I'll cut to chase and start with my need/request first. Below I will also summarize my pending plans for those interested, as I'm sure the title will bring some questions.
I am looking at swapping a 1GZ-FE V12 from a 2nd gen Toyota Century (GZG50) into an 80 series. I need someone who has more JDM Toyota access than me (or knows Japanese) to provide Electric Wiring Diagrams (EWDs) and Factory Service Manuals (FSMs) for a Century between April 1997 and April 2000. Specifically, I need to see ECU pinouts as I'm trying to use the factory ECUs for the swap, although complete documentation would definitely be helpful. I also believe an immobilizer was introduced in April of 2000 per the parts diagrams from Part Souq and the ECU part number changes at the same time. I think I have to avoid buying an engine and ECU with an immobilizer if I make it to that point. FSMs and/or EWDs prior to April of 2000 would be able to confirm the absence of an immobilizer. The best FSM/EWD resource I have found for the Century (CENTURY - http://century.trinom.org/) is not clear on the model year/s it is applicable to. The documents in the link do show an immobilizer. I assume there is a JDM equivalent to TIS (https://techinfo.toyota.com/) that I'm not aware of. I don't exactly have the skills to search around in Japanese though.
As for details on the build, I bought a 1997 LX450 in December. My first LC, coming from the 3rd gen 4Runner world. I am in the planning stages of the swap right now, but the project is feeling very possible aside from the hurdles I mentioned above and a couple more I discuss below. The build threads on these swaps are rare, and the ones you do find are normally going into something like a Supra. That adds many additional challenges and the builds frequently stall out. Tight dimensions make the front sump a huge (and expensive) headache among other things. The desire for forced induction requires an aftermarket ECU. It doesn't sound like there are many aftermarket computers that can support 12 cylinders and 48 valves on variable timing, not to mention folks who have experience tuning them. Then you will presumably adapt it to a manual transmission, the list goes on.
We will see how it shakes out as the research continues, but swapping the 1GZ into an off-roader looks to be an easier task and a better application than the sports cars. It's about an 85HP (40%) and 70lb-ft (25%) torque bump over the stock 1FZ-FE and it makes 300ft-lbs at 1,000 RPM. The engine was designed to smoothly and reliably transport executives in a 4,000lb land yacht after all. Engine performance peaks at ~310HP (that's a guess, google "Japanese automaker gentleman's agreement") and 340lb-ft.
80 series LCs built after '93 came with the A343F which happens to have the same bellhousing bolt pattern as the 4-speed A342E that came in the Century until 2005 (the transmission was then swapped for a 6-speed). From my reading the torque converter and flex plate from the 1GZ should be compatible with the A343F. Worst case I can use the stock TC and get a custom flex plate made to mate them.
As stated above, I plan to use the Century ECUs to run the engine and the stock LC ECU to run the transmission. I will have to convert the 1GZ throttle bodies to cable actuation but will keep the position sensors for ECU operation.
The front oil sump may cause issues, but the general arrangement drawings I have show the 1GZ only ~4in taller than the 1FZ at the front of the engine bay where the sump is a concern. I think I should be able to play with the engine positioning and angle to get it to fit without modification to the oil system. I will be able to do more measuring when I get back home to my 80 series next month. I'm also thinking an oil accumulator is probably a good idea as front sump isn't great on steep climbs.
Some of the imported 1GZs come with exhaust manifolds, which will be a requirement for me as I'm not looking to custom fab headers myself.
My goal if I were to proceed with the swap is to have adequate planning on the front end to make this mostly a wiring job. Obviously modifications will be required to mounts, intake, exhaust, etc. but I'm not looking for a thousand hour project with extensive custom parts.
Part of the reason I'm posting this is so that more eyes can poke holes in my plans. If you think I'm overlooking something or have further questions, feel free to ask. These are not all my notes and you won't hurt my feelings.
I am emailing back and forth with a Kiwi who has had two 1GZs floor running on stock ECUs and is working on a sports car swap. I'm hoping he can give me some drawings or guidance on wiring and ECU pinouts. I am also trying to get a hold of a guy in South Africa who has swapped a 1GZ into a 70 series and a 105 series. In the meantime I figured I would expand the audience and see if anyone on here has helpful knowledge or resources.
