Any Information on a Turbo Diesel swap in Gen 1 Trooper?

935 Views 16 Replies 7 Participants Last post by paulthepilot_5, 5 mo ago

SuperTroop

Discussion Starter · 6 mo ago

Looking to potentially swap a turbo diesel into my 91 Trooper.
Can't find anyone specifically who has done this. Been looking at NPR motors.
Anyone have any experience with this engine swap here?

1 - 17 of 17 Posts

JoeIsuzu

· #2 · 6 mo ago

Assuming you're in the US. The NPR engines are too big, too heavy. Quite a few members have used the 4JB1-T and 4JG2-T. Those are getting about impossible to find with low miles. Check with @bellavesus.

mudoilngears

· #3 · 6 mo ago

Which NPR engine are you looking at?

SuperTroop

Discussion Starter · #4 · 6 mo ago

Yes, I'm in the US.
Didn't have an exact motor in mind, just knew the NPR motors "Should" fit. Open to other options.
I know with some other old square trucks I've been involved with there were pretty simple diesel motor swap kits.
Anyone know of anything like that available for the Troopers?
Any recommendations on motors?
Any kits or guides anyone has run across?

Shawn Anthony

· #5 · 6 mo ago

I started to drop a 4HK1 into a 1994 trooper. It will fit after a body lift, SAS, full suspension & making a dry sump oiling system. The frame needs to be stiffen & gussets added throughout to prevent the engine from twisting the chassis in half.

the easiest big power engine to drop into a Trooper is a Yanmar 4.4L V8 diesel & 4-71 Detroit. Each have a much smaller foot print.

mudoilngears

· #6 · 6 mo ago

It would be far more intelligent to use a 4JJ1 than to use any of the engines you mention.

Shawn Anthony said:
I started to drop a 4HK1 into a 1994 trooper. It will fit after a body lift, SAS, full suspension & making a dry sump oiling system. The frame needs to be stiffen & gussets added throughout to prevent the engine from twisting the chassis in half.

the easiest big power engine to drop into a Trooper is a Yanmar 4.4L V8 diesel & 4-71 Detroit. Each have a much smaller foot print.

mudoilngears

· #7 · 6 mo ago

SuperTroop said:
Yes, I'm in the US.
Didn't have an exact motor in mind, just knew the NPR motors "Should" fit. Open to other options.
I know with some other old square trucks I've been involved with there were pretty simple diesel motor swap kits.
Anyone know of anything like that available for the Troopers?
Any recommendations on motors?
Any kits or guides anyone has run across?

The two simplest and best engines for this application are the 4JB1 and 4JG2. They fit without any major modifications and are reasonably powered. Both are mechanical injection, so no electronics to worry about.
If you want more of a challenge you can use a 4JJ1, very similar footprint but it is CRDI and requires an ECM. Much newer design and much more power than the other two.

Reactions: 1

Enemigo

· #8 · 6 mo ago

Who makes the gas 5.x liter motors that are in the NPRs? I heard one straight piped down in Louisiana once and it was awesome.

mudoilngears

· #9 · 6 mo ago

Enemigo said:
Who makes the gas 5.x liter motors that are in the NPRs? I heard one straight piped down in Louisiana once and it was awesome.

I would imagine Chevrolet, since they are rebadged as such. I never understood why they made gas ones in the first place.

Enemigo

· #10 · 6 mo ago

I thought that might be the case. So Isuzu never made a gas V8? I know they were about to put on into the Trooper before they bailed on the US market.

I've always been a little bit interested in NPRs. I assume that whatever gas motor is probably bolted up to a GM counterpart transmission and there isn't really anything useful for us off those vehicles or else there would be more info about them on here.

mudoilngears

· #11 · 6 mo ago

Enemigo said:
I thought that might be the case. So Isuzu never made a gas V8? I know they were about to put on into the Trooper before they bailed on the US market.

I've always been a little bit interested in NPRs. I assume that whatever gas motor is probably bolted up to a GM counterpart transmission and there isn't really anything useful for us off those vehicles or else there would be more info about them on here.

