Pros and Cons of owning a Boxer engine

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I would like for some of you to post some opinions about Boxer engines, also known as H engines or horizontally opposed engines. I hear that they are significantly more expensive to produce, but they last over 500k miles. Subaru and Porche are the only 2 companies that incorporate this technology in their cars. VW use to in the old beetle.
 
Doug Hillary is your man to talk to about Boxers. You ask about oil in your other post. Doug ,I believe , uses M1 5-40 Delvac 1.
 
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They are durable for sure.They also allow for a lower hood profile.When water cooled mileage seems to be on par with other designs.
Ferrari has used flat engines for years.Chevrolet had a turbo flat 6 long before Porsche had even a 6 on the market.
Citroen has also used them on and off for decades.
 
Originally Posted By: rudolphna
Pros: Inherently balanced design, like an Inline 6. Fairly durable.

Cons: Poor fuel economy.


Some questions: why do boxers have worse fuel economy/efficiency. Why are they more expensive to produce?

Boxers have less mass (balancers), so you think maybe that would help with both efficiency and cost.

I'll add to pro: 1. Low center of gravity. 2. Engine makes a noise that's music to the ears.

Re durability, there are some good durable boxers out there like the normally aspirated subaru 2.2 liter
 
Originally Posted By: Trav
Chevrolet had a turbo flat 6 long before Porsche had even a 6 on the market.


Didn't Chevrolet hire Porsche to design their H6 for the Corvair?
 
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Originally Posted By: Marukai
I would like for some of you to post some opinions about Boxer engines, also known as H engines or horizontally opposed engines. I hear that they are significantly more expensive to produce, but they last over 500k miles. Subaru and Porche are the only 2 companies that incorporate this technology in their cars. VW use to in the old beetle.


Depends what specific engine you are referring to. Porsche Boxsters and 911's in particular have failure rates sometimes quoted as high in 1 in 5 due to intermediate shaft failure, cracked piston liners, and slipped liners. This is only for about 1997-2003ish water cooled flat sixes. There are tons of them that failed within the first 30k miles even. That is why 911s of this vintage are so cheap. There are a few good articles on these failures online and some aftermarket companies have come up with remanufacture fixes for both problems. Older air cooled ones are pretty bulletproof.

Subi's 2.2 liter is virtually indestructable with many, many running around with over 300k and no issues. The 2.5 is also a great engine but some years, particularly 1997-2000ish that have head gasket failures.

As a rule boxers are more noisy and I can pick out a flat 6 porsche or a subi with some miles on it within a couple blocks because they have a distinctive "clatter". They are smooth and efficient engines, I love em. Would love to look into a subi diesel boxer if they brought to u.s. and no cvt tranny.
 
Originally Posted By: saaber1
Would love to look into a subi diesel boxer if they brought to u.s. and no cvt tranny.


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I come from a family that owns mostly all subarus...

I can tell you this:

PROS:
-the sound
-durability (try to use a 5w40 or something like that)
-low center of gravity
-easy to work on.. everything is right on top
-they can rev all day long (subarus)
-Smooth

CONS:
-plugs are difficult to replace (so use platinum)
-Cost a bit more (but it's more durable)

People say they get poor fuel economy, but my 2005 Legacy amazes me all the time, it gets 29mpg and I'm not exactly easy on it.
That is better that my SpecV... and my Spec is 2wd and weights 2600lbs(lightened, and it gets ~25mpg) ...my Subaru is 4wd, about 3200lbs and gets 29mpg! I love this car.
I am not defending subaru because I have a few of them... but I own a few of them because they have proven themselves to be some of the best cars ever made.
IMO the best part is that the B-pillars have 8 layers of steel + a steel bar.
 
There are Mid level maintenance costs on the subaru with the T belt/tensioner water pump required service replacement at the century mark and plug change half way at 50K. unfortunately the 2.5L subaru engine is not the best, in fact it has terrible reliability - partially due to the open deck block. The bore/stroke ratio is silly oversquare and it doent use shared crankpins. The 2.2L was the gem. Ive owned six subarus fom a 1.8L Loyale, a 3 cyl justy, flat 6 SVX, numerous imprezas and a current 09 NA pzev forester. All said though, The Impreza 4 door basemodel priceleader is a steal for the $16700USD out the door that it could be had for NEW around here this past summer. Not an exciting car, more soft and heavy and "legacy: like now.
- I wish you only good luck with yours, Marukai!
 
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Originally Posted By: Marukai
I would like for some of you to post some opinions about Boxer engines, also known as H engines or horizontally opposed engines. I hear that they are significantly more expensive to produce, but they last over 500k miles.


500k is a tough thing. Though a maintained diamond in the rough from any engine class/type with maintenance can likely do 500k, very few ever do. The only engines I view as true 500k engines for passenger cars/trucks are older mb 616/617 diesels, cummins b series diesels, older Toyota 4 cyl engines, ford i6 truck engines and the older gm 350/262 engines. Most others have too many issues too early to be true 500k engines.

