IS300 project

[Linas.P]

Just a placeholder for the moment, but going forward am looking to make full guide of everything you need to get IS250 with 3GR-FSE engine.

Why do it? Short answer - because I can...

Longer answer - because I always thought that IS250 is great car, but it is borderline sluggish (if only it had maybe 40 more hp!)... GS300 is also great car, but it is a bit of boat and styling... well let's just say "one need to get used to it"... I had it for just over a year now and it is best value Lexus one can get, very comfortable and luxurious car, I also find it attractive from certain angles, but being honest it is not the sexiest car ever made. So... logically, the solution is to take timeless IS mk2 body, also a more sporty chassis and fit little bit larger muscle in the place of it's heart. 3GR is not 2GR of course, but that is the engine which is readily available and also it costs cheaper if you take it together with the rest of the car (I know... it is madness that one can buy whole GS300 for £500, but the engine alone is closer to £1000... does anyone buy them?!). In ideal world I would simply have IS350, but in no world I am paying £11k for JDM import, when IS-F can be had for £16-18k. Obviously 2GR is just better engine, but even bare 2GR (non-hybridysed) is like £2000, ECU is another £500... and I can assure you to finish 2GR swap you would need 100s of small bits, which you simply don't get just buying the engine... and in UK we can't source it from any other model, so that will have to be sourced from US (remind me - why Lexus UK are idiots and didn't sell any 350s here?)... in short, it is hard to source and expensive. GS300s are on every corner and they are cheap. So it isn't 306hp, it does not have dual injection, but 252hp based on my calculations is 48hp more than you get in IS250 and for total cost of broken IS250 and rusted GS300 one can't even get bare 2GR, nevermind other nice bits like larger brakes. Also 3GR is "plug&play", that is because IS300 actually exists as a car (never sold in UK... again!) and everything is identical and simply bolts on.

As noted, this process just started, so more detailed steps will follow, but as general advice... you will need some knowhow, workshop manual, techstream, lift, few good friends, engine crane/trolley and a bit of tools (I will summarise key bits later, but ones does not need many specialised tools) and about 10 times more time than you would think. I said I can drop the engine in 1 hour, I did it in 1st hour... of day 2. In theory it is very simple, but in practice the cars you will be working with are not going to be brand new, and when you spend 2 hours just removing 4 rusted bolts, the days gone by quickly... or just forget to take wheel locking key... that happed... not even once... that said engine can be removed without removing the wheels at all, but needless to say, it is much easier with them off.

Current status - I have an IS250 that is missing the engine... and also a 4GR-FSE engine on the floor. Target status - IS250 with 252hp, "big" brakes, with MOT and ideally running as it should. Didn't have much time for taking snaps, as it was all consumed sweating, eating rust and cutting stuck bolts, but just few pictures for tasters. Also - thanks to @H3XME for lending a hand... I still have your 18mm and ball joint splitter 🙂 

 

[J Henderson]

Nice. This should be interesting.

Will everything else (gearbox, diff etc) be standard IS250 stuff?

[Linas.P]

3GR + ECU + transmission (a760e instead of a960e) will be from GS300, for time being diff will be standard. Also at the same time as a matter of "housekeeping" I will transfer the bigger brakes from GS300, both front and rear as my IS250 is early car with solid rear brakes. 

In theory standard IS250 transmission and ECU should also work, but it is just easier to just transfer everything from GS300, also a760e is little bit stronger transmission and does not have as much issues with stuck solenoids/solenoid performance as a960e.

It would be cool to get LSD (was available with some manual IS250), but it is hard to know which cars got them. For some reason I thought GS300 had LSD, but sadly that is not the case.

[J Henderson]

Ah, I didn't realise GS300 had a conventional gearbox. I had got it into my head that it came with a CVT.

LSD from GT86/Subaru BRZ is apparently an easy swap, albeit probably expensive to obtain.

