Isuzu G-series Twin Cam

Cheers everyone.
Im an American in southern California. I stumbled upon your board looking for some information on the isuzu
made 1978 Chevrolet luv. It came factory with a g180 engine. Standard gearbox.
Please forgive me for my use of American english. Dont wish to offend. I wish to have a wonderful machine that
is unique and only I have one.
I never knew the twin cam engines were even made.
I am factory trained by Isuzu in college but mostly we trained on troopers and rodeos.
is there a way to get a g200w with side draft or again I apologize for my novice and english I belive you guys call
it side draught? Shipped to me in California usa?
Put the thing in a box and send it no?

I know you boys get the proper equipment. We get the rubbish. I am exempt from inspection so id
rather keep my truck (lorry? ) all isuzu. I think you call it a "faster"
If anyone can assist please message me or email me

Also..... whats a jackroo? I love your country. I wish I could get over there someday.

A Jackaroo is a male Jillaroo.
Or if you prefer, it's the equivalent of a cowboy, though wiki etc refer to them as trainees. And jillaroo would be a cowgirl, though I know that better as a verb, or should that be a position (adverb; adjective?)...?
Actually that segways to two technical issues. One is not to worry about your yankeeisms or 'merkanisms - we generally tolerate all sorts here, even septics.
The second is that hopefully you (already else eventually) understand our** sense of humour, or irreverence etc. If not, I do apologise for any offence that you would already have suffered at the expense of my, er, ... excuse for wit & humour.

The 3rd of those 2 tech issues is that despite your successful attempt at brown-nosing the Isuzu marque, by owning such a vehicle you are obviously a person of fine taste and intellect, and your being a statesider is a non-issue.

And 4th of 2 tech points is that my opinion(s) may not agree with those of this site not its members nor decent human beings nor be endorsed or tolerated by any of those.
**Hence my aforementioned "our sense of humour" should really read my sense of... whatever it is.

BTW - we understand trunks etc, and draft is still draft, and we often use zeds (zees) in words tho I pedantically use esses even when incorrect - as in magasines. And oops - I slipped there - I used tho instead of though - mainly because I mostly write on Yank forums, but that's another story.
The point is, just write normally. If we don't understand, we'll ask.
The same goes for you. If you don't understand what we mean, just ask. It's not only septics that have that problem. And BTW, google & wikipedia etc can be a big help. (I could add how we support & root for our members, but we generally won't root them.)


So technicalities aside, if you're still here you probably haven't taken offense etc and you should fit right in.
Welcome to twincam!
It's a somewhat quiet forum but IMO gives good technical information and tips rather than the mere socialising or tech crap that busier forums have.


The G200W...
Sorry, I'm out of time.
Actually I'll make that my next reply. Not that I'm known for long rambling posts... (LOL!!)

As I said, Welcome!

And if I don't get back soon, KICK ME!

Ok, LUVing the G200W.

The problem with the G200W is its rarity. They were never 'exported' from Japan due to GM (or American?) restrictions on Isuzu. However some were privately imported into other countries whether by wreckers (auto recyclers) or individuals importing Gemini ZZRs etc.
The only exception I know of is NZ (New Zealand) which apparently got several Piazzas with G200Ws.
[ In brief, my Isuzu Guru claims none were exported yet a well respected Kiwi (New Zealander) I know swears that G200Ws were marketed in NZ. It is a conflict I may one day resolve. ]

I don't know how much you know of GW (twincam) history etc but I think it's been covered elsewhere here on twincam.
But all G200Ws were EFI. The originals were fitted to the Isuzu 117 coupe and are recognised by their "outward right & forward" intake manifolds and upright fuel filters, and steering-box sump. Early versions had hydraulic-only cam chain tensioners whereas later G200Ws had a ratchet fitted which overcame the common noisy startup (loose chain until oil pressure built up). They all had mechanical dizzies (reluctor types) and - I think - a licensed Jap version of a Bosch Jetronic EFI.
The Piazza (Impulse) G200Ws (1980 to ~1985) with forward-down Gemini/i-Mark oil filters & rack&pinion sump had the Gemini (and 4ZE1 Jackaroo/Rodeo) style leftward over the top inlet manifold. They all had I-TEC EMS - ie, a solid optic dizzy (same module as the 4ZE1 Jackaroo but not Rodeo) with EMS controlled ignition and EFI.


Now, my suggestions...

