[Mullett86]

Hi all. I've been looking over the posts over the years, but never registered before now.

So, after having a few Vitaras, I've settled on a 2001 Grand Vitara to use as a weekender/tow car. I've been really impressed with it, but (like always) I feel an urge to fix and modify.

I've picked up a complete, wrecked early 2003 manual XL-7. So far, from what I can make out:

I should use the front and rear diff from the XL-7, as the front is the iron casing, and they both have a shorter ratio (does anyone know what this ratio is?)
The H27A shouldn't have timing chain rattles (this was fixed in 2002?)

Regarding the H27A conversion:
> Should I use the H25A ECU/loom/injectors etc etc? Obviously the H27A ECU is a better choice, but quite a bit of effort to redo the loom, work out the immobiliser etc.

What other changes should I make while I have both cars?

Thanks

[tanshi]

xl7 rear diffs are completely different to the GV. as such there are no lockers or anything for them if your looking in that direction

[oldschool]

Pretty sure the xl7 diffs are 4.3 for manual. The auto diff is 5.125.

[Mullett86]

Thanks guys.

What are the factory GV Diff ratios?

[henno]

4.3, 4.6, 4.8 and 5.12.... but ratio alone does not make it the same diff.

[Mullett86]

Thanks Henno.

My concern is that if I fit the front diff, and the ratio is different...problems.

Are the diff ratios specific to a model? IE the manual 2001 GV diff ratio is xxx and the 2003 manual XL7 is xxx?

[ninjamoses]

I presume you have a manual trans?
If so, forget the diffs, they'll be the same ratios as you have currently (4.3). Use the H25A loom. Use your H25A injectors.

For the V6 models:
Manual GVs are all 4.3
Auto GVs are all 4.8
Manual XL7s are all 4.3
Auto XL7s are 5.12 up to 2003, then changed to 4.3 also afterwards (when they swapped to the 5spd gearbox).

All rear XL7 diffs are useless/orphans as mentioned above, completely different and no aftermarket support. It was around 03 they changed to a completely different front housing also.

If the front diff looks the same but is just steel, pull that to use. Then if you are planning on running bigger tyres either get 4.8 R&Ps out of an auto model or 5.12s our of earlier vitaras to put in it and your current rear diff. Ideally get 12 bolt versions for the rear, and you'll want 26 spline versions for the front.

Most people will also piss off the vacuum operated front diff centre at the same time and swap to manual hubs. This requires either using a vitara centre, or dropping in a locker (ARB or the Trail Tough auto locker etc). Be aware you'll need to do something with the RHS CV shaft if you do, as the circlip position to hold it in the diff is in a slightly different position (search/google it - either stubby shaft, use a SV CV or get a new groove machined in the side gear to resolve).

[Mullett86]

Great info.

Yes, mine is a manual. It's also got 225/75/16s on it, so the ratio is a bit off. I'm hoping the 2.7 makes up for the increased rolling diameter a bit.

On the engine swap side, are all of the sensors from the H27A suitable for the original ECU? IE I would leave everything alone, lay the loom back, swap the injectors onto the 27, and then lay the loom back over?

[Mullett86]

Ok: progress.

I've taken the XL7 for a short drive, runs nicely. However, my GV doesn't use an AFM: it's MAP sensor'd (where the GV is AFM).

So I'm thinking I have no choice but to use the XL7 ECU and loom, but this could be a bastard...

Does anyone have any info? A wiring diagram for both cars would be a favourite, but right now I'll settle for anything useful or informative!

[Mullett86]

Back to square one. Looks like it does have a MAF sensor after all, just not where I expected to find it!

[kingkom]

Don't overthink. This is the easiest engine swap in the world. I am running a 2004 XL7 H27A in my 2003 formerly H25A GV. You use the XL7 block. Bolt on all the GV ancillaries (though you can go with the XL7 alternator as it has a higher amperage). Shouldn't need to disconnect the aircon compressor at all so just bolt it back on and you won't have lost your gas. You use the GV ecu and wiring harness along with the GV intake manifold with all the fuel rails and injectors bolted to it. You swap the radiator hard pipe from XL7 to GV (again bolts on) unless you want 2 radiator caps. Ignition coils are the same so just pick the best looking ones. Fit a HD clutch while you're at it. GV flywheel. Done.

Remember the H27A is the SAME block, just bored out.

I have definitely noticed that the GV extractors are limiting. So I will be fitting some of those aftermarket wildcat ones ASAP.