[Linas.P]

Yes - in the past for some reason I also thought GS300 was CVT, even checked specifically before buying. Not sure why people thought it is. A760e on other hand is good gearbox, it also came in IS350, so it has more than enough strength to handle power, I know people swap them into supercharged/turbocharged IS250s on the other side of the pond. Apparently a960e is just about enough to handle supercharger (as the power comes more gradually), but breaks apart on turbocharged cars. Also there is manual mod for a760e (at least there was company in US that had it figured out), I just can't find any info anymore, will need more research, but again apparently people who took their IS350s to drags had them programmed to do proper sequential shifts (not like it normally works on IS mk2, where it is not really a shift, but more of suggestion, a "limiter"), and apparently a760e should be able to handle such things like shift-lock etc. 

I thought it is other way around - the cheap way to get LSD in GT86 was to get one of IS250 manual ones... I might be mistaken... either way - LSD is something to consider for the future. If I get to the point where car runs and drives... and is perhaps even road worthy, then the next mods will be in order.

[Shahpor]

What a great idea for a project!

Nothing against those that spend thousands on their cars, but I do love a 'cheap', drop in upgrade when it can be done.

Is the 3GR engine much heavier than the original?  Can't imagine there is much in it, either way.

Best of luck!  Looking forward to seeing the results.

 

[Mr Vlad]

Blimey what an excellent project to do Linas. It's good that you're in a position to do it. Looking forward to this project of yours. Best of British to you 👍

[Linas.P]

1 hour ago, Shahpor said:

What a great idea for a project!

Nothing against those that spend thousands on their cars, but I do love a 'cheap', drop in upgrade when it can be done.

Is the 3GR engine much heavier than the original?  Can't imagine there is much in it, either way.

Best of luck!  Looking forward to seeing the results.

I have not weighted them, but that is good idea... I may try. Checked online and there is no information about it at all... and whatever information there is makes no sense... 2GR service weight - 166kg, 3GR - 174kg and 4GR - 180kg... that would suggest that smallest displacement engine is the heaviest?! I guess the logic could be that larger displacement engines are bored more, so there is less material left in the block?! I really doubt it is correct... but even if is opposite is true, then we are talking about 14kg difference between the three and maybe 6kg between 3GR and 4GR... which is what I would expect, considering that they use all same parts, except block and rotating assembly, even heads are the same. 3GR will have few kg more fluids in it, so let's say whole engine maybe 20kg more all in... that is really nothing. Obviously, weighting them will not be exact science, because some fluids, rust, dirt etc. will be left on the engines, so the results will be approximate at best.. but wouldn't it be amazing if it turns out lighter then original 😄 

2 hours ago, J Henderson said:

LSD from GT86/Subaru BRZ is apparently an easy swap, albeit probably expensive to obtain.

You were right - IS300 (mk1) and BRZ has suitable LSD, maybe next project if I could pull this one off and have at least one working car in the end. 

GS250 mk3 anyone? Arguably ahead of it's time solution, Lexus only did it with mk4.

[H3XME]

As Linas already said, it wasn't a horrendous job for us, I've struggled more with stuff significantly less radical than removing an engine in the past. But yeah, if anyone is thinking of doing this, make sure you have a whole weekend free and a lift. The rest are just basic tool from Halfords Advanced line up! Oh and my £30 Battery impact from eBay really proved itself useful 😁

[Linas.P]

Going back this week to (hopefully) finish the job.

Got the scales for the engines so will report back what is the difference in weight. 

Any other ideas? 

[Linas.P]

Ok... so the progress so far... We mechanically have GS250 and IS300, all connected-up and bolted back on. Total time for swapping two engines around was ~28 hours.

Neither car is driving yet, but that is expected... I have not swapped ECUs, because I did not have time to program them yet and strictly speaking it is not necessary just to confirm that swap is complete, I hoped to make both cars running and driving at least a little bit and only then start swapping and programming ECUs, but it seems I will have to take time to do it before any of them moves on their own power.

