Planning an LS swap in to my 1993 Lexus LS400, need advice.

[IneptusMechanicus]

Alright, it's almost 5 AM and I really don't feel like modifying my original ClubLexus post, so I'm gonna just copy and paste it.

Here it is:

Hey folks, It's me. Again.

And yes, you read that title right. I'm considering LS-swapping my 1993 LS400. This is gonna be a hell of a long post, so let me break it down.

WHY?!

Yes, I know, the 1UZ-FE is a fantastic engine. I love it, it's reliable, it's gotten me where I need to go for the last two and a half years with the only real problems caused by me misreading a date on the ECU and failing to change a fuel filter. However, there's one glaring flaw with the engine, and one that can't be fixed: Aftermarket parts are either made of gold, or nonexistent. EVERYTHING that isn't shared between other Toyotas costs an absolute fortune. Some stuff, like the California-specific parts I need for my car, can only be gotten from another junked LS400 from 1993-94 or from a sketchy seller on Ebay for ten times its actual worth. Performance parts do exist, but they're few and far between with very little in the way of options. Most of them, like a stage 1 cam swap get you what, ten HP? For about a thousand dollars in cams? Ridiculous. A supercharger would be pretty neat, but that's not possible due to the second issue.

The engine is dying. This car's had a very hard 250k miles, and it appears as though at least six of the eight previous owners never really changed the oil. The inside of the engine is gunked up badly, and oil pressure is complete garbage - with 10W-30, I get about 10psi at warm idle. It's not enough to make it constantly knock, but lifter tick is getting steadily worse as time goes on. Add that to the fact that I stupidly let it spark knock for well over a year because I thought the ECU had been replaced (it hadn't) and the engine is currently REALLY not doing well. It's got a pretty bad shudder when it's cold, almost no power until you stick your foot in it and hold it, and tons of other smaller problems and leaks. I've replaced the entire fuel system, tested the AFM, replaced the coolant temp sensor (yes, the ECU one, and yes, it was bad), The O2 sensors (had crap on them), you get the idea. I'm doing a fuel pressure test tomorrow to see if the pump's dying again - this is pump #8, the old ECU was a serial killer - but chances are the pressure is fine and I'm back to not knowing anything new. I've gone through every vacuum line (twice, don't buy Prestone hoses). I've tested the coils, even going so far as to buy a new one as a control group. But even if I do get it running right again - which at this point I doubt will ever happen - it's not going to last much longer with the oil pressure it's got left.

HOW?!

No idea! I know it's been done before - I still need to do a fair bit of research on the subject, but my swap's probably gonna be a little different than others. Y'see, I want to keep the interior of the car exactly the same. I know the dash gauges run off of separate sensors than the ECU, so wiring those up is going to be easy. Tach signal would be a little harder except my tach needle has fallen right out of the gauge, so... no worries there, I guess. I also want the radio, ABS and A/C to work, which means the LS400 ECU needs to stay powered. It might also need an RPM signal; I don't know. I plan on tying most of the harness out of the way and not cutting anything, just to keep it simple. I'm planning on fabricating some brackets for the power steering pump and AC pump. The LS is quite a bit smaller than the 1UZ owing to the fact that it's a pushrod engine, so I'll have a bit more space to work with. I'm almost sure that a 4L80E will fit in the stock LS400 trans tunnel, and I can use the stock shifter cable to shift it. Don't know much about that trans so I'll have to figure it out as I go. Obviously the LS is going to require its own aftermarket ECU, I'm not sure if the 4L80 requires a separate computer to run it or if it can run off of the same computer the LS does. This is all going to require some serious fabricobbling to work properly (or at all) so I'll need to get a welder and some other tools too.

You know this is gonna take a *****load of time and money, right?

Yeah, I do. Besides the tool and material costs, there's always the unforseen costs of all the little things you never knew you needed - and they add up damn quick. My preliminary cash budget for this project rests at about $4500. That's with a bone-stock truck engine straight out of the junkyard and very little research done on my part. I know people love to screech on the internet how they LS-swapped their mom's bicycle for $3.50 and some pocket lint, but having already had two project cars, I'm not nearly naive enough to believe it's going to be anything approaching fast or cheap. Speaking of time, My estimate for completion is one year from when I start, and I still think that's being waaayyyy to optimistic. Wiring is going to be a nightmare, so's fuel delivery, hell just FITTING the damn thing inside an engine bay it was never meant to see is going to be an absolute pain. In short; This ain't gonna be easy.

So that's it? Just a stock truck engine? Nothing special?

HA. No. Stage One of this plan is just getting a truck engine, cramming it in my LS400, and getting it to run and drive properly afterwards. I want to make sure it's all put together right and won't light on fire the second I hit 88mph before I start spending any serious money. Stage Two is a bit different - I'm looking at getting a 6-liter engine and boring it out a bit, probably to around 400cui. Get it? It's LS400 with a 400 LS. I'm so funny. Anyways, I'll probably stick a supercharger on it at some point; I know turbos are way more efficient but I really hate exhaust work and I'd rather just stick some block hugger headers on it and be done with that part. Obviously for this part I'll need a way beefed up transmission and differential (it'll be a stock differential, I know a place that'll modify the stock drive shaft to fit on a GM output shaft). Stage Two is probably gonna be one of those in-a-decade-or-so goals given the extreme cost and time associated with it.

...So what do you need us for, anyways?

Pretty much anything you can give me. Welder recommendations, other tools you think I'll need, any information or links to threads where this has been done, dimensions of the 1UZ compared to the LS1 in terms of things like the oil pan, you get the idea. Hell, if you've got any ideas on things I should add to this post, lemme see 'em. I only have the barest clue what I'm doing and I'm going to need to learn a ton of stuff and do at least a year or two worth of preparations just to make sure this project is even feasible. I also need to get my other car running first so I have something to drive around, but that's going to happen by the end of October so it's less of a concern.

TL;DR - Idiot attempts dumb modification to broken LS400 instead of fixing it properly or rebuilding engine.

Aaaannd back to the present. The people over at ClubLexus didn't really feel like helping much (or couldn't) so I figured it was time to bring over to the forum I should've started in.

[Tree98]

So I have done a couple of LS swaps before (me and the guys at the shop I work at) but mostly on older stuff and I can tell you the electronics are the hardest part, a good body shop can change any panels you need and keep it looking stock A dry sump oil pan will save you room and I would highly recommend it especially considering your phase two plans

[Tree98]

And as far as dimensions for a LS 6.0 I personally I like to go to -Engine Dimensions — BD Turnkey Engines LLC
Easy and they give you pictures 😄

[Tree98]

-Engine Dimensions — BD Turnkey Engines LLC

[Doostun]

Let me know how this goes; California smog laws are annoying so I'd like to see how you work through it.

[obthomas]

California. Get a crate engine with computer that meets California standards. A truck engine and a tune is going to be a stumbling block with the referees.