hey folks,
so heres what i got. i bought a basket 1973 74" shovel. i took all of the bottom end parts to the shop for a rebuild. guy did a great job, i bought new cyclinders, pistons and rings. for a 74" when i install the pistons and turned it over by hand the piston skirts hit the flywheels at BDC. also at TDC they are coming up to far which makes sense because then i checked the stroke and it is 4 1/4, turns out they are 80" flywheels from a shovel not 74 wheels. i don't want to buy all new 80" 3 1/2 bore pistons and cylinders since mine are new. question is are the any pistons out there that are 3 7/16 bore for a 74" that will work with a 4 1/4 stroke. or any other ideas would be greatly appreciated.
thanks

 

Are the pistons really hitting the flywheels OR are the piston skirts hitting ( front cylinder piston rear rear cylinder piston front ) The reason I ask is when I did a 4 3/4 stroke with 80 in cylinders I had to grind on the piston skirts ( front piston at the rear rear piston at the front to clear each other )

 

pistons are actually hitting the flywheels not each other
thanks

 

In the old days we used to use stroker plates That was a spacer between the bottom of the cylinder and the engine case In your case 1/4 in to make up the difference of the 4 1/4 stroke I don't think you want to go there so let's get into the pistons shorter skirt length ? Or get the 3 1/2 bore cylinders / pistons Can you exchange these cylinders and pistons ?

 

Give S&S a call, They may be able to help you, Or at least give you the bad news.

 

Basically, you need stroker pistons. As KT 77 said call your local indy, S$S or Keith Black has them. They are a off the shelf item. You are not the first person to have a stroker 74.