Isuzu G-series Twin Cam

Started dropping the DOHC in during the week, so far so good - engine is sitting on its mounts, havent tried bolting the gbox crossmember up yet but it seems to have lined up spot on etc etc. Going well.

Two questions.



Notice three sensors on the termostat housing/pipe - what the fark are they all for? One is broken [not hard to see] so will have to be tapped and replaced, but what are they all for? Im guessing one is an input for the computer, the other for the factory temp gauge, and the third? Would it be an aftermarket gauge?

Also, connecting the heater core to the engine. Im assuming where this hose is looped [engine came out of a track car, hence no need for heating] is where i connect both hoses - one being water in, one being water out. Correct?

yes you are right on the heater hoses

temp sender
ecu sender

and the third was some emissons control (i think) g180 and g200 water manifolds are quite different

will have a look on my g200 117 motor

Thanks elky. Im guessing one on the left is temp sender, one in the middle is ECU sender and the third one is the one i have no fucking idea. If no one can come up with WHY i need it there, just going to re-tap it and put a plug in there.

That's my plan. Let us know if you figure out which one's which, btw

Are you using a factory ECU?

Also, the temp gauge sender will probably resemble G series SOHC senders, pic's pretty blurry but I'm gonna guess the one on the left being for the gauge.

Nah, Haltech E6k

Could the third one be a thermo switch for the Electric fans? Especially if it was off a track car. The two i have only have 2 sensors on it, as stated by someone earlier, its has a pin type like on the under side of a standard gemini inlet for the temp gauge, and a two pin with the same sort of plug as the injectors for the sensor to the ecu.

This has the two-pin one like the injector plug for the ecu, and 2 x gemini style ones.

I doubt one would be to turn the thermo fan on as the computer should be able to do it with the input from the middle sensor

GeminiCoupe wrote:This has the two-pin one like the injector plug for the ecu, and 2 x gemini style ones.

I doubt one would be to turn the thermo fan on as the computer should be able to do it with the input from the middle sensor

When I put 180 in my Bellett the 2 sensors are all that is needed. Make sure you have the correct resistance on the sensors. As they are different for puter and guage.
Mine is a 1995 conversion using wolf 3D the first piston motor with one.

So general consensus is the third sesnsor is pretty much pointless and i should be able to tap and block it with a bolt. Anyone know the pitch/thread size?

GeminiCoupe wrote:So general consensus is the third sesnsor is pretty much pointless and i should be able to tap and block it with a bolt. Anyone know the pitch/thread size?

I'm not sure of the size but I used a standard BSP threaded plug. If you can get it out and take it to your local bolt shop they will be able to help. Should only cost a dollar or two.

Managed to get it out, with of all things, a pair of scissors. Wedged em in the hole and turned, came out fine. Used a little allen-headed plug and it seems to be perfect.

Hey 65er,

bellett65 wrote:Mine is a 1995 conversion using wolf 3D the first piston motor with one.

What's your fuel economy like now?
(Last we spoke it was under 20mpg.)

I'll let you know once I get it going again. Have got 5 speed in. But as usual dry fit on floor all OK. Put in Bellett top 2 bolts on bell housing have decided not to screw in. Ratios will assist as the old 65 Bellett box was not happy in the end with the power. It runs the other diff ratio (forgot what it is) not the 411. I will have 2 programs loaded economy and power, I will be able to interlope between the 2 on the run. It has taken me 8 years to pluck up the courage to cut the hole in the floor. As I did it yesterday the song " The First Cut Is The Deepest " came to mind.

Jeez yeah! 4 speed with Florian diff (4.1:1). The Florian was bad enough with 3.9 diff and .782 5th Gem box - it needed a 6th gear!
I thought you mounted that LHS-starter Rodeo bell to a Gem box (ie ZZR ratios except low 1st and taller 5th)? (You mean I got that box out for nothing?!)
I was wondering what box? I used the st'd holes without the extension - the problem is replacing the cross-rib for the cut (or am I confusing the Wasp?), and then finding somewhere else for the drink cooler.

With apologies to out local GemCoupe for the hijack.

Im not fussed

Brett, if your chasing abit of economy AND power it might be time to turf the Wolf3d for something abit newer. Most new aftermarket ECU's are able to run an O2 sensor and as a result closed loop [+++++economy]. Haltech E6k ive got to run my DOHC has it, and i know MegaSquirts [roughly 450 for the full kit @ current exchange rate] does too.

Ill let you know what economy [and power] mine makes once dyno'd. She should be running on saturday if all goes well, its off to get the exhaust done 2morrow.