Isuzu G-series Twin Cam

G'day,
I found this japanese site a while ago that has some basic G200W info, as well as a couple of other isuzu engines. Have a looksee, if it asks you to install japanese language packs, just click cancel

LINK TO SITE

Bastard, i was going to start a basic post but you beat me to it.

Anyhow, there were/are two different G200W engines availible from Isuzu cars. The first was found in the relatively rare hand made Isuzu 117 Coupe, while the later is from a JR130 Isuzu Piazza. Most major components are the same however there are some differences that should be noted.

The first is the engine mounting system. I am unable to confirm this 100% however the early type will require a Diesel crossmember to bolt into a Gemini while the later model will not. I think this has something to do with the oil filter locations. The 117 Engine [see below] has the oil filter pointing vertically in the centre of the block, whilst i beleive the later model Piazza-type has it at the front pointing down much like a G180W.

The next most noticeable difference is the fuel injection manifolds [again refer to pictures]. The 117 uses a completely different style of EFI manifold/plenum with the throttle body facing towards the front of the car, with a completley different plenum shape whilst the Piazza item is much like the other Isuzu efi manifolds [G200Z, 4ZC1/D1/E1, G180W] in pointing ACROSS the cam cover towards the passenger side of the car. I beleive they also used a different throttlebody and injectors.

The most major difference inbetween the two versions is the actual fuel injection system. The Piazza runs the more advanced I-TEC system, which features a CAS type dizzy and a fuel/ign computer featuring maps. The 117 makes do with the ECGI version as indicated by the vac-advance unit on the dizzy.

Identifying versions

Cam cover colour - The 117 engine will have an orangey or olive green coloured cover while the Piazza engine uses a Red cover.

Distributor - Vac Advance unit on 117 engine as its mechanical. Piazza uses a CAS.

Oil filter location - Verticle and centre of block on 117, at the front pointing down on Piazza.

EFI Manifolds - Throttle body facing forward on 117, across on Piazza.

Air Flow Metre - 117 engine uses vein-type AFM, because of ITEC setup JR130 uses a hotwire AFM.

Bore x Stroke : 87mm x 82mm
Capacity : 1949cc
Comp Ratio : 9:1 [For JR130, may be different for 117]

Max power is quoted as 103kw - closer to 88 in reality.





Above 117 Engine. Pictures pinched off Elky.



above JR130 engine

Nick-

Minor correction to "Cam cover colour - The 117 engine will have an orangey or olive green coloured cover while the Piazza engine uses a Red cover. "

I think you'll find the olive-green cover is the 1600cc DOHC (which incidently seemed to be the "fastest" DOHC for reasons I'm not entirely sure of - the only unique feature I found was higher than normal compression).

I have (at least) 2 117 2L DOHCs and they both have red cam covers which is consitent with all info I have about them, and the photos posted above. FYI - the 117 is essentially built on a Florian floorpan.

Cam covers are often swapped. EG - My 2L DOHC (fitted in a Florian) has the blue 1800cc DOHC cover as it's obviously a 1800cc engine - I wouldn't fit a 2L to an old 1600cc Florian would I!?

From memory the various DOHC cam covers are:
black - early 1600cc (eg Bellett GTR with carbies)
darkish (olive) green - later 1600cc (eg 117 coupe)
light green - early 1800cc
blue - later 1800cc (ZZR Gemini?)
Red - 2000cc (117, Piazza etc).

Incidentaly, I fit DOHCs to older Isuzus (Bellett, Wasp, Florian) and hence I am very keen on the front engine mounts and "upward" oil filter housings that DO NOT suit Gemini & Piazza. I may be able to swap these for their Piazza/Gemini equivalents. This includes "left-side" (nearside) starter assemblies (ie, gearboxes & backing plates) as found in Gemin ZZRs, C190 diesels etc.
I'm also after the "over the top" EFI manifolds etc - eg, the "ECGI" type - for a DOHC into a Bellett. I have quite a few of the RHS side intakes (as per the 117 pics above) but these are only suitable (perhaps) for my Wasp & Florian.
(I'll get some "ad" to cover all the above for posting one day.....)

Cheers - Peter (aka IZU069)

A possible correction to the above... I may be confusing my engines...?

I'm wondering if the olive-green cover was 1800cc, but I'll have to check... The olive-greens came out in the 117 coupes and were fast.
But I think the fastest was the 1600cc DOHC with black covers (10.5:1 compression ratio; used in Bellett GTR with carbies; manifolds moulded to the head in GTRs). But maybe early 117s had the blackies also (but with EFI?).

From memory, the early 1800 DOHCs had a lighter green cover, and later G180Ws (from the ZZR Gemini) had blue cover. (Hence the darker olive-greens being 1600cc.)

I'll try to confirm within the next 18 months. Or PM me if you're impatient.

And thanks to Robbo for his post, and GeminiCoupe for the pics - most valuable!

And PS - I want the 117 upright filters and front-mounting engine mounts, but the Piazza & ZZR "over the top" throttle body. Not that I have the Gemini/Piazza type downward oil filter, but I'll gladly swap any I get as well as the 117-type throttle bodies.

Peter, how hard does the oil filter pick up foul the front of the Florian/Bellet/Whatevernastycontraptionyourputting it now? You could use an ebay-special Oil filter relocation kit...

It doesn't - I only have the Bellett/Florian types out of a 117.
I don't have any Gem-type forward-down filters.
And I have both types of sumps.
But thanks for the tip - I'll check out the eBay kit...

it actually puts the filter right thru the middle of the engine mount.
and if its a long filter, then it fouls the crossmember too.
same prob when putting a gemini sohc in a bellett.
i got around the gemini to bellett prob in the race car with a filter adaptor and a remote filter (has a cooler too, but not really needed on a road car).
funny thing is that i machined up the adaptor on the lathe, then found out i could of bought one off the shelf, coz it the same as a Z9 filter in thread and diameter... DAMN IT!!


cheers.

There are usually standard parts to handle the various engine swaps.
There is even a standard Isuzu part so that the Piazza turbo oil-filter assembly can be changed to suit Bellett 7 Florian (though I've lost the info).

And it's nice with the Z9 type filters - just pick the size you need (Z79A, Z148, Z68)