Why large displacement v8 for SuperDuty

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Originally Posted By: Brons2
Nobody has mentioned customer preference. Perhaps Ford has polled customers to see what kind of engine they want in the SuperDuty.

I for one would prefer a larger, lower stressed engine in a big truck like that.


That's one key factor right there.

Commercial outfits want reliability, durability, simplicity, and low cost.

The Coyote is a cool engine, but do we know how it performs when getting put through the ringer hauling commercial loads?

The Ecoboost is a great engine, but pretty much nobody is going to be keen on buying either a premium engine for their fleet, or a complex gasoline turbo engine.

I'd be very worried about the aforementioned heat density issue, especially doing heavy hauls at low speeds when those turbo-fed catalytic converters are going to want to turn into Roman candles. I could definitely see that being one of those engines that suffers from heatsoak blues with a good multi-ton load and an already elephantine 3/4 or 1-ton truck.

Where the "overpriced diesel" comment is concerned; there are loads for which there simply is no gasoline option. The towing capacity is literally not even in the ballpark.
 
Originally Posted By: DoubleWasp

The Coyote is a cool engine, but do we know how it performs when getting put through the ringer hauling commercial loads?



The powertrain engineers know, which is also why I specifically mentioned duty cycles.
 
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Originally Posted By: DoubleWasp
Duty cycles, yes. But what about high combined weights?


The GCVWR is a factor in the duty cycle of any engine.

Just so we're clear. You and I are on the same page.
 
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Originally Posted By: CT8
Originally Posted By: SilverFusion2010
With the eco boost making 470 lb-ft from 2250-3500 and most of that in up to redline I think it could pull just as well as the 6.2L. I’d love to see a side by side test.
I would guess the big V8 would get better MPG under load. Before the big Retirement at work we had Ford E350 vans the ones with the 460 and the V10s were really nice to drive, they would go up the hills at 75 mph with out breaking a sweat and the smaller V8 both the push rod and the overhead cam engines [ I don't know the displacements]would be in second gear wot a 55 mph struggling to keep up with traffic . The vans loaded weighed close to 9,000lbs with the compressor the parts and tools etc. The big engines got better mpgs.


How much of that was because of old school four speed autos, with their limited range of gearing?

I do like the idea of larger displacement engines that can turn more slowly, giving more time for expansion before going out the exhaust valve. I also suspect that since volume of the cylinder goes up as a third order effect, and the parasitic heat-robbing surface area goes up as a square order effect, that power output can rise faster than power losses. That's just a SWAG though, and apt to be wrong.

I wonder if it's harder to hop up NA motors. As opposed to turbo motors. As in... BillyBob's ECU tuning service with their magic screwdriver. I'm not saying all tunes are automatically bad, just that it's usually hard to get much extra power out of a NA motor whereas a turbo motor seems to often have a bit left in. And it's often easy(er) to add a large(r) turbo when all the piping already exists. Pure SWAG again.

I say, maybe GMC should bring back their big block V6 to compete.
 
Originally Posted By: cb_13
Low compression, simplistic 2 valve per cylinder design and relaxed emissions/mpg ratings on Superduty class trucks would be my guess as to why the 6.2 is the engine of choice. I feel like the 3.5 EB would need one heck of a cooling system to handle the loads a Superduty is rated for daily.


Don't most of these engines make pretty similar efficiency in conversion of gasoline to power? As in, the same 1/3 of heat goes into exhaust, 1/3 into coolant, and 1/3 to driveline? So if 300hp is needed to climb a hill, then the same 100hp is going into the radiator, regardless of NA big V8 or small boosted V6.

21.gif


Although, 'nother SWAG here: the water jackets inside the Ecoboost have less surface area, no? Less area to transfer heat out. Might the EB need higher pressure in the cooling system. I recall seeing the press reports about the EB being tested for days at a time at WOT, alternating between HP and torque peaks, so I'm guessing getting heat out isn't an issue. So I'm not sure this line of thought works. Just need the same massive radiator for either engine when being worked hard.
 
Originally Posted By: bdcardinal
The 6.2 is extremely reliable. We literally don't see them for anything except maintenance. When the 6.2L was available in the Raptor up until 2014 that was the truck to get.
20.gif


Now the 5.0 Coyote is the engine to get in the F-150 is you want to avoid turbos.

Something to keep in mind, the 6.2 has 2 plugs per cylinder. One up top under the coil like where the 2V and 3V mod motors had them and then a wire going down to where a plug would have been on a pushrod engine. People for some reason miss that and freak out when they see 16 plugs billed out.

Also there is supposedly a new actual large displacement, 7.0L, V8 being run around and tested to be used in Super Duty trucks in the 2020 range.


Yes, I recall that when Hurricane was originally drafted that displacement >7.0L was part of the plan.
 
