Building a 2.7 / 2.8 engine.

[teveo]

Finally decided to upgrade my 74 Carrera with a stronger engine ( originally US CIS).

I was hoping to buy an RS style engine but I had little luck finding, and I have the space and hopefully the time to build myself this winter.

Any recommendations or advice would be helpful and thanks i advance.

Target: A street and trackable 911 with approx 1000 kg

The suspension is already well setup, the car used to do some PCA racing while it lived in the states.

My idea of the Engine:
Afermarket Injection from TWM or Jenvey, megasquirt or electromotive?
Clewetts crankfire with electromotive ?
Engine size... 2.7 or 2.8 ?
Must work with pump gas
Any suggestion on good cams/profile for injection and 9.5-10 compresson?
Heads should be ported and perhaps twin plugged

I believe I have to find a case/rotating assembly that has the bells and whistles and take it from there. Any leads to such or whom I could ship a decent short block to?

Thanks!

[Steve@Rennsport]

Hi,

Can I assume that you do not live in the US? If so, what octane fuels will this need to operate with??

For a 2.7 or 2.8, I would use the PMO throttles and manifolds with DTA Engine Management. No Electromotive stuff for me!!

2.7 or 2.8 litres is fine, but the latter will require twin-ignition and 98 RON fuel.

Camshaft choice will depend on what the car will be used for and what gearing you have.

Head work is necessary for a race engine and a strong street engine. Twin-ignition is a MUST on a 2.8 and optional for a RS-spec 2.7. Anything over 9.5:1 requires such hardware.

You'll need to get a good 7R case and do ALL the necessary machine work to make it reliable.

Such engines run extremely well if properly configured, assembled, and tuned.

[teveo]

Hi and thanks, live in Norway and can get 98 octane at the pumps.

The gearbox is my std 915 (carrera 74) and it has rather close ratio compared to other 911's I had/have. No idea on gearing but quite close ratio.

Twin plug would be nice. I need the car to be streetable ("80%"), and it will most likely be driven less than 1500 miles a year.

I have no "verifiable" porsche machining expertise at hand so would most likely shop for a good case in the US, have it machined and perhaps built up with cylinders or at least the rotating assembly in place before shipping it over here.

[Steve@Rennsport]

Originally Posted by teveo

Hi and thanks, live in Norway and can get 98 octane at the pumps.

The gearbox is my std 915 (carrera 74) and it has rather close ratio compared to other 911's I had/have. No idea on gearing but quite close ratio.

Twin plug would be nice. I need the car to be streetable ("80%"), and it will most likely be driven less than 1500 miles a year.

I have no "verifiable" porsche machining expertise at hand so would most likely shop for a good case in the US, have it machined and perhaps built up with cylinders or at least the rotating assembly in place before shipping it over here.

98 RON is OK for up to 10.5:1.

With the gearbox out of the car, you can determine gear ratios by counting rotations of input shaft and axle flanges since you really need to know what they before making a sound decision about camshafts.

Twin-ignition is needed for the above CR. It helps in engines with less CR, too.

It won't be a problem to have all the machine work done here in the US, but the toughest part is finding a GOOD 7R case. I would recommend having at least the short block assembled to eliminate expensive errors.

Please let me know if I can be of assistance.