Author Topic: For the Gearheads here! (Read 15956 times)

Crofter · « **on:** December 27, 2013, 06:30:44 pm »

I have done a bit of competition chainsaw cutting: once you have run a modified saw you never want to go back to stock!

Here is a few pics of a cylinder for a Husky 365 getting some mild modifications for a working saw. My own in this case.
If you go too wild with mods it narrows the power band and takes more attention to keep it happy. You can easily overheat them too if you lug them down.

This is an easy cylinder to work on as it is open port. The cylinder base gets machined down to raise compression and increase squish velocity and at the same time increase intake duration.
Bottom of ports get matched in shape to the crankcase openings and the discharge openings of the transfer ducts angle back above the top of the intake port for scavenging. Intake and exhaust ports are enlarged
Power goes up about a third and gas consumption near doubles but you cut twice as much wood in the same time (that is the rationale anyways!)
Oh yes, and it puts a big smile on your face when you can find someone innocent to bet against you!
My son is doing the whittling!

Riverrat · « **Reply #1 on:** December 27, 2013, 07:52:06 pm »

I been thinking about having my dolmar 5105 tricked out. Not sure if I will do it myself or have it done.

Crofter · « **Reply #2 on:** December 27, 2013, 08:13:32 pm »

I am not familiar with that model. Some saws dont yield much in the way of gains without losing longevity and or developing bad habits. Others have left lots on the table.

LazyBkpr · « **Reply #3 on:** December 27, 2013, 11:35:04 pm »

ALWAYS nice to have POWER when cutting wood.. but,, I usually work on things that have more than one Cylinder..

Slowmodem · « **Reply #4 on:** December 28, 2013, 12:31:11 am »

LazyBkpr · « **Reply #5 on:** December 28, 2013, 09:23:43 am »

LOL!!! WOOT!! NOW THATS A CHANSAW!!!!

blueblood · « **Reply #6 on:** December 28, 2013, 10:48:40 am »

Wow, that is awesome, but must have been heavy!

Perry · « **Reply #7 on:** December 28, 2013, 11:02:42 am »

Yeah!! LOL

Slowmodem · « **Reply #8 on:** December 28, 2013, 12:16:12 pm »

It's a two-man lift (two BIG men).

riverbee · « **Reply #9 on:** December 28, 2013, 12:20:19 pm »

lol way funny, had to send that to two of my brothers!

Crofter · « **Reply #10 on:** December 28, 2013, 03:03:36 pm »

Definitely not a limbing saw.

Perry · « **Reply #11 on:** December 28, 2013, 03:46:15 pm »

Who needs a hive lift with a couple of friends like that?

G3farms · « **Reply #12 on:** December 28, 2013, 04:46:49 pm »

Crofter, how many rpm that ramped up saw of yours run?

Crofter · « **Reply #13 on:** December 28, 2013, 05:37:20 pm »

If you are talking wide open throttle at no load probably 14,600 rpm. Not much higher than stock will give you with an opened exhaust. Its maximum torque though will be greater and will be at about 1,000 rpm higher than stock. It will hold a higher rpm in the wood which is where it counts. Some of the very high revving mods have a peaky torque curve. They take a good ear and good hands to keep them where they have to be to produce.

G3farms · « **Reply #14 on:** December 28, 2013, 06:01:06 pm »

Make ya wonder how them little fellas stay together.

Crofter · « **Reply #15 on:** December 28, 2013, 06:49:36 pm »

On tuned pipe and alcohol my son has run them up over 20,000 RPM.

Really though it is short stroke and small mass. The piston speed in feet per second is not a lot higher than on an old international pickup.

They usually come apart starting at ring flutter and getting sheared off at the exhaust or intake port. It is common to just use the upper ring if it is a two ring piston. The bigger you make all the ports the harder it is to find a solid place top to bottom to locate the piston ring ends.

There is probably more ifs, ands, and buts, than there is in beekeeping!

Slowmodem · « **Reply #16 on:** December 30, 2013, 06:17:34 pm »

Of course, if you want to do your lumberjacking sitting down.................

Crofter · « **Reply #17 on:** December 30, 2013, 07:17:45 pm »

That guy is pretty hand with that skidsteer!

I went to a wood harvesting equipemnt show a few years ago. Quite a few firewood processors, band saws, feller bunchers.........some expensive toys there I would have liked to have.

G3farms · « **Reply #18 on:** December 30, 2013, 07:38:19 pm »

now that is a slick rig, would hate to see the rice tag on it though.

Slowmodem · « **Reply #19 on:** December 30, 2013, 08:11:57 pm »

Quote from: G3farms on December 30, 2013, 07:38:19 pm

now that is a slick rig, would hate to see the rice tag on it though.

ROFL I don't think it is made in Japan (but I could be wrong).

)