90 & 110 stroke limits

[firepower354]

I'm just digging in to an old-school project, and figure wide x far for bore and stroke makes sense.
I see 62mm in threads, after a lot of searching the site. Is that with the 26 or 30mm big end pin? Oil pump shaft the limiting factor?

[shortline10]

61.5 is about as big as you really should go . Yes the oil pump shaft needs to be turned down to go that big and also going bigger leaves less meat on the radius part of the crank and the back side of the rod for clearance reasons . I have seen and built bigger but for the average Joe 61.5 is best .
Couple of my threads .
http://www.3wheelerworld.com/showthr...d-Out-To-185cc

http://www.3wheelerworld.com/showthr...d-out-!-Video-!!!!

http://www.3wheelerworld.com/showthr...ever-275cc-WOW

[firepower354]

Thanks for the info!

[firepower354]

So, does any one have a set of machined crank halves for sale? Even a whole crank?

[shortline10]

I have a few NOS strokers or if your looking for a fixer upper I have one of those as well . You looking for a atc90 or 110 stroker ? Yes they are different .

[firepower354]

Fixin up, I can do, and may have rod swap need any way. Shoot me a price? terry@firepowerminis.com or here. Thanks!
*ducking* It's going to be used with CT90 stuffs.

[firepower354]

OK, so it's gonna get a 61.5 crank. Thanks, Mike!

What jug did that 185cc job run? 61mm in a 125 cylinder? Re-sleeved? Does the oil passage swing wider on those?

[shortline10]

Not sure on the oil passage on the aftermarket cylinders but I have had several stock 110 cylinders resleeved to 61mm and no issues with the oil passages .

OK, so it's gonna get a 61.5 crank. Thanks, Mike!

What jug did that 185cc job run? 61mm in a 125 cylinder? Re-sleeved? Does the oil passage swing wider on those?

[firepower354]

It's looking like I'll end up at 58x61.5 for 162.48cc and reasonable head gasket life.

[firepower354]

I'm making a base spacer, and swapping a longer rod, to go with the sleeved aluminum S90 jug.


Cases got bored to 62mm for spigot clearance.


Alloy jug.

[whitetail hunter]

hows the build coming? looks good so far.

[shortline10]

Big motor build Nice . What piston are you using ?

[firepower354]

I think I'm going to use a 61mm Wiseco

[Joseph Farrow]

What sleeve are you using and where do you source them?

Nice work.