ALFAGTV6.COM

[Alfa GTV6 NZ]

Hi Guys,

Looking to rebuild my 2.5 as a 2.8 using 3.0L sleeves and pistons.

I was sure someone had done this before but cant find the info.
Anyone have a link to their project or can give any pointers?

Many thanks
Karl

[MR2 Zig]

That used to be done a fair bit before the 3.0s became a little more common.

Sidneyjules here on the board either has or had one and could tell you more.

[SydneyJules]

Hmm no I was enquiring about it one stage too- more just out of curiosity- I do believe GTV7 has one though. My time and effort is going into my body at the moment- the engine will have some love coming at after a year or so.... watch this space...

And yes- I recall that is the way he has had it done too- with the liners and pistons...

Which begs the question, if you're going to go to the extent of boring out for the wider liners, why not look into going wider still and get a larger increase in capacity?

I'm pretty sure that Cummins liners (diesel) are available in many sizes...

Yes- custom pistons etc, but it'd almost be cheaper buying a 3.0 these days, anyway. It's getting harder and harder to go past Greg's blower kit!

[Alfa GTV6 NZ]

Cheers guys,

Will have to do some more digging.

My brother builds race engines so he will be building it and I wanted to do something different than just dropping in a 3.0L.
No offence to anyone that has done a 3.0L conversion, just thought it would be more interesting to keep the 2.5 block but get some more power out of it.

Any further information is welcome

[GTV27]

yep, mines a 2.8.

It makes for a nice engine, and is not common, but is not really cost effective given the machining involved as well as the risk of stuffing the block. I'd give you the name of the engine builder who did mine, and he's a top bloke, but he is not likely to want to do another (or he would REALLY charge for it) and probably wouldn't want the hassle regardless.

Go for a 3.0 or a 3.0 24V or a forced induction for better bang for buck. Further thought, put the money into making the 2.5 rev like buggery and get el primo ECU for better results.

If you are still keen, recipe is 3.0 liners, 2.5 crank and custom pistons (forged if possible). There is a mob in NZ whose name escapes me who make good pistons and could do this...

There used to be a kit from schankle out of the US - but given the demand now is low, good luck getting onto that!

[Giuliettaevo2]

original pistons can be used also... just need to move the 'eye' in the conrod up a bit to get the right compression.

[GTV27]

you might get a bit of piston slap with the original pistons, but you're welcome to try it

[Giuliettaevo2]

original 3.0 pistons that is...

[SydneyJules]

I can def. vouch for making the 2.5 "rev like buggery" as an option!

The only issue that I have with mine at the moment is the ECU. A good ECU is really needed to take advantage of the work- mine is a fuel only job (ancient Haltech F6 or something), and using modified dizzy curve. It runs well, and certainly works when the engine's on cam, but the off cam response is hurt by the dizzy not being as good as an ECU would be for ignition- and by the wild cams interrupting the intake of air- ie one cyl. draws air in, interrupting the inlet of the next cylinder etc etc
Cheap fix is two throttles, ultimate fix is six. I don't plan on undertaking either at the moment.

Keeping the cams a little more tame than mine won't hurt the lowdown torque as much, but keeping the gearing short (and the car light) will help keep it in the meat of the rpm range. With my 4.3 diff the engine snaps to the redline real quick after a standing start launch, in 1st and 2nd, and pulls strongly through 3rd.

Solution to any HP and torque issue is forced induction! Cheaper than cubes....