I am building a turbo’d gen 2 engine using a gen 2 crank and a gen 2 head but using gen 1 rods and gen 1 9:1 pistons for the 20mm pins.
I will be using a base spacer to account for the difference in pin size. But, i have planned on using gen 1 9:1 wossner pistons to match to the 20mm pins.
Here is where my confusion is and wossner was no help. The gen 1 and gen 2 9:1 pistons crown shapes are very different. Gen 1 crown is flat and gen 2 is a dome.
Has anyone used 9:1 gen 1 pistons in a gen 2 engine that is turbo’d? Any issues with too low compression or did someone modify the gen 1 piston crown? Am i looking too deep into this?
Thanks
I have this EXACT setup because I couldn’t find gen 2 Carrillos or wossner rods ANYWHERE. Maybe I suck at finding parts. The manufacturers were between production runs I think.
I Used gen 1 Carrillos and gen 1 wossner 9:1 pistons. Yes they look totally different. I have both sets. Richard Peppler and I discussed it prior to my build. ( he has done this before) The gen 1 piston is taller due to wrist pin diameter, but sitting them side by side the piston crown is substantially thicker especially at the valve reliefs where it gets close to the top ring land. Definitely seems like it’s more robust.
Your spacer thickness will be somewhere around .120” with this combo, of course measure your exact deck height and quench calculations. I had my block decked at Millenium when getting replated so I had to make fine adjustments on deck height using .005” shims(buy the stock Suzuki base gasket and pull it apart). Cam chain length will be a challenge, I ended up using stock Suzuki tensioner and standard length chain- you WILL have to make a larger spacer for this than any currently on the market. (.125”) I originally ordered +2 pin length on the chain and it was TOO big for even the manual tensioners from APE.
The standard pro-mod studs will be slightly short now, there are longer one’s available. Search 190hookup.com or Schnitz racing for the custom length you will need.
Isn’t that much additional work. If you’re REALLY building an engine versus assembling a pile of parts, you will be making all these measurements and verifications anyhow.
My engine has 1000 miles on it, runs great, good low end power for the compression ratio and I’m about a month away from upping the power with an Davis intercooler and stage 2 RCC fuel system. Standby for more.
Thanks
Brian
