Come on, idler, PS Pump, alternator, tensioner they're all just bearings and when they seize they damage the belt. The serpentine belt system was a quantum leap in reliability over the old v-belts.

As best I can discern your objection to belts is really based on v-belts & more particularly things that have multiple v-belt drives. I've been around such things over the years. No complaints about your predilections. In the v-belt days for cars I always found them problematic.

But serpentine belts are far different, more reliable, and they just plain last longer.

Don't forget that gear drives cost money to design and implement. If that cost is higher than the cost of the serpentine belt system then cars will continue to produce engines with serpentine belts.

But you know, my learning process on the Suburban taught me that the serpentine belt is a separate system and should be treated that way. In my case when the idler bearing seized, it shredded the serpentine belt.

A part of the belt continued to whip around and severed an oil line. The engine pumped itself down until there was no more oil. Could have lost the whole engine that day, but didn't (another story).

I should have taken a hint when the tensioner bearing seized and shredded the belt at 189k. The idler bearing went on until 287k before it seized. But I didn't have to be hit with that 2x4 a third time...

Waste heat recovery, as in your cars heater, is free energy... it would be lost no matter what. The fact that you can direct some of inside your car to your benefit is free. Don't play games.

Direct drives seem better, and usually are, but they do fail. When you install the replacement coupling, the alignment is far more detailed than that of a belt. They are just far less forgiving than belt systems.

Pay me now or pay me later.

 

Keep in mind that the 2.3L Duratec engine in the FEH is a standard engine for Ford. They just change the intake valve system to achieve the pseudo-Atkinson cycle of the FEH.

Until Ford is ready to do the kind of things like a gear drive for auxiliaries on all of their cars with this engine they'll continue to use this technology.

 

Don't forget that the native/static/base compression ratio is also raised. ~13:1 so that the dynamic compression ratio can remain in the higher efficiency ratio of ~10:1. The latest Toyota innovation keeps the "dynamic" compression ratio at 13:1 as long as the cylinder isn't getting a full charge.

It would be nice if the next generation FEH/MMH would use this new technique plus DFI. 15:1 static and 12:1 dynamic CR.

 

While serpentine belts can last longer than v-belts I'm not a big fan of belts period. I just chose the air compressors as examples since we have both kinds and one is clearly and obviously better than the other. Most of our other belted systems lack a direct drive equivalent, hence the compressor example.

Sometimes belts are necessary but often they are just a way to avoid good engineering. Instead of designing a proper drive train, a belt allows someone to use the wrong part for the job and "gear it down (or up)".

 

Something you don't pay notice to is complexity. If you think of the gear train involved in driving an alternator, a water pump (or two for the FEH), a power steering pump, and an A/C compressor the complexity goes thru the roof quickly.

I have learned over the years that the simplest mechanism that can reliably accomplish the job is likely the best. As engines were evolving into designs with 4, 5, & 6 layered v-belts, I would agree with you. That was just nuts.

But the serpentine belt system stopped that progression and replaced it with a far more flexible and simpler system. Changing a serpentine belt is so simple as to be a 2 minute job. Changing a v-belt was never that simple, even for the first belt in a stack.

I just think your viewpoint is jaundiced by a real world, but inapplicable, set of experiences with machinery. By the way, as it regards v-belts, I agree with you.

 

OK I'll give you that the serpentine belt was a huge improvement over the V-belt.

That said and getting back on topic we are not comparing V-belts to serpentine belts, we are comparing serpentine belts to motor drive, specifically the AC on the FEH.

You claim that the problem is frozen bearings, not the belt so let us imagine what happens to both kinds of systems when a bearing on the AC freezes up.

With a serpentine belt system the belt gets damaged and everything powered by that belt quits working. You have got no alternator, no PS, no AC etc.

With the new style electric system you blow the AC fuse and everything else keeps working.

I'm not sure how anyone could fail to see the advantage of the electric system. If nothing else it isolates one failure from causing other secondary failures.

 

One of my belt destructions was a seized A/C Compressor...

I replaced the belt and was back on the road in 10 minutes... with your experience you do carry a spare belt, don't you? (Smile)

BTW the engine kept on running. The Alternator light came on and surely there was no water pumping around, steering got stiffer and a gazillion dashboard lights came on... so I stopped quickly at a very convenient truck rest stop along I-80.

