what does it take to turn a 2.4 into a 2.7?

[x98boardwell]

I am looking at a 73' Targa with a 2.4 that has been "built up to" a 2.7.

My curiosity is that can this be done with just P's & C's and nothing to do with the crank or does the crank also need to be changed/altered within the 2.4 case? The car is not local to me so I wanted to gather as much information about it as possible as I'm assuming there won't be any paperwork once I arrive.

Is there a way to tell? The motor currently is carbureted with the large air box which travels from one side to the other and looks period correct. This was done years ago and the car has been sitting since... probably around 15 years. I would take the entire motor apart and then inspect, reseal it and replace what is needed and then put her back together. My thought was to try and avoid splitting the case if possible. i haven't bought the car yet so this is hypothetical at this point. If/Once I purchase then there would be an entire additional thread started about the project.. we shall see.

Thanks for any help on this!!

Cheers,
Bryan

PS.. I will be selling this which will be in the FS section in the coming days as well.

[Trackrash]

Only difference between a 2,4 and 2,7 is the size of the bore. (the case and heads were machined for the larger cylinders).

If you split the case on this motor you are risking it warping.

Do a search on the 911 Engine rebuild forum.

[x98boardwell]

Can you elaborate on why the motor would warp due to case splitting? And, since the case needed to be machined that would mean it had to be split when they did this.

I thought that maybe larger pistons and cylinders could've been added without machining the case so thanks for the clarity. I'm curious to know on the potential for warping.

I will also do a search on the engine rebuilding forum as well.

Thanks

[Trackrash]

Here is what the experts have to say.
2.4 refurb question
align bore a 72T

[x98boardwell]

That was helpful, thanks. Will continue to look for more info on this.

Thanks,
Bryan

[DSPTurtle]

Someone had the heads machined to accept the larger bore of the 2.7L piston. They also the spigots drilled to accept the larger bore of the 2.7L cylinder. Hopefully they installed case savers at the same time, and did the oil bypass mod. It would be good if you can at least get the receipt for the 2.7L upgrade. This was not an insignificant amount of work. They should have those receipts.

[RSTarga]

Displacement is only P&C, but if you have a T or E and want RS type you need rods, cams,S heads and different bore intake stacks + space cam on MFI Pump. If you start with an S, all you need are correct P&C's and space cam.
If you start with a T or E and go to carbs all you need are proper carb pistons for larger bore.
The case has to be split to open bore.
The 2.7 has quite a bit more torque than a 2.4. Nothing really noticeable on the outside.

[x98boardwell]

Thanks again for the help. Still word on the car, hoping to hear soon and need to sell my Cabrio as well.

[Quickstep192]

My Car is a '73 that was converted from 2.4 to 2.7 and from MFI to Webers. It runs fine, but several people have told me that it would be a great improvement to replace the T cams with E cams. I've always wanted to, but I've never gotten around to it. For What it's Worth, I always got some pleasure from tinkering with the Webers - Well, at least the first hundred times. Now it's getting old and I often harbor desires to convert to EFI.

[gliding_serpent]

0.3 more litres. Sorry, could not resist. ;-P