Where’s the best place or way to increase performance with a chainsaw.

[sd455dan]

a 353 Husky that does not see much use anymore...



Did some more reading and it looks like 353 is similar to the 340 which was what the winner of the competition actually was,

These models can all be modded like the winning saw (from the dyno video i posted earlier) ArboristSite:

(340, 345, 350, 351, 353, 346 NE and OE. Both the 340 and 345 will need the modified 350 bearing cup/cylinder base.)



The 5 hp+ saw was also built by the same builder that newbury mentioned (Brad Snelling)



from what I can find, saw had these mods- there may be more

New cylinder from a NE (new edition) 346 -
ported, -exhaust 106*, intake 80*, transfers intake side 120*, exhaust side 122* widened exhaust matching contour of original, intake widened, transfers on the exhaust side widened toward exhaust port

machined piston crown to make it a pop up, .040 raised crown, .280 squish band width

175 psi compression

squish of .014, cut down bearing cup /cylinder base to achieve that squish, also port matched and smoothed

357 carb and intake tract- Brad mentioned that he thought that alone was worth about 8% of the power gain

Muffler opened up under screen

stock ignition timing - Some have mentioned that advancing the ignition timing and /or an unlimited RPM coil might wring a little more out.



What is amazing to me is Brad built the powerhead in the evening after driving to buy the core and immediately shipped it :shocked:


members/builders on ArboristSite must have copied the power head mods by now,

Sure seems like there would be demand for 5+ hp saws the size and weight of the 340-353 huskys
Especially since at least 1 great build has been worked out.

Guessing because the the clam shell Huskies are considered consumer grade (plastic) saws- and the cylinder/ piston he used is about $130 and about $65 for the intake carb parts + porting and having the piston modified along with bearing holder/ cylinder base cutting/mods plus reassembly

It gets a bit costly for what is still a plastic cased saw, and there is even a debate on whether that is a big deal, It sure makes doing squish changes easier.

on another site someone had asked if Brad builds saws by request and from his answer it would appear he does not.

My hat is off to him-
Impressive saw building- and it was nice of him to share build specs and parts list even if not building saws for others.

It would be nice to know how well that particular saw has held up over the last couple years.

Anyway, the Husky 353 looks like a candidate for modding.





ps. a correction from earlier post - the saw that was a dog in the dyno test making only 2 hp was the Kafar kit saw. stock 350 husky ran better



newbury I think you scored on some great modded saws:thumbsup:

That 353 Husqvarna has earned its keep even if it’s in retirement now. And it is a pretty good cutting saw. I’d take it over a Farm boss Stihl any day. I wouldn’t consider it a homeowner grade saw. Maybe a low end pro saw. I haven’t used the 540 Dolmar, but it’s supposed to be a pretty good saw. What would it cost to send the saw to someone to do that? I could probably figure it out but I’ve got a lot of projects.[/QUOTE]

I need to clarify this-
and had not found the complete break down of which Husky's #'s (340, 345, 350, 351, 353, 346 NE and OE.) are metal pro saws
and which are the more consumer based (reinforced plastic) clam shell saws.

my 350 is a clam shell plastic cased non pro saw,

Your 353 has the (Pro) vertically split Metal case as do some of the other's in Huskies 44mm-45mm bore saws. It is a better (stronger) foundation to start with I would think.

 

[Gregg56]

Re: Where痴 the best place or way to increase performance with a chainsaw.

Simple, 16 inch bar, 8 tooth drive sprocket, 3/8 chain.
It will cut like a "hot" saw. Be sure to hang on!

 

[Kyle_in_Tex]

Re: Where痴 the best place or way to increase performance with a chainsaw.

We all know that we should run the octane rating that's recommended by the manufacturer. 93 octane in an 87 octane engine will do nothing. Unless, of course, you have say, a large carbon buildup in the saw that is raising compression and creating a predetonation condition. Then a higher octane could help with the predetonation and seem to increase power. It's not increasing power. It's running like it would on 87 if it were carbon free.

If you have a saw that you want to get some more oomph out of, the easiest way is to modify the muffler and adjust the carb. But before you do that, as others have suggested, pull the muffler and look inside the cylinder to see if it's all carboned up in there. If it is, get some gaskets, tear it down, clean it out, and put it back together again. Adjust the carb correctly, etc... and off you go.

All the talk about adjusting the squish.... don't go there unless you want to, but it's a waste of time. The saw should run well in stock configuration. A muffler mod is easier to accomplish. Buy a second muffler if you're not sure, so you can go back to stock configuration easily. Also fun to switch back and forth to see the differences.

I did quite a bit of work on my motorcycle back in the early 80's. It's a Yamaha RD400 two-stroke twin. Once you start messing with getting more power out of a two stroke engine, you're going to go down the road of compromise. The more power you try to make at the top, the harder it is to have any low-end power. Now you don't need power at the low end on a chainsaw, because you typically run them full trigger. So you're after more power at the top end. That means you want it to suck in and burn as much fuel as possible. Opening up the muffler a bit is a pretty easy way to accomplish that.

