New to the 911 club and need some P&C help

[GeminiBlue911T]

Hello all,

I was lucky enough to recently acquire my dream car 1972 2.4L 911T Targa.

Now, at 27 years young and getting married I am trying to not destroy my wallet more than I already have. However, I want to do it the RIGHT way.

GOAL:
Build a robust 911 driver, get some additional power (if possible) while maintaining reliability. Trying to stay with factory or OE supplier parts.


THINGS I HAVE ACQUIRED/DONE:
Machine work including Oil Bypass mod, cleaning, case savers, crank magnaflux and micropolish etc.

Heads cleaned and valve job, keeping them the original T spec 29/30MM ports. Keeping the T cams as they are in good shape.

Tensioner upgrade, new chains, etc.

New oil pump, later Carrera style

Car has weber carbs when I got them, and I dont have the original MFI. Seeing at how expensive a replacement MFI is I don't think I will be investing in that, rather keeping the carbs.

QUESTION:
So, now I'm stuck as to which Piston and Cylinder options are available to me...

-2.2L T P&C? 2.2L E P&C? 2.2L S P&C? I am keeping the 2.4L T heads and cam, will all/or any of these options work. If I could increase the power slightly I would like to. I was originally going to go with the 2.2L E pistons and cylinders which I believe gives closer to 10:1 compression, but, will my heads work with this option. (I was also quoted ~$4k for the E option, new)

- JE Pistions in original bored T cylinders?

-None of these? Keep it a 2.4L T? Regardless, this was one of the points of failure with the PO so they need machine work or replacing.

Thanks for the feedback and help here!

[Bill Verburg]

Originally Posted by GeminiBlue911T

Hello all,

I was lucky enough to recently acquire my dream car 1972 2.4L 911T Targa.

Now, at 27 years young and getting married I am trying to not destroy my wallet more than I already have. However, I want to do it the RIGHT way.

GOAL:
Build a robust 911 driver, get some additional power (if possible) while maintaining reliability. Trying to stay with factory or OE supplier parts.


THINGS I HAVE ACQUIRED/DONE:
Machine work including Oil Bypass mod, cleaning, case savers, crank magnaflux and micropolish etc.

Heads cleaned and valve job, keeping them the original T spec 29/30MM ports. Keeping the T cams as they are in good shape.

Tensioner upgrade, new chains, etc.

New oil pump, later Carrera style

Car has weber carbs when I got them, and I dont have the original MFI. Seeing at how expensive a replacement MFI is I don't think I will be investing in that, rather keeping the carbs.

QUESTION:
So, now I'm stuck as to which Piston and Cylinder options are available to me...

-2.2L T P&C? 2.2L E P&C? 2.2L S P&C? I am keeping the 2.4L T heads and cam, will all/or any of these options work. If I could increase the power slightly I would like to. I was originally going to go with the 2.2L E pistons and cylinders which I believe gives closer to 10:1 compression, but, will my heads work with this option. (I was also quoted ~$4k for the E option, new)

- JE Pistions in original bored T cylinders?

-None of these? Keep it a 2.4L T? Regardless, this was one of the points of failure with the PO so they need machine work or replacing.

Thanks for the feedback and help here!

When stating w/ a 2.4 you have the same basic cc and crank shaft as was used on the 2.7-3.0 in MY'76/77. The re ire 2 possible cc, the 7R is the stronger and is recommend for a 2.7 up grade. Look at the #s cast into the side of the cc to see.

For street use you can probably get away w/ the weaker case, I think it was 4R

for a 2.5(actual 2462cc) use 89mm p/c on the stock block, 10.3cr(so no pump gas unless you go to twin plug), No machining of case or heads, use MFI or carbs and do upgrade the cams the T are petty anemic. I'd use E for street and S for track oriented, You'd need to use a 66mm crank instead of the stock 70.4mm. If you keep the stock 70.4mm cranks you get 2626cc

for a 2.7(2687 actual) stock bottom end, 90mm p/c case will need to be machined for these, cr from 8.5 to 10.5, again cam upgrade S for all uses, maybe E if you want a really docile engine.

for a 2.9 use 93mm p/c for cis 9.4cr for MFI/Carbs 10.3 cr, other wise as above

for a 3.0 use 95mm p/c w/ wedge dome for cis regular dome for MFI/Carbs, otherwise as above