2.0 to 2.3 Build Plan
 

I wanted to run the specs of my planned upgrade to a 2.25 from a 2.0 by the experts and get some opinions on compression ratios.

The case is an Al 2.0 with all the oil upgrades, 66mm crank, std rods and bolts, recently rebuilt no issues. Mahle cylinders bored to 85mm and JE pistons CR 9:1 to 9.8:1 not sure? Rebuilt 2.2/2.4 heads to S pecs ported and polished 46/40 valves 36/35. Running L cam (same as E) topped off with Webers. In conclusion a 2.2 with "S" P/C and heads with an "E" cam.

My first thought is to run a CR of 9.8:1 same as the 911S. But I want to ensure that's the best choice with 91 octane street gas in CA. JE Pistons offers a 9.8:1, 9.5:1 and a 9:1 option.

TIA

Getting ready to do the same thing.Went with 9.5 cr JEs,opened up the 70T heads to 35mm on the intake,left the exhaust at 32mm.Going with the solex cams and 40 IDA webers,67 S dizzy.Would like to know how yours turns out!

Chris

2.2 cams cr etc.
 

Use of the finished product would determine the cams. If mainly street with a little DE I would stay with an L/E cam. If track only you could use the solex. I would also stay at 9.5 CR unless you want to twin plug or use race gas. Best