Over on the VOLT Facebook group Wayne Anthony Jones asked: “What will i have to change on a volvo 2.4td engine to make it fit my lt?? thanks”. To preserve some of the knowledgeable responses I have summarised the responses below. 

Read this in conjunction with the threads on the Brick Yard forum such as this one: http://www.brick-yard.co.uk/forum/d24t-info_topic32717.html

The spigot bearings vary. Martin got an insert machined to accept the LT gearbox input shaft.

Engine mounts are different and it will also depend on the model – 35 and down are coil, 40 and up are beam suspension.

The oil pickup in the sump differs from a 4×4 LT to the normal LT and the Volvo. These parts can be easily  bolted over.

Here’s Martin’s transplant engine being tested:

Following stuff also has to be changed: coolant flanges, one outlet needs a core plug, oil pressure sensor and the rocker cover. Volvo has oil filler in the front, LT in the back. Be a right pain to open the entire engine cover every time.

Volvo 740 donor engine:

 – spline on the crank at flywheel seems to have changed on the later ones. ’97 Volvo 940 differed and needed to be machined up. 

Volvo 940 donor engine 

 – engine mounts, pipework for intercooler, oil cooler needs a home, core plug blank where pipe comes from engine case, other bits and bobs, never had to do anything with the crank 

Volvo 940s with the NV engine (D24TIC) are the ones to go for if you can find them

From https://www.facebook.com/groups/voltowners/permalink/10153653004044421/ re Volvo 940 engine transplant with turbo diesel intercooler:

An intercooler cools the air for the inlet making it more dense i.e. it burns better. The Volvo engine is VW so mates straight up you – just have to block off one hose from the rear of the block (Simon Gallimore)

Fabricated up an engine mount using an old Cortina rubber bush and the original LT bracket, placing a 2p in the hole in the back of the block where the gearbox mounts. Hasn’t leaked in 4 yrs. 

The Volve 940 was a TDiC and had an intercooler which is too wide for the LT so a Peugeot 305 tdi intercooler was used instead.

When I asked Marlow what sort of performance improvements you get I had this response: “Quite a bit. The Volvo has bigger injectors, a more aggressive cam and a wider setup on the waste gate, so the turbo kicks in earlier.” Chris Batey added: “Original DV engine outputs107HP; Volvo TiC 121BHP, or 127BHP depending on what you read.”

More useful info from Marlow:

Intercooler was in the LTs from 93, if they had a turbo. Well … And Volvos wink emoticon .. 740/940 are the same engine, but different wastegate (turbo kicks in earlier), intercooler, more aggressive cam and bigger injectors. Either way, you could always do it in stages. Start turning the pump up, maybe retrofit intercooler. Those the are the cheapest tuning options.

Cheapest option is getting a late Volvo 940 2.4TD. That’s the upgraded engine. A few bits have to modified if you swap the entire engine. Or you just bolt sump, manifolds, turbo over. That’s another option. Gives you a lot more grunt.

It depends how good your mechanic is. In my case the center piece/spline at the back of the crank had to be machined. There’s one hole at the back of the Volvo engine that needs a core plug. Sump and pickup changed over. All flanges bolted over. Engine mounts bolted over. From there its straight forward. So if you have a guy that isn’t scared by that sort of thing or you can do it, you’re on to a simple engine swap. If he’s not capable of maybe machining one or 2 bits, then you should just bolt over whatever you need to get the turbo conversion done.

There are 3 generations of the LT engine. First one has shimmed valves, second hydraulic controlled ones and third then additionally got the intercooler if turbo charged and more sensors and egr in general. Egr you obviously want to blank off. There are also 2 versions of the cooler fan. One rigid, one on viscous. The viscous fan engine has 7 bhp more because of that, but tends to have more overheating issues, so people convert back to rigid fan.

A recent transplant was conducted by Dave Townend over on VOLT (here’s the link to the thread). Dave makes the job sound easy and did it over a few weekends on his drive! The finished results looks ace:

Rupert Davidson put a 4 litre Rover V8 in his Nellie. He runs the zf4hp22 box from a Range Rover but with a BMW output as he don’t need the transfer box. He adds: “if I knew then what I know now I’d go crate chevy lump and box,same price if not cheaper after all the performance bits, parts are easier to get and you get more gee gee’s for your buck which is surely the end game.” e.g. LS3 6.2 crate engine

Dan Monstercrawlers Reading is planning to swap to a Merecedes OM606 engine which should reach 350-400bhp returning 30mpg.

Chris DeLong posted the following pic of an Audi A6 2.5 TDi engine that he has fitted in his LT 4×4. He’s sticking with the original gearbox:

Bernd Köhler posted another A6 TDi install in his LT. It’s an AAT engine. He did have to make his own crank pulley and alternator bracketry. The build gallery is here:

Another route to significantly add more power is to add more fuel and boost. The D24 forum has lots of info on modifications to turbos and intercoolers. Some stick engines (like the 95hp ACL) came with an intercooler. But they are a fairly small box: 2400cc @ 4000rpm and 0.7bar = a lot of air. The Volvo intercooler is much bigger. 

