2.7 swap for 2.5? (Blown motor)

[78F350]

I'm in the middle of putting a '97 2.5 into a 2001 base, sort of the opposite swap. In my case, I swapped over all of the 2.7L intake, fuel, harness, and vacuum stuff to the 2.5. The only real creativity involved was making a template and re-drilling some of the mounting holes in the intake a few mm over from where they were.


There's a big difference in the 2.7L intake and the 2.5L intake. By my HF calipers the intake port on the 2.7L engine is 54mm vs 43mm on the 2.5L. Between that and the resonance tube, I'd want to keep the 2.7L intact and look at swapping the DME and adding some wiring and pedal for e-gas.

Easiest way to do it and be back on the track would be a direct swap of all the intake, throttle, engine harness, vacuum, and injector stuff from the 2.5 onto the 2.7 - the reverse of what I did. To re-drill the intake mount, just make a template, knock out the steel spacers, (fill the old holes if you want quality) and drill holes in the replacement intake.

[78F350]

I just realized there may be a problem putting the 2.5L intake runners on the 2.7L engine: The rubber seals may not contact the intake ports on the head due to the smaller diameter.
Solution? ...Fabricate a bolt-thru adapter plate to fit the 2.5L seals and cover the excess port.

[911monty]

Originally Posted by 78F350

I'm in the middle of putting a '97 2.5 into a 2001 base, sort of the opposite swap. In my case, I swapped over all of the 2.7L intake, fuel, harness, and vacuum stuff to the 2.5. The only real creativity involved was making a template and re-drilling some of the mounting holes in the intake a few mm over from where they were.


There's a big difference in the 2.7L intake and the 2.5L intake. By my HF calipers the intake port on the 2.7L engine is 54mm vs 43mm on the 2.5L. Between that and the resonance tube, I'd want to keep the 2.7L intact and look at swapping the DME and adding some wiring and pedal for e-gas.

I will be following this swap with great interest!! I would imagine there would be a dramatic loss in low end torque going to that large an intake on a 2.5. Intake velocity should take a major loss. It will be interesting to hear your impression. Of course if it works out then Porsche really did put the hurt to these engines!

[truegearhead]

I still don’t understand why a 3.4L 996 manifold wouldn’t work. If you don’t have this problem on a 3.4 than why can’t you just use the 3.4 manifolds