Skip to main content

No rush because my car isn't ready for an engine yet (color me impatient ) but I wanted to get thoughts on the available options. I don't know yet what the planned details are for my car outside a EF2.5.  I of course have been reading up on the variants, issues, etc of these engine (plus some cool YouTube videos of various engine builders, good stuff) and thought the collection of wisdom here might be useful.

Anyone considered a 2.0 vs 2.5 and having closed deck block halves used? OutFront Motors is the supplier for my car and they have some nice looking bits on their site.  I plan not to track this car as aside from having really zero safety features it's plastic after all.  But I do want an engine that can last for the long haul, not trouble me with blown head gaskets or other historical challenges sometimes found in these boxers.

The 2.0 supposedly cool a little better due to more metal around the cylinder liners FWIW but the stiffer deck, even in a NA engine, gets commented on for being much less likely to blow gaskets.

Anyone have the oil pickup upgraded as this is another item that seems trivial to address before the engine is put together? Supposedly Subaru added some baffles in the sump to keep oil from sloshing where it's not supposed to so guessing that's standard but some folks say even a simple windage tray might even add a few hp from less oil frothing etc.

Any other things that a semi motor-head geek might want to know?  Eager to hear Subie owner experiences.

thanks

Last edited by msjulie
Original Post

Replies sorted oldest to newest

Hi Julie,

As your research likely showed, there are 3 versions of a Subaru block available regarding strength and cooling: open deck (which is standard, except for early 2.0 turbos), semi-closed, and closed deck.  The difference is the addition of sleeve or billet material that is added to the block to form a larger and stronger surface area for the head and block to seal.  Stronger surface area means less flex or lifting.

The prevailing theory is that head gasket failure can be reduced if the mating surfaces don't flex, especially with high horsepower and/or high boost.  In addition to adding material to the block, larger and higher quality head bolts help to insure that the heads don't move or lift under extreme load.

The downside is that the added material reduces the space for coolant to contact the cylinder walls.  Not surprisingly, Outfront says their closed deck blocks don't overheat.  That may be true in a Subaru vehicle, but our replicas place an added cooling burden on both the 2.0 and 2.5 versions, by virtue of the body configuration, tight engine compartment, and radiator placement.

Since you don't mention turbo or high HP, only reliability and longevity, I think a closed deck block is a poor choice for your needs, since you want the most efficient cooling options for your replica.  A semi-closed deck retains most of the open cooling channels, and would give you the advantage of a stronger mating surface with little reduction in cooling efficiency.

I purchased a Killer B oil pickup and pan with windage tray and was not disappointed, as they correct the weak points of Subaru design for our applications.  Be aware that an oil cooler and fan will also lower coolant temps, as well as oil temps, and are a smart investment for our replicas with Subaru engines.   

You will have lots of choices as you go forward.  Reaching out to this forum is a smart move, but, if you make all the right choices on your initial application, you will be the first person to do so.

Please keep the group informed as you move forward.  That's how we all learn.  Best of luck!

Last edited by Jim Kelly

@msjulie , who is building your car?

@msjulie posted:

No rush because my car isn't ready for an engine yet (color me impatient ) but I wanted to get thoughts on the available options. I don't know yet what the planned details are for my car outside a EF2.5.  I of course have been reading up on the variants, issues, etc of these engine (plus some cool YouTube videos of various engine builders, good stuff) and thought the collection of wisdom here might be useful.

Anyone considered a 2.0 vs 2.5 and having closed deck block halves used? OutFront Motors is the supplier for my car and they have some nice looking bits on their site.  I plan not to track this car as aside from having really zero safety features it's plastic after all.  But I do want an engine that can last for the long haul, not trouble me with blown head gaskets or other historical challenges sometimes found in these boxers.

The 2.0 supposedly cool a little better due to more metal around the cylinder liners FWIW but the stiffer deck, even in a NA engine, gets commented on for being much less likely to blow gaskets.

Anyone have the oil pickup upgraded as this is another item that seems trivial to address before the engine is put together? Supposedly Subaru added some baffles in the sump to keep oil from sloshing where it's not supposed to so guessing that's standard but some folks say even a simple windage tray might even add a few hp from less oil frothing etc.

