Jörgen

Hello

I.m modifying a 2.7, fuelpumps, injection, distributor, cdi-box and exhaust are from 3.0-3.3 turbos, an intercooler will be mounted, I will use standard ( or the sc ) cams.
The heads are almost standard 32-34 ports.
I will use a rotomaster turbo.
The crankcase is modified and strengthened, I might dowelpin it too.
I will use the 915 original gearbox
I am planning for 1.0 bar boostpressure and 320-340 hp.
The big problem is to find forged pistons with a flat dome, I have found Mahle pistons, but the dome is not flat, for about $1500.

Is there someone who has converted a 2.7 with a turbo ?, suggestions ? , problems... etc.

Ps. You have to excuse me for my english............

Super Space Monkey

Your a brave man to turbo a 2.7.

Have you tried JE pistons? I believe they can do what you need.

What compression do you plan on running (I personally would not go above what the 3.3 motor was)?

Ideally with the setup you are proposing and a euro spec 175hp motor your hp numbers would be right, however I'm thinking your motor will need lower compression even than the us motor. In a perfect world the us motor with a turbo at 1 bar (2bar absolute)and no heat should result in 300hp (300/ (2.7*2bar absolute) = 55.55. Remember the volumetric efficiency of the US 2.7 is 55.5hp/ltr or (150hp/ (2.7liters * 1bar absolute). Then you will make a little less due to heat and you will likely need to back off the ignition timing.

This sounds like a fun and challenging project and my hat is off to you, I myself would find a 3.0 factory turbo motor, or a 3.3.

Let us know what parts you decide on as your project progresses.

Thom Fitzpatrick

How does one strengthen a crankcase?

Jörgen

Hi !

The compression ratio will be about 7.0:1,
brave ?...... well I started up with this 2.7 motor since it was in a bad condition when I bought the car.
As the restauration of the motor has proceeded I have now come to the point where I have to make up my mind.
Either I build this 2.7 or I will buy a 3.0-3.3 instead and rebuild it.
The 3.0 or 3.3 is a better choice really, they can also handle more power.....
I thought when I started that it would be cheaper to build on a 2.7 but since I started to buy the parts.................

I will dowelpin the crankcase, exchange the headstuds and install timeserts, I have also modified it so that the air will flow more easy.


Jörgen U

Jörgen

Hi there !

I have now decided to buy a 3.0 or 3.3 turbo instead..... then I will have an engine to develop in the future.
It will be rather easy to get about 350 hp and the engine will still be reliable, that is rather important.....

I will get a pair of Sc-cams, a K27, low resistant muffler, intercooler ( a bigger and better than the stock ), and set the boost at about 1 bar.

I will probably put my 2.7 together later when there is time.....

Jörgen U

Ps. Jon where can I search for the JE pistons ?

Dean

Good idea to go with the motor swap. I would suggest going with the 3.3L turbo instead of the 3.0L. This is due to parts availibility. I think Porsche only made 500 3.0L motors. Try getting dist. advance springs for a 3.0L turbo.
Dean

Super Space Monkey

Hello Jorgen,


The factory turbo motor approach sounds like a good plan. I'm sure it will be a lot easier and safer to get the power you want. And if you get a good deal on a good motor you may even spend less money.

As for JE pistons for your 2.7 their address and phone# is below.

JE pistons
15312 Connector Lane,
Huntington Beach, CA. 92649
Phone 714-898-9763 - Fax 714-893-8297

I don't know if they have a website or not.
(also I am not associated with them at all)

Best Regards

Jörgen

Hi Dean and Don

I have thought about the parts availibility too, a 3.3 is not much more expensive than a 3.0 and the bigger the better......

I now have some engines that are for sale, hopefully one of them is mine soon...

I. will be back when I have made up my mind, thanks for your help guys.

Best regards, Jörgen U

Thom Fitzpatrick

Heck, while you're at it, why not just step up to a 3.6L turbo? Why do anything half-assed?

Jörgen

Hi

Sure it would be nice to step up to a 3.6 turbo, but I believe it would be too expensive. I have already put too much money into this car, my wife wants a newer family-car too.......

I think a 3.3 will be nice, there is enough power for my use.
If I go above 350 hp I have to change the gearbox etc......

Which K27 would you recommend ?

Best regards Jörgen U

Dave Banazek

I have a 76 3.0 930 motor 50,000 miles. Runs great, includes K27 turbo from later model 911 turbo and stock 3.3 intercooler. Just bolt it in and go fast. $6500. Add SC Cams (you install) $250, I install $450