I think we should have a thread that encourages IS250 owners to do the lazy man's big block swap.


For the uninitiated, the 3.0L 3GR-FSE is the engine that came in Japanese Domestic Market 2003-2008 Toyota Crown and 2004-2009 Toyota Mark X, as well as the US market 2006 GS300. When swapped in place of the 4GR-FSE, the 3GR-FSE offers IS250 owners roughly 40 lb-ft more of torque that arrives 200 RPM sooner in the powerband, and roughly 40 additional horsepower at the top of the powerband. Aside from bore, stroke, and compression ratio differences, the two engines appear otherwise identical when used in the same platform (caveat: intake manifolds differ from one application to the next, but are all interchangeable). Which means you can buy a low-mile JDM 3GR, take off it's plastic intake and all the wiring, then plug your existing IS250 wire harnesses/ intake onto the 3 liter engine, and your car won't know the difference...it'll tune fuel and timing just as if you had an impossibly healthy 2.5l mill under it.

So who all's done it and what're your thoughts? Anyone ever get it dyno'd? I'm curious how much long tube headers add to it's torque production, given the intake air doodads' effects being amplified in the larger combustion chamber.

This 3GR was purchased as an insurance policy in case I destroy our 4GR while swapping ported/polished heads, and to be a semi-permanent resident in the engine bay after I move on from there. Poor thing looks like it was cut out of the donor with hedge trimmers and left covered outside for years. First order of operations for the swap for me is to obtain two M10 and two M12 bolts so the thing can be on an engine stand and not the pallet.

Oh, and shoutout to myjdmorlando on ebay for including the residential liftgate service charge in their freight shipping. Most freight shipping charges on ebay will require you to contact the shipper and either go pick it up or pay them a liftgate fee, if not going to a business address with a loading dock.

 

In the spirit of helping the next guy figure their swap out, a couple things:

The engine block bellhousing bolts are M12x1.25

The RWD oil pan bellhousing bolts are M10x1.25

The engine is extremely top-heavy and wants to flip upside-down while on your typical Harbor Freight engine stand. I bolted my mount to the engine in the air, then put the stand on the mount and pinned it in position before lowering it to the ground. If you want to lower the engine down to the stand, be aware of that proclivity and pin the mount before loading the stand...I'm a pretty decently strong 35 year old and can't rotate the engine back from 90 degrees on the stand just using the HF handle, I had to get creative to pin the engine back vertical. So take note, fellow solo shadetree mechanics.

Also, I will amend my previous statements about just the plastic intake needing to be swapped. Apparently, US market engines have SCV position sensors, while JDM do not. I find that quite curious.


Additionally, I suspect most all JDM engines will have had their fuel supply lines cut similarly to mine, so I will be swapping our existing high pressure fuel pump over. Most JDM engines have between 40k and 65k miles on them, which I was hoping would translate to a lower-carbon engine, but alas...this engine's just as bad as any of the 4GR heads I've played with yet. So I suspect every other 3GR swapper out there will want to inspect and clean their intake valves while swapping your SCV plate over.

I'll be decarbing by barring the engine over and pouring MEK into the ports. Don't do that unless you've already played with MEK before, it's extremely dangerous stuff...but dissolves our intake carbon (and many other things) in no time flat. Once that mess is soaked up, I follow it with isopropyl alcohol on rags for the detail work. I'm not saying my way is the right way, just that's the way I'm doing it.

 

Some more saving the next guy time:

the kind of coolant pipes you see my pinkie touching do not have provisions for the glow plugs that go to the plug at my index finger. Almost positive y'all down there in no-snowsville can get away without swapping for the cast aluminum piece our US market engine has, but that call is on you. I will be making some backward progress today to swap the cast piece over.

 

I missed your new arrival. Any chance the 3.0 TB offers more area or is it the same as the 2.5? Of course this also makes me wonder how much further the 2.5 ECU can go? Would it adapt to a 3.5 long block? I think you can get around the fueling, but the MAF sensor could be the death nail exceeding limits the 2.5 never dreamed of. But w the 3.5 lid, maybe it's a wash? That leaves us with the SCV motor drive and sensor which you gear together and throw under the manifold.

