Need help on 2.0 liter build for my '68

[Fritter]

I have been searching and haven't found exactly what I have been looking for so....new topic!

I want to build a "normal" 130hp '68 motor into a nice street weekend motor with more power. Power in the 160hp range would be nice. My mod ideas are:

1. 9:5:1 or so compression with 81mm JE pistons in bored out Birals
2. S cams or some kind of cam in between Solex and S
3. Stock rebuilt normal 2.0 heads

I don't need a huge displacement screamer, I just want a nice tight motor with a kick in the pants in my '68.

Oh, and I want it to be as cheap as possible, and also with a DIY philosophy in mind. It would be my first 911 motor build.

My current '70T/Weber motor runs out of steam at 5K revs or so, I want more revs!

Any opinions/comments welcome!

[Grady Clay]

Mike,

There are lots of choices.

The basic philosophy “There is no substitute for cubic inches.” is still the deciding factor.
Another is the improvement in technology. Mahle forged pistons and Nikasil plated
aluminum cylinders are far better than anything Porsche used prior.

My choice would be to find some 2.2T heads and use the 2.7RS P&Cs. This will give you an increase in displacement with the ability to use regular pump fuel (about 8.0:1 CR). It will be dramatically more torque but not be a high rpm ‘screamer’.

For outrageous fun, I have a MFI engine that started life as a 2.4S (2341 cc, 8.5:1 CR) and is now 2808 cc @ 11.5:1 CR. It happily turns 7500 rpm but the power peaks about 6800 rpm. If there weren’t for a passenger headrest, I would have injured some friends. I had this engine in my ’68 911 but it is now in my ’70 914-6 (200# lighter).

These are probably the extremes you might consider.

While relatively inexpensive and more flexible (you have more choices), the JE pistons are very short lived compared to the Mahle. Considering the difference in cost, you may choose to buy new pistons every 15K miles or less. With careful work (like Steve Werner and Jerry Woods provides), you can extend this interval.

Your stock 901/14 engine is a great performer. With 130 hp and the ability to turn 7000 rpm, it is great fun to drive. The issue is you need to keep the rpm in the ’power band’. I tend to ‘buzz along’ at 3500 rpm all the time. I find myself even doing that in a 3.0SC.

Best,
Grady

[304065]

Mike, much of what you need to know is applicable to all two-liter engines. Have you been following my saga below?

Thread where I ask for help on what to do:
Suggestions for warmed over 2.0 901/05?

Teardown:
Teardown of 1966 901/05 Engine

Tumble-Polished Case:
Aluminum 901/05 Engine Case Tumble-Polished: Perfection Defined

Rods:
Bored? You'll think about stroking when you see these rods.

Pistons:
Jugs and Slugs: Confessions of a JE Piston owner

Heads:
Bouffant hairdos, Miranda, Grace Slick and THESE HEADS

Carbs:
Carburatori Bellissimo! Restored Weber IDA3C

Oil Cooler:
Oil Cooler rebuilt by Pacific Oil Cooler

Measuring things:
Measurement, Instruments and Metrology

Sorting out hardware:
REAL Cadmium Plating of Engine Hardware

Assembling Bottom end:
Assembling 1966 901/05 Engine- Phase I- Bottom End

[Fritter]

Whoa, thanks John. I've seen some of your threads but not all of these....I'll have to study these in the near future.