C&D Article on the new FB engine

[Legacy777]

http://www.caranddriver.com/news/car/11 ... r-car_news

There was also an article in Subaru's Drive magazine. I haven't had time to read it yet.

Sounds like they're a lot more room/potential for growth and improvements on the FB

[mike-tracy]

I do like the sound of upcoming direct injection and the chain driven timing. I don't like the asymmetrical rods, and I've read articles on Nasioc lamenting the EZ36's apparant lack of strength to withstand boosting (the rods being only one of the weaknesses). Course this article mentions an upcoming FB-based WRX so I guess the engineers have those issues addressed.

[evolutionmovement]

Where the hell is DI already? I want to get a couple as donors—one for a future Duchess transplant and another for the Tigershark project, and I want them both as 2.0s. The sooner they're out, the sooner they're cheaply available in wrecks. This is ridiculous that with Toyota's resources they can't do something Hyundai has already done. I would not buy a new car that didn't have DI, and I think AWD is a superfluous waste in light of proper snow tires even in our record snow this year (and fwd with performance tires are still doing OK with the Mazda), so that's not a selling point. Their current mileages are unacceptable compared the competition, most of which can touch 40 mpgs when Subaru is lucky to hit 30. It's a mystery to me that, along with the ugly looks, they're selling very well. Perhaps I'm looking at it wrong in comparing cars to cars when they're probably selling as an alternative to SUVs, which makes the mileage more competitive. I guess the fear mongering marketing pushing the necessity of AWD is working. I will admit that AWD has advantages and Subaru's system has traditionally been greatly superior, but the advantages in the real world are highly overrated. All my Subarus have been fwd and with decent all seasons they'd still get better traction than many SUVs, even body on frame type and Duchess will be going rwd before I'd bother with awd and the much higher expense a bullet-proof transmission would cost. But I'm buying a Ford next, maybe an Alfa Romeo after, so I'm no longer a customer anyway.

[AWD_addict]

"The lamb-chop-shaped rods also ease assembly of the bottom end."
Ha! Marginally at best. I bet this is one of those kaizen 10th-of-a-second-per-so-many-engines type gains.

Kind of lame about the rods, but I'm looking forward to the destruction pictures from "tuned" engines.
I was hoping for DI in the Toyobaru, I thought that was part of the deal when developing that car. If it gets good fuel economy, drives well and doesn't look shitty I might actually buy it.

[PhyrraM]

DI is not yet the end-all-be-all. Two of the biggest problems on early DI motors is coking on the back of the intake valve because of the lack of the solvent effect of gasoline and dealing with the super high fuel pressure in the long term -as evidenced by the fuel pump failures on some brands.

While I also look forward to a day when Subarus also have the advantages of DI, I can understand while some manufactures are waiting and trying to solve some of the problems before releasing them under warrenty.

[evolutionmovement]

Would one of those manufacturers be BMW? They've had high profile failures. It's a German car, so the faults aren't specific to the type of hardware, just that it is hardware. DI has been around since at least the 1930s (uh oh, the Germans again, but M-B that time, but I guess that would qualify as a success) and in cars for several years now, so any issues are/will soon be gone. I understand caution as well, but I wonder where that was when they introduced the 2.5 and its head gasket issues or the kept with the transmissions they never really got right. Perhaps they're returning to their old ways of properly engineering something first and to be late on the scene, but at the head of the curve as the EJs were when new. One can hope. I guess I have to hope as this is really my only option for Duchess and far and away the best choice for Tigershark.

[jefferson]

One place I feel they really messed up is the upside down oil filter. Makes a hell of a mess when you change the oil and there are always times when upon startup, the filter has to fill before getting the oil to the running engine. I think that is bad for engine longevity.

Jeff

[PhyrraM]

It's been my experience that most modern filters designed for top down operation have silicon check valves to keep the oil in the filter.

Also modern engines and oils can tolerate a few seconds of idle without oil pressure while the filter fills.

