Another chainsaw dyno...

[huskyboy]

Honestly don't have the numbers off the top of my head. But it made more hp than the stock 500i. Tq would be close

So muffler mod the 462, save the 300.00 and buy spare bars/chain? That’s what I’d do imo.

 

[HYPERSAWS]

So muffler mod the 462, save the 300.00 and buy spare bars/chain? That’s what I’d do imo.

Nah still not the same power band

 

[huskyboy]

Nah still not the same power band

So I guess results in the wood still matter to a degree?

 

[RI Chevy]

Wood testing matters.

 

[Red97]

So muffler mod the 462, save the 300.00 and buy spare bars/chain? That’s what I’d do imo.

That is an option, if you like a more top end type saw.

The 500 still makes more tq.

Nah still not the same power band

Exactly, the stock 500 is starting to wind out where the 462 is really coming on.

So I guess results in the wood still matter to a degree?

Yes, you need to figure you cutting style, vibration, and ergonomics. A dyno can't decide that for each individual.

You mentioned in a different thread handle spacing, having an effect on balance. Those types of things really change the feel. More effort to get the same leverage while dogging in etc.

Wood testing matters.

Nobody ever said it didn't.

But hard to see how much the small changes add or lose.

 

[RI Chevy]

Yes. True Joe. All valid points.

 

[MustangMike]

Joe, (I know it is easy for me to say) it would nice to see the 390, 500 and 462 all muff modded on the same graph!

 

[MustangMike]

That is the 390 vs a stock 500i

Sorry for my misread Joe, busy as heck this time of year so I just "speed read" this stuff!

Did 3 returns this morning and came home to 8 messages on the machine. As I try to retrieve my messages, 2 more calls come in.

Then, as I try to return the calls, I get 3 more calls!

Seems like Monday's are often like that for me this time of year!

Guess I can't complain about being busy, but it sometimes gets real tough to keep up with it.

 

[d997tt]

Hey guys. I’ve been lurking for a while (About 2 years) and finally signed up. I have quite a few chainsaws I play with for fun and sometimes necessary on several of my properties. Various Husqvarna, Stihl, Dolmar/Makita, Jonsered and a few old Homelites and McCullochs.
Interesting results here. Really shows how far some chainsaw engines can be pushed and how little some need to improve.
My background is modifying engines (car/truck/bike and occasionally chainsaws)
A lot of what’s discussed here is common knowledge in modifying and tuning engines, besides the occasional error such as “made more power with lower octane” and that really annoys me because obviously that will only ever be true if you don’t tune for the higher octane. Higher octane allows for more ignition advance which in turn makes more power, and this is true whether naturally aspirated or forced induction, 2stroke or 4stroke, and of course on diesels it’s injection advance.
Another thing is matching flow throughout, filter/carb/engine/muffler. A bottleneck anywhere on those will limit power. Proper tuning for the fuel you have determines power limits also. Sure you can make good power with 220psi on 87octane, but you can make more with higher octane if you tune for it.

 

[RI Chevy]

Welcome to the forum!
There was testing done a while back. Fastest cut times were made from the lower octane fuels. Saws also ran cooler.
Test was done as straight up and as equal as possible.

 

[d997tt]

Welcome to the forum!
There was testing done a while back. Fastest cut times were made from the lower octane fuels. Saws also ran cooler.
Test was done as straight up and as equal as possible.

That’s obviously because those saws were tuned for lower octane at the rpm used in the cut. A higher advance and higher octane at those same rpm levels would make more power and obviously cut faster if the chain was matched for the power level and the wood that was cut.
Was the timing and fuel mix afr changed when using higher octane? No? Well there you go, of course it will make less power since the tune wasn’t changed and optimized for the higher octane.
It’s not difficult to install a afr O2/meter to prove this. Most saws are tuned for max rpm 4stroking. Ok, but what saw is used at 14k in the cut? Can that chain keep up? The cut rpm should be at an rpm where you have a good balance between hp and tq and chain capability to match.
Many factors come into play.
Also, a richer mix will always keep the engine cooler regardless of octane.

 

[RI Chevy]

I'm not going to argue here.
It was an Mtronic saw (661) if I remember correctly with NIB chain.
Do a search for RedBull661 on U Tube. He did lots of great unbiased testing.