Also, depending on the stand and block pattern you can shift the CG and make most engines neutral so they don't break your arms rotating the mass to new locations. i.e. don't align the cranks center with the center of the stands pivot. Let them arms do some spider action (abdomen down low, legs bent sharply) so the cranks center (when block is upright) is well below the stands center. Which is great until you pull the heads off.

 

It seems everything that takes voltage is the same between the 3GR and 4GR, the differences I've noticed so far are the exhaust ports and US/Japanese equipment differences (evap, cold start, SCV position, so on). Throttle bodies, injector drivers, injectors, VVT equipment all seem to be identical from 3GR to 4GR.

Can't be bothered to look up who, but someone on here is currently running a 3.5L bottom under a 4GR topend. If he posted a week earlier, I'd be bolting Head Games to a 3.5L then porting/polishing that 12-injector top for someone on here. But like a year or so ago when I mentioned such a combo, JL voiced his opinion that the ECU couldn't keep up with the air demands and I now have a 3GR. My 3.5l plans now involve -FE heads, boost, and aftermarket fueling.

 

^This is the guy currently on the bleeding edge of 6-injector performance...for now.

Sure wish I had a multimillion dollar facility with 2-post lifts to use...instead of doing my best Uncle-Nephew Randall impersonation. I'm missing the lightbulb full of artisanal go-go crystals and a chain hoist screwed to a dead oak limb, though. Not quite dropping a Max Wedge into a Dakota here, either.

 

The 3GRFSE swap idea is far more easy to do than doing the mix with the 350 (although I m not sure if it can be done properly ).Even with the 3GR swap alone the dyno numbers where 230hp and not 250 as we expected.I m supercharged after the 3GR swap with a C38-81 Rotrex and the car made 377WHP.I m using 2GR injectors and are maxed out at this power.AEM meth kit is helping fuel after 5000RPMs

 

Did you max out 3GR injectors on the dyno, or just go straight for the 2GRs? My assumption is that you're still on the 3GR camshafts. If your piggyback fueling/meth has the overhead for it, a 2GR cam swap might be a worthwhile effort for you, particularly since you've got the blower.

I'm curious what the flat-spray injectors that 3/4GR gets will max out at. The 2GR injectors have the V-slits to take the place of the SCV butterflies that the 6-injector heads get...because the 12-injector heads have fuel coming in from the ports, when port velocity is high, the whole cylinder gets fueled. The flat-spray 6-injector heads have to rely solely on air gimmickry to stratify the fuel charge at lower port velocities, because the flat spray aimed directly at the center of the combustion chamber at TDC is going to give you the best charge density at high port velocities, as well as take the greatest advantage of the latent heat of vaporization.

Not saying the flat sprays are better for you or worth more power, just navel-gazing with some of the info I remember from that white paper I believe redspencer posted. My assumption has generally been that the 3/4GR flat spray injectors aren't going to give much past 300whp, but their torque potential is greater in custom 6-injector applications than the V-slits would be due to how the spray is directed at the highest BMEP. At least, naturally aspirated.

Meh. I gotta chew on this more. Thanks for the input.

 

mine is turbo supercharged, custom fabricated by a secret auto mechanic which I cannot disclose due to proprietary and environmental political reasons...

LOL


Ultra, good job on the DIy engine swap thread with pictures

 

I have swapped to 2GR injectors because the 3/4GR ones maxed out at 0.5 bar.I m using 4GR ECU after the swap and everything is working fine after the custom tune but with the help of the AEM meth kit.Even the 2GR injectors are maxing out at 0.7bar I m running now.The 12injectors from the 2GR would defenatelly help a lot but it would need 2GR ECU I guess and would be much more complicated.For more boost you ll certainly need internals so no need for that kind of power.I guess of course because I don’t know how my engine will hold up.I hope it will….

 

Heh, I know this is bar napkin as hell, but a 200hp engine at atmosphere (14.7psi) being fed .5bar (7psi) should make about 300whp...which is right about where I expect the injectors run out of steam.

 

That’s the power I had with the Procharger at 0.5bar.Now Rotrex which is far more efficient needs larger injectors even from 2GR ones for 0.7bar.If I didn’t have the AEM meth kit I wouldn’t know which injectors to use

 

Too cool brother. Proper engine work.

