Newbie upgrading perf. on 69 911T
 

Hello all. First post here. Newbie when it comes to Porsche, but I am an ASE master tech of many years and run my own auto repair business up here in Alaska. I picked up a kit car with a 69 911t in it. Engine is in great shape minus some water intrusion in one cylinder. Prior to me owning it someone ripped the engine cover in half and stole the Webers. I boroscoped everywhere possible and everything looks new except a shadow the size of a quarter on one of the cast iron cylinders. I picked up the NOS 88mm pistons and biral cylinders advertised on here. These will make it a 2.4 after installing by having the cases bored. My understanding is the 69t mag cases are the least stressed due to low power output. My goal is 180-190 hp. I would like to keep the non-counterweighted crank. I will stay carbed. Should I keep the 69t heads or change to say a 2.7 sc head? Also what carb size? Its a light car, 1600 lbs. 5 spd 901 trans. Thanks for any and all help.

I know the later heads will help with the detonation issues the earlier heads had but was curious if the larger valves would help on a 2.4 short stroke. Or would the larger valves not be required?

EFI or MFI would really help with cold starts in Alaska, not to mention power

- have you looked thru Wayne's engine book? it gives tested configurations

valve size depends on how much cam you run...

This wont be driven in colder weather. No top, and not really the "winter" type car lol. I can go EFI in the future but I'm sure that I wont be taxing the upper end of carb limits with this build. I'm waiting on the P&C's to get here so I can figure compression. Then it's on to cam selection. I was certain I would need some larger valves and ports to get the hp number up but I read a thread here recently that stated the 69t heads were good for a theoretical 300hp based on flowbench numbers. Now I'm curious, but still have the poor roof design.