Vectra GSI 2.5 to 3.0 Conversion

Dont know... How old is the 2.5?

My dad many moons ago bought an ex-demonstrator W reg Vectra with the 2.5. Going down the Autoroute to Le-Mans it decided to go bang. Head Failure IIRC, in the end though it needed a whole new engine. Not sure if that was a design fault with that engine, or a one off.

Not that thats a bad thing - it did lead to the first of 4 Audis.

Reply 4

OP

prodriven

Nice project :gthumb:

. Keep us updated!

But I'm just curious, why go for a complete engine swap for 20-30bhp gain? Is the standard engine not very tuneable? Would breathing mods/cams/remap not yeild similar results for comparatively less work?

Well the 2.5 GSI is already tuned up from the standard 2.5; it has got the 3.0 cams as standard so theres not a lot of room for improvement in that respect. Other things to do would be tubular manifolds etc but that would be the best part of £1000. Remaps don't tend to do a lot of these particular engines as the ECU's are pretty much bang on for performance/efficiency. I have done a few things to the 2.5 like a bit of inlet manifold work, and upping the fuel pressure, lightening the flywheel etc but all that can be carried over to the 3.0.

It may only sound like a small increase but this is 30 bhp right across the entire rev range rather than top end, plus the 3.0's torque peaks much, much earlier than the 2.5 (around 3500 rpm rather than 4600rpm). There are about 40 or so 3.0 Vectras on the specialist forums and the guys say the car is completely different to drive, makes them easily oversprint 2.5's and makes the car what it should of been.

Plus its an experience in itself, stripping the engine down, taking the old engine out and putting this one in. Its something I've always wanted to do, plus I'll probably put in a 6 speed gearbox out of a Calibra when I need to change the clutch.

Reply 5

OP

UPDATE:

I've completely stripped the engine right down to its block now; heads off, sump off etc. Just waiting on a head gasket kit to start to put it back together again.

Reply 6

Friggerpants

Look sweet.

Stick a blower on it!

Reply 7

rishisen

wow, nice idea, jsut a quick questions do these conversions cost alot whats your budget, will it sky rocket your insurance or do they not mind this kind of thing too much

Reply 8

The Hitchhiker

Always great to see some engine stuff :biggrin:

Keep us posted!

Reply 9

OP

rishisen

wow, nice idea, jsut a quick questions do these conversions cost alot whats your budget, will it sky rocket your insurance or do they not mind this kind of thing too much

Budget isn't alot really since I'm doing the entire job myself. All's I need is:
- Timing Belt and Tensioners,
- Drive Belt,
- Head Gasket kit.
which comes to about £200. The engine cost £250 but as you can see from the top post, it had all its ancillaries with it so I've put them on ebay and sold most of them for good money so apart from the engine cost, I've hardly spent any of mine own money so far.
I've bought an engine stand, I already had the engine crane from previous jobs, and I think I'll buy the timing tools as I'm fairly sure I can use them on my 16v Vauxhalls.
A garage would probably charge the best part of £1000 for fitting alone, plus its much more gratifying doing it yourself.

Insurance premium won't budge as the car this engine come out of is a group 16 and my car is a group 16. When I finally fit this engine, I'll send off all the docs updating the engine number and what not.

A blower would be good, that would chuck out some serious power then but it would cost an absolute fortune lol. The next thing I'd like to do after this is fit the 6 speed gearbox out of a Calibra/Cavalier turbo; that should help with the motorway fuel economy.

Reply 10

Mr Catbert

Isn't that a 24v engine though?

Reply 11

The Hitchhiker

I imagine setting the timing on that thing is a beast to do with four camshafts!

Reply 12

OP

Mr Catbert

Isn't that a 24v engine though?

Sure is, its just that I'm sure the cam shaft locking tools for the Vauxhall V6 are just two lots of Vauxhall 16v locking tools if you see what I mean; the 16v 4 pot engines are just one bank of 16 valves with 2 cams whereas the V6's are two banks of 3 pots with 12 valves so you need two cam locking tools whereas for the 16v you only need the one.

Reply 13

gbduo

15

Wouldn't you need to skim the head when you rebuild? Or am i being dense?

Reply 14

Mr Catbert

Shouldn't unless its damaged.

Reply 15

gbduo

15

ah ok, thought i was being dense.

Reply 16

The Hitchhiker

gbduo

Wouldn't you need to skim the head when you rebuild? Or am i being dense?

only if warped from HG failiure, overheating etc...

Reply 17

OP