Join isuzupiazza.com. That has a lot of Kiwi (& Aussie) members and you may have luck finding a Piazza G200W, tho they are pretty rare these days.

I suggest any standard G200W no matter how worn. Or paraphrased, avoid worked or modified G200Ws - or any modified GW twincam for that matter. The GWs are very reliable engines (hey man, they're Isuzu!) and yet you will read on many forums just how 'bad' they are. But when you have seen what people do to them (and how they think), well, IMO it comes as no surprise.
I have bough ONE G200W that was being rebuilt, but that was after appropriate investigation.

G180Ws can be rebored to 2L tho I'd suggest the later blue G180Ws - ie, EFI; they had blue rocker/cam covers (except some with hot up kits that included a black cam cover) - noting of course that covers may have been swapped or resprayed.
And also the G180S block is the same as the G200W block - except for the bore. The G180S is the Japanese SOHC which is totally different to the G180Z & GZ SOHCs. (Forget the G161S.)

G180Ws can pull the same power as the G200W but the G200W features great low-down torque.
And using good inlet manifolds with (say) twin DCOE45 Webers - and their correct jetting - it is EASY to get nearly 400Nm torque at 3000RPM instead of its standard ~186Nm @ 5k. Mine got 300Nm @ 2k & 383Nm @ 3k with no engine modifications. (And 27mpg (~10L/100km) or maybe 24mpg if a bit if extra lead footing around town - not that you'd have much chance to leadfoot 300Nm @ 2kRPM.
With a cam grind and a bit of porting, the above 150HP build (up from st'd 35HP) converts to 230HP tho forged pistons should be used since the originals are only rated for 180HP.
I'd suggest using the GWs for their low-down 8-valve torque. I don't know why hi-revving hi-HP racers etc don't use a modern 16-valve beast (eg, Mitsubishi/Hyundai 4G63 2L - 500HP with cams $1,000 ex-USA).

As to turbo, well, if a near standard 400Nm 230HP isn't enough - and that with reliability as good as the original G200W which is a reliable engine - I guess you could add a turbo.
Alas I do not know the turbo build tho I know of a 390HP turbo G200W that was build by someone 'of the guru clan' (meaning one of MY respected gurus - hence a proven track record etc) and that was supposedly also 'as reliable as OEM'. (It was sold in a GT Bellett some years ago in Adelaide, South Australia.)


I'll leave it here for now other than to say not to worry about GW dizzies other than the dizzy drive gear - unless using the G200W I-TEC EMS with its solid (fixed shaft) optical dizzy. The GZ series dizzy is now 'the standard base dizzy' for all G-series engines. Into that we transplant the reluctor ignition from an RB (FWD) Gemini/i-Mark - omitting the ignitor if being used for EFI/EMS. (We refer to that as the RG dizzy.)
And EFI/EMS-wise, I'll just say Delco. Or Delco. Else Delco. (Or Delphi as Delco have become.)
Gasket kits - MDS (else maybe Permaseal is they still exist tho they do not have the front head chain gasket - ie, the rubber gasket between the front of the head and its underlying cam-chain tunnel).
Cam shells may be a problem tho there are/were various (stalled) possibilities.
Conrods & main- & big-end bearings are no problem. Pistons should be obtainable - the usual hassles with forged if that's required (ie, expense, specification). Dummy cam bearings might be a problem (they weren't, but lately I've heard...). Cam chain, valves, etc should not be a problem.

Maybe also a caveat - I haven't sourced parts for several years so I'm hoping things haven't changed too much. Other forums may have up to date pertinent info tho I know they can contain a lot of misinformation - many seemed ignorant of sparts availability, and some still seem totally devoid of sound mechanical advice.


PS - I forgot to mention my G200W Florian - Florian being the sedan version of the Chevy LUV.
Also, the original 117s were built using the Florian floorpan.
A LUV would probably require the 117 sump and its upright oil filter (good, the Gemini masses do not want those bits tho Bellett owners want the filter assembly).
And the over-the-top Gemini/Piazza inlet manifold is the one sought by all, tho the 117 type could be used in a Florian and might better suit the LUV - I can't recall if it was turret or brake master cylinder issues. The Florian used a small Master-Vac brake booster and had a linkage clutch (no clutch master cylinder), and I think the LUV lacks the Florian suspension turret, instead being a self-contained front end. (Similar to the turret-less Wasp aka Bellett-ute versus the Bellett sedans.)
But the 117 inlet manifolds are solid and may be less suited to Delco refits (tho they incorporate a 5th injector...)

