Score, both engines use the same timing chains!

On using the FA24 cylinder heads....finding other issues, different High pressure fuel pumps, & mounts. May not be interchangeable. Also will need to find a solution to additional water lines that feed the cooler....

Yikes. I'm guessing that's the same for Canada, and I'm guessing the complete assembly is P-R-I-C-E-Y! Likewise trying to piece together complete FA24 heads with cams, etc.

Makes working with the FA20 heads definitely seem like a better option.

EDIT (2): Found a listing on one dealer's parts website that said "Engine Assembly - Long Block" priced at $7,393.82 US. Contacted the dealer for more info, and they said it isn't available to order and won't be available period very shortly after the 2022's start heading off of dealer lots. Basically, they're only available to dealers in case of a DOA motor with a car they receive, or something along those lines, and once cars start getting into customer hands, the availability for even that will go away, and as Opie said, only short blocks will be available.

Regardless, that list price is more than the price of every supercharger kit on the market...LOL. Heck, the difference in price vs. the short block is about $5,500. I can definitely see a STRONG cost argument for sticking with the FA20 heads, even without all the other complications.

Yay...and ouch.

May have just found something useful....the FA24DIT pistons are a flat top design...they are not domed like the FA20/24 N/A engines.....possibly a fix for 2 issues....FA20 N/A cylinder head clearance and not increasing compression ratio......

Interesting... So, flat piston with just a minimal blending of the combustion chambers in the heads to allow for the bigger bore (removing the stepped profile). It'd be interesting to see how close to the factory 12.5:1 C/R you could achieve with a flat-topped piston.

Could work, but is there a performance (E.G. combustion control) reason for the pent-roof / domed profile of the FA20 and FA24 pistons, or is it just to increase compression? My guess from the fact that the peak of the dome on both pistons is offset to one side is that it also helps with combustion control, although that *could* just be due to the angles of the intake vs. exhaust valves.

EDIT: For those that aren't familiar with the idea of piston shape controlling cumbustion, here's an article that talks a bit about the concept of the offset dome being used to control combustion for both power and detonation resistance. It's talking about an even more complex design, the "Endyn Roller Wave" produced by the company, but explains the basic principle pretty well. http://www.theoldone.com/articles/rollerwave-intro/

Thinking further about it, if the dome is offset for combustion control and the valves have been moved further outward in the FA24 head, it's possible the FA24 piston's offset would be in the wrong place to work properly with the FA20 valve placement. That said, it probably wouldn't be that big a deal as long as the peak didn't end up too far inboard of the intake valves (which I think would cause the mixture to move the wrong way) and it would likely be the opposite - further outboard than the FA20 piston.

That could be another argument to go for a flat-topped piston, I guess...

Blending something like this?
https://www.youtube.com/watch?v=Vk-GY4_UXso

More efficient and even combustion, improved knock resistance. The turbo FA heads have quench pads in them for even more knock resistance.

But aren’t you buying an assembled shortblock? Wouldn’t it make more sense to use the FA24F shortblock, or is the shortblock too different? And I’m sure the FA24F rods would be preferred too. I thought they looked beefier. The FA20F pistons might be a bit beefier or heavier because of the lower redline.

I wonder how much this would change compression. I think you will still want to machine the head. If the piston is perfectly flat then the 4mm lip might be a ring of increased risk of preignition. Not only could the corner get hot, but there could be a diesel effect where the air/fuel mixture gets compressed too much, especially at higher rpms where the air doesn’t have time to squeeze out of the space. At minimum, it might cause some weird flow patterns in the chamber, good or bad. Even if the piston is flat, I would chamfer the edge of the head, but I think you are at risk of losing a lot of compression with chamfered edges and the piston change.

Dont want to lose squish area. Super important but who knows? This may work just fine.

[QUOTE=NoHaveMSG;3479913]I'd still call using the FA24 heads a possible win when you consider what a K swap costs. If it all still works that is, which I believe it will. I would be over the moon happy if this thing does at least 220whp with bolt ons. I am not looking for big power.[/QUOTE]

But doesn’t the FA24 still have the same oiling issues and RPM limitations of the FA20? So wouldn’t Element Tuning’s secret machining, killer b oil pump, baffled oil pan, running a quart extra, oil cooler, etc. be required for reliable, high g track driving?

