CASE VOLUME DISPLACEMENT ? / Introduction

[SHOVELHEAD]

Photos of the 272xp before dismantling & the 2156 side by side for size comparison. (In the back)
Getting the 2159 ready for the hot tank.

(far back L side)
Making a round plate on the LE Blonde turret lathe, to bolt too the (up front R) 272xp flywheel so it can be pulled.
As it came back out of the wash with baked on bar oil & sawdust.

 

[XP_Slinger]

Photos of the 272xp before dismantling & the 2156 side by side for size comparison.View attachment 112672 View attachment 112673 View attachment 112674 (In the back)
Getting the 2159 ready for the hot tank.
(Up front)
And making a round plate to bolt too the 272xp flywheel on the (far back L side) LE Blonde turret lathe, so it can be pulled.
As it came out of the wash with baked on bar oil & sawdust.View attachment 112675

If I could have your shop for a day I could do...well nothing, don’t know how to use any of it. Lol!

Saws are coming along nice man. Bet the hot tank saves a lot of headache in the cleaning process.

 

[SHOVELHEAD]

If I could have your shop for a day I could do...well nothing, don’t know how to use any of it. Lol!

Saws are coming along nice man. Bet the hot tank saves a lot of headache in the cleaning process.

Yes the hot tank is (SET IT & FORGET IT)

 

[SHOVELHEAD]

If I could have your shop for a day I could do...well nothing, don’t know how to use any of it. Lol!

LMFAO

 

[SHOVELHEAD]

It's been a Busy Week, so I've had NO Shop time.
I'm In hopes before the weeks gone to be Pulling Cylinders off all 3 saws & get the case volumes measured.
Till then...

 

[drf256]

Great job and thanks for sharing. ‘

If I had your shop, I’d never go home.

 

[PA Dan]

I wonder if the 576 has crank stuffers? If I remember right the 562 and 550 have them and the purpose was to reduce case volume so that the stroke of the piston was more directly moving air. If that makes sense, less case volume meant there was less space for fuel charge to sit about. Low volume meant that movement in the piston created more flow of fuel charge up the transfers.

If that’s all true then you would want case stuffers, but the 550 and 562 have less low end end grunt and that may be a result of the stuffers.

I did some light research and this scientific paper seemed to find very little difference for flow rates between large and small crankcase volume http://www.bridgestonemotorcycle.com/documents/crankcase_volume6.pdf

The paper identified inlet pipe length as a serious contributing factor to flow rates of fuel charge into and through the engine. I wonder if anybody has changed the distance between cylinder and carb on race chainsaws or maybe little thought has been put into it.

So many variables at play too, I really think without building the hole system specific to one of those cases then crank volume shouldn’t play a big role.


Sent from my iPhone using Tapatalk

Yes the 576 does have stuffers...

 

[SHOVELHEAD]

Been right out straight,
But I was able to get the plexiglass cut last night so I can measure case volume.

 

[SHOVELHEAD]

I have the Plexiglass clamped down to the Cincinnati Mill, to start milling the crankcase cover.

 

[SHOVELHEAD]

1st I milled the 272xp bolt pattern, & cut out for the connecting rod.

 

[SHOVELHEAD]

Next,
Offset the holes, so the same plate that bolts to the 272xp can be used to for the 2156 & 2159 as they share the same pattern.
Went back to center to start the second pattern.
In this photo you can see how close the 2156/2159 bolt holes are,
(I haven't gone all the way thru, to show the difference ) Now getting ready to mill the plate out from the sheet of 1/4 plexiglass.

 

[SHOVELHEAD]

Finished plate & placed on the crankcase.

 

[SHOVELHEAD]

Till next TIME...

 

[Marshy]

Looks really nice. Are you missing the dill hole?

 

[SHOVELHEAD]

Looks really nice. Are you missing the dill hole?

Yes
My thoughts (had) been that I'd fill from the connecting rod location.

 

[SHOVELHEAD]

Okay,
After a Busy work week, I finally had some time this evening to pull the saws back out and CC the crankcases.

 

[SHOVELHEAD]

I started 1st with the 2156 with crank stuffers the 2156 is ready for CCing

 

[SHOVELHEAD]

Had to take a nap during posting,
Actually fell asleep while uploading photos.
Start my days @ 2am I'm guessing 22hrs latter it's ok to pass out.

 

[SHOVELHEAD]

Here's the 1st victom a 2156 ready for Case Volume measurements,

 

[SHOVELHEAD]

I measured all 3 cases with rods at TDC 1st then @ BDC