The All Aussie Hort Wanker Thread

[Terry Syd]

OK, I get the power vs resistance analogy and how it won't be a linear increase in resistance. However, the 660 appears to have the extra torque to pull the higher gearing, maybe..

It appears we need to look at torque rather than horsepower. It will be the torque that twists the sprocket. A 8-pin is a 14% overdrive, so we need 14% more torque to twist the sprocket with the same load. However, using a non-linear increase in resistance due to the increased chain speed through the wood, the increased torque requirement will be in excess of 14%.

That sounds reasonable. Thus, the racer running a 10-pin is using a race chain with reduced resistance in order to run the chain speeds he does. Likewise, a Narrow Kerf chain is also reducing the resistance and thus dropping the torque requirements.

Hmm, now that I've argued myself into that corner, I've got to figure out why raising the cutting speed, say by porting and muffler mod (no increase in compression ratio), increases the cutting speed. The torque of the engine stays the same, it is just happening at a higher RPM. OK, so now were talking about increased horsepower, the ability to do more work.

Whereas using an 8-pin to increase chain speed (14%) relies upon a given torque figure, a modded saw that turns 14% higher RPM is using the same torque figure, BUT with the addition of 14% more power pulses to move the chain. Yep, that works.

Bottom line, if you want to turn the chain 14% faster, then pushing the torque higher in the power band is the easiest way to achieve the extra chain speed. If you are going to use a bigger sprocket to achieve the chain speed, then reducing the load (faster chain, shorter bar, smaller wood) is required. - I'm still having a hard time imagining that 660 not pulling the 8-pin, I thought they had more grunt than that.

So horses for courses, if your doing a lot of cutting of smaller wood or soft wood, you can get by with the 8-pin, it will just slow down some when you bury the bar and put a big load on it. If you don't want to use the 8-pin for the increased chain speed, you can spin the engine 14% faster with the resulting wear that occurs from the increase internal forces with the velocity squared function. - Compromises, always compromises.

Yeah, I agree on the harder wood and the cutter not wanting to take a bite, especially if the edge is off the chain. I'll pick up a 7-pin for my bucking saw and see if it improves the chain life. Crikey, I'm already on the spikes trying to keep the RPM down.

EDIT: It just occurred to me that maybe I should increase the cutting angle (drop the rakers) on a chain and see if that slows things down enough by taking a bigger bite, resulting where I can get an extra cut or two out of the chain. I'll get a 7-pin just in case it is too much for the saw.

 

[Brewz]

I used my 066 with a 30" 3/8 bar in 30+" timber recently.
I started with the 8 pin and it pulled it no problems. It cut fast but there was more vibration and the wood chips were smaller.I switched to the 7 Pin and vibration was reduced and the wood chips were bigger, like the teeth were getting a better bite at the wood at the slower speed.

Cut speeds could have been a couple seconds either side of each other but to be honest, I dont give a rats about the couple seconds difference either way in a 22 second cut.
I was looking for comfort and chain life and these were definitely better with the slower chain speed.

I didnt want to start a speed debate by posting that video. I more wanted to show that faster is not always better.

 

[Terry Syd]

Yeah, but it does get some of us thinking. I'm going to try the increased cutting angle and maybe the 7-pin. I may come up with a combination that works better in what I'm cutting.

 

[CR888]

Inner top plate angle will effect how fast the chain pulls itself through the wood. Fast full chisel chain may be 60° factory spec where as semi chisel may be 75° factory spec. This can be adjusted for better or worse according to the density of wood being cut. The chain also needs to be able to remove the chips. Having the fastest setup is an understanding of what your cutting and then matching the most suitable chain size to power head then tuning the chain itself. Overly aggressive chain is not fast as energy is lost everywhere, IMO its about delivering that energy in the most efficient way. Like my XR650 dirt bike, it has a stack of power, but is not always capable on dirt of turning that into speed (but it will throw a nice rooster tail of mud when twisting the throttle @100). A better setup YZ250 will blow me into the weeds as it can better utilise the power converting it into speed. I am probably not completely right but that's how I view it.