GS250 started right away, but for some reason can only sometimes drive forward a little bit, I have two theories here - 1. 3GR ECU does not like A960E gearbox (there was code P0705), or 2. when Copart "decontaminated" the car, they have drained the ATF... which is major bummer, because refilling ATF is very complicated task and just ATF alone is few £100s (and I am not exactly inclined to spend £100s on a parts car that I am planning to scrap - if you confused... there were total of 3 engines 2x4GR and 1x3GR, the reason being the 4GR from my IS250 was probably mechanically sound, but had electrical problems and I just had spare 4GR, so it was simpler just to put it into the car rather than transferring all accessories onto faulty engine... and it turns out to be sweet engine, runs smooth, kind of sad it is going into scrapper car), or 3. likely both of those things.

IS300 is no crank/no start, little bit disappointed as I expected for it to at very least crank, but in other hand it may be easier as problem is likely to be more obvious in the end. That said none of the codes reported had anything to do with no crank condition which is kind of weird and caused me to leave it for now... I have few theories here...  1. is just coding of the ECU 2. just a bad ECU altogether (car was in limp mode even before the swap) 3. now thinking about it ... I may have put wrong ECU (stupid things happens after wrenching on the car for 12 hours at 11PM), so then it is basically back to #1 - just needs coding 4. it also has same code for gearbox as likely 4GR ECU does not like A760E gearbox. I have not confirmed yet, but there may be electrical difference between them (like pins being other way around despite harness being identical otherwise). 5. I also put different power steering ECU, so that may need to be synced... or 6. I simply just didn't connect something correctly in a rush and being tired, maybe something as stupid as fuse or ground wire somwhere.

In short both cars needs a little bit of time "in private" with Techstream and I need to trouble shoot the codes one by one, and also confirm I have not missed anything. So far they have been just thrown together so that they are complete cars with the engines again.

Wait that is wrong engine...

Ohhh here we go - that is more likely:

...and that is GS250 (the only one mk3 in the world as far as I am aware... so that may be first):

Interesting discovery on the exhaust ports in the head, despite internet sources claiming that 4GR and 3GR heads are the same (basically 3GR suppose to have 2GR block bored for smaller cylinders and with 4GR heads), they are clearly different - 3GR clearly as much bigger ports for more power and 4GR is clearly choked for economy. I would assume they are physically interchangeable, but 3GR head must be much better flowing (at least in theory). Interestingly the headers and exhaust is identical, it is only the head ports that are different. Which kind of settles the question of whenever IS250 benefits from aftermarket headers... no it doesn't... I know I may be answering the question that was asked 10 years ago and irrelevant for just as long.

4GR:

3GR (also would say - less carbon build-up despite higher mileage and likely poorer service history):

Also I have discovered few small differences, vacuum lines are routed differently, few small components are in different location, nothing really major, but it would be major headache if one got only bare 3GR engine and tried to put it into into IS250. It is not rocket science, one just needs to buy some suitable diameter hoses, but it isn't exactly plug and play. Having both cars side by side really helps a lot and I didn't need to buy any other parts or to make anything custom, because they connect at the same spot on the car, just located in different place on the engine, meaning engine needs to be transferred together with hoses, at least in some cases... except I still need solution for airbox. Basically MAF is different (which is minor thing, but I did not expect that), and connector is different (although I assume electronically compatible, meaning I could just chop the harness and replace connector, but I am not inclined to-do it just yet and have not confirmed that is the case). So far I have just dropped GS300 airbox into IS250, it just barely fits and mounting holes are different... will need to research what is the solution here, maybe I will need to "true" IS300 airbox from states (I would like to have bigger airbox and bigger filter from 3GR), or maybe I can just swap around harness and connect it to IS250 airbox (I think it may be separate harness which can simply be disconnected, will need to confirm).

