Compensation for stroke difference in H-HS?

FirePowerMinis

FirePowerMinis

Active Member
#1
#1
I have an HS40 with a grooved bore, scored rod, and galling on crank.

Can the block be bored to accept an HS50 piston?

What I'm wondering, is, can an H40/50 crank be put in, bumping displacement even farther? Too wide?
 
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fastruppsfrompa.

Member
#2
#2
No, when you bore an hs 40 block to accept an hs50 piston the little hex screw bolt hole that holds the tin around the fins on the cylinder will be exposed in the bore; ask me how I know. Also the cranks are completely different, not even remotely interchangeable.
 
cheezy1

cheezy1

#3
#3
fastruppsfrompa. said:
No, when you bore an hs 40 block to accept an hs50 piston the little hex screw bolt hole that holds the tin around the fins on the cylinder will be exposed in the bore; ask me how I know. Also the cranks are completely different, not even remotely interchangeable.
Click to expand...
How do you know?:laugh:
And pics or it never happened :hammer:
 
cdoublejj

cdoublejj

Member
#4
#4
Wiseco PN# 2001P8 is an .80 over for the HS40 if i'm not mistaken that's 2mm over stock. There used to be on ebay but, it wasn't listed as such. it was just listed as Tecumseh piston.

IF you want to see what it looks like, http://shop.ruppparts.com/Piston-Rings-HS40-Tecumseh-Rupp-engines-080-over-hs40psitonkit80over.htm

EDIT: found the guy's store, best i could find is this, it's number off. i could have swore he had in the same color box but, with the EXACT same part number (2001P8), maybe he finally sold it.

Not necessarily right piston: http://www.ebay.com/itm/P4-motorbik...rcycles_Parts_Accessories&hash=item3a8c29d997

Found one here for a pretty penny, http://hudons.com/WISECO.cfm

EDIT: There is another part number on the box "061026" yup might ask that eBay seller if that number is on the other side of the box. at least on my box that is.
 
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FirePowerMinis

FirePowerMinis

Active Member
#6
#6
Haaaa. Good stuff. I stumbled in to the H-HS being different ducks, after posting.

Good to know on the bore. Or bad. I was hoping for a cheap up-size.

Thanks!
 
FirePowerMinis

FirePowerMinis

Active Member
#10
#10
cdoublejj said:
What the heck!!! I haven't seen you in a long while, i just caught your user name! Still rocking my Z155 I got form you all those years ago. :laugh:

Didn't know you were in to the classic American bikes too.
Click to expand...
Haaa, yeah, I get around. It's for a buddy's 1970 Rupp Roadster.
I'm doing a 10hp Tec for Pop's snowblower. The 7 broke the rod. I cleaned up the ports, upped the squeeze a tad. I'll pulley it up, govern it down, for long life and ability to really chuck the drifts up north where he is.

My Kohler K341 has a long rod, Chevy piston and valves. I'm not well. lol
 
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