[ZUZUKI]

Ok, I've had a bit of a search, but haven't found anything quite like I'm after.

Lots of info on converting a Jimny to M16 or M18 engines, but has anyone done an M engine conversion into a Sierra?.
This could be a way of getting a little bit more go than a G16B provides & getting a newer, fresher motor that might not be subject to block cracking like older G16B seem to be randomly capable of.

I know a J20 has been done, but it apparently is a very tight fit - is an M18 + Jimny manual box equivalent in size / weight to a G16B?
Does the Jimny manual box cope with the extra urge of the M18 ok?

Just thinking that this could be a good combination.....

Thanks for your thoughts, Michael

[Blkfxx]

Little bit of info here.

viewtopic.php?f=4&t=10300&hilit=m15a+lwb

[greenzook89]

And here also. Jazzor built up the SWB with a m13 but the principles are the same. He also has a LWB running a M series

viewtopic.php?t=14345

[ZUZUKI]

Thanks guys, I was sure that it wasn't an original idea, but does seem like a tantalizing option.
Seems like the Jimny gearbox is able to hang on behind a M18 ok, Sierra transfer case & rear axles might be another matter.
Rgs, Michael

[monley]

The jimny gear box will fail before the sierra tranfer and rear axles. Its made of cheese

[Gwagensteve]

I believe the swb NGV used/uses an m16 with an aw-4 variant behind it.

Like always, the viability of any engine swap in a Sierra is dictated by the gearbox choices.

[ZUZUKI]

Not looking for an auto - I agree with you Steve, about their ultimately superior capability in hard off road conditions, compared to a manual, but they don't engage me enough with the car & what it is doing.

I think I am getting closer to a position to work again on my LWB Sierra - haven't touched it in 10 years & it is sort of 1/2 way through a big build.
Current set up (which I've never driven) is G16B - AW4 auto - Vitara T/case, with the front output cut off - super silly short jack shaft arrangement - Sierra T/case mounted into a combined cradle made by Joe Leban in his 4Play Offroad days. 4.625:1 W/T diffs on N/T spacing (1985 N/T 1.3 / 5spd LWB ute base vehicle) with 7.50/16 Firestone SATs, but probably end up pinching the Silverstone Xtreme 33 x 9.5 R 16 I've run on my Rangies.

However, the idea of twin transfers I have now gone away from, due to extra weight & problems with aligning the T/cases, when there is no jack shaft length to play with. I have also decided (after owning 3 auto Range Rover Classics in the mean time) that an auto is brilliant offroad, but boring to drive.

I'm looking at 3 options, drive train wise:
1) Stick with the G16B I have (was a Jap import 1/2cut - should be ok?) mate up to a Vitara 5spd with the t/case removed, jack shaft to Sierra t/case. Adequate engine performance, well strong enough g/box, great gearing options with the Sierra T/case, but associated t/case weakness, axles should copy reasonably ok.
2) M16 / M18 - Jimny g/box - Sierra t/case. Good power from newer engine, more complicated to bolt & wire up - will need Liana bits, Jimny bits & a fair bit of mucking around in the middle. G/box & t/case strength marginal, rear axle will like M18 less than M16 or G16.
3) J20 - Vitara 5spd + t/case combo. All can come from a late SV420 Vitara or SQ420 GV. Engine bay tight for J20, gearing options not as extensive for the Vitara t/case & hard to get deep enough gearing in the axles - aftermarket 5.72:1? - rear axles are going to be under a fair bit of stress if the J20 is used in anger & the housing is offset, when it doesn't want to be for the Vitara t/case = custom Vitara based housing & axles.

I like option 3 the best - I've been a passenger in a SQ420 J20 5spd reduction t/case geared LWB & it flies (for a Sierra anyway).
Thoughts anyone?
Rgs, Michael

[Gwagensteve]

I'm going to be 100% honest - you haven't finished this car in many, many years. Pulling out a complete, running driveline (that many would consider about the best possible combination) to replace it with a much more complex solution, (or an inferior solution) doesn't make any sense if you actually want to drive the car, because you'll be messing with this forever to get options two or three right.

