Stihl 07 (non-S) scrapyard find today

[Brmorgan]

:agree2:Yep, true dat!!!

That's too bad you can't use my 08s crank, Brad!

I know, because 08 parts are common and cheap like borscht around here; I'm discovering 07 parts are more of a challenge to find. One guy has pretty much an entire 07 parted out on eBay right now but there's no crank in the mix...


I just wanted to make sure I was understanding crank/stroke physics properly there... I know that longer and shorter rods change the angle between the bottom end bearing and the wrist pin when the crank is at 90° to the center of the piston's vertical travel (if that makes any sense ) and can have an impact on torque and RPMs, but I didn't think it would make any difference as to the actual distance the piston travels from top to bottom.

 

[jockeydeuce]

I just wanted to make sure I was understanding crank/stroke physics properly there... I know that longer and shorter rods change the angle between the bottom end bearing and the wrist pin when the crank is at 90° to the center of the piston's vertical travel (if that makes any sense ) and can have an impact on torque and RPMs, but I didn't think it would make any difference as to the actual distance the piston travels from top to bottom.

You've got it all bang on there, Brad......Perfect description of the effects of conrod length, opposed to stroke, which is the amount of offset of the rod journal from crankshaft centerline times two.

 

[sefh3]

Yeah your right. Sorry getting my 2 stroke and 4 stroke confussed. I've been working too many hours and my brain is fried. I wish I could help you out with a new crank for that oldie. I have a 08 on the bench right now.