Isuzu G-series Twin Cam

Nice. I was expecting some crunch...
(Sorry, is that a spoiler alert?)

There were other giveaways if you're familiar with the series - like the smaller (head) vent, plus the head manifold angles. And the GTR was the only GW with integral intake manifolds. Black (cover) was also the G161W colour - except for the G180W hot up kits that were release for the Geminis, but o...

2 litre LOL! It's the original Bellett GTR G161W. The 161 is clearly visible on one pic. The integral intake manifold means its GTR & not from a 117. Amazingly original for a 45 year old engine - black cam cover; Mikuni Solex (note their high mounting angle & better head clearance compared t...

During this lull in reason to reply, I thought I'd attempt a torque . BTW - if increasing torque don't forget to upgrade your clutch. Remember, " a clutch is torque ". You can increase power all you want, but if torque does NOT increase, you can leave the clutch as is. (With thanks to OzFe...

As I recall, 36 or 38mm "chokes"; mains 165. I did write the specs somewhere - maybe here on twincam, else maybe OzFemini - probably circa 2005-2006. I wonder what twincarb manifolds you have since they never came out for the G200W. The best are the "Hughan" manifolds that were m...

IMO why increase compression? Isn't 400Nm/230HP enough? Or 390HP with turbo? Keeping in mind that they are without major mods; merely cam profiles, forged pistons, some minor porting, and external add-ons. If you want to increase compression, get a 16V engine, Why use a GW? Sell it to someone that w...

I should say that I don't know how they adapt a profile grind (like L1) to a different engine, but from what I gather, just specify L1 and the grinders will know what to do. (Of course if that is yet another skill that has been lost...) The L1 info came from my Guru, and she or he has yet to be wron...

The L1 will suit a G200W with standard pistons.

I have no idea... All I know is "L1", and that it's a "mild" racing profile - and apparently too cammy for street use in most engines, but GWs are not most engines . Also that is is a well known or common profile. (I think Cortinas were mentioned.) I also recall someone (I think)...

Hopefully it's the MDS kits (Moorabin, Melbourne). They include the front cam chain "valley" (usually orange) rubber gasket that sits between the front covers and head. The Permaseal VRS kits omit this (which they shouldn't) and I'm not sure if they are included in the Permaseal full gaske...

The 3kRPM peak torque tuning is a 26" to 29" two-into-one section from the standard exhaust manifold. I know Geminis could not use the OEM exhaust manifold - unless perhaps(?) they used the diesel cross member (and maybe Bellett/Florian/Wasp front-type engine mounting?). As to extractors t...

Yep, it's the L1 profile for the GW engines. An L2 causes the valves to hit the pistons. The ~400Nm is all in the exhaust tuning. And of course if your Webers don't have F2 emulsion tubes, forget everything. BTW - the pistons are only because the OEM G200W pistons are only spec'd to 180HP tho a few ...

Why deck the block? (Never deck heads!!!) Isn't 230HP enough? Or you can have 400Nm with the standard engine and twin DCOEs as per my 150HP with 300Nm@2k & 383Nm@3k - I didn't do the 220-230HP mod because I didn't want to spend on forged pistons. PS - I preferred early Gem boxes with their 0.782...

Just letting others know that I have explained to that new blow-in Septic offline that DOHC heads won't bolt onto GZ blocks. But if anyone can help with a DOHC that can be sent stateside... Not wanting to usurp yankieluv , but I'd suggest the following (the usual request list): - GW engines - prefer...

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 exce...

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 ...

I'm just wondering if the purple GW is out of a purple Bellett. I was amused at the purple Bellett with its grafted Camira or Nissan or whatever dizzy. Poor sods - the RG dizzy is just so superior, plus a lot cheaper (ie, it's easily DIY). Anyhow, I only ever exchange complete gearboxes. Currently I...

I've seen a lot of people spend $100's getting their dizzies recurved and I think for what? It's still only a 3-step curve for the RPM and up to 4 steps for the vacuum (double diaphragm) with no "exception dips", and it wears out, and and then if you want to change the timing again... So w...

Ah - forget Bursons if it's for gaskets (Permaseal). The Permaseals have a thin inter-cylinder gasket width and are reputed to blow (more easily). (I did a sample/theoretical comparison somewhere - 22% thinner hence 44% weaker if I recall..?) And the Permaseals omit the cam chain tunnel rubber gaske...

You can of course use a cut-down Gemini dizzy and retain the points, but if you do the reluctor conversion itself then you'll know how to fix it. I keep a spare breaker plate with reluctor pickup and spare ignitor in my car. They are very reliable (despite what people seem to think) and the only fai...

Welcome to twincam! At first I thought yours looked a contender for sparts and I was going to suggest getting another complete GW if you want a working GW unless you find someone with all the missing sparts. (But afaik cam bearing caps need matching to the head - ie, line boring.) You could have got...

The best is the RG dizzy. RG is our name for (FWD; early model) RB Gemini dizzy guts into a Gemini (T series) RWD dizzy and it's the standard dizzy solution for all G-series Isuzu engines. (Not sure what construction threads exist here, but OzGemini had a few.) For the GW, cut the shaft 10mm below i...

I don't know the length. But the OEM Weber-types (Hitachi etc) had too high an angle for DCOEs (10 degrees max as I recall, though maybe 12) and the top of the (Weber) float chamber or choke would hit the top of the head - ie, the upper cam-cover gasket webbing. And note that the taper was on the po...

IMO no. There are plenty of 117 manifolds and all they are good for is 117s and their original Florian base and hence Chevy LUVs, KBs, Rodeos etc. Even then most would use the more common "over the top" EFI (Piazza, ZZx Gemini etc). The best manifolds are those that a NSW Bellett-Gemini CC...

Well, for airflow, yes (but not fuel). Alas I lack that "experience" and it was my one concern with the EFI version of my 400Nm G200W which used the twin DCOE45s albethey choked to ~36mm. But I figured RAM air maybe with (electric) fan assist should make up for any air shortfall, else that...