Thread: ENGINE TRANSPLANT???

Well I've pretty well settled on what will be done to make it able to be engineered etc. Short story is -
1994 Disco 3dr manual
Current
Maxi-drive back end
2" susp lift
1" body lift
Stock 3.9 on dual fuel

Planned
350 Vortec crate motor (330hp) on straight gas
Rebuild R380 & LT230 while engine is out
Marks 4wd adaptor kit
Replace petrol tank with underbody LPG tanks for 120L useable.

Other plans in mind for when funds become available too.

Originally Posted by PeterM

Well I've pretty well settled on what will be done to make it able to be engineered etc. Short story is -
1994 Disco 3dr manual
Current
Maxi-drive back end
2" susp lift
1" body lift
Stock 3.9 on dual fuel

Planned
350 Vortec crate motor (330hp) on straight gas
Rebuild R380 & LT230 while engine is out
Marks 4wd adaptor kit
Replace petrol tank with underbody LPG tanks for 120L useable.

Other plans in mind for when funds become available too.

I've done a little hunting, you can buy a 153 tooth flywheel/ring gear for LS engines from Summit, they are sourced from Mcleod flywheels, also matching starter

I'd do this, you'll find 120L of LPG a nightmare for long high country trips and once you run out on straight LPG you'll curse yourself

I think you'll get a far better result this way, you just need to use the adaptor plate from marks to chev....they'll argue about selling bits seperately, but they will

Agree with matt, straight lpg is not a good idea, what range will that give you? 300 odd K's? Less in the high country.

The emissions compliance is the bit that is moving me towards straight gas. I can't get it engineered without emissions and to do that will cost a fair bit for the test, let alone the hardware to ensure I have a shot at passing! I've done some sums and the costs are such that to go petrol will cost about the same as going to straight gas (including extra tanks) but then the test cost goes on top of that. If I wanted to retain dual fuel then there are additional costs due to the extra under bonnet gear.

I could be dodgy and remove the petrol gear for the engineering and re-fit afterwards but I come back to the only advantage being the ability to refuel from a jerry can.

Fit an LS and I will pretty much have to swap the transmission. More expense as well as the custom work with adaptor plates for things that haven't been done before.

120L of LPG should be good for 500-600km on road but I appreciate that it won't be an option for longer duration trips away from towns. The most I've done previously has been long weekends away and the existing combination of LPG and petrol has been sufficient with a range similar to what I'd get on straight gas. If I was looking at a vehicle to do longer trips on I'd be heading in a very different direction. As it is, its going towards more of a capable rig for day trips or weekends.

Its a bit of a conundrum and not completely straightforward.

Ls using factory ECU, cat, purge solenoid, airflow, tune etc should have no requirement for emmissions testing

120L usable with a small block che in the bush expect 350-400kms

Now if you ever decide to go to talbotville for example, your in for a crap time on straight LPG

Why is it that you think a 350 will be fine with the R380 and an LS won't?

I've run straight LPG before and even for weekend trips it can be a total PITA. Take a wrong turn after hours anywhere from a major road or township and you are in the poo. With that many cubes and that amount of weight you will hoover up the LPG offroad like it is going out of fashion.

I've run old chevy trucks, 2wd and 4wd, for the past 20 years and had lpg of some sort on every one. I can't recommend enough the option of dual fuel, you will find that there will be a heap of places you wont go, and things you wont do due to the risks associated with getting caught out a long way from a fill station without enough range to get back for a re-fuel. Every trip ends up getting planned out like you are flying there....calculating fuel loads, establishing turn around points etc etc

It will take the shine of all the work you are proposing to do.

Just my 2c.

Jas

I was figuring that based on the output of each engine that the LS would be too much for the R380.

You're right that an LS with stock injection & emissions system would cruise in on the emissions front. I could do the same with an injected 350 in Suburban spec but they are like hens teeth.

How much moving around of ancillaries on an LS is required to fit around the steering box etc.?

Are the LS's the same bolt pattern to permit the use of the same adaptor plates as a 350? What about engine mounts?

Thank you for your input guys, it is an unknown for me and I don't want to screw the pooch with it. Do it once and do it right is how I like to do things.

Hmm, further investigations have been interesting......

The guys at Marks 4wd Adaptors have been busy. They have a very comprehensive list of bits for this conversion with the sole exception being engine mounts.

They've developed their own engine harness to eliminate the various sensors that are not present on the Disco, brackets for ancillaries, billet flywheel and starter (153t) the adaptor kit itself and also headers to fit between the chassis rails. They also have other bits on hand such as fuel pressure reg, up-rated fuel pump etc. Given that I can get a decent used LS1 engine with ancillaries from $2500 the overall cost isn't too bad actually. A bit of a tune should help the off-idle torque response without resorting to camshaft swaps.

On the LPG front, as I've got existing tanks I could have injected gas fitted down the track with only the under bonnet stuff needed.

So, with that I'd have an unchanged capacity of gas and petrol with a compliant engine that *should* be more efficient while being more powerful.

Hmmmm.