SOURCE: FORD TO DISCONTINUE V8 MOTORS IN MUSTANG, F-150 AFTER 2017, WILL RUN 4-CYLINDER AND V6 ECOBOOST EXCLUSIVELY

[7Mary3]

Nope, you need to keep the valves closed in the cylinders you are deactivating. Otherwise, the fresh air pumping out of the deactivated cylinders will cause problems with O2 sensors and catalyitic converters. You will also loose efficiency compressing air for no reason. Closing both valves in a deactivated cylinder results in very little power loss, you compress air and then allow it to expand again.

 

It can be done to an OHC engine, it is just complex and takes up room in the head. DI futher complicates the issue, thoose injectors and the fuel lines also take up room on the top of the engine.

Edited January 15, 2015 by 7Mary3

[ANTAUS]

I believe BMW is usually the yearly winner of paying the highest CAFE fines each year. They simply don't care as been stated in some of their public comments. Essentially they say that THAT is what a luxury customer seeks, and they give them what they want. I was just in a BMW dealership 2 weeks ago, and the car I was looking at had a $1700 gas guzzler line item on the window sticker. But of course, if you HAVE to ask, then you can't afford it. And usually those who do purchase it, won't really care. Granted, majority of their "sales" are leases anyways, and it's always the cheaper strip down, with whimpy engine that gets leased.

 

And as mentioned here as well, its the cost to do business.

 

Now you have the Benz engine in the CLA class, and it's 355HP from just 2.0L, imagine how many models that engine can be placed in across the board in their portfolio. And add to how Ford can do the same and consolidate engines across the board will make you wonder how much longer, or what MORE could a V8 add, when you can probably get it covered by 4 or 6 cylinder and be done with it.

[RichardJensen]

Nope, you need to keep the valves closed in the cylinders you are deactivating.

 

Then you modify the clutch used to advance and retard the camshaft timing on the gears to disconnect the shaft from the gear.

 

But talking up DoD when GM's pushrod DoD engines aren't even in the same ballpark as Ford's twin-turbo OHC engines----I just don't get that. I don't see how easy implementation of DoD is an advantage when, in this application, it provides no advantages.

[7Mary3]

Declutching a cam would be tricky too, unless you were going to deactivate an entire bank of a V-type engine. Even then you would have to lock down the cam(s) in a position with all valves closed on that bank. Might work, but would be an 'all or nothing' approach with no intermediate steps. A V-8 so designed would operate as either an 8 or a 4, a V-6 as a 6 or a 3. Losing all the cylinders on one bank would have some very difficult to resolve balance issues as well. I am not comparing this directly to an Ecoboost, just presenting it as a potential way to make a V-8 viable if upcoming regulations don't change. In addition, I think it is important to point out that D.O.D. type technology could be applied to turbocharged engines, it is not that this a mutually exclusive feature that can only be applied to GM LS type engines though a pushrod design facilitates its use.

Edited January 15, 2015 by 7Mary3

[DearbornDerek]

too much tech talk...I'm off to bed...

Edited January 15, 2015 by DearbornDerek

[lfeg]

Hey, does it really make any difference where the camshaft(s) are located as long as the results are there? I would not care if the camshaft was under the back seat and communicated with the valves via telepathy as long as the performance and economy was there. And with regard to FCA, the only way that they are currently avoiding heavy non compliance fines is by buying credits from other automakers. One of Tesla's larger revenue streams is selling credits. If or when the practice of buying and selling credits goes away things will get very interesting.

[silvrsvt]

I thought DOD was a bunch of horse hockey? I remember Honda having it on a couple of its products (granted it was a couple years ago) but it really didn't improve MPG's that much, if at all?

[jpd80]

Declutching a cam would be tricky too, unless you were going to deactivate an entire bank of a V-type engine. Even then you would have to lock down the cam(s) in a position with all valves closed on that bank. Might work, but would be an 'all or nothing' approach with no intermediate steps. A V-8 so designed would operate as either an 8 or a 4, a V-6 as a 6 or a 3. Losing all the cylinders on one bank would have some very difficult to resolve balance issues as well. I am not comparing this directly to an Ecoboost, just presenting it as a potential way to make a V-8 viable if upcoming regulations don't change. In addition, I think it is important to point out that D.O.D. type technology could be applied to turbocharged engines, it is not that this a mutually exclusive feature that can only be applied to GM LS type engines though a pushrod design facilitates its use.

A much better way is to increase compression to say, 13:1 or even 14:1 and use the VCT to delay inlet valve closure

thereby making the engine's capacity around 70% of its total. In effect, a qasi Atkinson cycle similar to hybrid engines.

 

In that instance, the 5.0 V8 would then approximate, a 3.5 liter engine but unlike a V6 or a GM V8 on AFM,

the power flow of all eight cylinders would be much more evenand balanced compared to the others.

Edited January 15, 2015 by jpd80

[akirby]

I thought DOD was a bunch of horse hockey? I remember Honda having it on a couple of its products (granted it was a couple years ago) but it really didn't improve MPG's that much, if at all?

 

The problem is/was it's very difficult to keep it engaged. Any slight throttle input deactivates it.

[RichardJensen]

just presenting it as a potential way to make a V-8 viable if upcoming regulations don't change.

 

Ford is not going to engineer a brand new, ground up pushrod V8 in order to implement DoD.

