Hi all, picked up an '01 Disco 2 and I'm looking into LS swapping it.

I have two primary questions:
1. I've read that the 4hp24 in the Disco 2s uses a BOP (Buick/Oldsmobile/Pontiac) bellhousing bolt pattern, but I've only seen it mentioned very sporadically; can anyone confirm that this is correct?
2. Those who have LS swapped with the 4hp24, how are you controlling the transmission? I know there was an ACE conversion kit for a while, but it seems as though the company shut down. From what I understand they were actually controlling the LS with the stock Defender ECU, but it's hard to come across information as the website seems to have been taken offline. Hoping someone can chime in with some information here. I'm am, however, wondering if this is incorrect, because that is a very unique way to control a swapped engine.

Would be great to get into contact with someone who's done it.

Thanks!

 

Can’t help with the bolt pattern, but ACE kit uses an LS ECU that controls the engine in stand alone mode. It then feeds necessary signals into the rover ECU through a “translator box” to control the 4hp24. The conversion that uses the rover ecu to control LS is a different conversion kit.

https://www.trailhead4x4.com/lsd2

and as far as I know they only offer this as a service, not a DIY. They use the rover sensors to control the LS and retain the rover ecu to control everything. No in between conversion box.

 

LSDisco,
To your first question, I am doubtful the trans has this bolt pattern. It is possible since the Rover V8 is a Buick based engine. I have the Rover sitting in the garage with two transmissions separate. I can take some measurements. Here are some photos of actual differences in bellhousing shape.




So first is two BOP housings, next is a Rover housing, and finally the GM/LS housing. My own suspicion is that ACE was buying these removable bell housings and having the center section of the Rover bell housing welded in or the pattern machined in. Also, the BOP pattern is very different from the LS pattern. I am very curious if the Mark's 4wd adapter for the Holden V8 to Rover ZF would work. When I talked with them, they didn't think it would. I think the mating of the two would work. I think their fear was more along the lines of getting everything working electronically. https://www.marks4wd.com/mfk564ta.html
​To your second question, I believe the Rover ECU was being fed all the information it needed to make the trans controller happy. This ideally, requires the Rover MAF, crank speed, throttle position, and possibly some others. I have a lot of respect for these guys because they blazed a new path, but this stuff all posed a problem in my eyes. Trailhead, retains the LR throttle body, which chokes the LS beyond belief. The retention of the Rover MAF does the same thing. If you wanted to go this route though, you could simply use the Rover ECU as a passthrough to feed the rest of the truck the info it needs. Jensen is right, utilize the GM PCM to control the LS. The aspects tied to the magic black box were TPS and VSS. There are some ways around those hurdles I'm sure. You could rig some way to retain the LR TPS and run it off of your GM throttle body.

Now, my own experience and suggestion is to ditch the LR trans altogether. Go GM engine and trans. Not only do you gain the power and reliability, but also additional/better gearing. If you are confident enough to do the engine swap, you are capable enough to swap the engine and trans. You won't regret it!

 

If you can find a way to adapt the Rover trans to the Chevy engine, compushift makes a programmable transmission controller for our our HP22 and 24 slush boxes.

As disco Mike says, the best/easiest method is probably buying an LS with 6l80 transmission, then buy the adapter to make the lt230 fit the 6 speed. It can also be modified to fit the 6l90 if you have a machine shop to modify the output shaft.

The lt230 will not work well with older GM transmissions like the 700r4, 4l60e or 4l80e as the transmission pans kick out on the passenger side where your front prop shaft needs to go.

I'd argue the 4hp22 and 24 are much more reliable than the 6l80 which has issues with the torque converter, if it goes it takes the transmission with it. This is easily rectified with an new improved torque converter. The transmission is about the most reliable part of the disco 2 and that only needing to touch it every 75k.

What the 6l80 excels at is gearing. If I can ever find a way to control the torque limiter with it matched to a TDi VW motor I want it, 4.88 gears on 33 inch tires. 85mph at sub 3000 rpms. More gears better.

 

The 6L90 I believe is a little more reliable than the 80. That said the gearing abilities coupled with the Lt230 you can almost end up with a crawlbox type ratio in 1 and 2 in low range. The rover slush box sucks so much power and is super meh except for minimal maintenance. I'd chance whatever the risk of a 6speed mated to a LT230 every day and twice on sunday if LS swapping.

 

Rick,
I know we have chatted in another thread. I am really praying you find a way to mate the 6L with the TDI. It would be epic! Let me know if you need any help.


Whowa,
You are absolutely right. Even stock axle ratios and the 3.32 low range make for an insane crawl gear with the 6L 4.03 first gear. By the way, you have some nice looking rigs. I think I saw you post one in another thread. You are out here in CO right?

 

Doomsday diesel has released a of set test Discovery 2 adapters for the TDI engine. Originally I planned on being in on one of the testers. Unfortunately life throws curve *****. After 2 seasons playing beer league hockey with me my 17 yr old son was kicked out after a complaint of his age(under 18). He joined the school academic team and those are all day Saturday events that take most of our usable weekends. Then Helene came through and my industry which sells and repairs equipment went into overdrive. Much of our service area extends up into the Appalachian, not likely going to slow down before our spring rush ramps back up again

​​​​​​If his limited test kits end up successful i plan to purchase the next set released this March/February.
​​​​​​I would rather go with either a 6 or 8 speed, unfortunately I'm limited on spare time for the foreseeable future.

Fingers crossed the price of used discos continue to drop, perhaps I can gather a few more before Christmas to have a few to play with.