CIS and performance mods
 

I have a 76 S and am now considering doing some engine mods in an attempt to get around 240 HP. How limiting is the CIS? I am very new to 911's and have just purchased the Bruce Anderson book. I do not really want to go to carbs if I can help it and an aftermarket EFI system is cost prohibitive. But, alas, I will do what needs to be done.

Don
Chance Favors the prepared mind.

Beyond exhaust mods....nothing much. I had a 3.0 that I did a cam modification, and that worked out well....I did it after I found out that I had a broken stud. I laso did the valves and a complete top end.

If you want that kind of horsepower, there is no cheap solution.

Dear friend theres no inexpensive solution in this matter,i own a 3.2 what i ended doing after all the little things ,exhaust,this and that,i finally install a turbocharged,plenty of horses for now.

You don't mention what motor you have in the car, I assume a 2.7CIS. A freind of mine made a project out of seeing how much power he could get out of a 3.0L CIS in an SC. The end product had tuned exhaust and muffler, modified fuel distributor, expensive headwork, flowed intake runners, and custom made camshafts. The result was 191 HP to the rear wheels (~225 at the crank). This makes me beleive that no more power is easily had for the CIS motor. The cost of all this was staggering. The fellow has sense moved on to turbo cars. Another freind did it the easy way. He laid down seven large and had SOK install a whipplecharger. This was good for 260 HP at the rear wheels. He is very happy with it, but it is a little on the ruff side for every day use.
Just some ideas for you.

Sorry, but 240 hp is not reachable with CIS ... not even at 3.2 liters!!! Just to put it in perspective, the factory hot-rod RS 3.0 only had 230 hp DIN, and it had MFI, equal-length header-heat exchangers, and the high-reving, 7300 rpm early 'S' cams, AND 9.8:1 compression ratio ... Webers in a similar attempt to clone the RS 3.0 loses about 10-15 hp! So, unless you find some GE-60 cams and do some serious head work ... extrude honing, etc. ... your goal is not reachable, even beginning with an SC or Turbo core, and nobody thinking rightly would even attempt a 2.8 these days with a magnesium block 2.7 core.

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Warren Hall
1973 911S Targa