 

[Brewz]

For really hard stuff, I would go with a 7 pin and keep the rakers up high between .020 and .025.
Really hard wood will tend to chip out as opposed to shave out like soft wood will.
As the wood chips, the chain will tend to lift with the cut and then have to dig back in again.

With shallow rakers, your not asking as much of the teeth in one hit so they will be less likely to dig in deep and the chip up.
I think, and its only my opinion, the best balance will be where you match the cut depth to the timber hardness to achieve a smooth cut where the teeth stay at a level where they are removing more material as opposed to chattering while attempting to cut deeper.

Once again, referring to your super hard tree, slower will be better.

Another comparison....... drilling stainless steel. Its harder so you cut it slower.
What happens when you try and drill it fast........ you get lots of heat and a blunt drill.

Slow and steady wins the race.

 

[Terry Syd]

346oe fastest with 3/8lp-7, but 325-7 is close and lasts better.

How does 325 chain work on really hard wood? A 325-8 is close to the same chain speed of 3/8-7, so since 325-7 is moving even slower, then theoretically it should get a better bite.

Perhaps it comes down to chip clearance, but what is the maximum bar length in 325 before chip clearance becomes a problem? Then again, on really hard wood there isn't the chip clearance problem one can experience in soft wood.

 

[Brewz]

325 has a narrower kerf so will sap less power in the cut but with my limited experience so far cutting with 325, the smaller teeth do tend to dull faster

I used my 026 to quarter up some of that big timber I cut on the weekend and the 325 cut it fast but dulled and slowed after 4 or the big rounds.

I bolted my 25" bar running .404 Stihl RC on my 066 and did the remaining 10 rounds, and the chain was still sharp.

The bigger the teeth the longer they last.

404 is fricken awesome!!!

 

[Terry Syd]

I wish there were some guys around here running various combinations that I could try. I normally get 4 cuts (maximum) with the 3/8 chain, it would be freaking great to get 10 cuts! Was the .325 on the 026 also Stihl chain?

 

[CR888]

IMO stihl .325 cutters are near exactly the same size/kerf width as standard 3/8, they are just closer together so there's more of them in the same size loop making for smooth controllable cutting. Get some 36RM and 26RM in your hand and take a good look. Narrow kerf .325 there is a difference for sure. Take from this what ya's will, once I dropped the depth gauges too much on a chain and it was dangerous and not usable in the average green hardwood I was cutting. I put the chain aside as the cutters were half used up believing I'd ruined this chain and filling back the cutters was not an option as the chain was already half used up. On a job one day a customer wanted garden sleepers cut up that had been in the ground 30+ years that were packed with dirt but still solid and heavy. I thought I'd give this 'useless' chain a go and save my other good loops. Well to my surprise this chain that was unusable in softer greener wood cut smooth and much better than new 'off the roll' chain in this stuff (it was as hard as concrete) and sank in water like a brick. It made me rethink my understanding of depth gauge height and its effects in different wood. Initially I was gob smacked until I started thinking about it a little more. This wood was so hard the chain was unable to take that chain stalling, sprocket wrecking, chain stretching bite and cut really really smooth.

 

[Brewz]

My 325 is Oregon

 

[weedkilla]

How does 325 chain work on really hard wood? A 325-8 is close to the same chain speed of 3/8-7, so since 325-7 is moving even slower, then theoretically it should get a better bite.

Perhaps it comes down to chip clearance, but what is the maximum bar length in 325 before chip clearance becomes a problem? Then again, on really hard wood there isn't the chip clearance problem one can experience in soft wood.

A lot comes down to the sharpening and depth gauge shape.
Two things first - I don't think you'll get a 325-7 rim on your 365.
And generally the lighter 325 chassis doesn't take abuse like 3/8.

However the smoother cut of 325 might help. The 3/8 might be chattering in the cut and that can be reduced with 325. It usually doesn't matter to me, as if it's hard it's usually dirty too.

