Short stroke v's long stroke saws

[CR500]

Yeah...
Me too..

They work bigger than what they are..

Then there's the 9010..
It's big...
And works bigger.

Is it hard to find a 9010? In either color?

Sent from my non internal combustion device.

 

[Rob Stafari]

Is it hard to find a 9010? In either color?

Sent from my non internal combustion device.

I've personally only seen one for sale and its a PS-9000 not a 9010...
http://mansfield.craigslist.org/grd/5809191871.html

 

[mdavlee]

Is it hard to find a 9010? In either color?

Sent from my non internal combustion device.

A little. Might be able to find a Dolmar dealer with one sitting on the shelf for years that would love to sell it.

 

[SOS Ridgerider]

Is it hard to find a 9010? In either color?

Sent from my non internal combustion device.

There are ways to find them. I've been looking for one, and am very close to ordering one up. We have a member here on the forum who is a Dolmar dealer in the U.K. @ajschainsaws
I believe Amazon U.K. will ship one here as well, but I'd give my money to Andrew long before I give it to Amazon.

 

[Hedgerow]

A little. Might be able to find a Dolmar dealer with one sitting on the shelf for years that would love to sell it.

I think Boyd has one on a shelf in dresser, WI.
His handle on here is wetgunpowder.

 

[exSW]

I've personally only seen one for sale and its a PS-9000 not a 9010...
http://mansfield.craigslist.org/grd/5809191871.html

Dang went right the Frick past there yesterday.

 

[mdavlee]

I think Boyd has one on a shelf in dresser, WI.
His handle on here is wetgunpowder.

He probably still does

 

[ajschainsaws]

On 660 vs 661
A difference of 2mm in stroke change the bore and stroke ratio from :
660 : 54/40 = 1.35 ratio
661 : 56/38 = 1.474

From my exemple above we determined the best bore to stroke ratio is 1:1 .

Knowing these numbers it is evident that porting design and other factors impact much more final comportement of the saw than a variation of .124 in stroke ratio making it go from very very oversquare to very oversquare.

Low rpm ?
I would like to hear why you can't have a long stroke small bore saw to rev 13.5k . I have successfully built a saw with a 38mm stroke and 42mm piston holding 15000rpm in the cut with a 9 pin sprocket . Plans for this year are 16000 rpm 10 pin sprocket with a custom built CNC cylinder .

Also note that 125cc gp engines are 54mm bore and 54mm stroke and make close to 54hp at 13000rpm .

Why do they do chainsaws manufacturers do it ?
A bigger bore and smaller stroke makes for a more compact and light engine wich is why chainsaws are designed this way not for performance reasons.

On rod length
Rod length reduces piston friction that's one point but not the most important . There are two other aspects :

-Long rods increase ''dwell time'' at both ends of the stroke wich means more time for the mixture to burn .

-Transfers , due to their overall height and BDC position , are the most impacted by the increased dwell time . Meaning that for the same 120° of opening they will be opened for a longer period of time on a long rod motor than a short rod .
Now , we should also know that any well designed race engine is limited by the transfers . Makes sense now why long rods is superior everythingelse being equal ?

Great post

There where several stock production chainsaws with square motors
Including many of the earlier jonsereds

But my interest has been with the two saws listed below which have square motors and are at both ends of the RPM spectrum

Solo Rex 125cc 54mm x 54mm
Solo twin 100cc 40mm x 40mm

Two square engines from 50+years ago
The Rex will cut and chew through wood at 4K - 4.5k rpm and
The twin is at the other end proving that a square engined chainsaw can rev out and perform so well at that speed

Solo Super Rex 140cc 58 mm x 54mm. .??? Haven't used one yet
Solo twin 110cc. 42mm x 40mm if you cut into wood at 3/4 load then open that throttle too full load , go slap yourself f##### quick and hang on tight

The big twin reminds me of an bike I had in the late 80's
A Yamaha RD125 Twin awesome It had micron pipes tuned up to our road legal limits so loud it also had a square engine maybe 42 x 42 or 43mm x 43mm I think ??

 

[ajschainsaws]

There are ways to find them. I've been looking for one, and am very close to ordering one up. We have a member here on the forum who is a Dolmar dealer in the U.K. @ajschainsaws
I believe Amazon U.K. will ship one here as well, but I'd give my money to Andrew long before I give it to Amazon.

Thanks for sending me the SOS my friend there are a few scammers attacking amazon uk sellers I know one guy selling Bath and kitchen sealants that suddenly had 20-30 makita products being sold under his name

Yes those 52mm x 42mm long strokers are getting ready to rock

 

[Locust Cutter]

Is it hard to find a 9010? In either color?

Sent from my non internal combustion device.

I know where a ported one is that could be for sale for the right price, but I doubt you'd want to drop the coin for it... It's an Osage Orange eating Mother...

 

[Locust Cutter]

In fact I probably need to convert it to .404 as it's rather abusive to 3/8" cutters...

 

[Locust Cutter]

Mike Lee has some knowledge of this saw too... Now cutting cookies? No way.

 

[mdavlee]

Mike Lee has some knowledge of this saw too... Now cutting cookies? No way.

You'd be surprised what they'd do turned up with a good chain. Kind of wish I'd kept it around long enough to figure out the problem and see it run to its potential.

 

[jmssaws]

You'd be surprised what they'd do turned up with a good chain. Kind of wish I'd kept it around long enough to figure out the problem and see it run to its potential.

Ive never ran one but I hear there stout.
Same bore as a 7900 just a longer stroke?

 

[Iron.and.bark]

Yes , designing everything from the ground up by myself , Solidworks skills come in handy !

You persuadable to make a custom pistons?

 

[mdavlee]

Ive never ran one but I hear there stout.
Same bore as a 7900 just a longer stroke?

Yep

 

[ajschainsaws]

I didn't realise but the 9010 has the same configuration as another great saw you don't see much of these days the Dolmar 144 52mm X 42mm

Here's a few more

122. 44mm x 40mm 1.1
122 super 47mm X 40mm. 1.175
123. 47mm x 40mm. 1.175
133 52mm x 40mm. 1.3
143 55mm x 40mm. 1.375
152 / 153 55mm x 42mm 1.309

6400 47mm x 37mm. 1.27
6100. 47mm x 35mm. 1.34

603. 56mm x 42mm 1.333
662. 46mm x 38mm 1.21
Rex 54mm x 54mm. 1.00
Super Rex 58mm x 54mm 1.074
Twin 100 40mm x 40mm 1.00
Twin 110 42mm x 40mm 1.05

Jonsereds XF. 56mm x 45mm 1.244

 

[huskyboy]

Longest stroke saw I think is the dolmar 166 at 48mm.

 

[Locust Cutter]

Ive never ran one but I hear there stout.
Same bore as a 7900 just a longer stroke?

I just ran my 9010 today removing the last 4' of 3-stem 30" combined stump of an Elm of some iteration (not Siberian)... It was nasty and previous to the cutting today the 562 had done a darn fine job of it, but it was taxing it a bit. The 9010 just grunted through it like it does everything else.

 

[huskyboy]

My jonsered 930 super is a pretty torquey saw.