On my bike, I installed expansion chambers and mildly ported and polished the exhaust ports. I also installed lighter reed valves and HUGE carbs, and milled the heads to increase compression just a bit. We never messed with squish adjustments (it wasn't called squish back then, that I recall, but it's the same thing). It wasn't worth the effort for the amount of power gained compared to all the other modifications. Exhaust and carbs is where it's at.

Forgot to mention that I had that little 25 cubic inch engine taking me down the 1/4 mile track in 11.92 seconds at 119mph....

Agreed. Moss, you and I have a lot in common. Commuting in Impalas until the antenna is sticking out of the dirt. (mine has about 332K, but is retired)...And I bought the first the first 1976 RD400C model to come to our town when I was 16. Loved it. Also had an '84 RZ350. Did a bit of porting on both. Toomey pipes on the RZ.

For 98% of people, just get a bigger saw if you need more power.....and keep the chain sharp.

A few weeks ago I was working on a sticking choke cable in my Power Trac. I leaned over to pick up a wrench and that was that. I was on my knees crying like a baby. Took me about 20 minutes to get 40' to the house. Took a full day before I could move without wincing, and it was sore for a week. Got out my empowered woman yoga mat and started doing my back excersices again that I'd been slacking off on. :laughing:

Oh my, hope your back is better.

Cubic Boron Nitride sharpening wheel. CBN is the way to go. You can sharpen your chain without turning it blue and tempering it.

 

[Kyle_in_Tex]

Re: Where痴 the best place or way to increase performance with a chainsaw.

Here's a question.

Will 4 strokes ever be able to be light enough to be chain saws?

and

Are Shindaiwa/Echo saws designed and made by Shindaiwa or Echo? They are both the same, just different colored plastic shells and stickers...

 

[4570Man]

Re: Whereç—´ the best place or way to increase performance with a chainsaw.

Here's a question.

Will 4 strokes ever be able to be light enough to be chain saws?

and

Are Shindaiwa/Echo saws designed and made by Shindaiwa or Echo? They are both the same, just different colored plastic shells and stickers...

I hate 4 stroke handheld equipment so I’ll probably never own one by choice.

 

[4570Man]

Re: Whereç—´ the best place or way to increase performance with a chainsaw.

Simple, 16 inch bar, 8 tooth drive sprocket, 3/8 chain.
It will cut like a "hot" saw. Be sure to hang on!

I don’t see how the bar is going to make any difference. Cutting a 12” log with a 16” bar or a 20” makes very little difference. I’m betting the 20” bar will actually hold a better average since it dulls slower. Cutting a 18” tree with a 16vs20 bar the 20 will still win. I think they cut slower with the tip buried and you have to walk to the other side of the log with the short bar.

 

[ericm979]

Re: Where痴 the best place or way to increase performance with a chainsaw.

Will 4 strokes ever be able to be light enough to be chain saws?

Cam, cam drive, valves, rockers, pushrods can only get so light. Pistons and cylinders can be lighter than two strokes but that does not make up for the cam and valves. Also a four stroke needs more displacement to make the same power, which adds weight.

Another problem is having to run in any orientation. Stihls 4mix solves that problem by using premix and routing oil vapors through the head to lube the cam and valvetrain. But that requires rolling element bearings which add weight. It also does not improve emissions over a two stroke as the engine is still burning premix oil. It's only used in string trimmers which don't need to run upside down like a chainsaw does. I don't know if it can handle running upside down at full throttle for long periods.

There's a chinese four stroke chainsaw that's appeared in Australia.

 

[MossRoad]

Re: Where痴 the best place or way to increase performance with a chainsaw.

....

Oh my, hope your back is better.

...

Cyclobenzaprine and alcohol.... :thumbsup:

 

[MossRoad]

That's a very good point about 4 stroke engines and angle of operation....

if it has a crankcase with oil in it it has to be able to suck and pump oil at all angles so some sort of tubes with multiple pickup points with balls to block the ports as it rolls around up and down, sideways, etc...

you could put a separate oil tank with a flop tube in it (like your fuel filter on the hose in the gas tank), but again, you'd have to have several return ports and pump, etc.... to get the oil back to the tank.

It just starts getting complicated to keep the 4 stroke engine lubed and so many different angles of operation VS a 2 stroke engine.

 

[ericm979]

Even a dry sump system depends on gravity to get the oil down from the head into the crankcase where it can be picked up by the scavenge pump (or to get oil in the head down to the pickup located there). It also depends on gravity to separate oil from air in the tank.

Husaberg's first four stroke dirt bike didn't use an oil pump. Instead they used the crankcase compression with strategically placed reed valves to move oil/oil mist up from the cases and into the head then back down. It worked better than it sounds but not well enough- they went to an oil pump in the next version.