Guy24

Hey guys, I have a 2008 Lexus IS 250 awd and I have been offered 350 engine for relatively cheap. I was wondering if this could be done or would be too much of a hassle? I’ve heard that for the awd versions the transmission should be the same, but im not sure.

southbaby

bump I'm wondering the same thing

2013FSport

iTrader: (2)

You folks are all in the same boat looking for answers....


In the 2IS community is Jeff Lang who did a 250 to 350 swap on his manual 6spd 250. Read the entire thread!!!

I have a thread about simply getting control of a US made 2013 350's fog lights. That where really learned what Toyota did to lighten the cars freeing them of a 1000 pounds of wire by implementing their proprietary CAN bus system that uses 4 types of communication depending on what data is required.

Take a look here https://www.clublexus.com/forums/is-...e-on-help.html

​​​​​​​And here....
https://www.clublexus.com/forums/is-...s-or-data.html

GL...

Ultra4

If you can get a cheap 2GR-FSE, best thing I'd say you can do with it is swap your heads and intake over to the 3.5l bottom end and retain the 2GR camshafts.

Not exactly a beginner mod, I'm only aware of one community member that has done such a mod--Armadous1--but you would ostensibly be able to get the absolute maximum power possible from the 6-injector topend--which I estimate to be about 300whp--without the need for a tune or forced induction, and the rest of the vehicle stays the same.

Heck, I just swapped the 2.5 for a 3.0, and they even sound exactly the same.

Edit: just saw you were AWD...if you get a RWD engine, you'll need to swap oil pans. An AWD 6-injector 350 sounds like a fun little rocketship

2013FSport

iTrader: (2)

What injectors go in this beast?

Ultra4

I'm always going to advocate for using the smaller engines' flat-spray injectors in a naturally aspirated 6-injector application, so as to have as healthy of a flame front inside the chamber as possible. I'm not sure if the 2GR's V-slit injectors would do too well in a 6-injector N/A build, I imagine that the fuel charge being concentrated away from the exhaust valves would cause some thermal issues that might lead to pre-det at WFO...not to mention a flame front going the wrong direction

2013FSport

iTrader: (2)

I'm all questions and no answers....
Are the 300 and 250 injectors the same PN? Concern being fuel starvation in the upper RPMs.

What are the differences between the 250 and 300 combustion chamber? IIRC the 300 and 350 share the same bore, I may need to find a 250 and 300 piston to compare the shape... the 350 is sculpted well...

Ultra4

2GR and 3GR share 83mm stroke, not bore. I'm under the impression that the 3GR's 87.5mm bore is the smallest you can get the port-injected *GR heads onto due to intake valve diameter, while the 3/4GR heads can fit on the 77mm bore of the 4GR because they have the smallest valves in the GR family.

I base that assumption off of what the other markets--notably china--are offering. China has the 5GR-FE, which seems like it's merely a destroked 3GR wearing Camry heads. I'm guessing they opted the destroke option because that's a singular part to change--the crank--as opposed to having to engineer a -FE head with smaller valves to fit the 77mm bore already available.

I could be wrong.

Edit: yes, injectors are shared between 3GR and 4GR. Either that, or my 3GR showed up with 4GR injectors...neither I nor the engine can tell

Guy24

So you’re saying u think it’s possible to do the 250/350 engine swap on an awd platform? What I’m getting is that I’d maybe only have to change the oil pans and keep the intake and headers from the 250?

Ultra4

Unless there's an AWD version of the 3GR-FSE engine, I don't think there's any swap that doesn't have you taking an engine apart. Either the top half of your 6 injector engine goes on another bottom half, or you have to swap the bottom parts of another 6-injector engine with yours to make it fit your AWD powertrain. Easiest would probably be to leave the topend of a 3GR-FSE sealed up and bolt whatever AWD equipment you need to it. Best, IMO, would be to step into the highest displacement we know works--2GR-FSE--but that also involves breaking two engines down to their short blocks and building a franken-motor.

If there's an AWD version of the 2GR-FSE (I think there is...at least in the GS), then you can leave the short block sealed up. You will still need to take the timing cover, timing set, valve covers, cam cradles, and cylinder heads off of the 2GR-FSE and replace them with those from your current 4GR-FSE, as the 2GR and 4GR have fundamentally different ECUs, due to the 2GR having twice the number of injectors as the 4GR, as well as the 2GR not having ACIS or SCV to control.

The 4GR-FSE ECU you have can control a untouched 3GR-FSE wearing AWD oil pannery, or a 3.5L Franken-GR with your oil pannery and your topend. Both hare a level of difficulty above the swap I just completed.

Guy24

So it would be easier to transfer the 3.0 L engine into the is250, i would be happy with it making around that 250 hp range but I wonder how many more power mods are available for the 3.0 than the 2.5

Ultra4

They're practically the same engine, so what you'd do to a 4GR should also help a 3GR.