911/21 or 901/23
 

I have an opportunity to build another 911 R clone. I built one several years ago using a 912 chassis, but I used a 2.7 webered engine, and it was a great car and I'm sorry I parted with it. The pallet I am offered is a 66 911 with supposedly a matching numbered engine and trannie. I'm inclined to remove the matching engine and build up a 66 aluminum case (I have several) to R specs. Already talked with Walt at CE about the twin plugging and valve and porting to R or 906 specs. I have 66mm cranks and cams. I have sets of weber 46s. Other than a twin plug dizzy, what else am I going to need? I will not race this and I know it will not be street friendly...be nice.

That’s sounds fun.

The most important aspect to building one of these cool little motors is the important differences that exists between the 2.0 and 2.2. The 2.2 had a vastly improved head. Much bigger valves, a better valve angle and a vastly improved combustion chamber.
Look for a set of 2.2, 2.4 or even 2.7 heads and your project takes on a whole new performance level. Now you start imagining an "ST" build rather that an "R"
Any of the heads I mentioned above will work but they with facilitate the need for larger cylinders. Any 84mm cylinder will work with these heads, You can also think about bumping the bore to 87.5mm. That was about as large as you can go without boring the case. Once you chosen this path, your options for more street-able cams and reasonable compression ratios enter the picture.
Everything else remains the same. Same case, crank, rods, cam towers, sheet metal, in fact, all the ancillaries remain the same. Now you can think 210 hp vs the 170 a reasonable street 2.0 cam produce. The same hp you could make with an unruly 906/911R on the street.