As far as I know there isn’t a production V8.

Shawn Anthony

· #12 · 6 mo ago

mudoilngears said:
It would be far more intelligent to use a 4JJ1 than to use any of the engines you mention.

The 4JJ1 engine is a good engine. It's rated at 144 hp with 294 Nm of torque which makes it not very powerful. This low power makes your COST to INCREASE PERFORMANCE ratio not much above the stock engine. The 4JJ1 engine also isn't common in the USA. making parts and service a issue to be concerned about.

To repower any vehicle is difficult. It requires a lot of time, work, planning and money. Therefore, it makes absolutely no sense to invest all this to only yield mediocre results.

This is why with any repower the rule is to repower with a engine that's common and always repower by going big or don't bother.

Shawn Anthony

· #13 · 6 mo ago

Enemigo said:
I thought that might be the case. So Isuzu never made a gas V8? I know they were about to put on into the Trooper before they bailed on the US market.

I've always been a little bit interested in NPRs. I assume that whatever gas motor is probably bolted up to a GM counterpart transmission and there isn't really anything useful for us off those vehicles or else there would be more info about them on here.

The gasoline V8 offered in the NPR's are a General Motors 5.7L, 6.0L and 7.4L.

Enemigo

· #14 · 6 mo ago

Those are big boys.

mudoilngears

· #15 · 6 mo ago

It is not difficult to repower a Trooper with a mechanical injection 4J series.

Reactions: 1

bellavesus

· #16 · 6 mo ago

I agree with @mudoilngears . A straight forward swap to go 4j series diesel. The early ones, as mentioned, need no electronics aside from power to fuel cutoff switch- to run. I can source any engine from that series, from mechanical to common rail. These engines were designed to fit in the small truck platform which makes them an ideal candidate for consideration, especially from a cost to complexity standpoint . You can get plenty more HP than stock if that is your goal, but in my experience driving a 3": lifted truck with custom bumpers, ladder racks, 31" AT tires and towing a WW2 jeep trailer loaded down, i could still cruise at 75 down the highway. No, its not a big block- but it bolts right in.

paulthepilot_5

· #17 · 5 mo ago

Shawn Anthony said:
The 4JJ1 engine is a good engine. It's rated at 144 hp with 294 Nm of torque which makes it not very powerful. This low power makes your COST to INCREASE PERFORMANCE ratio not much above the stock engine. The 4JJ1 engine also isn't common in the USA. making parts and service a issue to be concerned about.

To repower any vehicle is difficult. It requires a lot of time, work, planning and money. Therefore, it makes absolutely no sense to invest all this to only yield mediocre results.

This is why with any repower the rule is to repower with a engine that's common and always repower by going big or don't bother.

while the 4JJ1 is not common over your way, it is a very popular engine for conversion over I here in Aus. Stock engine with a remap make 250hp comfortably, and it’s not uncommon for 300, 400hp setups daily driven vehicles, Thai’s will happily push them past 1000hp. It is a good option if you want a modern diesel with minimal fitment issues. For simplicity an earlier 4J family engine is the best option and somthing they were designed to run.

bellavesus said:
I agree with @mudoilngears . A straight forward swap to go 4j series diesel. The early ones, as mentioned, need no electronics aside from power to fuel cutoff switch- to run. I can source any engine from that series, from mechanical to common rail. These engines were designed to fit in the small truck platform which makes them an ideal candidate for consideration, especially from a cost to complexity standpoint . You can get plenty more HP than stock if that is your goal, but in my experience driving a 3": lifted truck with custom bumpers, ladder racks, 31" AT tires and towing a WW2 jeep trailer loaded down, i could still cruise at 75 down the highway. No, its not a big block- but it bolts right in.

100% 4JB1t, 4JG2t or 4JH1 with a mech pump. Will fit up with out too many dramas. They were never designed for big lump engines

1 - 17 of 17 Posts