Another chainsaw dyno...

[Red97]

Should try a saw running a pipe and nitromethane on the dyno

Those saws always seem to make awesome looking videos while cutting wood.

While my pipe and pump gas made less power than the muffler on the 260, the saw sounded awesome and had neighbouring farms phoning in asking what’s going on over there

Did nitro without the pipe, it made a lot of power

 

[BonScott46]

The benefits of the 272 were originally the ease of running fingers and it let you get more intake. You don’t need to machine a lot to get your trans and intake right with a 46 piston. So that left you grinding down to get 79-80, whatever your target is. To grind the intake with good shape and lower that far, it was very easy to grind through. Thus, the reason for the 272.
I never thought my hybrid vibrated more than a 440 or 460. To each their own though.

Could a guy shave the intake skirt instead or both?

 

[Red97]

Might have first of the 5 deliveries tonight

4 others tonight/tomorrow, last should be Wed Thursday...

But animals....

 

[Red97]

In this dyno "down" time I would like to talk reasonable expectation from a saw model.

I realize the numbers are only 1 part of the entire build.

Dyno can't show the feel, attitude, balance, weight, taste yada yada yada....

I know personally I port at different levels.

Work saw
stock mannered, prolly out last and out produce a stock saw. Expected to run 20+ hours a week

I would call 10-20% + gains a win.

Firewood saw

little hotter, only has to work 2-3days a week and not all the hours a true work saw will see.

I would call 20-35% gain a win

Fun saw
May enter some try races, try funny fuel. V stack no filter etc.

Would expect 30%+ gains.

Now realize some can skirt the category a bit one way of the other.

But I know those are the 3 basic categories I use when someone wants a build done.

I feel that is one thing we have to keep in mind while looking at all of these numbers.

The type of build.

Any other thoughts on this?

 

[Dieselshawn]

I’d like a supercharged saw please.

660 stihl.

30 hp

 

[Terry Syd]

Did nitro without the pipe, it made a lot of power

Hmm, if you wanted a lightweight work saw without a pipe hanging off it, a bit of 'liquid oxygen' in the tank would be interesting. I'd never do it, but there are plenty of blokes on this forum that would.

Anybody want to risk their saw for a nitro run on the dyno?

 

[dall]

Might have first of the 5 deliveries tonight

4 others tonight/tomorrow, last should be Wed Thursday...

But animals....

View attachment 249037

i see @P.M.P. visited you not too long ago

 

[P.M.P.]

i see @P.M.P. visited you not too long ago

WTF are you talking about.

 

[dall]

WTF are you talking about.

lol

 

[huskihl]

WTF are you talking about.

Talking bout your girlfriend

 

[Deets066]

Could a guy shave the intake skirt instead or both?

Yes, you sure can. I tried a notch once on the intake skirt on a hybrid, cut skirt once also. Not really sure why, but they just didn’t perform as it should. It was most likely something else besides that. But it just left a sour taste in my mouth.

 

[Nutball]

In this dyno "down" time I would like to talk reasonable expectation from a saw model.

I realize the numbers are only 1 part of the entire build.

Dyno can't show the feel, attitude, balance, weight, taste yada yada yada....

I know personally I port at different levels.

Work saw
stock mannered, prolly out last and out produce a stock saw. Expected to run 20+ hours a week

I would call 10-20% + gains a win.

Firewood saw

little hotter, only has to work 2-3days a week and not all the hours a true work saw will see.

I would call 20-35% gain a win

Fun saw
May enter some try races, try funny fuel. V stack no filter etc.

Would expect 30%+ gains.

Now realize some can skirt the category a bit one way of the other.

But I know those are the 3 basic categories I use when someone wants a build done.

I feel that is one thing we have to keep in mind while looking at all of these numbers.

The type of build.

Any other thoughts on this?

I think keeping such categories in mind would be most useful to the guy who modified the particular saws run, since everyone has their own style, and some build them hotter than others no matter what category they aimed for.

My categories would be something like:

MM, BGD

Ported work saw, not super high compression, aiming for 20-30%, could be peaky or torquey

Ported work saw, high compression, aiming for max gains >35% without swapping parts, could be peaky or torquey

Fun saw: whatever makes more power.

 

[MustangMike]

I think most work saws should not be peaky, even if it means a little less top Hp.

I was pleased that mine had 8 or more Hp from 7,500 to 10,250 RPMs.

A saw that is hard to stop likely makes you think it is stronger than it is.

 

[Nutball]

I've found torque saws seem weaker than they are, just not impressive, but you can lean on them, while peaky saws seem every bit as powerful as they are, they just have to be kept in their peak power rpm. I like peaky for short bar cutting, even if it is a 30" log with a 20" bar on 90cc.

 

[huskyboy]

Why not shoot for both qualities in a saw? Is it possible? Model dependent? Not possible? Interested to hear what you guys have to say.

 

[Bjorn]

This is one of my favorites.

 

[RI Chevy]

I've found torque saws seem weaker than they are, just not impressive, but you can lean on them, while peaky saws seem every bit as powerful as they are, they just have to be kept in their peak power rpm. I like peaky for short bar cutting, even if it is a 30" log with a 20" bar on 90cc.

You been running your 2511s too much. Lol
Nothing like having a chainsaw PULL you into the log your cutting. Gives you whole new respect for the saw...

 

[Nutball]

Why not shoot for both qualities in a saw? Is it possible? Model dependent? Not possible? Interested to hear what you guys have to say.

I think you can find an in between. Some saws feel like they have 2 peaks: a high rpm HP peak, and a low rpm torque peak. My Chinese 660 feels like that on a 7t, Medicine Man's big Mac felt that way it too.

You been running your 2511s too much. Lol
Nothing like having a chainsaw PULL you into the log your cutting. Gives you whole new respect for the saw...

when I had my 2188 running a 8t rim with 20" skip (the 8t made it feel kind of peaky) I should have had a smooth bumper on it instead of spikes because there was no time to stop and dog it in, and it was a workout trying to hold the saw back enough to keep the spikes from catching.

 

[Redfin]

Just lock the crocs in 4wd when that happens Jeefy.

 

[CR888]

You been running your 2511s too much. Lol
Nothing like having a chainsaw PULL you into the log your cutting. Gives you whole new respect for the saw...

True....or push you up on your back heels on an uppercut.