I need education,,, engine that is
 

Ok i have the engine apart,, the oil was white,, not a good sign but all the parts are moving freely once the cylinders are off,, will do bottom end anyway,

, here is where i need education,, i am looking to keep the cost down,, so i am looking for a set of used piston and cylinder, my pistons are ok but will buy whatever makes sense,,

as i shop around for old 911 engine gear, i have seen that they have T/ E / S version,, what is the difference??, is it just the cam, what was the -6 original came with
????, i have seen piston set for sale but they the valve pocket seems deeper,, is it just my eyes or what

does the carb need to be modified??

There are 80mm (2.0L) and 84mm pistons/cyls (2.2; 2.4 gained displacement by stroke). T=Iron Cylinders, cast pistons, about 8.5:1 in a 2.2. E=Biral (Iron liner/Alu fins) cylinders, cast pistons, about 8.8:1 in a 2.2E. S=Biral cylinders, Forged pistons, 9.5:1 compression ratio in a 2.2L.

When Porsche made the 2.4L engine, they reduced the compression of each of these 2.2L sets by approx. 1 point, across the board (S=8.5:1, E=7.8:1, T=7.3:1).

Valve pockets are deeper as the compression goes higher (more metal on the pistons means more space needs to be cleared for the valves).

Porsche also changed the cams and head port sizes on each model, respectively. 911E (middle-priced) and 911S (top-of-the-line) have Mechanical Fuel Injection, 911T (base model) used carbs. Before 1970, with the 2.0L engines, Porsche also had different valve sizes between the 911E and the 911S.

If you have decent cylinders, a great option is to bore them out 1mm, to 85mm. Then you can order new JE pistons (I do this as well) which are forged and come in any compression ratio you want. Cheaper: get some used pistons and cylinders that you know are within specifications (machine shop).

Best,
Scott

The best answers to these questions will come from Bruce Anderson's book: Porsche 911 Performance Handbook. If you don't own it or both of Wayn'es books, you need them. This portion of the forum kind of assumes you have read these. The answers are a bit long and Bruce does such a good job of answering them.

(edit) Scott did a good job of a high level summary.