A friend of mine's dad used to run the engine for a bit after he drained the oil for an oil change. He did this to flush the oil out of the filter before he removed it. This was done every 60 days, about 3k miles. That motor went over 240k before he traded it in.

While I wouldnt condone much of this, it shows that there is not much to worry about in the big picture.

[evolutionmovement]

I always fill the filter with oil first. Even upside down ones, as long as they're accessible, can have oil added first (though not filled completely) and quickly tipped and screwed on without spilling any. Probably won't work with 0W, but I've done it with 5W.

[jamal]

if you've changed the filter on a modern bmw, which is a cartridge insert on the top, you'll see how easy it is and how little of a mess it makes. There's a big cup there to catch oil for one.

I don't like that they've gone with a longer stroke and shorter rods. That's really going to hurt power and rev potential.

[beatersubi]

I don't like that they've gone with a longer stroke and shorter rods. That's really going to hurt power and rev potential.

But then, Subaru engines have never really made their power in the top end. But I don't understand why they would make the rod/stroke ratio worse.

[entirelyturbo]

A longer stroke boosts a turbo faster.

I looked at a new Forester at work and I'm quite surprised it doesn't have direct injection already. The injectors go straight into the heads just before the intake valves, not the manifold.

Considering that, I don't understand the point of the new standard TGVs since the fuel is injected into the middle of the swirl, which would make it less effective in atomization.

One advantage of the porkchop rod, however, is that it has more leverage on the crank when the fuel combusts. Honda's been doing that for a while... my old Fit included.

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[BC5RSRA]

Umm, the injectors going into the head before the intake valve would be normal port fuel injection...direct injection would usually require a piston that had a secondary dished surface creating a pool and swirl in the combustion chamber...looking at this would determine that Subaru boxer engine unfortunately cannot take advantage of this due to gravity...all the fuel would drain to the wall of the cylinder...washing it. Especially at the required pressure of DI...atomization of the fuel would literally spray a very localized area.

If they were to do it the piston shape would be completely different maybe a hybrid top along with a very different head design...eliminating it's natural dynamic balance...DI is not feasible on Subaru motors yet. We just arent there. Either way, as far as economy is concerned, they do quite fine considering the equipment they are provided with in my opinion. But I'm no one special...literally I'm not. Lol.

[entirelyturbo]

Though I'm well aware that the FB25 is not a direct-injection engine (that's why I said it wasn't), it seems to be quite feasible on the diesel engines Subaru has been selling in Europe for about 5 years now.

[beatersubi]

A longer stroke boosts a turbo faster.

Considering that, I don't understand the point of the new standard TGVs since the fuel is injected into the middle of the swirl, which would make it less effective in atomization.
I would think that the turbulent air would better atomize the fuel and make it less likely to condense and drop out of the air charge.

One advantage of the porkchop rod, however, is that it has more leverage on the crank when the fuel combusts. Honda's been doing that for a while... my old Fit included.
How does the shape of the rod transfer more torque to the crank? I'd be very interested in any info you have seen to support this theory.

[entirelyturbo]

I would think that the turbulent air would better atomize the fuel and make it less likely to condense and drop out of the air charge.

I would think the fuel pressure would have a better chance to dissipate and follow the flow of the turbulent air if the injector is before the TGV.

EDIT: Nevermind my post about the rod having more leverage on the crankshaft, as I was confusing it with Honda's method of offsetting the cylinder relative to the crankshaft. That gives the rod more leverage on the crankshaft.

Sorry about that.

[Legacy777]

I would think the fuel pressure would have a better chance to dissipate and follow the flow of the turbulent air if the injector is before the TGV.

I don't think any of the setups with TGV's have the injector before the TGV.

Overall the TGV's are just producing a little more turbulence at lower air flows/rpms. At these lower airflows/rpms, I don't think placement of the injector is going to make a huge difference. Once the flowrate drops below a certain point in a given volume, the flow will go laminar. The TGV's are simply just trying to keep the airflow turbulent.

[entirelyturbo]

You're right Josh. Nevermind.

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