Pelican Parts Forums - Need help on 2.0 liter build for my '68

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Need help on 2.0 liter build for my '68

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!

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

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.