Another chainsaw dyno...

[MustangMike]

Low quality bait.
Not maybe. I could. But I won’t do that for several reasons:
1. What I’ve mentioned is nothing new, it’s old news and has worked for decades on all platforms of gas combustion engines (especially 2strokes, chainsaws included). There’s no magic “build a better mousetrap” here, to claim that is ignorant. I never claimed that. Are you implying I claimed that?
2. Factors that get forced into the excuses of availability or bs reasons against, interjecting rules, ignoring supporting mods especially, etc, will render these long proven modifications (not theories) a waste of time and the results will not be proven.
3. Not a long time established member, which means no authority according to keyboard commandos.
Therefore, bait ignored. Carry on.

Before I started playing with chainsaw motors I was in full agreement with everything you have said, so I'm not trying to offend you.

Please read the reasons I've mentioned (which I've learned from others) and see if they don't make a little sense, even when everything you say is true for most other engines.

Obviously you are a person with knowledge, so we would like to have you here, but please don't close your mind to new things. Also, don't forget that we don't burn gas, we burn mix, which will generally have a lower octane rating (flash point) but a higher cetane rating (burn time). All this stuff factors in.

Diesel fuel has lower octane rating than gasoline, which is why diesel engines need direct injection and don't need spark plugs. Most diesel engines have about twice the compression of gasoline engines, but they also generally operate at much lower RPMs. 7,000 RPMs with that much compression would likely tear most of them apart.

Lots of folks here from all over the world do lots of testing, and everyone here has learned from it.

 

[TreeLife]

Low quality bait.
Not maybe. I could. But I won’t do that for several reasons:
1. What I’ve mentioned is nothing new, it’s old news and has worked for decades on all platforms of gas combustion engines (especially 2strokes, chainsaws included). There’s no magic “build a better mousetrap” here, to claim that is ignorant. I never claimed that. Are you implying I claimed that?
2. Factors that get forced into the excuses of availability or bs reasons against, interjecting rules, ignoring supporting mods especially, etc, will render these long proven modifications (not theories) a waste of time and the results will not be proven.
3. Not a long time established member, which means no authority according to keyboard commandos.
Therefore, bait ignored. Carry on.

Fabz? Is that you? Lmao

 

[Red97]

Ok, those runs are done. Just finished swapping the jug. I'll see if this recipe adds any low end.

 

[d997tt]

Before I started playing with chainsaw motors I was in full agreement with everything you have said, so I'm not trying to offend you.

Please read the reasons I've mentioned (which I've learned from others) and see if they don't make a little sense, even when everything you say is true for most other engines.

Obviously you are a person with knowledge, so we would like to have you here, but please don't close your mind to new things. Also, don't forget that we don't burn gas, we burn mix, which will generally have a lower octane rating (flash point) but a higher cetane rating (burn time). All this stuff factors in.

Diesel fuel has lower octane rating than gasoline, which is why diesel engines need direct injection and don't need spark plugs. Most diesel engines have about twice the compression of gasoline engines, but they also generally operate at much lower RPMs. 7,000 RPMs with that much compression would likely tear most of them apart.

Lots of folks here from all over the world do lots of testing, and everyone here has learned from it.

That’s great that you learned from others. I did as well, difference being I’ve verified the claims as real or BS. How much of what you’ve learned have you verified yourself without limiting factors, excuses and rules set?
Why bring diesel/cetane combustion into the discussion? Are you mixing at 20:1 where that discussion would be relevant?
I know what a 2stroke burns, and only when going extremely rich on the oil would your mention of it begin to have any relevance. Yes the richer your oil mix is, the lower the octane rating will be and at some point you start measuring in cetane vs octane. That would be a relevant discussion if all we were referring to were old McCulloch and Homelites prior to 1970s. Not the case here.
You can always find reasons to counter something. Usually it involves rules or availability or set tuning or whatever is popular.
Close my mind to what? Accepting popular claimed rules and limits? 12 years ago it was unheard of to do anything on a chainsaw besides maybe a slight muffler flow increase. This is simple sh*t, why are you trying to claim it’s complicated and/or impossible?

 

[huskyboy]

View attachment 289162

All with a Muffler mod

661,390xp,500i

661 had less torque than the other two smaller saws below roughly 9000rpm... Interesting. I guess you’d feel that with dogging it in. Maybe a port job would fix that?

 

[d997tt]

661 had less torque than the other two smaller saws below roughly 9000rpm... Interesting. I guess you’d feel that with dogging it in. Maybe a port job would fix that?

Combinations of factors. Powerband, etc.

 

[Nutball]

7,000 RPMs with that much compression would likely tear most of them

It does, but they can't make crazy power on tons of boost at low rpm. I was surprised to hear they run diesels that fast. Makes sense for 2-4000hp

 

[John235]

D997tt This is my favorite thread. And I’m tired of reading through your ranting. Please find another one to share your superior knowledge in.