 

My swap is basically done, so here's my retrospective commentary:

There are essentially two ways to swap the engine, hoisted out of the front of the vehicle the way I did it, or dropped by the subframe the way Jeff Lange shows you in his 6MT 350 thread. The vehicle is clearly designed to do it his way. His way also requires significantly more in the way of resources than your average DIY enthusiast has on hand...although I bet a QuickJack and some creative blocking/jackstand placement can be used in lieu of a 2-post lift; I do not have a QuickJack. I succeeded on a somewhat level concrete slab with a quick pump floor jack, 4 jackstands on their lowest setting (I usually knock a hole in my ceiling during swaps and was trying to pre-empt that), and a 20-yr old Harbor Freight engine hoist that spent at least 2 of those years outside in FL with a JohnnyRude 3 pot dangling from it, unprotected from the weather. Hardly precision equipment. All of my tools are hammers first.

I would definitely recommend you go out of your way to find a 2-post lift to do this swap on. I had originally planned to, but, as per usual, something I said lost me that opportunity.

If you've already taken your front clip off of the car, you're already ahead of most of the difficulty I encountered. Had I previously taken my front clip off, then most of the seized fasteners I encountered would not have been as far gone as they were, which then would have saved some of that plastic the heat exposure of the fastener being extracted. My best advice to anyone who thinks they may be interested in swapping their engine through the top/front of the car is to go out and get comfortable with removing the underpan, front bumper, and all of those associated plastics off the car before obtaining the new engine. Not only will it keep you from hitting the, "oh...I was supposed to have this sandwiched between those before putting the screw in" moments that eat so much time, but it'll also let you know which fasteners you're going to need to replace ahead of time. Forward and below the crashbar/center support, the only metal in the entire assembly is the fasteners and the working bits of the fog lamps. And a lot of those fasteners are plastic, too. All of it exposed to road spray. It's not a nightmare, just be prepared...there are way worse platforms out there, this one is just demotivating in that regard. Once you do it a few times, I bet my comments will seem petty.

The other big hurdle I hit was separating the electrical connectors from my old engine while it was still in the car. Try to avoid doing that, as some of the connectors on the backside of the engine get pretty well glued together from dust and deterioration through the years. If I had to do it over, I'd pull the connector that attaches to the transmission's RHS, separate the starter powerfeed from the + terminal going to the relay box, pull the ECU box up from the body of the car (go ahead and disassemble/clean that), unbolt the grounds/pull the few plugs that're leftover attached to the body, and pull the engine as dressed as I could get it. Even with all the superfluous wiring I have on hand to use as a reference, I wasn't sure if I was going to hit any crazy harness splits that make sense when you're manufacturing it and never again to anyone else, and I found out that there are no such game stoppers. Just a staggering amount of plastic that was never intended to be re-used. You can help save some of your electrical connectors by first spraying it with something (I like Iso alcohol) and blowing it dry with a compressed air wand to try to loosen some of the grit that might be locking up the retention mechanism. The older your vehicle is, I suspect the worse your connectors will be. You do not want to re-pin these things, my generic weatherpak tools don't work with any of it. I suspect the heat-soaked and locked-up connectors I struggled with would have been significantly easier to separate if I could actually see them and get tools to them. So pull the old engine with the harness on, then swap the harness to your new engine.

When it comes time to hoist the engine for install, I would leave the plastic intake off, tie the starter in place, torque the LHS exhaust to the engine, hoist the engine by the SCV plate (I used the JDM one without the position sensor, sandwiching a seatbelt to the heads to hook to), and leave the rubber engine mounts bolted to the subframe. Once the engine sits on the perches, torque the starter and bellhousing bolts, then install the RHS exhaust. You got all the room in the world over there because they balanced this thing for RHD. Unbolt that 12mm bolt holding the dipstick tube in place to make header install easier.

The rest of the install is reverse of removal.

That's about all I can think of right now...my first start had two sensor bank low voltage codes because I forgot to plug my new o2 sensors in, once they were plugged in and I cleared the codes, the thing just wants to work. Between the additional 500cc's and new clutch setup, I can chirp the winter tires through 4th gear, whereas before it might've given you an aggressive-but-bouncy 1-2 shift, but that's about it.