69 T engine upgrade choices

[red67]

hi guys
my stock 69 T is (to cut a long story short) needing new pistons and cylinders all round.

can you help a layman with a simple answer?

this cars great around town and the box is really low geared which makes it a lot of fun until one heads out on the highway on long trips where the motor's screaming to keep pace after a few hours it gets a little painful.
it's a weak engine 911-wise but i love the car and its all matching numbers with full history back to day 1 and original window sticker, near concourse condition etc etc

i figured while changing the p+c's, then upgrade them to 2.2S or E, and inch out some more HP, while keeping it matching numbers and on original webers.
can i do this on a stock 2.0 69 T crank, and if not--- what's the best option for more highway driveability? (a higher geared 5th is also an additional option as my synchro on second is a little tired so a rebuild on the box simultaneously is an option)...

what are your thoughts? i'd like a little more oomph and keep it matching numbers.

[Grady Clay]

Paul,

Tom is giving you the best advice: “I'd leave it stock myself.”

Rebuild the 2.0T exactly as original (stock 2.0T P&Cs should be very reasonable) and return anything modified or missing to original.
There are a few necessary internal upgrades (case savers, lay-shaft bearings, Turbo tensioners, wide-bearing idler sprocket supports, etc.)
Break it in and then properly preserve it.



An idea:
Find yourself another engine to play with.
Here is where “How fast do you want to go? How much money do you want to spend?” applies.

There are some very good and not unreasonable choices.
There is no substitute for displacement – 2.5/2.7 is a reasonable choice. This also allows the very high quality (and long-lived) Nikasil P&Cs.
911E-like cams are very pleasant for the street yet still have excellent performance at 6000+ rpm (limits about 7000 rpm).
Compression ratio is usually limited by your access to high octane fuel. Twin ignition will extend this somewhat.
You can build this engine where it appears almost exactly as your original ‘T’ yet has almost double the performance.


You can apply the same process to your original transmission.
It is prudent to do a ‘maintenance rebuild’ at this age.
This way, you can find out what gearing you have (original should be AFMSZ) and replace wear parts.

You might consider finding the latest type 911/01 (’71) transmission and gear it to your taste.
Once you are experienced re-gearing your transmission, you can always change ratios again.
This also has the advantage of a more robust differential and stronger magnesium castings.
You can have your choice of the original 215 mm push-type clutch or the later 225 mm pull-type clutch.


None of this requires any permanent modification to your 911.
You will have the original engine and transmission rebuilt, preserved and ready for reinstallation some day.

All of these are straightforward DIY projects that are well documented and others willing to help.
All of the ‘subcontract’ specialty work is readily available.


Back to your original idea:
The 2.0 heads are not bolt-on suitable for the 2.2 cylinders – the heads would need to be machined (not good for returning to original) or replaced with 2.2/2.4/2.7 heads.
The 2.0 (’68-’69) magnesium crankcase is least suitable for additional power. The ‘7R’ case (‘73-’77) is the latest refinement (‘73T usually being the best choice).
Your ‘69T 66 mm stroke crankshaft is cast steel without counterweights. It is suitable for its intended purpose.
The 2.0 connecting rods are the lightest weight but not as robust as 2.2 rods (the 2.4/2.7 rods are different for the 70.4 mm stroke crankshaft).

Having two engines gives you the luxury of time. You can ‘tinker’ with one while driving with the other.
Same with transmissions.
Once you gain experience, swapping engine & transmissions is an easy Saturday project.


Before you light into anything, take a critical look at your 911.
Enlist knowledgeable PCA/Pelican/EarlyS helpers to look over the chassis condition (rust, previous damage and repairs).
The same is true for running gear and all the other appointments.

Consider the ‘slippery slope’.
Making your 911 faster (more powerful engine), will probably require at least ventilated brakes and possibly other suspension, wheel width, tire size choices.
Too often owners get ‘carried away’ with modifications, some difficult to reverse.

It is your 911 and you can maintain it or change it to your satisfaction. Many (most?) do.
There is significant value to retaining the ability to easily change it back to absolutely original.

Enjoy.

Best,
Grady

[DAVSER]

Excelent summary Grady. Thanks!!

[Eminence Gris]

I'm going to toss out a different suggestion altogether. Take that 2.0 and put it in the corner of your garage and shoot Marvel Mystery Oil in the Cylinders. Turn it a couple times by hand every month or so. Find yourself a nice 2.4/2.7/3.0 engine. Install and enjoy.

[Macroni]

I am of the leave it stock contingent. I have multiple friends w/stock 2L that are driven very spiritedly w/much bigger motor cars. They always hold their own.