I’m optimistically hoping the OP gets this to work reliably and power and torque is what we expect.

Yeah I was thinking use the WRX STI FA24 short block! 400 rated HP! Unlike the previous gen which didn’t use fa20 but RA based instead. Also lower compression to start. Probably also around $2400

Will the starter/transmission bolt up?

Where did you get 400hp? The car isn't out and there are no part numbers or prices for the engine parts... The FA24D would already have lower compression from having to open up the combustion chamber...

All speculation of course see here.

https://www.motortrend.com/cars/subaru/wrx/2022/
https://www.torquenews.com/1084/new-...ation-revealed

But for sure it’s gonna be 310+ (Gotta be higher then current gen) and FA24 based instead of RA based like the last generation ( don’t recall where I saw this but I can dig it up) so not unreasonable to assume it can handle 400HP from 310+ stock. RA shortblocks are only $2K

No idea really since no diagrams are listed yet for wrx or sti but since its going to be FA24 based maybe it could be semi-compatible to a 2022 86 tranny. Maybe custom bell housing? who knows but if it avoids fucking around with cylinder head volume and equalizing it across all 4 we'd probably all take that.

I think 350whp or less is more likely, just so they can get reliability into a warranty, but it could be a beast. It sounds like it could be a D4S version of the FA24F in the Outback and Ascent. If that is the case then that would be potent. Even if it wasn’t, if all they did was do what Honda did with the K20C1 for the CTR and C4+ variants for the Accord/etc, which is remove some balancing shafts, change a few internals around and add a top end turbo for the CTR, then the FA24F variant in the STI should still be a beast. If they add some forged internals or other things to boost the strength then watch out. Check this out:

https://forums.nasioc.com/forums/sho....php?t=2907007

https://img.nasioc.com/i/Xq0qh.jpg

I think you would need to either do a custom adapter, custom bellhousing, or you would need to machine a relief into the block or cut and weld the bellhousing swapping the starter relief to the other side. Most likely a custom adapter plate and just go with a CD009 or BMW transmission for the torque.

You can see here that the starter is on the driver’s side and not the passenger’s side like in the 86.

I'm not going to speak for the OP, but if you're looking for huge power numbers this probably isn't the solution for you..

In my eyes, this appeals to the HPDE/TT/Misc Road Course market. A cheap, same manufacturer solution that adds a good bit of power and torque.

Yes, shortblock comes assembled from Subaru. Haven't research thoroughly, but there are some significant differences in the 2 blocks....

Contacted two machine shops regarding cylinder head matching and a piston manufacturer regarding a forged piston developed for this swap that maintains CR....awaiting replies...shortblock still has not arrived...there will be solutions....

Update: Short-block now expected the week after Thanksgiving...
Gasket set...... sometime in December

Curious where you ordered the parts from? different online subaru dealerships have different prices. Ordering from no tax states like TX usually give a discount and no tax!

Here it's only $1810

https://parts.diablosubaru.com/oem-p...-ay-10103ad100

I buy from my local dealer...get special pricing because I buy so many parts. Just ordered 3 sets of 2022 BRZ front knuckles....

Three sets? Lol

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So a little roadblock on this "project", SOA cancelled my order because they are currently not releasing shortblocks without a dealership confirmed failure and VIN due to inventory delays. Said I could re-order when shipping delays / inventory is at normal levels.

noooo :paddle:

booo...lol your project can't be too successful @Opie else they might institute this rule permanently. Did they ship you the upper oil pan/timing cover though or cancelled your entire order

BOOOOOO for sure!

2022's are hitting the roads now, so just wait a few weeks and the first few will be hitting the wreckers after folks crash them - you can then pick up a complete motor...LOL. Seriously, though - crappy news.

Find a wrecked one to use the vin. Pay the guy at the dealership to say the short block is bad

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Dang this in unfortunate.. I've been looking forward to following quick progress... Soon soon back on track hopefully

This or a K24 swap is going to be next up for my car when my current motor becomes to tired. Has 86K on the ODO.

I ordered just the shortblock and gasket set to start with...hadn't ordered anything else yet.

I am a little late to the conversation but with old school Toyota motors we used to machine the stock pistons for valve clearance and to modify compression. If there is enough meat in the top of the piston it will be a more cost effective way to get where you want to be than custom made ones. I wouldn't use them with boost tho.