But in the end you haven't listened to me. I have not touted the benefits of the serpentine belt system over an electric drive for A/C. My remarks were limited to a discussion of why Ford had not gone to such earlier.

Principally, my point was that Ford had to realign their thinking to the presence of the HVDC battery for its power. A 12vdc motor would be huge relatively speaking while a HVDC motor would be physically far smaller. In this day & age 3D real estate inside an engine compartment is pricey!

Ford had to realize that and then decide to abandon a known and pretty reliable technology that they will necessarily continue to use on other versions of this engine.

I felt you evidenced a clear bias against serpentine belt systems that was unwarranted and derived from your obvious experience with v-belts (and I do agree with your conclusions on v-belts).

So I took you on, on the serpentine belt issue.

If production costs were not a consideration with driving auxiliaries, all of them should be electrically powered... but you know, each time you do an energy conversion you lose some % of efficiency and drive up production costs.

Thus MPG will go down since you will be adding another energy conversion along the way and the purchase price goes up a little.

Probably not a big deal in the grand scheme of things, but it helps if Ford continues to make a profit.

My point about complexity is that just because you have a stack of finely machined gears driving each auxiliary doesn't mean it's better engineered. In my experience simple things run better and longer and I put the serpentine belt drive in just that category. In particular the tensioning part of the system solves a lot of sins in such a system and allows far more resiliency when things start & stop.

I just had to learn that it was an independent "system" and should be maintained as such. Only had to be hit in the head with a 2x4 twice for that lesson to stick.

I decided to keep the Suburban for the long haul while getting 3 kids thru college. I learned a lot along the way since I keep a spreadsheet on my cars (& yeah, I can tell you the mileage at which each belt failure occurred & why). Things like the serpentine belt thing that you just don't learn any other way.

 

I will now! So far I've never kept a vehicle over 100k miles. I've got rid of them before they could cause me any serious trouble. My budget is not as good as it once was and I will be keeping vehicles longer and thanks to your experience I'll not be stranded due to a belt. I've got the week off and plan to buy belts and perhaps idler pulleys as well. In fact I've got to go to the auto parts store to return a battery core anyhow...


Ah but I have listened to you. If that is your main point I'd agree. A serpentine belt is not so bad you are overly motivated to get rid of it and I don't hate belts so much I'd be willing to purchase electric replacements at my own cost. However if I had a chose between 2 vehicles with the only difference being that one had a belt and the other didn't, I'd take the beltless vehicle every time.

 

OK...

As my three kids came up on college I decided to stretch our family Suburban to 200k to help the family cash flow. Previously I'd kept cars to about 150-160k. So I started keeping a spreadsheet on whatever I did to track things.

When I got to 200k I realized I there was no reason I couldn't keep on going. I learned alot from this process. Having spent a career in engineering on ships I knew alot about preventive maintenance techniques.

Didn't intend to apply them directly to this process on the family Suburban but they just popped out of the spreadsheet. For example the alternator thing at 85k. Might as well replace the alternator when you roll up on 85k.

The serpentine belt thing just boggled my mind when I got to looking at it. Once I realized that the cause of failures wasn't "the belt" but rather other things, I changed how I looked at the system.

In the end, electric driven auxiliaries, while a good idea, isn't practical in a 12vdc car. The motors would be just too big. But in a car with a HVDC system that can be used to drive things the motors will be far smaller physically. Ford just had to readjust their thinking.

The driver in Ford's thinking about electric powered auxiliaries will be a function of how many hybrid vehicles they think they will sell. The engine in the hybrid is an off the shelf engine, so if they modify it in a way that cannot be used on non-hybrid vehicles they run up their cost of production.

Take a good look at your serpentine belt system. When I replaced the tensioner (yeah, it's got a bearing too!) and the idler on my Mustang I was surprised to find that there were two(!) idlers in the system. So, back to Napa for another idler bearing. (BTW if you have access to a bearing press you can replace just the bearing itself.)

In contrast my Mustang has gone 252k without failures of any kind in the serpentine belt system. The Suburban has been a workhorse vehicle, I guess we just drive it harder!

You'll find that your experience with machinery can easily enable you to keep a car well beyond 100k. You just need to look at replacing components on a planned basis.

 

Ford must be looking forward to the time that they are producing high-battery-capacity hybrids or possibly all-electric models. I suspect someone has decided to develop some expertise and a supply chain by making this modification to the FEH drive train.