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4jg1t "franken-engine"

Share and discuss mod ideas here that make your Isuzu safer, faster, more homely, more user friendly or just crazier! The best from here will be made into a full DIY write up for the FAQ and DIY mod section.

4jg1t "franken-engine"

Postby handymanny01 » Mon Jan 06, 2020 9:05 pm

The build is finally complete! 4jg2 direct injection conversion.. just cause I wanted to see if it resulted in the ideal Isuzu engine! 4jg2t block , crank, rods, 4gj1t direct injection pistons with hard anodised crowns, 4jb1t direct injection head, 4jh1t injectors, and 4jg2 pump modded with 12mm head and Toyota direct injection cam plate, Initial impressions are good, starts with zero glow plugs, Good torque, Def down on horse power compared to the modded 4jg2, but there is more tuning to be done yet,, Running 22lb boost, egt is low at 550 , Many many pics to follow!
handymanny01
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Age: 43
Country: NZ
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Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby mh1989 » Wed Jan 08, 2020 6:38 pm

Wouldnt it just be easier to use a 4jh1?
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1992 Isuzu Rodeo 4jb1t

Re: 4jg1t "franken-engine"

Postby handymanny01 » Wed Jan 08, 2020 8:44 pm

It's the common comeback to the 4jg1 conversion,, reality is, it's just not that easy, as 4jh1 is electronic pump ,gear drive,,, if you've already got a 4jg2, "dropping in" a 4jh1 is actually kinda hard, You need a direct injection belt drive pump, belt drive front cover, gearbox plate, and LOADS of other bits,, plus a decent 4jh1 used engine,, (expensive) Ultimately I'll be building a 30lb boosted 4jh1 for the MU, but in the mean time,, building a direct injection 4jg1t out of standard parts was actually pretty economical, and teething issues aside has been pretty successful!
handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Wed Jan 08, 2020 9:34 pm

Piston masking for hard anodise
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Thu Jan 09, 2020 1:35 pm

Con rod bush fitting
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Thu Jan 09, 2020 1:37 pm

Cam sprocket hub , speedy sleeve fitting
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Thu Jan 09, 2020 1:40 pm

New liners in block, new pistons in!
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Sat Jan 11, 2020 6:50 am

Machining out the valve seats, and tidying up ports in head
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handymanny01
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Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby isuzurob » Mon Jan 13, 2020 4:00 pm

Your engine looks good, I have built 4, 4jh1t engines now all running over 30psi, they go ok but not power houses
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Re: 4jg1t "franken-engine"

Postby handymanny01 » Mon Jan 13, 2020 8:46 pm

Hey Isuzu Rob! Thanks,, looks good, but not performing as I'd like just yet,,, 100kw at wheels, 360nm, both at 2700rpm, so heaps to come if we can get it to inject properly,,, There is def a compatibility issue , either with the 4jh1 injectors and 4jg1 pistons,, or possibly in the custom pump,,, What sorta pump and turbo Combo are you running?
handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Mon Jan 13, 2020 8:52 pm

3.1 block and 2.8 head come together!
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Mon Jan 13, 2020 8:57 pm

Port matching head and manifolds ...
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Mon Jan 13, 2020 9:11 pm

Direct injection is a go! And the water to air top mount, and VF10 hybrid turbo ..
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handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby isuzurob » Tue Jan 14, 2020 4:59 pm

I'm running a custom 12mm pump only the fuel pump body is original and modified 4jh1 injectors, you will need the injectors to match the piston bowl or you will have issues, I'm running a high flowed td04 turbo but it's far to small
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Re: 4jg1t "franken-engine"

Postby handymanny01 » Tue Jan 14, 2020 9:16 pm

isuzurob, Sounds like a similar setup to me,,, mine is 12mm pump, Toyota 3.7 direct injection cam plate, and mods to boost compensator , and pretty much everything else that can be tweaked,,, double factory fuelling ,, Turbo is Isuzu 3.1 exhaust housing and turbine, Subaru core, and VF10 comp housing machined to take hilux 3.0 upgrade billet wheel,, 44/58mm ... we are currently working on the best injectors to suit the 4jg1 pistons,, And the best position in relation to the bowl,,, The 4jh1 injectors have worked best 1.0mm closer to bowl than stock,, Am at 100kw and 360NM (at the wheels) so far,,, but def more to come... as these figures were achieved at only 2700 - 2800rpm,,,, falls off after that What mods did you do to your injectors? We plan to try 4jb1 injectors too,, and possibly a 4jb1 standard pump just to see what happens,,,
handymanny01
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Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby isuzurob » Thu Jan 16, 2020 6:10 am

That turbo is way to small for your setup, I'm running modified twin spring injectors so they run single spring and still achieve full flow, I'm running 32psi and exhaust temps are 1200 pre turbo, as I said my turbo is way to little
isuzurob
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Vehicle: 1990 Isuzu Bighorn 2.8t/d, 3" extended shackles, 2" body lift, 33" silverstone extreme tyres, Front+rear bars, winch with 40m dyneex rope, 21/2 inch exhaust, lokka's front+rear, custom turbo, emissions removed, injector pump modified and more

Re: 4jg1t "franken-engine"

Postby geeves » Thu Jan 16, 2020 1:37 pm

1200 pre turbo. I hope thats F not C
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 4jg1t "franken-engine"

Postby handymanny01 » Fri Jan 17, 2020 10:00 am

thats what i was thinking Geeves!! hahaha
handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby handymanny01 » Fri Jan 17, 2020 10:07 am

Curious why you think the turbo is too small Rob? (open to all ideas / opinions though) this is the same turbo that was previously on the 4gj2 with the monster injection pump that was making an estimated 130-140 kw at crank..(for 2 weeks then it blew up). so it clearly flows enough air,,, the isuzu exhaust housing is small for sure, but go any bigger and its gonna get laggy,, which is not the desired result.. but like I say,,, very open to ALL ideas!
handymanny01
Isuzu Junior
 
Posts: 68
Joined: Tue Jul 12, 2016 9:39 pm
Age: 43
Country: NZ
City: Wellington
Vehicle: Isuzu MU 3.1 Direct injection 4JG1 conversion, Vf10 hybrid, ported wastegate, mild port head, custom 12mm pump, 3"dump and system, 3" inlet / pod filter, EGR delete, 2" body lift, 2" (ish) suspension lift, 33" on 15" steelies , recaro seats, nardi wheel,,, rear LSD , front "lokka"

Re: 4jg1t "franken-engine"

Postby isuzurob » Fri Jan 17, 2020 5:25 pm

That's degrees c was like that for 2 years of solid abuse and gudgeon pins got punched straight through the pistons 3 weeks ago now running custom forged pistons, I have full 32psi of boost at around 2200rpm and dies at 3,000rpm as exhaust wheel is to small this is why egt are so high also, no power without fuel remember, will rev to around 4200rpm, that's with a high flowed td04 which is far bigger than what you have, so as I said I'm thinking your turbo will be choking your engine setup
isuzurob
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Vehicle: 1990 Isuzu Bighorn 2.8t/d, 3" extended shackles, 2" body lift, 33" silverstone extreme tyres, Front+rear bars, winch with 40m dyneex rope, 21/2 inch exhaust, lokka's front+rear, custom turbo, emissions removed, injector pump modified and more

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