Most out of 2.4l engine

[Daviboy]

Guys,
The guy I bought my sc from has a 72 911 for sale which is possibly an S but some idiot has made it into a SC clone. It is going really cheap as it needs a fair amount of work to get it right. It has a 2.4 l with carbs and my question really is could this motor be bored out to make it a 2.8 (like to go for RS clone) and what would need to be done to get +200hp out of it?

[gestalt1]

the 2.4 can have the spigots enlarged for 90mm or 92mm cylinders, however there is the possibility that that engine has the 7r mag case with smaller spigots. these cases are rare and valuable to racers who use them to bulid 2.0 - 2.3L race engines. the advantage is that the case is the strongest of the mag cases and did not suffer the heat stresses of emmissions equipment on the 74-77 7r cases. if it is the small spigot 7r case - do not enlarge the spigots to increase the displacement! find a 3.0 - 3.6 engine to put in there and sell off the engine, or re-build it original.

[rvanderpyl]

If this is an S chassis, check the number on the engine, if it is also the original S engine, do not bore it out. I believe the original 2.4S with MFI was rated at 190hp by Porsche. If you are going to make the effort to restore this car to original then do the engine as well. If not then replace it, it is cheaper than building a big HP motor based on the early cases.

[kenikh]

You can get 200HP froma 2.4 pretty easily, and with Nickies, even on a smaller spigot bore, you can get to 87.5mm pistons. That would get you 2540cc, for a long stroke 2.5L. That should get you easily over 220HP.