Joe Scrows states: “The D24 has a seven bearing main and 23:1 standard C/R which is a strong base. We have seen almost 1000bhp/850lb/ft from the cummins 6bta base , this was achieved with full engine work.”

Dan’s response: “…the ultimate factor will be how much power the LT trans can take.. I keep thinking that a tuned d24t would be cool but the high ratio gearing of the LT would just render any gains pointless. Think the answer will be in the diff.”

Stefan Berendijk: “The ARVW had 175bhp (-200bhp? ed.) @4500rpm with 25psi boost. Turbo’d CP engine “

As has been agreed before the turbocharged and intercooled D24TIC engine from a 1991-1995 Volvo 940 or 960 is the easiest route to more power. Once the engine is in upgrade the intercooler, turbo and injection pump. How much upgrading would depend on what the series 1 LT transmission would endure.

For those already in this situation the boost pin is on top of the aneroid. but start with the fuel screw. Chris’s really useful write up – How to make your 2.4 LT1 faster – is up on the Brick Yard forum here. Jason Knapman suggests that the pumps are different between the VW and Volvo engine (Chris’s is the Volvo engine)

Jason Ewing added: “18PSI on the DV engine with ACL intercooler works fine in our Florida. (Ok modified pump too – full fuel to 4000rpm) Now I need more gears. “

More photos of Bernd’s transplant here: http://www.vw-lt-karmann.de/Allbum/index.html

Exhaust is from Volvo. The Engine is from Audi 100 AAT

More from VOLT!

Ash Ley is fitting a 4.7L power tech V8 from a Jeep Grand Cherokee in his LT50 recovery truck, with a 545rfe auto gearbox. 

The Land Rover Discovery ZF auto gearbox bolts straight onto the D24t engine. This means there’s an opportunity to fit a V8 Land Rover engine but you would need a Volvo bellhousing and flex plate to do so.

From a thread on VW LT MKI Owners of the Americas…

LT in attached photo has “a complete drivetrain swap by an unknown previous owner. Late 70’s early 80’s Chevy Suburban or K5 with a Sbc 305, Th350, NP203, Dana 44 and a Corporate 12 bolt. “

A Isuzu 4BD1T engine transplant is taking place. Further info from owner Arthur Degen Naldoza:

“Since the engine bay was already expanded for the SBC I decided on the Isuzu. Was also waiting on the Cummins Repower but the cost and displcement 2.8 dictated a more economical diesel. I’m using the stock Isuzu MSA5D gearbox with a divorced NP 205 TC. There are a few manufacturers who make adaptors from the 4BD1/2T to the popular 4×4 and 4×2 transmissions – NV4500, 4L80. Should also mention COR Conversions out of Australia. Isuzu NPR/ELF gearboxes are cable or linkage operated. Ideal for our cab over LT’s but not the more popular Land Rover, Land Cruiser, 4BD swaps. They make a top shifter for the various Isuzu gearbox along with gearbox to TC adapters.”

Archived photos from the now defunct Overland Junkies page after they fitted a Cummins engine in their LT in the States

OK more chat around VW MTDi and Merc OM606 engine swaps between Bouke Muis, Martin List-Petersen & Chris De Long:

MTDI pump on a 2.5 TDI – engine code = AEL, ACV, others. there are a few variants. The 2.5 directly bolts to the LT bellhousing.

Merc om606 – nice high revving engine to match with gear and axle ratios but wwill need an adapter for the bellhousing. But consider that you’re fabricating engine mounts for the 2.5tdi it shouldn’t be too much of a challenge to adapt the bellhousing for the om 606 and at least you gone with a 3l engine which is all over the world. The om606 is natural aspirated and can do 5000 rpm. The tdi is significantly more powerful but at 4400 rpm. The om606 with a mechanical fuel pump made by dieselmeken would be a good choice but finding a block with low mileage would be hard.

It would be a big upgrade to go to 130 kw 330 Nm

dieselmeken builds mechanical TDi engines from Merc om606 for racing. So the 2.5 tdi are rather simple to do: shorten the sump on the 2.5, make engine mounts…

Merc om606 has the series pumps not the rotary ones and can rev significantly higher then the VW one. Bigger tyres would help drop the revs by about 200-300.

Found a Mercedes OM606 turbo motor for sale at € 1.250,00 http://link.marktplaats.nl/m1404532559 A guy who specializes in om606 engines for offloading and motor boats can do automatic gearboxes with standalone controllers which would be much better for off-road as you have no clutch and never lose torque and friction when changing gears. The only place where automatic falls behind manual is gear selection downhill for engine braking. The torque converter has friction plates inside – no new wave magic. The 5g tronic 4matic automatic gearboxes that where on the om606 also have a torque converter (https://en.wikipedia.org/wiki/Mercedes-Benz_5G-Tronic_transmission) The DV engine weighs 182kg dry; the om 606 (210kg) would be an increase of 30 kg; automatic transmission will also be heavier; plus engine mounts. With the 2.5tdi you lose a cylinder so even if that is 200kg at least you have the weight further back.