I had heard of older subarus being long-life cars, but never saw proof myself.
 
Is the durability and fuel economy inherent to the boxer design, or other factors of specific engines? Does it avoid the balance problem in 4's?
 
The Chevrolet version was built at a time when Porsche was using nothing more than a modified Bug engine.It was far more advanced in materials and design.It seems to be closer to a Lycoming engine design than VW which probably also had its roots in small pre war aviation engines.I dont know but i suspect that Porsche saw the advantages of the Corvair 6 engine possibly leading them to adding 2 more to the VW boxer.

IMHO the Corvair could very well have been one of the best and technically advanced cars ever made in this country if it wasn't for a nut job that IMHO took a payoff to give the car a bad name it didn't deserve.I wish i could see what it would have become with better engineering,aerodynamics and liquid cooling.
 
The boxer design only has two inherent advantages: they are perfectly balanced (no matter how many cylinders they have) and they help keep the car's center of gravity low.

Everything else -- durability, power, fuel economy, maintainability, etc. -- depends on other aspects of the engine's design and construction.
 
Hi,
saaber1 - You said this:
"Depends what specific engine you are referring to. Porsche Boxsters and 911's in particular have failure rates sometimes quoted as high in 1 in 5 due to intermediate shaft failure, cracked piston liners, and slipped liners. This is only for about 1997-2003ish water cooled flat sixes. There are tons of them that failed within the first 30k miles even. That is why 911s of this vintage are so cheap. There are a few good articles on these failures online and some aftermarket companies have come up with remanufacture fixes for both problems. Older air cooled ones are pretty bulletproof."

Sadly this is not the correct situation - and certainly not a major failure rate of 25%. With the M96 engine family there very few IS failures and a number of engines were replaced by Porsche. This engine was a radical new design from Porsche and a departure away from air cooling. These were random failures and a number of reasons were given. It was more prominent on Manual vehicles and particulary on the bored "S" - and not too dissimilar to some issues with the 928! The leaking RMS was often thrown into the mix - this was a relatively minor matter and again random in nature. These were corrected under Warranty. Some cracked and chipped liners (ends) were also noted. There were variously attributed to contaminated fuel and suspect manufacturing-machining processes. Slipped liners.........?

You also said:
"Older air cooled ones are pretty bulletproof."

This is simply not the case and Owners will speak openly about valve component, heads and other expensive "issues". One such expensive thing is the main web and case caused by distortion over time and use. This is a common VW and Porsche issue going back to the 1950s and the 356 is the case of Porsche. Other were chain tensioners, rapid valve guide wear and head studs and top end sealing matters

No engine design is perfect! By and large boxer engines are a great design and everybody will have an opinion of course - this is mine, laced with some other data

If I was to design an engine for today's environment from scratch for a mass production small/mid car it would be a boxer! IMO Subaru's new diesel range is a great starting point

The German Auto Industry's "public notaries" - Horsch, Porsche, Benz, Maybach and etc all flirted with boxer engines

Porsche's design criteria in the 1930s for a "Volkswagen" casued most German Auto Manufacturers to submit examples with horizontally opposed engines. That the VW emerged after WW2 to become a "universal" vehicle says a lot for the design of the engine - as well as the rest of it

It's not really simple to compare modern boxer engines from Subaru and Porsche with those of even two decades ago. Today's engines are more reliable and longliving. They can have excellent fuel economy and typically they have much longer lives to first overhaul. M96 engines have been taken aprt with 300k miles on them and no measurable liner wear

My first involvement with VW engines occurred in the 1950s, Porsche in the 1960s and Subaru in the 1970s. One of my mechanics (in New Zealand) successfully raced one of the first Subaru series cars - we both gained a lot of knowledge from that!!
 
Originally Posted By: Marukai
I too would like to know why it would have poorer fuel economy over a common Inline 4


AWD.

Headgasket goes on Subarus around 100K mi but I think they fixed this in '03 and later.
 
Yeah the 4WD or even just longitudal engine mounting would reduce fuel economy over traverse FWD. A very over square boxer engine cools very well that's what makes them more suitable for air cooled engines, but in theory would be less thermally efficient than an inline engine, but probably not nearly as bad as the rotary engine.

Higher parts/production cost for an H engine, close to V-engine's, is another consideration. Other than being more compact and lower center gravity than an inline engine and better balance than inline 4, I don't see much advantages to them as far as reliability. I6 and V8 are probably just as reliable or more and 60 degree V6's now have pretty good balance and are compact as well.
 
I own a 2006 Porsche Cayman S, and I've gotten as much as 28 mpg doing 70 mph, on flat highway.

The boxer engine design is the most efficient piston engine design, w/no need for counterweights or balance shafts, w/its only main drawback being its width. It's got a low center of gravity, which is exactly what you want for a sportscar.

There are some motorcycles that use this style engine, BMW and Honda, as well as aircraft.
 
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