Any other things that a semi motor-head geek might want to know?  Eager to hear Subie owner experiences.

thanks

regarding the BRZ and other newer Suby motors, there is a workaround by using an emulator to trick the ECU, however, as far as I know there is only one source for them, out of Australia,  and when I was first looking into them they were still pretty new.  The idea of having your entire driveline reliant on a single part with a single supplier that is over 5000 mile away was just a bit too much for me.

Regarding the EJ25, we take a lot of extra steps to ensure they are as trouble free as possible.  I don't advertise everything that we have done to a motor,  but I'll say that we address head gaskets, heads, valves, oil pump, oil pan, pick up tube, baffles, and some others.  The EJ25s have not been 100% without issue, but we've been able to resolve the things we've encountered over the years and to date have not had any head gasket issues.

As for Outfront, I've used a few of their motors in the past and I was very happy with them overall, however I wanted more usability and found that in the stock ECU, which led us to the packages we recommend now.  In addition, there are some states that actually check the engine number, and a JDM motor has to be EPA certified and approved for use in the US.  Fortunately for most Suby users, 90% of the states don't bother checking the engine number, and this is how so many get away with using them.  Hell, my daughter may even have a JDM in her bugeye...  ;-)

I'd listen to Carey on this one.

99.9% of Subaru customers have no desire to mess with programming, curves, tables, VVT, and drivability issues.

For people like Stan, Mike P, and I there are aftermarket ECUs, but from my experience so far they require BUCKETS of time to tune properly. VVT control is available, even in the cheap Speeduino. I'd probably have no idea how to implement it, but it's available.

I absolutely want the stock tune in my car, to be honest the engine has overkill horsepower for this car For Me compared to most air-cooled options and I want it to be under stressed and under worked in it's role in the Speedster.   I've had tuned turbo cars and they were for the purpose of going faster but this car is for enjoying the road at a more leisurely pace.

@chines1 would you suggest that I ask for any particular details for my engine? I want a 'boring' engine ie one that turns on every time I ask it, can take a long highway drive as needed (I plan to drive mine home from VM which is about 5-6 hours depending) and won't leak fluids on the ground or in places they should not be

Thanks all for the thoughts, learning is fun

@msjulie posted:

I absolutely want the stock tune in my car, to be honest the engine has overkill horsepower for this car For Me compared to most air-cooled options and I want it to be under stressed and under worked in it's role in the Speedster.   I've had tuned turbo cars and they were for the purpose of going faster but this car is for enjoying the road at a more leisurely pace.

@chines1 would you suggest that I ask for any particular details for my engine? I want a 'boring' engine ie one that turns on every time I ask it, can take a long highway drive as needed (I plan to drive mine home from VM which is about 5-6 hours depending) and won't leak fluids on the ground or in places they should not be

Thanks all for the thoughts, learning is fun

For what you desire I think you'd be happiest with a stock 2006/2007 EJ25, or at least  a built motor that was controlled via all stock sensors and a stock EJ25 ECU with a stock Subaru wiring harness modified to fit the speedster (they get modified same as a Vanagon swap).  I also like to keep the stock intake plenum, airbox, etc... as it seems to play a strong part in idle stabilization and recovery.  Its been my experience that you just can't get close to how reliable and easy the stock ECU is to live with.  It does things like cold start and idle stabilization, and AC kick-up, and self tuning, just like it was still in the donor Impreza.

And thats not to say you wouldn't be happy with a Stinger ECU and a JDM motor, I know lots of people who are, I just found that my particular client base did not want or need the features of the aftermarket ECUs and they were more of a detriment than a benefit.  Plus, we fond that with he stock ECU and retaining the OBD-II diagnostics port, you can scan the ECU yourself with a simple scanner form Amazon (if you don't have one) and the shops can do the same...  to me it just makes life easier.

@chines1 posted:

regarding the BRZ and other newer Suby motors, there is a workaround by using an emulator to trick the ECU, however, as far as I know there is only one source for them, out of Australia,  and when I was first looking into them they were still pretty new.

