3.4L Longblock replace a failed 2.7L
 

Got a 2.7L that has an engine failure.

Have a 3.4L 996 (from a 2000) long block that I am rebuilding.

Can I drop swap the 3.4L longblock for the 2.7L and
use the rest of the engine accessories, wiring harness, DME, etc from the 2.7L?

I can't conceive of any issues -- but I thought I would check...

thanks,

mike

Hi Mike,


The only problem you may have is using the 2.7 manifolds on the 3.4 heads. The pattern should be a bit different but you may be able to drill them to fit. Technically, the 2.7 intake is a tad small for the 3.4 but the 3.2 S uses the exact same manifolds, plenum tube and t-body as the 2.7 so it should not be overly restrictive. You will have to use all of your old harness, fuel lines, etc. to make this work. :)

The 996 plastic intake attaches to aluminum intermediate manifolds, the 986 ones, attach directly to the heads. If you remove the intermeddiate manifolds on the 996 motor, the 986 plastic manifolds will bolt directly to the 996 heads. The fact that you will loose power is correct. Unless you don't have the 996 intake system, I can see no reason why you wouldn't use it. You will also need to reprogram the 7.2 DME for the 3.4 maps.

-Todd

Nothing other than the block and the heads from the 996....

What would it run me to get the 7.2 DME remapped?

thx,

M

Do you mean that you only have the case and heads and not a complete engine with crank, rods, etc? You can use the 2.7 crank and rods but you will need the 996 pistons as they are 96mm Vs. 85.5mm.


Back to the induction system, the 3.4 plenum tube will not allow you to bolt on the 2.7 throttle body. Either use the 2.7 intake complete or you have to build an adapter to allow the 2.7 t-body to fit the larger 3.4 intake.

There are also a lot of other little bits that will need to be transferred from the 2.7 to the 3.4. I'm writing an article now on this detailing exactly what will need to be done. You'll have to use the shorter oil cooler from the Boxster too with the 2.7 manifolds...

-Wayne