I know you aren't digging the auto, but in your own words, you've never driven it. Have you ever driven any auto with really, really low gears? they're hysterical and nothing like a range rover which in comparison feels like a barge with loads of driveline inertia. If this car is for the bush, you need an auto. Additionally, the super tall overdrive on the AW-4 covers low transfer and diff gears really well. If you drive it with the AW-4 and really hate it, OK, drop a manual in. It will be easy after you've got the car running.

Get this thing on the road already. Pull the vitara case, buy a trail tough bush for the back of the gearbox, and run the aW-4 into a Sierra case with any gears you like. If you want to mess more with auto technique, run taller gears. If you want to point and shoot, run shorter transfer gears. Job done.

If you can't stomach the idea of the auto at all then just do option 1 and get back on the road, with a line lock and 6.5 transfer gears so you can get close to auto drivability. You'll still regret not having an auto for technical driving, but if you know that then by all means option 1 is the only sensible choice.

Option 2 will leave you in a mess of immobiliser, wiring, CEL throwing mess with a gearbox made of cheese and flaky gearing (no overdrive) I still don't believe that anyone with an M18 in a Jimny has it running right. Everybody complains of some sort of glitch, and progressively talks of all these tiny incremental improvements. The (sparse) dyno sheets I've seen all imply poor results under the curve. If you found a complete M13 Jimny or M16 SWB NGV and could deal with the wiring/immobiliser/BCM hassles, that would give you the best chance of having a clean running motor, but neither will be much advance on what you have now.

The J20/vitara case idea is crippled by the vitara transfer case. Slip yokes, your gearing will be too tall in high range and tall in low, even with transfer gears. You'll stretch the chain, loose a gear (5th) because your high range will be 40%-60% higher than now and as you pointed out have gacked driveshaft angles, no room for a fan, and more power than a 26 spline axle can deal with. You'll also need to convert to a Hydro clutch. If you MUST have a J20, it needs to be with an AW-4 or trimatic to take the hit off the driveline and give you some control back.

This is such a cool car it deserves to be on the road sooner rather than later. Don't overcomplicate it - drive it before you pull it apart again.

Steve.

[ZUZUKI]

I think I need to get to a Suzuki Vic day at Bills (been there plenty of times with the LROCV & trials days) when you are going top be there with Piggles Steve, & come along for a ride to see if I can live with an auto in this Sierra application - as you say & I agree, a RRC is a bit of a barge to pilot, so a Sierra auto could be a whole different kettle of fish.

The hydro clutch was the hardest bit of the conversion I got taken for a blast in - was only on road, but despite high gearing, had plenty of go. It has reduction gears - apparently a LRO set, that is deeper than currently available?. I didn't take any note of the rear tailshaft misalignment issue, but it is running a Sierra housing & axles.

Your right Steve, while I might like option 3 best, it doesn't make the best sense, but I've resolved to pull the current drive line to bits, to remove the cradle / twin transfer arrangement, so was thinking about what I really wanted the car to be / do - yes it will be a bush car, but also an occasional daily driver - probably with the roof off & windscreen flat (well, at least once, anyway).

We (Seriously Suzi) didn't get to see it, but a guy rang up the other day, requesting a 'strong' sierra transfer case conversion for his 2013 Jimny - has stretched 3 t/case chains in the original case - 1 replaced under warranty.
The reason for the chains stretching was that it is M18 converted & he has fun blowing off Commodores with it! Must be getting it to run sort of alright.
Apparently hasn't had gearbox or axle problems (yet!?) - running 215/75R15 tyres.
We didn't help him with his t/case request, but suggested he develop a lighter right foot!.

Rgs, Michael