There's no way I'd use that if I were building cars for a living, but for a guy who wants something on the bleeding edge - do you have any more information, Carey?

Last edited by Stan Galat

@msjulie I have an OutFront EJ-25 motor in my VMC Pre-A coupe (delivered this fall I think-hope-pray). I have lots of notes on why I went Subaru and which motor with which mods in my build thread (here's a link: LINK).  I've used the thread to capture some of my thinking on each of the car's systems and share it.  I was just working on a post about the engine management aspects of the car for that thread that I hope to have up soon.  In a nutshell I have a US EJ-25 block with head mods and a Stinger ECU (now branded as Link I believe).  The unit has 4 auxiliary outputs that will drive a cold start solenoid, fan on/off for temp, fan on with AC clutch, and that kind of thing.  John has done a lot of tunes on these, and even more since working with Carey, so I'm confident he'll give me what we talked about.  Carey has got a point, if you're building lots of Suby powered things then a stock ECU with the fly-by wire pedal is the easy button that guarantees the most customer satisfaction for the least amount of worry and has almost universal DMV approval.  With what I have coming the base tune was loaded before the engine was delivered.  Once the car is ready to be driven on the road, the engine will be fine tuned on the dyno before delivery.

I was lucky enough to ride in a sand-rail with an OutFront Suby similar to mine (no AC of course, and no cold start solenoid). It ran great! Turn the key, push the button, and rup-rup-rup down off the trailer. It sat there idling smooth as silk with an ambient temp of 50 degrees (and had sat on the trailer for a week before that start).  It idled and purred through what I guess one could call the paddock area like it was mom's station wagon, then got to the dunes and RIPPED!  It was like that all weekend with cool morning temps and searing hot afternoons, hot starts, cold starts, it just didn't matter. I was really impressed. I would also point one towards Michael Pickett's FI system he built for an air-cooled type one motor to calm fears that ECU tuning is really hard.  It's like this: Some folks like Stan and Danny are good at, and want to tune carbs. I did it on race bikes and I don't want to do it anymore. I know the whole computer aspect of tuning Fi is a turn-off for some, but other folks like to fiddle with the timing and mixture from a laptop (I probably fall into this band of weird-o's although I don't anticipate messing much with this one).  Many (most) don't want to fool around at all.  ANY good FI system will be a better choice for the last group.  A stock system will be the easiest to diagnose (CAN-bus port) when a sensor fails.  It's the simplest option if one can live with a drive by wire throttle and what the stock ECU does to induce throttle lag, etc. That's what killed that option for me. I HATED what the ECU would do when trying to heel and toe my MINI. The direct coupling of accelerator pedal to throttle butterfly is something I miss and feel is critical to the vintage driving experience.

Lastly, there is always a lot of fear about cooling. The beautiful nose of a speedster doesn't allow for a Mack truck upright radiator. The piping is long, and designing a system that doesn't trap air is an issue to be sure. I have confidence that Carey and Greg have worked all this out over many-many quality builds. But I will add my two cents.  Cooling isn't just a function of how much radiator and how much volume.  It is also a function of how stressed the motor is during use. Part of what makes these such a nice application for us is that a stock, or near stock, EJ-25 is under stressed in the extreme.  The car is half the weight of a fully loaded Suby station wagon. A free flowing exhaust and intake will also help (an engine is also cooled by the air that passes through it).  So I'm not any more worried than I am with any of my daily drivers. With a good system in place it all comes down to maintenance and having a good sense of mechanical simpatico for your car.

Hope that helps!

-Michael

@Stan Galat posted:

There's no way I'd use that if I were building cars for a living, but for a guy who wants something on the bleeding edge - do you have any more information, Carey?

Stan the SubaruGears teamed up with Subatech in the beginning but no longer I think they are now called.

https://www.agtengineering.com.au

https://www.agtengineering.com.au/engine-conversions

I am not completely sure but they make conversions to run pretty much any Subie engine in any car.

My issue has always been that the 2L BRZ only makes torque spinning at such a high RPM, I can't see the logic going with that engine.  There are so many 2.5L NA engines available

If you look here https://smallcar.com/latest-subaru-engines/  they have a list of engines that you can choose and they will modify the harness to meet your needs.

