405 engine transplant?

carlo14 · Post by **carlo14** » 29 Dec 2009, 10:10

Hi all!

Would anyone know anything about the following:

I have this mad urge to put a 605 petrol turbo engine into a 405 automatic 1992-96 vintage. I'm pretty sure the block on the 405 2.0 petrol engines is the same as the 605 2.0 SRTi/SVTi (both 1998cc), and as far as I know they both have a 4 speed ZF auto gearbox.

Any engine/gearbox experts out there who'd know if this is at all feasible? I suppose the box could be an issue if the 605 uses a beefed up version.

Post by **CitroJim** » 29 Dec 2009, 10:20

Basically, they're both XU engines so in theory at least, the conversion is possible. I'd make a guess that you'd have to transfer over engine mounts to the new engine from the old.

The standard 405 autobox I would imagine is the ZF 4HP14 whereas the 605 may well be fitted with the ZF 4HP18 (as in the Citroen XM). Again, it should fit but you may need to experiment with the mount and do a bit of mixing'n'matching. Also, if you use a 4HP18 in place of the 4HP14, you'll need most likely to use the 4HP18 driveshafts and possibly the 605 hubs too.

As the donor engine is a turbo, you may need to make changes to the exhaust.

By far the most tricky job will be the electrics. You'll need the ECU from the donor engine, the harness (preferably) and if the donor ECU used a keypad, that too and the code for it unless you know it has been bypassed.

An interesting project but why? What's you reasons and plans for thinking of doing this, just out of interest...

carlo14 · Post by **carlo14** » 29 Dec 2009, 10:29

No planning yet, but the simple reason is that I love the 405 (prefer it to the 406 as it's much more of a driver's car) and would have thought with the turbo engine it'd be a real flyer.

I've never driven the 605 version so don't know how well they go with the auto box - no doubt that would be a much cheaper solution! I remember from driving a diesel that they're nice handling cars.

Post by **CitroJim** » 29 Dec 2009, 10:43

I have to agree on the 405 being a better car than the 406. I've owned a couple of 1.9D and TD 405s in the past and thoroughly enjoyed them. The 406 (my son has one) is a bit of a barge in my opinion, a lardy old sofa, and lacks a lot of the old 405 character.

being relatively light, the 405 should fairly fly with the 2.0 CT engine in it.

One thing though, the 2.0 CT engine is not the most frugal on fuel, or at least in the Xantia it's not

evilally · Post by **evilally** » 29 Dec 2009, 11:03

Sounds good, but could it not be done with a manual box? Make sure you put it in a scruffy 405 with steel wheels, it's always good to be underestimated

carlo14 · Post by **carlo14** » 29 Dec 2009, 11:28

Can't drive a manual!