 

[wcorey]

That’s obviously because those saws were tuned for lower octane at the rpm used in the cut. A higher advance and higher octane at those same rpm levels would make more power and obviously cut faster if the chain was matched for the power level and the wood that was cut.
Was the timing and fuel mix afr changed when using higher octane? No? Well there you go, of course it will make less power since the tune wasn’t changed and optimized for the higher octane.
It’s not difficult to install a afr O2/meter to prove this. Most saws are tuned for max rpm 4stroking. Ok, but what saw is used at 14k in the cut? Can that chain keep up? The cut rpm should be at an rpm where you have a good balance between hp and tq and chain capability to match.
Many factors come into play.
Also, a richer mix will always keep the engine cooler regardless of octane.

Have you tried your theoretical tuning outcomes on chainsaws? Since it’s so easy...

Many of us used to think our experience with other types of engines could be applied to saws only to find that they’re very contrary little beasts that often defy theory and reason...

 

[RI Chevy]

 

[NightRogue]

Hey guys. I’ve been lurking for a while (About 2 years) and finally signed up. I have quite a few chainsaws I play with for fun and sometimes necessary on several of my properties. Various Husqvarna, Stihl, Dolmar/Makita, Jonsered and a few old Homelites and McCullochs.
Interesting results here. Really shows how far some chainsaw engines can be pushed and how little some need to improve.
My background is modifying engines (car/truck/bike and occasionally chainsaws)
A lot of what’s discussed here is common knowledge in modifying and tuning engines, besides the occasional error such as “made more power with lower octane” and that really annoys me because obviously that will only ever be true if you don’t tune for the higher octane. Higher octane allows for more ignition advance which in turn makes more power, and this is true whether naturally aspirated or forced induction, 2stroke or 4stroke, and of course on diesels it’s injection advance.
Another thing is matching flow throughout, filter/carb/engine/muffler. A bottleneck anywhere on those will limit power. Proper tuning for the fuel you have determines power limits also. Sure you can make good power with 220psi on 87octane, but you can make more with higher octane if you tune for it.

I believe that theory, I've said this in the past. When i wrongly discovered on 084 with the dual flywheel key, with wrong slot key(overly advanced) you can run 100 octane without ping/detonation and it made crazy power and response was off the roof. Until i fried that coil, not sure why

Anyway, you'll need that high compression and ignition advance to fully harness the high octane benefit. Question is who's gonna do it among us lol, dont look at me haha

Sent from my INE-LX2r using Tapatalk

 

[Egg Shooter]

I, for one, am willing to chip in $ to Joe to do the octane testing on the dyno. Takes the wood and operator out of the equation. Id like to see 87 E-free vs the rest including VP 94 and Sunoco Optima 95. Both are small engine fuels.

 

[Egg Shooter]

Same oil exact same ratio for all octanes of course.

 

[d997tt]

Have you tried your theoretical tuning outcomes on chainsaws? Since it’s so easy...

Many of us used to think our experience with other types of engines could be applied to saws only to find that they’re very contrary little beasts that often defy theory and reason...

Theoretical? No, actual experience with many types of engines although the only ones I haven’t dynod are chainsaws. I don’t have a small enough dyno. (My mustang 4whl only reads down to around 50hp)
Again, factors. Any point can be made or argued when you set certain rules.

 

[wcorey]

I believe that theory, I've said this in the past. When i wrongly discovered on 084 with the dual flywheel key, with wrong slot key(overly advanced) you can run 100 octane without ping/detonation and it made crazy power and response was off the roof. Until i fried that coil, not sure why

Anyway, you'll need that high compression and ignition advance to fully harness the high octane benefit. Question is who's gonna do it among us lol, dont look at me haha

I've pushed the limits of tuning pretty far and have yet to achieve detonation in a saw running 87 ron/mon.
I guess I could maybe add some water to the fuel...

Some say this immunity is due to the relatively small bore sizes, narrow squish bands and low output.

If you don't think a boatload of people haven't already tested for this stuff I don't know where you've been but you haven't been paying attention or something.

Could be the larger size of the 084 pushes those boundaries...

 

[wcorey]

Theoretical? No, actual experience with many types of engines although the only ones I haven’t dynod are chainsaws. I don’t have a small enough dyno. (My mustang 4whl only reads down to around 50hp)
Again, factors. Any point can be made or argued when you set certain rules.

If you haven't done it on saws then from my perspective it's still theoretical...