911 engine questions
 

i have 2 questions about a 69-70 911 T engine

1) keeping the stock crankshaft, can the displacement be increased to 2.4L and if so, what p/c's would those be

2) is the engine cooling shroud (piece on top of the engine and shaped to fit behind the alternator) interchangable with what other year engines?

just in the fantasy/learning/info gathering stage.....

1. Use the P/Cs from a 2.7 (iteration) to get a short-stroke 2.5! Great, great engine.

2. No idea.

Jim, the change from the 2.2T's crank to the crank used in the 2.4 liter engines lengthened the stroke and resulted in that displacement increase. The bore didn't change going from 2.2 to 2.4. If you went to the longer stroke, you'd end up with a hi-compression ratio 2.4T which would be an excellent engine in a street/DE car with as much or more HP than a 2.4E engine. The 2.5 short stroke Don N. mentioned is a nice racing engine.

If I remember correctly, the engine shroud changed in 72 or 73 to a two-piece unit that allows you to access the on-engine oil cooler without and engine drop.

so i found that 2.7 pistons are 90 mm. 2.0 are 80 mm (66mm x 80mm). so 90's would be machine in?

Just needs the head work. Oh, and the spigots may need to relieved. And, you might wanna look at boat-tailing and shuffle pinning (only because once you get it together and broken in, you MIGHT be living up in the 5500-6500/7000 range too much); it really is like crack.

I have what is supposed to be a ’70 2.5/2.2 engine. I was told that the engine has E cams, ported stock T heads & HIGH compression pistons. The car had enough problems (brakes, rusted suspension, old tires) that I never really opened it up, but it “felt” stronger than our SC. The motor was built using custom barrels & pistons from “Competition Engineering” in the early ‘90s. A very nice combination around town but pricy considering what 2.7s are going for.

The block spigots will require boring to accomodate the 2.7 piston skirts.

Attention to the block, as Don indicated, is critical because of the hp that will be generated, the age of the block, and material of the block.

Head studs (all should be replaced) and ARP (or similar) rod bolts should be used to help with engine durability. Shuffle pinning is also a must. I think that there is an oil pump upgrade, but my memory is foggy on that.

Oil cooling might be an issue with the bump in hp.

Wow . . . are we having fun yet . . . .

Hey Marc, don't you just love spending other people's money? :P

Oil pump upgrade, oil pickup tub upgrade, piston squirters & barrel air defecters on 2.0 engines. Carrera tensioner & cam chain upgrades. Don’t forget the older Carrera tensioner upgrades, the list is near endless! It is after all just money!