[Mullett86]

Thanks Kingkom. Hopefully mine runs as well as yours! The radiator hard pipes were identical (maybe the 04 was different?). Flywheel and clutch was also identical (from what I can tell)

Weekends progress:
H27 removed, degreased, rocker gaskets resealed, everything inspected, inlet removed. Generally in great condition.
H25 removed, inlet manifold etc put aside.
H27 and iron diff installed, along with the steering rack from the XL7 (mine was leaking)
Alternator and PS pump from H27 retained, original AC retained (had to swap AC brackets as compressor is completely different)
Tonight/tomorrow night: reinstall inlet manifold and exhaust.

PITA moment for the day: the engine mounts are different (the ones bolted to the block). Found that out the hard way, then spent two hours on rework. A shame, because otherwise it would have easily been done within the day.

[Mullett86]

Can anyone confirm for me that the gearbox is the same between the XL7 and the GV?

[oldschool]

If its auto then they are 99% the same, the bloody out put shaft is larger on the XL7. (and also the TC input to match)

I put a GV auto into an 02 XL7 and had to swap the OP shafts over.

[Mullett86]

Thanks mate. Mine's a manual, hopefully all is well (XL7 clutch/flywheel onto GV manual box)

Is that to say that the XL7 has a different transfer case? (maybe different low range ratio?)

[Mullett86]

Ok: it's all in and running correctly. Some lessons learned for anyone who might stumble across this thread (these apply to fitting the 2003 manual H27A motor from an XL7 to the pre-facelift 2000/2001 manual GV model):

> You can use the exhaust, headers etc from the XL7, although you'll need to shorten both the pre-diff and post-diff sections of the exhaust and fabricate new mounts. Alternatively you could use the original, but it's very restrictive in comparison.
> You can use the full injection, intake manifold etc from the original H25A GV, but you'll need to swap the CAS (the connector plugs in, but doesn't run).
> The H27A 02 sensors, water temp sensor, oil pressure switch are compatible with the H25A ECU/dash etc
> Using the H27A ECU etc will require substantial rewiring
> The engine mounts which bolt to the block are similar, but not the same. Use your original H25A ones
> The AC compressor from the original can be retained, swapping the bracket on the block
> The clutch fan is compatible either way
> The flywheel, clutch etc seems like it can be retained from the XL7. The clutch is a bigger diameter, and the clutch pedal effort seems to have increased a fair bit (although the XL7 could have had a HD clutch)
> The little rock/dust cover which goes behind the flywheel on the gearbox is very similar, but NOT the same. Very frustrating trying to fit the wrong one.
> The PS pump, PS rack etc can be swapped right in (the rack was in better condition than mine)
> The front diff is directly compatible and has a steel casing
> The CV shafts look compatible, but I haven't tried. As do the hubs, uprights, brakes, wheels etc.
> On the H25A there's a plastic valve on the passenger side valve cover, at the breather hose. The H27A has a straight barb, and I think this may lead to oil burning through blowby....


I think that's all. I'll update this as I come across any other little things.

[PsyCro]

Any new info on this project? I'm on the verge of doing my 1999 2.5 manual GV.. but using a 2006 2.7 engine. Any additional info is certainly welcome!

[losfer]

The left hand cylinder head needs changing when converting from 2005 onwards.

[PsyCro]

Realized the 2006 2.7 changed the lifters to mechanical, so i'm gonna stay away from that and wait for an earlier model.

losfer: left hand cylinder head??

[rallison203]

Hello from the USA. I just registered on this site, first time user.

I hope I can resurrect this old thread with a question.

In his above post, Mullet86 says "you'll need to swap the CAS (the connector plugs in, but doesn't run)." I assume by CAS he means cam angle sensor aka cam position sensor. The service manual calls it the CMP sensor.

Now -- Mullet86 hasn't joined this forum since 2016 so I'm hoping someone else might be able to help. I'm doing this exact swap. Mullet86 appears to be saying that I should pull the CAS from my old 2.5 and install it onto the 2.7. Is that right? Has anyone done this? Do I need to swap connectors from the XL-7 wiring harness?

I have some information, not confirmed, that the CAS reluctor on the 2.7 camshaft is the same part as the 2.5. If this info is accurate, this swap should work, somehow.

I haven't tried anything yet. I'm just trying to understand what the issue is, and how to address it, before throwing parts at it.

Any advice appreciated. Thank you in advance.

[losfer]

treat the motor as a "bare long motor" and bolt everything from the 2.5 onto the 2.7

[rallison203]

Thanks losfer, sorry I didn't reply (much) sooner. I didn't get a notification of your response.

Back on this project after a 14 month hiatus.

Am I reading oldschool correctly that this swap isn't so easy on a GV with auto transmission? That the GV A/T input shaft isn't correct for the 2.7 engine?

Can anyone confirm this?

Any other issues with automatics? Flex plate, torque converter, etc?

[tanshi]

I run a 2.7 with an auto transmission from an h20a with no issues