Isuzu 1.7 TD conversion

A petrol engine swap is definitely the easiest way to get more power. The main reason for going diesel over petrol is to gain 'low down torque' but, especially as you already have a Rocklobster, the gears ratios allow you to achieve the same thing.

I say 'low down torque' because it's a bit of a misnomer. At a given forward speed, with the correct range of gears, a 100hp petrol and 100hp diesel will generate exactly the same torque at the wheels. The difference will be in the gear ratio and engine revs.

I had a friend with a SWB fj40 running the diesel. I think it was the 3 litre 4 cylinder, so yes this was a long time ago.
He turbo charged the diesel, at the time turbos even in diesels was uncommon. That made the car excellent, and the revs were still good. So next step was he pulled out the diesel, and put in a holden 253 V8 conversion. It ruined the thing, rev’ed it's ring out at any normal speeds. He had an easy out because he swapped in the petrol diffs. In your case you are going the other way so you would have to find higher diff ratios to suite the diesel engine.
I guess the moral of the story is this could turn into a lot more work than a straight engine swap.
Swapping to an already compatible engine and giving it a tweak would be more reliable, cheaper and simpler.

I say 'low down torque' because it's a bit of a misnomer. At a given forward speed, with the correct range of gears, a 100hp petrol and 100hp diesel will generate exactly the same torque at the wheels. The difference will be in the gear ratio and engine revs.[/quote]

Really how does that work then ???????????

It's power that moves things. Torque is a measure of force and is increased or decreased by gearing. Power remains constant- no number of gears can change it.

Diesels have more torque but rev slower, so they need higher gear ratios to achieve the same speeds. Higher gears have less mechanical advantage, so the result is the torque at the wheels is the same.

As long as you have low enough gearing (e.g. a rocklobster, as TomDK has) you will get the same performance for both. The only time the diesel will be better is if your lowest gear isn't low enough.

Even If you could gear a petrol to deliver the same torque as a diesel it wont go any where in a hurry would be totally pointless on the road ive got diesel and the torque makes any of the petrol jimny engines look silly as for road gearing who knows ive got no idea what tyres or transfer box reduction they are running best to use one of the many 4x4 gear ratio calculator s that are available online they will tell you what mph for rpm you can expect

I'm sorry but what you are saying makes no sense. What gearbox and transfer case are you using that magically makes your truck better than a petrol Jimny at both slower AND faster speeds, even though it has a much lower rev limit?