Aspects of boxer engine design

I wonder if boxer engines are easier to work with for technicians or harder. I mean accessibility of parts technicians have to service regularly. I sure would like to see car designers to take that factor into more consideration than before.

Reply to
cameo
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Agreed: Check out the $21,000 Bugatti Veyron oil change at

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Reply to
Ben Jammin

Like most designs, the problem is not with the style of cylinder layout but with accessibility. I've stared at the 3.6R in my '19 OB and thought that, if everything not-engine was removed there would be no problem working on it. As it it the volume under the hood is pretty well exhausted by all of the accessory items so that even sticking a finger into some areas would be all but impossible. Admittedly I come from a generation where, despite a V-8 under the hood of a full-sized vehicle one could pretty well find space to crawl inside and reach anything. Then, although the engines stayed the same, the cars became smaller and the auxiliary items proliferated and, well, you can look under the hood of virtually any car and see the result. I looked under the bonnet of a 911 Carrera 4 at a car show and determined that there was probably no part that could be touched without dropping the entire drivetrain.

Reply to
John McGaw

There is one aspect of "boxer" style engines that I have worked on that made them a little bit more difficult to work on. Those included traditional VW designs and a Porsche 365. It doesn't affect "simple" things like changing an oil filter, but it can make deeper work more difficult and definitely more time consuming.

In most engines the main bearing caps are separate pieces. You can remove them as soon as you drop the oil pan. Depending on how much room there is you may be able even to replace the bearings with the engine in its mounts in the car. But in all of the flat engines I have dealt with or heard about, the block is in two pieces that clamp the bearings between them. So you have to take the engine completely apart to replace a bearing or to remove a connecting rod, etc. In some of the more usual designs you can even remove the crankshaft with the engine in place, although if you leave the crank in then you have to spin it by hand with a little piece of something stuck into an oil port to rotate a bearing out or back in.

And when you reassemble it, you have to put the two pieces of the block back together and then take it apart again to measure (e.g. with Plastigage) the bearing clearance. (I've known mechanics who would just assume that putting in the right bearings would guarantee the right clearance so that they could skip that more difficult measuring step.)

Bob W

Reply to
Bob Wilson

It sound then that repair jobs on subies tend to be more expensive than on cars with traditional engine design, everything else being equal.

Reply to
cameo

(I'm the guy who pointed out that difference in how the bearings are clamped in place.)

The only time I ever had a Suby flat engine worked on, it was warranty work and Subaru did a great job of supporting me so that I never saw a bill. One of the pistons had "blown up" after 37,000 miles, due to a bad casting, scattering bits of aluminum in lots of bad places and bending a valve over to bash in the end of a spark plug. The bent valve broke off so the remains of the piston proceeded to bash them into the head for a while. (Slightly amusingly, my race car once had almost the same damage after a mechanism failed and let the exhaust camshaft get out of synch with the lower end.)

I suspect that those design differences would "cost" me more in my time as an amateur working on the engine than for a pro working in a well equipped shop that handled a lot of such engines. The differences I pointed out would slow me down, but I am pretty finicky about how I work: A pro can't afford to spend as much time checking and rechecking things as a good amateur mechanic is likely to do, and the pro may have enough competence and maybe more importantly confidence to do it without so much checking and still get it right.

But that time is not what you get charged for anyway. I don't really know how the "official" times are created that go into the books at shops, the books that say the correct time to enter on the worksheet for replacing some particular part on a given brand/model/set of optional equipment. The pro in a shop that does much work doesn't put down how many minutes or hours he/she actually spent on something. Rather, he or some supervisor or secretary looks up what the official time for that task was.

I doubt that somebody, be it Subaru or some independent company, actually does the work while running a stopwatch. Maybe that was done years ago, but after that each year someone somewhere probably looked at some company documentation to see if the manufacturer had made much change and either leaves last year's times alone or estimates how much the manufacturer's changes would modify things. (And of course they can look at other cars and say "that task looks similar to what would be needed on an X" that we already had an estimate for.)

Among other things, note that you usually can get an estimate long before any work is actually done, perhaps with your getting a chance to say "go ahead" or not. So the time, and hence the bill, can't come from how long the work actually took!

Bob W.

Reply to
Bob Wilson

I agree. I suspect that when a certain job takes longer than it should, they just come up with some phoney excuse to charge me extra to make up for the difference. And who am I to say that the extra work was not needed, right?

Reply to
cameo

It has something to do with reading the entrails of a black c*ck killed with a silver knife in a graveyard at the full moon. And then tripling it.

Reply to
John McGaw

Is it that scientific?

Reply to
cameo

My shaman says yes.

Reply to
John McGaw

Even with the tricky spark plug swap on our 03 H6 Outback, I MUCH prefer working on my 2 soobs vs ANY transverse engine vehicle I have worked on. (9 of them representing 6 brands) No, I have not opened the engine block.

Reply to
1 Lucky Texan

Thanks. I just don't want to worry when I take the car to service and the assigned technician would think: oh, not another Subie again!?

Reply to
cameo

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