 

[CR888]

I put lopro on a 16" bar on my ported 660 once, not sure I would do it again. There gets a point where a saw just begs for more chain. l modded the nose sprocket on a ms200t so it would run standard full size 3/8, it was not too bad but not too good either. Terry will struggle getting a 7pin .325 on a 365 due too clutch spline size. I ran into this wanting to run .325 on my 555(59cc) and had to use a 9pin. But I hear a clutch drum off a 550xp is a direct swap on a 555 so soon I will try a 7pin on the 555. The 9pin worked a lot better than I thought it would, but were talking 15" b/c.

 

[weedkilla]

I put lopro on a 16" bar on my ported 660 once, not sure I would do it again. There gets a point where a saw just begs for more chain. l modded the nose sprocket on a ms200t so it would run standard full size 3/8, it was not too bad but not too good either. Terry will struggle getting a 7pin .325 on a 365 due too clutch spline size. I ran into this wanting to run .325 on my 555(59cc) and had to use a 9pin. But I hear a clutch drum off a 550xp is a direct swap on a 555 so soon I will try a 7pin on the 555. The 9pin worked a lot better than I thought it would, but were talking 15" b/c.

The clutch swaps - but I have no direct experience with the drum. Logic says you'll be fine. I can check for you though.

 

[CR888]

l have a 550xp too (bad cad) but I just have not tried it yet. I'm 99% sure the drum will swap....I could then put the bigger 555 spline drum on the 550 and run .404 on it for fun and games. Finding a small mount .404 husky bar may be a bit of a problem, I don't think there is a big market for such stupid ideas. I could put a 404 nose on a small mount rsn husky bar. This is getting too silly now, but I do dumb stuff when I am bored.

 

[VinceGU05]

$2349 aud
$1645 usd

What are they in the states?

but if you shop around you could get one for 2000 bucks. could take away at least 150 bucks for shipping (US to Aust). so thats 1300 US. and if ya get stung for import duty? and local will have 12 months warranty. its not that attractive now with the dollar at all.

 

[VinceGU05]

For really hard stuff, I would go with a 7 pin and keep the rakers up high between .020 and .025.
Really hard wood will tend to chip out as opposed to shave out like soft wood will.
As the wood chips, the chain will tend to lift with the cut and then have to dig back in again.

With shallow rakers, your not asking as much of the teeth in one hit so they will be less likely to dig in deep and the chip up.
I think, and its only my opinion, the best balance will be where you match the cut depth to the timber hardness to achieve a smooth cut where the teeth stay at a level where they are removing more material as opposed to chattering while attempting to cut deeper.

Once again, referring to your super hard tree, slower will be better.

Another comparison....... drilling stainless steel. Its harder so you cut it slower.
What happens when you try and drill it fast........ you get lots of heat and a blunt drill.

Slow and steady wins the race.

use a geared saw.. or a old banger that doesnt rev like the modern saw. it maybe slower but may not need the sharpen the chain all day, hence just as quick !?!

 

[weedkilla]

l have a 550xp too (bad cad) but I just have not tried it yet. I'm 99% sure the drum will swap....I could then put the bigger 555 spline drum on the 550 and run .404 on it for fun and games. Finding a small mount .404 husky bar may be a bit of a problem, I don't think there is a big market for such stupid ideas. I could put a 404 nose on a small mount rsn husky bar. This is getting too silly now, but I do dumb stuff when I am bored.

That would be silly.....

However you could turn down a 404-8 rim and run 3/8lp for a rocket in pine

 

[Brewz]

Does anyone in Australia use pine for firewood?

 

[Terry Syd]

I cleared a dead pine from a friend's property. I thought it might work ok as kindling, so I stacked it for firewood. I was happy to finally get rid of the pine, the stuff burns fast, not a lot of heat or coals and more ash left behind. There is so much good firewood available, I don't know why anyone would bother with it. - It was fun to cut, it would make any saw feel like a light sabre.

 

[Brewz]

Those green coloured pine logs you get at the landscape places are ok.

Smell funny though