Blast my bloody teachers in school! They never taught us to convert metric to SAE .........Ugh.
Ok
I assume my 78 g180 cast block is a g180. I have also found a G200 block. These engines are fully interchangeable.
What heads or carb set ups can I use plug and play?

G180W and G200W twincams are going to be quite difficult to find.


This info is only about The SOHC engines, not DOHC engines. Turbocharging a GZ engine can be done... better value than the twin DCOE setup.

US market G180Z and G200Z are similar to the ones we have here in Australia. Iron block, alloy single overhead cam.

The G180 and G200 blocks are the same height, only the bore diameter differs. You could bore out to take G200 pistons if you wanted.

The G161Z bore is 82mm, stroke is 75mm.
The block height (surface the head mounts to surface where oil pan mounts) is 205.5mm from factory.

G180Z is 84mm bore, 82mm stroke. The G200Z is 87mm bore, 82mm stroke.
The block height (surface the head mounts to surface where oil pan mounts) is 214.5mm from factory.

Differences.

G180Z and G200Z blocks ARE different when it comes to the castings. The water galleries between the head and the block are offset in the G200Z block and head. Here are images of the head gasket to show the differences.
G161Z/G180Z head gasket G200Z head gasket Cylinder heads are also different in two ways. The G161Z and G180Z are identical, both having small combustion cambers. G200Z heads have the offset water galleries as well as larger combustion chambers.

This gets tricky because G161Z pistons have raised lumps to kick the CR up while G180Z heads have dished pistons to account for the larger bore. G200Z pistons on the other hand have flat top pistons.

What I would do if you were wishing to turbocharge a G180Z, is machine it just enough to restore to new specs but don't overdo it. Use a G200Z head and a die grinder to open the water jacket holes in the block so they line up with the G200Z head gasket to ensure coolant flows well. Use a low boost like say 7psi and you should be able to run it well without the need to use decompression plates. If you otherwise turbocharge and still use the G180Z engine bored to G200Z size with the G180Z head, even just running 7psi boost you will need to use a decompression plate. Also, when it comes to head gaskets for ALL performance GZ engines, turbo or N/A, only use graphite type head gaskets. Normal composite gaskets tend to fail fairly frequently. Installing a head stud kit rather than the head bolts is also preferable.

Assuming propane is cheap for you there, a low boost turbocharged straight LPG powered G180Z would be a great idea. The ideal propane mixer to look at is a Blom mixer and set up as a straight propane engine.

G200Z engines also used a different type of timing chain tensioner. G161Z and G180Z used a spring and rubbing block to keep it tight and G200W use an oil pressure driven tensioner and a different rubbing block.

MIND BLOWN.
TAKEN A YEAR TO GET BACK IN THIS,

been chatting with some folks that seem to be pretty knowledgeable. just sent off pictures off to one guy that really been a good sport as i am not exactly an easy person to deal with and my grammatical skills very much need improvement.

so my standard usdm G180 is actually a G180z or s or something?
i have checked with my japanese connection and he says they are rare yet not extinct.

i have a volkswagen turbo made by rajay its a smaller unit not too pumpy. but im assuming the gemini inlet and outlets are the same or grind to fit? efi upgrade from the sohc gemini or our "GEO" will work for me?

we had alot of isuzu stuff but i was young and didnt have cars and now they are all gone. some here and there but not many. it very disheartening.

btw poida, deck height shortening will raise the compression ratio thus stuffing more boom into a smaller package.
hence shave 3mm off the deck, 6mm off the head and you just built a timebomb that makes about 170 hp. (forgive me for my lack of knowledge of metric conversion. i still cant comprehend the Kw-Ps conversion. i have built other engines american and jap that the piston apogee is so close to the valve that a slice of tissue paper wont fit. yet i ran several thousand rpm into the killzone (redline?) and never failed using mobil 1 and a domestic additive (LUCAS)
i very much abuse automotive machinery.

id add pictures of my builds but i am inept at computer technology.

im going to look around a bit to see if other quandaries can be fulfilled without provocation of admonishment. i have looked into other bellet and gemini and various aussie boards to lay my questions but most seem to be full of wanks and un assistive blokes that couldnt be bothered. this one make this outsider feel welcome. thank you for the courtesy and ill refrain from off topic posting in the future.

cheers everyone.

a yank tank drivin gun totin yankie wankie!