Thanks for reading.
Andrew
I am looking at swapping a 1GZ-FE V12 from a 2nd gen Toyota Century (GZG50) into an 80 series. I need someone who has more JDM Toyota access than me (or knows Japanese) to provide Electric Wiring Diagrams (EWDs) and Factory Service Manuals (FSMs) for a Century between April 1997 and April 2000. Specifically, I need to see ECU pinouts as I'm trying to use the factory ECUs for the swap, although complete documentation would definitely be helpful. I also believe an immobilizer was introduced in April of 2000 per the parts diagrams from Part Souq and the ECU part number changes at the same time. I think I have to avoid buying an engine and ECU with an immobilizer if I make it to that point. FSMs and/or EWDs prior to April of 2000 would be able to confirm the absence of an immobilizer. The best FSM/EWD resource I have found for the Century (CENTURY - http://century.trinom.org/) is not clear on the model year/s it is applicable to. The documents in the link do show an immobilizer. I assume there is a JDM equivalent to TIS (https://techinfo.toyota.com/) that I'm not aware of. I don't exactly have the skills to search around in Japanese though.
As for details on the build, I bought a 1997 LX450 in December. My first LC, coming from the 3rd gen 4Runner world. I am in the planning stages of the swap right now, but the project is feeling very possible aside from the hurdles I mentioned above and a couple more I discuss below. The build threads on these swaps are rare, and the ones you do find are normally going into something like a Supra. That adds many additional challenges and the builds frequently stall out. Tight dimensions make the front sump a huge (and expensive) headache among other things. The desire for forced induction requires an aftermarket ECU. It doesn't sound like there are many aftermarket computers that can support 12 cylinders and 48 valves on variable timing, not to mention folks who have experience tuning them. Then you will presumably adapt it to a manual transmission, the list goes on.
We will see how it shakes out as the research continues, but swapping the 1GZ into an off-roader looks to be an easier task and a better application than the sports cars. It's about an 85HP (40%) and 70lb-ft (25%) torque bump over the stock 1FZ-FE and it makes 300ft-lbs at 1,000 RPM. The engine was designed to smoothly and reliably transport executives in a 4,000lb land yacht after all. Engine performance peaks at ~310HP (that's a guess, google "Japanese automaker gentleman's agreement") and 340lb-ft.
80 series LCs built after '93 came with the A343F which happens to have the same bellhousing bolt pattern as the 4-speed A342E that came in the Century until 2005 (the transmission was then swapped for a 6-speed). From my reading the torque converter and flex plate from the 1GZ should be compatible with the A343F. Worst case I can use the stock TC and get a custom flex plate made to mate them.
As stated above, I plan to use the Century ECUs to run the engine and the stock LC ECU to run the transmission. I will have to convert the 1GZ throttle bodies to cable actuation but will keep the position sensors for ECU operation.
The front oil sump may cause issues, but the general arrangement drawings I have show the 1GZ only ~4in taller than the 1FZ at the front of the engine bay where the sump is a concern. I think I should be able to play with the engine positioning and angle to get it to fit without modification to the oil system. I will be able to do more measuring when I get back home to my 80 series next month. I'm also thinking an oil accumulator is probably a good idea as front sump isn't great on steep climbs.
Some of the imported 1GZs come with exhaust manifolds, which will be a requirement for me as I'm not looking to custom fab headers myself.
My goal if I were to proceed with the swap is to have adequate planning on the front end to make this mostly a wiring job. Obviously modifications will be required to mounts, intake, exhaust, etc. but I'm not looking for a thousand hour project with extensive custom parts.
Part of the reason I'm posting this is so that more eyes can poke holes in my plans. If you think I'm overlooking something or have further questions, feel free to ask. These are not all my notes and you won't hurt my feelings.
I am emailing back and forth with a Kiwi who has had two 1GZs floor running on stock ECUs and is working on a sports car swap. I'm hoping he can give me some drawings or guidance on wiring and ECU pinouts. I am also trying to get a hold of a guy in South Africa who has swapped a 1GZ into a 70 series and a 105 series. In the meantime I figured I would expand the audience and see if anyone on here has helpful knowledge or resources.
Thanks for reading.
Andrew