EVAP and Brake booster:

MAF (I know they may not look that different, but GS300 MAF connector and sensor itself is almost double the size):

Apart of that everything was smooth going most of the time, few rusted bolts were expected and painful, but they are nearly 20 year old cars, would say - powerful saw and grinder would have saved me 4 hours of time (the guy renting the garage lent me Battery powered grinder, which did the job eventually), also I guess spending a little bit more on new parts would save time e.g. if I were to go for all new exhaust (which I am planning to do anyway), then I wouldn't have to try to unbolt old rusty exhaust, or put it nicely back to place. In other hand I didn't want to start ordering all brand new parts before knowing it actually works. Obviously, If I didn't have to put 4GR back into GS, it would have taken half the time it did (it was all good, until the point I had to spend 2.5 hours aligning one of subframe bolts). I would say removing the engine is ~8 hours job and putting it back in more like 6, maybe even 9 and 5 respectively. In general - right tools for the job are key... engine crane is only good if you picking the engine up trough the engine bay, it is useless if you dropping it down with the subframe. Whole job could have been done in half time if I had engine table/lift... but that is very specialised tool not many workshops have... i.e. this is the thing you want for cars like IS250 where engines comes out of the bottom: 

So all things considered - is it possible to do engine swap in the day (as I optimistically estimated)... kind of... if you have all the right tools and you don't run into too much problems (aka rust), and you can afford to cut some parts (like exhaust)... and you just putting the engine in and not swapping the engines between the cars. 

@Shahpor - the weight...  there are loads of caveats, but in short basically the same, car becomes maybe 5-6kg heavier as result of this swap, but I would say my method accuracy is +/-10kg. On the scale it self it says +/- 2% (typical for such scales), so that is like 6kg alone, although one would expect the scale to be consistently off, so if it shows 2 kg less it is likely to do it for both engines and should not impact the comparison, either way - the difference was smaller than the accuracy... there is no way to estimate the amount of junk stuck on the engine and that could easily be a 1kg (generally 3GR looked more dirty, 4GR looked very clean from outside), how would one estimate amount of warmish or carbon build-up in the engine (4GR seemed to have more carbon build-up) - you just can't . Also it is not possible to say how drained is a "drained engine" e.g. I drained all coolant from both, but from time to time the engines would still spit some out, 3GR was leaking ATF trough real seal (that is problem for later), at least a 1L of it, 4GR with A960E had unknown amount of ATF in it, it can't be all drained, but it could be missing something like 1.8L. So those are all unknowns. Also it just happened so that I weighted 3GR with oil and 4GR without it, but that is known quantity so we can account for that.

All in all, math works out as such  - the hardness and chains to hold the engine on crane weighted 7.75kg, let's call it 8kg - 3GR weighted 275kg (283kg indicated on scales because of all gear holding it) with oil and A760E gearbox, all wiring, headers and all accessories, basically fully assembled running engine + gearbox, without most of the coolant, neither engine had belt, nor A/C pump attached (I chose the keep it on the car so that I don't need to deal with A/C refill or get sprayed with pressurised coolant - you need to take 1 stud with T8 socket to do it)... The 4GR weighted 264kg (again showing +8kg for crane) without oil, but all the rest was the same, and we know there goes 6.3L of oil, I assume ~1L=0.8kg, so 5kg of oil give or take.

   

So with all caveats out of the way we have grand total of 275kg for 3GR/A760E and 269kg for 4GR/A960E or 6kg difference. But we also know that A760E is heavier than A960E and has more ATF in it, so what is that just for the engine alone... can't answer it, maybe 3-4kg, assuming you mount it to weaker A960E gearbox. In grand scheme of things, it will be imperceptible when driving or handling, wouldn't move car balance, not even by 0.5%

 

 

[Shahpor]

Interesting stuff indeed Linas, thanks for the update 👍

6kg is negligible, so it looks like an excellent candidate for a swap.

Looking forward to see more progress soon!