I would ensure they leave the Cruise control wiring but you could easily add it to the ECU plugs / 8 wires.

In any case there are enough older engines that you could rebuild without a problem but a new engine from a wreck is the only way that you could get one then you need electronics to fool the Immobilizer.  In any case you cannot buy a crate engine from Subaru if you could many would do it.   Carey buys a short block and uses the heads and the VIN from a REAL car that has been wrecked.

Subaru Engine List

@IaM-Ray posted:

Sure seems to help when you have millions of cars with the same setup out there in the world with the stock ECU which makes Subaru the biggest or most experienced tuner so to speak

Its hard to compete with Subaru in term of engineering and tuning their own motors, especially when stock is more than adequate in most cases and we're not trying to squeeze every extra HP possible.

The subie Tuner that I use has asked me many times if I want to have a tune of the stock ECU but with my K&N and custom exhaust they tell me the hp improvement would be minimal.  They have extensive knowledge of Stinger but have moved to Atom or Link if I remember right and someone on the Quebec side has a spyder that they did up with and Atom ECU.  They find them much more tunable.  The owner of the shop holds multple rally championships and sells all over America.  These were the guys who advised me against believing anyone who said they could get over 200hp with a stock NA.  

In any case,  for an owner who wants to turn the key and go, and cruise, it is a solid option and what is not to like about the torque curve and drive by wire.

Carey had a suggestion on changing the pedal sensor curve, so I bought a module to vary the curve but the ECU kept throwing a code and going into limp mode.

So if you do not like the rheostat stock ECU throttle positioning and response, you could get a tuning package for the stock ECu to allow you to modify only that parameter... a bit expensive but dooable.  

Last edited by IaM-Ray

i had vw 's in my youth....and was a semi-expert whether i wanted to be or not....which is why (no offence to the vw guys)...i went with SUBARU power....with a STINGER brain ....i have been reading these comments and it is all gibberish to me since i know zero about this engine....along with all the EFI  etc stuff...all i know is 7K miles in and it is TURN KEY.....zero tinkering so far....which makes me smile ....if and when needed i will be calling the OUTFRONT guy for expert help living by my own advice of "save your dough & hire a pro"    happy motoring to all!

@chines1 posted:

I was not aware of the other 3, the really early "meaneye" we always referred to as the RS and I guess I don't do enough with the motors out of the later cars to know them, although my youngest owns a Stinkeye Impreza so now I have that ammo in reserve

Raptoreye?  Never heard of that descriptor for the newer WRX/STI.

I just ended my lease on a 2018 STI, and leased a 2021 STI.  Great cars for driving when the Intermeccanica can't be taken out.

@IaM-Ray posted:
Carey buys a short block and uses the heads and the VIN from a REAL car that has been wrecked.

With my new Spyder in the build queue at Special Edition there's no detail too small for me to be interested. The sentence above caught me eye, and I think that may be out of date, but perhaps this is not mutually exclusive with the below that Carey Hines wrote in a different post on this forum:

"We already use a brand new US OEM complete short block.  It was part of our deal with Subaru/FUJI and they ship them to us directly from Japan still wrapped in the factory paper and crate...  this also gives us a factory direct Subaru warranty on the engine!"

I'm also interested in learning more about the throttle pedal being electronically connected to the engine vice the old-fashioned way?

Lastly, can someone post some photos of a Suby engine in a recent Special Edition Spyder please?

Thanks!

Last edited by Foleydb

I'm also interested in learning more about the throttle pedal being electronically connected to the engine vice the old-fashioned way?



Old way: throttle cable directly connected to throttle body.

New way: Gas pedal has a potentiometer(variable resistor) and a heavy spring.

Throttle body has a stepper motor attached directly to drive the throttle plate.

Electronic controls and wires in-between the two, hence drive-by-wire. The benefit is possibly quicker throttle response and other things that mileage misers(EPA) want. The idle speed control is super easy this way with the throttle controlled by the ECU.

Last edited by DannyP

Add Reply

Post Content
×
×
×
×
Link copied to your clipboard.
×
×