7 or 8 spline sprocket

[Lobo]

I need to go out and buck already cut to length maple, oak, elm and birch this stuff is mainly 4 inches to 10 inches in dia., some at 12 inches also.
This stuff has been there all winter and is frozen.

My chains are filed sharp and raring to go, I was thinking that on a 026 that is ''taching'' out at 13,600 no load with bar & chain I might have a gain in speed if I went with a 8 tooth sprocket over a 7 tooth.

Am I out in left field with this theory or is it correct ?

 

[TonyM]

8 tooth .325? You could try it, but based on some tests I've done, I think you'll find it's only faster in the smalllest of wood on a 50cc saw. Might be faster on the 4" stuff, but I bet it will be slower on the 12"

 

[Lobo]

Tony, thanks for the reply.

I can change over to 3/8'' also, but if this will not make any difference again because of the displacement, then why bother.

 

[bwalker]

A 026 stock is much happier with a 7 pin, but in the size wood you are talking a 8 will work great. I would also run it around 14k. I think you will find that the 026 is the most sensitive saw out there as far as carb tuning goes so your saw might be differant. Just use the cut and feel method to find the coorrect no load rpm.

 

[TonyM]

I went and cut wood with the Dolmar 115i again yesterday. This saw would eat an 026 for breakfast, lunch, and dinner. It uses an 8 pin .325 drive. In smaller stuff under 8", I can't tell the difference in speed between my ported Solo, which I found is faster with a 7 pin, and the 115i. I got into some 16" oak, and I felt the 115i didn't have enough juice for the 8 pin. I grabbed the Solo, and sure enough, it started to outcut the Dolmar fairly well in that size wood. I may even try a 7 pin on the 115i, but I don't have one here right now.

 

[Lobo]

I went and cut wood with the Dolmar 115i again yesterday. This saw would eat an 026 for breakfast, lunch, and dinner. It uses an 8 pin .325 drive. In smaller stuff under 8", I can't tell the difference in speed between my ported Solo, which I found is faster with a 7 pin, and the 115i. I got into some 16" oak, and I felt the 115i didn't have enough juice for the 8 pin. I grabbed the Solo, and sure enough, it started to outcut the Dolmar fairly well in that size wood. I may even try a 7 pin on the 115i, but I don't have one here right now.

Tony, why would a saw with equal HP and set at the same rpm eat another for breakfast lunch and dinner, assuming same bar & chain, wood etc.

 

[TonyM]

The 115i is rated at slighty more horsepower than an 026, and I have opened the muffler up a bit. This is the fastest stock 50cc saw I've run yet, including the 026 PRO, and Solo 651. My Solo was faster than the 026 PRO when both saws where bone stock. Now the 115i is nearly as faste as the ported Solo 651, which probably gained 15-20% after the mods. I don't have an 026 anymore to make a direct comparison with, but based on past results, I think the 026 would be no match for a 115i.

 

[Lobo]

Tony, the European 115i has 3.7 hp and I believe an injection fuel system, I am not sure if the ones sold here are identical or not. That is however 0.2hp advantage, slight but it is there.

Stock for stock, (excluding all modifications) same conditions, equipment, wood etc., to say that it will eat another model for breaky, lunch & dinner maybe IMHO a bit exagerated, does it have a possible advantage, yes by 0.2 hp, but making it sound like a Ferrari over Miata may not really be very accurate as they are not that far from one another. (excluding all modifications)

Sachs/Dolmar have always made good products and I will never dispute that as a Dolmar may well be my next purchase if they can get their act together here, however keeping everything in perspective you could only established a true picture with controlled tests and timed cuts, then quantify a difference.

 

[chainsawworld]

rim size is based on your application. your 026 should have little problem with .325/8 on a 16" bar. as the bars grow longer the rim should get smaller. if you are cutting a steady diet of soft woods and you can keep your chain at peak proformance you MAY get away with .325/8 on a 20" bar.
as you can see by this photo, a great deal of options are available.......
marty

 

[eyeinstine]

Lobo,

Dont always assume that equal HP means equal performance.. Maybe i'm wrong speaking from a automotive backround, but theres MUCH more to the power numbers than what the dyno meter peaks at. Its the amount, or volume of power collected through a large, and wide power band. Kinda hard to describe with some dyno graphs to show it.. That dolmar could very well only have .2 peak HP more, but if it makes more HP (torque would be a better word) over a longer range than the competion, then it will perform much better.. It will also be more forgiving to operator error and more forgiven to bar length, chain, sprocket etc..

Ron

 

[Lobo]

Lobo,

Dont always assume that equal HP means equal performance.. Maybe i'm wrong speaking from a automotive backround, but theres MUCH more to the power numbers than what the dyno meter peaks at. Its the amount, or volume of power collected through a large, and wide power band. Kinda hard to describe with some dyno graphs to show it.. That dolmar could very well only have .2 peak HP more, but if it makes more HP (torque would be a better word) over a longer range than the competion, then it will perform much better.. It will also be more forgiving to operator error and more forgiven to bar length, chain, sprocket etc..

Ron

Having spent 20 years in the automotive industry myself I ahve to agree with you, let me put it this way torque gets the grunt work done and usually in automotive applications the lower the rpm the torque starts the better it is.
That is why in real heavy applications today the power plants have noticeably less revs than 25 years ago but lots more torque starting at as low as 1000 rpm's. Which is also part of my thinking when I posted to Tony.

 

[Lobo]

rim size is based on your application. your 026 should have little problem with .325/8 on a 16" bar. as the bars grow longer the rim should get smaller. if you are cutting a steady diet of soft woods and you can keep your chain at peak proformance you MAY get away with .325/8 on a 20" bar.
as you can see by this photo, a great deal of options are available.......
marty

Marty the picture is worth 1000 words.

Thanks

 

[tony marks]

i have saws that easily handle 8 pin with no trouble.. however ive found i didnt have to watch rpm as much with the 7 .. it cuts just fine an almopst as fast in smaller wood.. some stronger in thick hardwood.. somebody into total speed would go 8 ..me im in to getting the job done.. 7 pin does just fine..jmo

 

[TonyM]

Well, like I said, I no longer have an 026 to compare to. I did have an 028 Super in for repairs, and that 115i was faster than the 028 Super, enough so that I feel comfortable in saying that without using a stop watch to test it. I think that horsepower numbers are only an indication, but the final determination has to be made by using and timing the saws. A 4.0 Hp stock Solo 651 doesn't outcut an 026 enough to feel like it makes that much more horsepower, but yet that's what the peak power measures at. That 115i may be rated at 3.7 Hp, but it feels like it cuts a lot better than that. The 8 pin sprocket may be part of the reason, up to a certain diameter wood, anyway. I wish I had an 026 to do some timed cuts against the 115i in maybe three different diameters and using 7 and 8 pin sprockets. That might prove to someone else what I "feel" by just running the saws.

 

[Lobo]

A 026 stock is much happier with a 7 pin, but in the size wood you are talking a 8 will work great. I would also run it around 14k. I think you will find that the 026 is the most sensitive saw out there as far as carb tuning goes so your saw might be differant. Just use the cut and feel method to find the coorrect no load rpm.

Sensitive, yikes, adjusting it the other day I really had a screamer, didn't pay full attention to what i was doing she started to really scream, when I put the tach to it she was up at 16,800 rpm's , brought it back down real quick and eventually adjusted it to 13,600.

Ben, do you feel yours is better at 14,000 ?