Engine Choice in a 72. What did you pick and why?

[SteveJ]

Hello,

Looking for some advice (typical newbie).

I just got a 1972 911 project. I have a had a few early 911's and never seem to finish them...

The project I have is a 1972 911T non sunroof coupe with blown motor. It also came with a 3.2 and G50 (by way of targa donor, have almost the whole car).

I am not so sure I want to keep the 3.2. Here are my reasons:

I own a 1995 993 and a 1962 356. Both are pretty stock cars.

I want to build a sleeper, real clean, no wing, nothing crazy with the paint. But I want a serious wake the neighbors, awake the sleeping beast kinda car.

What engine would you or did you pick and why?

Thanks

[boba]

Hi Steve, welcome to the board.

The 3.2 would make for a fun car and could be used with the 915. Transplanting the G50 would be significantly more involved.

Lots if 3.6's also get used in early hot rods.

A built motor on your 2.4 case is an option, but that would take some planning and cost more than just using the 3.2.

Stick the 3.2 in drive it for a while and if not satisfied build your spec motor, you may be very pleased with that 3.2 though.

[Jeff Higgins]

I chose a twin plugged, high compression 3.0 liter with MFI for my '72. I went that way because with the 3.0 it still feels like an early car, albeit with a good deal more power. And there is just no beating MFI for throttle response and "fun factor" - it's as "raw" as it gets on an early car, or on any Porsche, for that matter.

[72targa]

How about building up a 2.5 liter engine as found in the 1972 ST racers?

http://www.qv500.com/porsche91124p2.php

[SteveJ]

Thanks for the advice so far...

I don't really want to throw it together unfinished. So driving with the 3.2 in it for a while is not really an option.

Rough estimate on cost to build that 2.5? Sounds mean.

Also, whatever I use, I plan to have the motor gone through checked out and if for example I use the 3.2, at least do a top end rebuild.

[boba]

The best way to help you reach a decision would be to ask you a series of questions.

First what is your budget for the engine, the total project?

Will you also be changing the gearbox?

What do you plan for the suspension, chassis?

How do you plan to use the car? Daily driver, street/track, track only, occasional street and tours? How do you plan to drive it?

What level of engine maint are you comfortable with? Track motor, 8000 rpm+ is a hour motor; Street motor is routine oil change and valve adjust.

Do you want to stay with the 2 core motors you have for this project?

These are a start. The answers to these questions will narrow field of view. Rather than the wide view what is possible, all is possible.

[Tom F.]

For purity, you'd have to build something on a magnesium crankcase, such as the 2.5. It is much easier, IMHO, if you go the 3.0 or 3.2 route, with an aluminum crankcase. But this is not as true to the spirit of the original car, some might say. One wrinkle with a 72 T is that you'll need to add a front cooler with any of the higher power output motors. If you just build a simple (??) T or E spec motor, you could probably skip the front cooler.

You have to change the torsion tube to fit the G50, as far as I know.

[SteveJ]

Engine budget, $10K but I would also have more funds if I sell what's left of the original motor and the 3.2 as well as the Targa or sell that whole thing, car, motor etc. For the $10K, I would like something that has been well sorted...

Will you also be changing the gearbox? Open

What do you plan for the suspension, chassis? Probably do a Elephant Racing Kit or something similar

How do you plan to use the car? Street and Tours

What level of engine maint are you comfortable with? Street Motor

Do you want to stay with the 2 core motors you have for this project? OPEN

[Tom F.]

You should check out the latest excellence for a description of the engine that Supertec built for an early 911. If you sell off your existing drivetrain spares, your budget might stretch that far.

[boba]

Will you be building the motor yourself or having a shop build it? $10K will limit you if it includes labor.

For street / tours you might look at something a bit softer than the racing setup in the Elephant line, such as their Sport setting.

If you stay with the 3.2 and stock induction and engine management, some 964 sport cams and a Steve Wong chip would be within your target budget. You could also uprate your valve springs and retainers.