subie engine thoughts

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!

Has anyone used a BRZ engine yet? 

@Marty Grzynkowicz posted:

Has anyone used a BRZ engine yet?

If I'm not mistaken, the ECU is the issue.

I think the immobilizer circuits make it really hard (impossible?) to use the factory ECU and retain all the VVT programming, and the stand-alone systems aren't robust enough to handle it.

Shame, it's an awesome light weight and nice reving engine. 

@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

Vintage Motorcars

i trust them completely I just like to be informed 🙂

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.

"Hell, my daughter may even have a JDM in her bugeye...  ;-)"

Wait...  A Subaru in a Bugeye?

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

@Lane Anderson posted:

"Hell, my daughter may even have a JDM in her bugeye...  ;-)"

Wait...  A Subaru in a Bugeye?

Impreza owners name the EJ25 Impreza generations by headlight shape, bugeye, blob eye and hawkeye.

@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.

Thanks, stock bits sound fine. The engine will feel like a super hero in a light speedster vs it's life in a 'heavy' car

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

@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?

@msjulie posted:

I absolutely want the stock tune in my car, ....
I want it to be under stressed and under worked  .....

I want a 'boring' engine ie one that turns on every time I ask it,  .....
.....won't leak fluids on the ground or in places they should not be

Thanks all for the thoughts, learning is fun

Me Too!   I'm signing up for the same class!   

@chines1 posted:

Impreza owners name the EJ25 Impreza generations by headlight shape, bugeye, blob eye and hawkeye.

STINK EYE !   

Ok, that makes a LOT more sense!

@Lane Anderson posted:

Ok, that makes a LOT more sense!

he got me too, I had to google it,

Kids nowadays!