total noob with boxer engine

[koyv90]

i got a total noob question why is FI harder in a high revving engine? Why were the rsx type s and integra type r, which all supposedly had high revving engines, able to have huge amounts of turbos and FI options available?

[serialk11r]

It's not, high rev engines have stronger rods from the OEM if anything. Well okay that's probably not right to say, but increasing revs is VERY hard on the internals.

As for this particular engine, everything is speculation at this point but direct injection makes it hard to FI because if the injectors can't give enough fuel, the direct injectors are going to be much harder to find replacements for, and tuning will be harder.

[OrbitalEllipses]

I've always thought the reason that, in this application, direct injection makes it more complicated to turbocharge or superchage the engine is due to the naturally high compression ratio. DI is what allows you to raise compression, which in turn makes it harder to FI simply due to the higher propensity for knock. In addition, I believe the piston dome governs the specifics of direct injection spray patterns (or something like that), but a high compression engine will need low compression pistons in a FI setup to keep it from blowing. Thus, arises additional complexity from having to design a piston that lowers compression, but retains the correct spray properties.

[DEnd]

Originally Posted by fatoni

i dont know how much gravity will change the wear but i dont think that you can say that

I know it's not 100% true, because cylinders are not perfectly round (an neither are the rings). But there might be a 1-2 psi difference in the pressure the rings exert between the top and bottom which is neligable.

[webidiot]

Originally Posted by ForReal-Someday

I will have to look up where I saw it, but i read that boxer engines see more wear at start up due to inherent lubrication issues. Of course I read it on the internet, and they say that 75% of things on the internet are made up.

What you have said is completely opposite of what is true. Boxer engines have pistons close to the bottom of the engine unlike the inline or V formation. Because of this configuration the pistons are ALWAYS lubricated unlike the inline or V. Here is an example;

[Sasquachulator]

Originally Posted by webidiot

What you have said is completely opposite of what is true. Boxer engines have pistons close to the bottom of the engine unlike the inline or V formation. Because of this configuration the pistons are ALWAYS lubricated unlike the inline or V. Here is an example;

You know, this only makes sense.
You can't defy gravity.

[3MI Racing]

This is just all kinds of funny amusing.

I am curious to see what is entailed in plug changes with the new engine/platform.

[NESW20]

Originally Posted by webidiot

What you have said is completely opposite of what is true. Boxer engines have pistons close to the bottom of the engine unlike the inline or V formation. Because of this configuration the pistons are ALWAYS lubricated unlike the inline or V. Here is an example;

this is too funny.

[mrtodd]

^Hah. Imagine how that would be with the pistons sloshing all the oil back and forth. Silly.

[blu_]

Originally Posted by 3MI Racing

This is just all kinds of funny amusing.

How so? Stop being smug and tell us a story about boxer engines

[PERRIN_Jeff]

With more and more NEW customers being drawn to Subaru and flat four engines, some of us that have been dealing with Subaru engines for years, need to learn to be nice to the new guys

The reason for it being funny is that graphic shows oil in the engine as though it rides behind the pistons and its always lubing them. This is not the case, and in no engine does the oil level ride on the pistons or rods. In fact it doesn't even ride on the crank. If that graphic came from an engine oil manufacture, they should be bombed!

In these engines, oil gets squirted or flung at the pistons and piston walls that that is what keeps them lubed. There are pistons rings that keep the oil from getting into the combustion chamber. But keep in mind this is how all engines work, not just Subaru engines. The only difference is the pistons are arranged differently.

Yes the pistons are laying on piston walls, which sounds bad at start up,but within a couple of cranks, oil is being squirted onto the back of the pistons, and lubes them up. Again, this is normal for all engines. The other thing is its not like these are new engines. Subaru has been building these for a very long time and its not uncommon to see Subaru or Porsche engines with well beyond 150k miles.

Now if the issue is friction while running, well Subaru (like many) uses offset wrist pins on their pistons. This helps offset some of the load on the piston as its being pushed back and forth also reducing friction.

It may seem as though their is an inherent flaw with the flat four engine and added friction, but proof is in the years and miles put on these engines.

Hope that helps answer the question better.

[YaX]

What Jeff fails to mention is that the boxer engine does require additional maintenance that's not necessary with other engines. Many owners don't budget for this critical maintenance, and therefore drastically reduce the operational life of their engines. Don't make this mistake.

Every 75,000 miles, as part of your other regularly scheduled maintenance, steps must be taken to offset the frictional inequities induced by gravity on the underside of the pistons. Although expensive and labor intensive, it is recommened by Subaru that the engine be dropped, rotated 180 degrees, and reinstalled. That's right, you need to have your boxer engine flipped over from time to time. Which reminds me - I need to flip my mattress... it's good practice for owning a BRZ/FR-S.

[Kunzite]

That was good, I almost fell of my chair!

[Want.FR-S]

Originally Posted by YaX

What Jeff fails to mention is that the boxer engine does require additional maintenance that's not necessary with other engines. Many owners don't budget for this critical maintenance, and therefore drastically reduce the operational life of their engines. Don't make this mistake.

Every 75,000 miles, as part of your other regularly scheduled maintenance, steps must be taken to offset the frictional inequities induced by gravity on the underside of the pistons. Although expensive and labor intensive, it is recommened by Subaru that the engine be dropped, rotated 180 degrees, and reinstalled. That's right, you need to have your boxer engine flipped over from time to time. Which reminds me - I need to flip my mattress... it's good practice for owning a BRZ/FR-S.

I was reading it until the last statement. Way too funny..

Does that mean you need to flip the intake and the exhaust pipes, and the top-mounted intercooler becomes bottom-mounted intercooler...