Sierra_rider
Super OPE Member
- Local time
- 4:18 AM
- User ID
- 23728
- Joined
- Jun 10, 2022
- Messages
- 129
- Reaction score
- 708
- Location
- State of Jefferson
What is the benefit of the 660 piston?
It's a longer piston, but the same bore diameter. It facilitates being able to do machine work to the cylinder without increasing intake duration. Gives you room to also make a pop up, or in the case of my version 2 piston, a domed top. It's labor intensive to do though, requires a lot of work on the piston, cutting the squish band for the taller piston, and some work on the cases.
I dunno if it's totally worth the effort involved, but hopefully with some tweaks I'll get it there. Version 1 actually ran really well. It felt like it made some gains across the board, but not as much as I was originally hoping for. Another thing with the 500i, I'm not sure that increased intake duration is a bad thing. I might be trying to solve a problem that doesn't exist. I need another cylinder just to be able to compare the hybrid versus a ported oem piston.