[robertlane]

That article has certainly generated traffic for the that website. The Ford V8 isn't dead and you might even see an engine larger that a 5.0L in the future.

[Deanh]

V8 dead?...doubtful, all I can add is .............

[bzcat]

 

I thought the fines were going to go away in '17 or something like that, and either you met the regs or you don't sell vehicles. I could be wrong, but I thought that was pointed out on here before??

 

Nope, the fines stays. It was a compromise to get VW, Daimler and BMW to agree not to litigate the 2017 CAFE. Their business model in the US depends on paying fines to avoid compliance.

 

Ford, GM, Chrysler, and Toyota also got a compromise on truck fleet MPG, which is converted to CAFE using the "footprint" formula. They got to keep the "footprint" conversion rule but the conversion rate got flattened in the 2017 CAFE. This was a major impetus for Ford to replace the E-150 because it would have seen a huge penalty, and why GM will stop selling the Chevy Express 1500 and GMC Savana 1500 soon.

 

I believe BMW is usually the yearly winner of paying the highest CAFE fines each year. They simply don't care as been stated in some of their public comments. Essentially they say that THAT is what a luxury customer seeks, and they give them what they want. I was just in a BMW dealership 2 weeks ago, and the car I was looking at had a $1700 gas guzzler line item on the window sticker. But of course, if you HAVE to ask, then you can't afford it. And usually those who do purchase it, won't really care. Granted, majority of their "sales" are leases anyways, and it's always the cheaper strip down, with whimpy engine that gets leased.

 

And as mentioned here as well, its the cost to do business.

 

Now you have the Benz engine in the CLA class, and it's 355HP from just 2.0L, imagine how many models that engine can be placed in across the board in their portfolio. And add to how Ford can do the same and consolidate engines across the board will make you wonder how much longer, or what MORE could a V8 add, when you can probably get it covered by 4 or 6 cylinder and be done with it.

 

I believe Daimler is the perennial winner in the CAFE penalty game. BMW sells a lot more 3 series and MINI with good MPG so its CAFE is not that horrible.

 

Gas guzzler tax is something different. It is applied on individual models, and not based on CAFE. Gas guzzler tax is triggered when the model MPG is certain % under the industry average for that class of vehicle. So it generally hit high performance sports cars because they are typically classified by EPA as "compact cars" according to interior volume... and compact cars generally have good MPG so these sports cars end up significant below the class MPG for compact cars.

Edited January 15, 2015 by bzcat

[MadManMoon]

That article has certainly generated traffic for the that website. The Ford V8 isn't dead and you might even see an engine larger that a 5.0L in the future.

 

Yeah, it's called the Voodoo 5.2L FPC.

[papilgee4evaeva]

I thought DOD was a bunch of horse hockey? I remember Honda having it on a couple of its products (granted it was a couple years ago) but it really didn't improve MPG's that much, if at all?

Small-block V8s would see better returns on DoD than Honda's engines ever would, percentage-wise.

[akirby]

Small-block V8s would see better returns on DoD than Honda's engines ever would, percentage-wise.

 

Yep. If you weigh 300 lbs you can lose 50%, but not if you weigh 180.

[30 OTT 6]

 

Then you modify the clutch used to advance and retard the camshaft timing on the gears to disconnect the shaft from the gear.

 

But talking up DoD when GM's pushrod DoD engines aren't even in the same ballpark as Ford's twin-turbo OHC engines----I just don't get that. I don't see how easy implementation of DoD is an advantage when, in this application, it provides no advantages.

Deactivating the cam is simple enough with a clutch. Getting it spinning again at the proper timing is a whole other story. I have visions of bent SHO V8 valves dancing in my head.

[RichardJensen]

It's doable. Honda did DoD on OHC engines.

[fordmantpw]

It's doable. Honda did DoD on OHC engines.

 

There version was to shut off the entire bank IIRC.

[30 OTT 6]

It's doable. Honda did DoD on OHC engines.

Definitely doable. Honda does it with oil pressure actuated pins inside the rocker arm assembly that when released will disconnect the valve from the cam. The cam still spins.

[jpd80]

Definitely doable. Honda does it with oil pressure actuated pins inside the rocker arm assembly that when released will disconnect the valve from the cam. The cam still spins.

Except that Ford's DOHC engines don't have rocker arms, how about sliding cam lobes that allow the cam bucket and valve to stay closed.

Or if that's no good use a variation of charge motion throttle blades in the inlet to deny air to deactivated cylinders.

 

the 6.2 Boss has rocker arms, so maybe that's a possibility

Edited January 16, 2015 by jpd80

[fordmantpw]

Just use electronically actuated valves. Tell the computer when to keep them open or closed. Problem solved!

 

Yes, I know there are others issues with electronically actuated valves.

[jpd80]

Hypothetical,

F150 really hits its marks and sells on average 50,000/mth, the 3.5 DI makes up 10% of that with 5,000/mth

while 2.7EB, 3.5EB and 5.0V8 are locked in a 3-way split of 15,000/mth for each engine type.

 

That little scenario would mean that only 30% of F150s would be V8s but the nett result for Ford would be

converting the majority of its F150 buyers to efficient V6s with an EPA highway rating of at least 23 mpg

and that's before we even get to new gearboxes with even more ratios.