A post in the Harrop superchargers thread made me think of this - how about an FA24F block swap? Do the cooling passages, etc. line up between the FA24F block and the FA20D heads?

You could likely find a wrecked Ascent and get the block from that. To regain compression for the NA application, you'd need custom pistons OR maybe longer rods (which would improve the rod-stroke ratio as well...unless the lower compression in the Ascent is achieved with more cylinder head volume vs. shorter pistons or rods).

I don't want to see the 2.4L 1st gen dream die!!! LOL

Just reached out to my Dealer connect to see if I can assist with this build for you.

Turbo motors had the starter mounted differently and the case half wont accept the BRZ starter with the stock trans.

:( :( :(

Just thinking this through a bit.

Our engines are actually symmetrical with the starter relief already available on both sides. I think this is because they want to start off with the same block half as other FA20/24 engines and CNC differently depending on model. This makes sense in the whole Subaru global platform thing.

Mounting our Bellhousing onto FA20DIT or FA24DIT would only require us omit one stud circled in red. Would this matter for strength/rigidity? probably not in the short/intermediate term.

That leaves machining the bell housing which can be done at a CNC/machine shop. There's enough room without upsetting the slave cylinder mounting, but will need some cad work but not too hard. Mount points for the starter already exists on the opposite side but you do need to shave down or "deck" themount points a bit to get the starter in the right depth. This can be done in the same subtraction process of the bell housing relief.

The brz starter might even be mounted on the other end, its still rotating in the same direction. Just need to look at clearances a bit.

2013-2022 MT Bellhousings are the same parts so you can even use 2022 beefy transmission instead of fitting CD009 if power levels aren't ridiculous. plenty of free bellhousings laying around. What other problems do you guys foresee? would like some community inputs

THIS IS NOT WORTH THE TROUBLE for an Accent motor or even 2022 WRX...This is only worthwhile for the STI FA24 motor which should be even stronger then the 86 FA24. Won't know or even get one for another 1.5 years.

Someone got ahold of one, copying the translation / images here since Facebook

https://www.facebook.com/permalink.p...24654421103670

https://i.imgur.com/y5Nfw5K.png
https://i.imgur.com/rtSWLdO.png
https://i.imgur.com/StPy43D.png
https://i.imgur.com/4gPaiWY.png
https://i.imgur.com/5lf2juX.png

I wonder why they say it "won't work on 2017 models without replacing the ecu with a fairly programmable one" - as far as I'm aware, the early and late 1st gen ECU's are equally programmable with ECUTek...?

The trigger wheel for the crankshaft sensor could be an issue. I wonder how it "doesn't fit" - are they trying to fit the FA20D's trigger wheel to it? Is the tooth pattern different, or the diameter, or...? Is there a reason the FA24's trigger wheel can't be used? Could be that a custom one would need to be machined... EDIT: just looked up some pictures, and I guess the trigger wheel is a pretty convoluted stamped steel piece. Might be hard to replicate. Maybe it would be necessary to use the FA24's trigger wheel and sensor, and THAT makes it difficult to adapt to the 2017 ECU?

EDIT #2: Looking at this thread RE: swapping a 2017+ MT (red aluminum intake manifold) motor into a 2013-2016 car, maybe the issue between the FA24D and 2017+ FA20D is similar - the signal from the crank position sensor to the ECU is different enough that they're incompatible (E.G. one is reading high when the other reads low?). This post specifically says that a Subaru tech told him the 2017+ AT (plastic manifold) motors don't need to swap the trigger wheel and sensor, but the MT (aluminum manifold) motors do (which makes sense because the AT motors were a carryover). If that's the case, then it would seem it will be necessary to somehow make the 2017 trigger wheel and sensor work to use the 2017 ECU.

I'm also curious about the motor mounts, since they don't mention anything about them as an issue, though Subaru's info on the 2nd gen said something about the mounts being moved.

Interested to see where this goes! I've "Liked" their page on Facebook, so hopefully we'll see updates.

Anybody already knows about the weight difference of the shortblock only and/or complete engine with accessoires between FA20 and FA24?

No way to know unless someone posts pictures of the parts.

I don't see why they couldn't modify the FA20 trigger wheel to work or have one made that will work. solidsnake11 used the FA20 trigger wheel and crank position sensor when he made his K swap run on the OEM twin ECU.