A Merc om606 engine would cost €3,200 with a 6 speed gearbox with 0 miles on it. It will be checked pump rebuild to mechanical and fitted with larger plungers, tuned and test run

Rebuild head will cost 800 and rebuild turbocharger to choice – hp 550, so €5k in total plus fitting? He can get easily 400hp out of it but will tune it to 225 hp. Around 200 he says will be very reliable for a long trip.

The limit would be of how long the engine plus gearbox fit between the transfer case and the front of the engine bay. Also the LT sump sits over the front axle. Plus the height of the gearbox may mean that you need to modify the front of the floor. Gearbox controls also plus cables/levers & joints…

Initial om 606 measurements are: 800mm long, 750mm high, 500 wide without turbo, 600mm wide with turbo.

Volvo 850 TDi engine could also be an option. Engine code is D2525. It’s the same motor as the VW 2.5 TDi. The d2525 exhaust manifold is needed to fit the turbo. It’s basically a T4 ACV with a bigger turbo and injectors but still a wastegate turbo whereas the AXG T4 is a VNT turbo. You can pick an Volvo 850 up for around £500 quid. It’s nice to have a wastegate if you want to convert to mTdi. Never seen anyone manage to control a Vnt turbo without an ECU properly. With a wastegate turbo, you replace the seals and it’s good for another few 100k km. Wastegate turbos are vacuum controlled. All acv and/or d5252t are ECU based engines, so MAF, EGR, etc. but as they are 1st gen TDI I imagine they can be converted back to a mTDi. The M606guy is doing the same with the Merc om606 engines with a custom mechanical diesel pump with larger plungers and injectors pressured to 150 bar which would allow you to get 400 hp out of the om606 depending on turbo and intercooler, priced at €3,200 which includes tuning and test running.

Uk-based alternative: https://www.dieselpumpuk.com/shop/crate-engines/crate-engines/

These guys do a sump mod for the Merc engine too which looks rather like the LT.

Another post worth archiving from Facebook for anyone contemplating upgrading to something much better instead of fixing the existing engine. In this case a 2.5l TDI from an Audi A6.

Shortening the sump will be required unless you port over the original LT sump. New engine mounts will need to be made. 

The stock AEL sump pan is too deep. 

You will need the loom and ECU and the air flow meter. 

The engine mounting/clearance under the pan different between 2wd and 4×4? Is yours a 2wd? 

The LT sump has a deep bit & a shallow bit for axle clearance. A Turkish guys took a slice out of the shallow bit to shorten it for 2wd.

For an LT40 4×4 transplant the engine carrier is different between the 4×4 and 2wd stuff. 

The Lt 40 4×4 gearbox will mate up no problem.

It’s a pretty straight forward transfer using a LT2 the 2.5 Tdi AEL LT2 engine (arguably one of the best diesels VW ever produced… and gearbox two) coupled up to original 4×4 transfer box, obviously you can retain your original box if need be. It can return 35MPG even running 220HP. This video shows a T4 running the above with a VNT 20 turbo, which revs to 5000rpm: 

The factory LT2 109BHP runs a VNT 20 turbo as well, that would be far more suited to the LT1 set up. It is vacuum controlled, so all you will need is the LT2 manifold oil return and feeds pipes.

The biggest problem may be the main bearing bolts snapping so suggest running ARP hardware.

Uprated valve springs also a must as it likes to rev and can catch you off guard once tuned.

AEL is wastegate turbo

The LTII turbo manifold will bolt up to an AEL. 

The engine in the video is the T4 factory engine (102BHP), the same engine used in the Audi 100, Volvo V70 and LT2 with a variety of sumps, turbos, fuel pumps and manifolds to suit each application.

The LT 2 came in a 102HP option, with wastegate turbo and 109HP with VNT 20. The T4 came in 88 and 102hp with wastegate turbo and 151hp with VNT 20 and all the manifolds are interchangeable. Early Audi 2.5’s run doweled con rods, and different Pistons.

The VNT equipped LT and T4 runs lower compression Pistons but that’s about the only difference across the range.

The T4 had a 2.4 5 pot diesel engine  from 90 to 2000, but the 2.5tdi was OE fit from late 96 to 2003, most european T4s on the road today are 2.5TDis 

LT1 6 cyl is a 8 bolt flywheel so use your original flywheel and clutch 

Thinking about ‘chipping’ the engine and/or put nozzles in it… Anything more than stock and it would be best to up rate clutch meaning you may have to have one made up for you which should be fairly simple (in the UK it cost around £350 to have your clutch reworked, up rating your original pressure plate and modifying your stock friction plate to Organic