 

[MustangMike]

That’s great that you learned from others. I did as well, difference being I’ve verified the claims as real or BS. How much of what you’ve learned have you verified yourself without limiting factors, excuses and rules set?
Why bring diesel/cetane combustion into the discussion? Are you mixing at 20:1 where that discussion would be relevant?
I know what a 2stroke burns, and only when going extremely rich on the oil would your mention of it begin to have any relevance. Yes the richer your oil mix is, the lower the octane rating will be and at some point you start measuring in cetane vs octane. That would be a relevant discussion if all we were referring to were old McCulloch and Homelites prior to 1970s. Not the case here.
You can always find reasons to counter something. Usually it involves rules or availability or set tuning or whatever is popular.
Close my mind to what? Accepting popular claimed rules and limits? 12 years ago it was unheard of to do anything on a chainsaw besides maybe a slight muffler flow increase. This is simple sh*t, why are you trying to claim it’s complicated and/or impossible?

Well, when you build an Asian 660 (or any 660) that you want to run against mine, let me know. No pipes, etc, just a usable woods port saw, and we will see if I learned anything on this site.

 

[Red97]

661 had less torque than the other two smaller saws below roughly 9000rpm... Interesting. I guess you’d feel that with dogging it in. Maybe a port job would fix that?

I'll finish the other run in the morning and put the ported 500i on the same graph.

If you notice the 661s curve is a bit flatter. It is less but it dosent feel like it is gaining/losing where the others feel like they lack top end and the tq just keeps climbing as you dog in.

 

[d997tt]

Well, when you build an Asian 660 (or any 660) that you want to run against mine, let me know. No pipes, etc, just a usable woods port saw, and we will see if I learned anything on this site.

Thanks for thoroughly answering all my questions that were in direct relation to your last post and flexing your Asian 660 Holesfagma. Now will you teach me to count to potato?

 

[d997tt]

I'll finish the other run in the morning and put the ported 500i on the same graph.

If you notice the 661s curve is a bit flatter. It is less but it dosent feel like it is gaining/losing where the others feel like they lack top end and the tq just keeps climbing as you dog in.

Very nice of you to do all this work, I hope you’re compensated for it.

 

[wcorey]

Well here I go again, at least we're talking chainsaws...

You can always find reasons to counter something. Usually it involves rules or availability or set tuning or whatever is popular.
Close my mind to what? Accepting popular claimed rules and limits?

It's kind of funny that you claim we're closed minded here and stuck in the rut of popular beliefs while it's you who's just as guilty of refusing to accept that there may be exceptions to your own long held 'rules' of tuning where saws are concerned.

And yes, I do put more weight on peoples (that I've known for years) research, opinions and claimed results (and where I've seen their outcomes with my own eyes), over someone who just joined today and for all I know has never even run a saw. This is the internet after all...
Unfortunately you do have to put in some time and maybe some proof of what you're pushing before you're taken seriously here or anywhere for that matter.

12 years ago it was unheard of to do anything on a chainsaw besides maybe a slight muffler flow increase.

Don't know what rock you've been living under as to the chainsaw modding world but...

I started with saw porting and the whole saw forum thing just about 12 years ago now and at that time, people were spouting just about the same quote as well as that there wasn't much new being done in all that time. Been there done that sort of deal.
I guess it's true that history repeats itself.
I think what has really changed is the shear numbers of people getting into it and a much more open proliferation of information.
And a lot more emphasis on work saws as opposed to race saws, whereas the line between the two is much thinner than it used to be.

In 'the old days', you had to be somewhat in with the in crowd to get good detailed porting info, the well known builders in particular held their cards tight to their chests and if you spilled info and it got out you got labeled a rat or heretic.
No secrets to the unwashed masses, lol.
Still a bit of that of course but usually for very specific 'recipes' and things that would only apply to a single model of saw.

One of the big things many of us have learned here is that yes there are general rules for saw porting/tuning (that sometimes buck the trends used on other types of 2t motors) that can be followed for a favorable outcome but there also seems to be more exceptions than there are rules.

 

[RI Chevy]

Well stated Bill...

 

[mdavlee]

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.

I tested a *s-word ton of fuels and with these short stroke saws with compression ratios of about 7.8-8.3 :1 87 was always fastest. Cants with the same chains and milling cuts 4’ long all showed the same. Test saws were ported with 185-210 psi on a gauge. Map them out by chamber and everything and they’re still low compression compared to other engines. Methanol in one 046 was turning 13k or a little higher in a Cant.

 

[SOS Ridgerider]

Here’s a thread for the hot topic of the day, so we don’t clog up Joe’s dyno thread.

I suggest we move the discussion over here:

https://opeforum.com/threads/what-octane-is-best-and-why.23934/

 

[dall]

aft

 

[Red97]

Ported 661. I'll add the other recipe to the graph in the am.

See if it can make some more tq. I expect it to be a little less hp, but maybe it will surprise.

 

[Woodpecker]

Fabz? Is that you? Lmao

Nailed it!

 

[Mastermind]

I deleted the troll. Sorry Joe. I would have sooner, but was busy.