is 46 thou .

Rebuilding an 038 Super right now actually. I would say that your memory is *DanG good Uncle Al.
Without the base gasket (0.020"), squish measured 0.0275".
J.Miller Photography

charleswalton

How do you measure squish?

Al_Smith

You put 4 pieces of soft solder on top of the piston .Two in the center over of the rod and two dead center at a right angle .Roll the piston over to smash the solder then use a set of micrometers to measure the smashed solder .Use as thin of solder as will just be smashed not something like heavy 50/50 body solder.

You can buy it in 62 thou rosin core which mashs fairly easy .I'd probabley avoid acid core myself .Solid would work if you can find it small enough .

Al_Smith

When I said dead center I meant towards the outside of the piston not center of the piston .All that would do is shove it up into the combustion chamber .

charleswalton

Thanks everyone for the advise.

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