Originally Posted By: MParr
Another thing to compare is power at the crankshaft and power to the ground.


Are you thinking less frictional losses due to less gear ratio difference? Every tooth being wiped looses some fixed amount of power, displaces some amount of gear lube, etc.

Seems to me that the EB winds up turning slower when under high boost, so wouldn't that lead to less driveline loss?
 
Originally Posted By: supton
Originally Posted By: cb_13
Low compression, simplistic 2 valve per cylinder design and relaxed emissions/mpg ratings on Superduty class trucks would be my guess as to why the 6.2 is the engine of choice. I feel like the 3.5 EB would need one heck of a cooling system to handle the loads a Superduty is rated for daily.


Don't most of these engines make pretty similar efficiency in conversion of gasoline to power? As in, the same 1/3 of heat goes into exhaust, 1/3 into coolant, and 1/3 to driveline? So if 300hp is needed to climb a hill, then the same 100hp is going into the radiator, regardless of NA big V8 or small boosted V6.

21.gif


Although, 'nother SWAG here: the water jackets inside the Ecoboost have less surface area, no? Less area to transfer heat out. Might the EB need higher pressure in the cooling system. I recall seeing the press reports about the EB being tested for days at a time at WOT, alternating between HP and torque peaks, so I'm guessing getting heat out isn't an issue. So I'm not sure this line of thought works. Just need the same massive radiator for either engine when being worked hard.


That’s a really good point and I do not know the science behind it. I would suspect the liquid cooled turbos to be putting exhaust heat back into the cooling system.

I know the Super Duty has a higher cooling system capacity than an F150 even with the max tow. I have seen complaints online of the 3.5’ EB temp gauges really climbing on steep hills with heavy loads. So I would question if the 3.5 would need increased system capacity over the 6.2 being as the 3.5 is all aluminum and FI while the 6.2 is iron block/aluminum heads and NA. I’m sure engineering knows by now.

It would not surprise me to see a variation of the EcoBoost in the Super Duty eventually. We have already service the Minnie Winne style motor homes equipped with the 3.5 EN. I will however be disappointed to see the 6.2 go. It’s been a great work truck engine. Enough power to get most jobs done and excellent reliability.
 
Originally Posted By: cb_13
Originally Posted By: Dave9
The ultimate answer to this is what your term of ownership is and mileage put on. Highway miles are easy, if you're only going to own it for a few years and put a lot of highway miles on, go for the most fuel efficient modern design that will tow (if anything) what you need of it.

If you're in it for the long haul, choose the highest displacement old school design that will tow what you need. You will lose a few MPG and more than gain it back with reduced maintenance and repairs.

If you doubt this, price a low mileage pull or rebuilt 5.0L vs a 3.5 EB, and this is being generous to assume the EB is the newer design where intake valves don't carbon up and need cleaned every 75K mi. or so.

Might be a different conversation if it were a heavier duty than F150 but it is a good, popular vehicle for many uses. Seems like there was a survey or three on youtube a while back where the Ford mechanics that work on these were asked which engine they would choose, and the 5.0L won. If they don't have experience with which engines have more problems, who do you suppose does?


Those same Ford mechanics were stating that you would need the V8 for pulling power. Which shows they know nothing about the 3.5 EcoBoost. I’d say the techs were on break and they talked to the lube rack guys.



I saw that youtube video prior to buying my truck. Only one of them seemed to be an oil change guy. Most noted reliability, not towing, as the reason for their choice.
 
Small displacement, forced induction engines aren't always a good fit for every vehicle. In fact, I'd rather have a larger displacement N/A engine in any vehicle of mine...I like the torque curve of the bigger engines better...
 
Originally Posted By: OVERKILL
Originally Posted By: bdcardinal
The 6.2 is extremely reliable. We literally don't see them for anything except maintenance. When the 6.2L was available in the Raptor up until 2014 that was the truck to get.
20.gif


Now the 5.0 Coyote is the engine to get in the F-150 is you want to avoid turbos.

Something to keep in mind, the 6.2 has 2 plugs per cylinder. One up top under the coil like where the 2V and 3V mod motors had them and then a wire going down to where a plug would have been on a pushrod engine. People for some reason miss that and freak out when they see 16 plugs billed out.

Also there is supposedly a new actual large displacement, 7.0L, V8 being run around and tested to be used in Super Duty trucks in the 2020 range.


Yes, I recall that when Hurricane was originally drafted that displacement >7.0L was part of the plan.


Supposedly the new 7+L is a pushrod engine where the 6.2L is a SOHC. The pushrod design makes it physically smaller to maybe, fingers crossed, fit in a F-150 somewhat similar to a LSx style engine.
 
Originally Posted By: bdcardinal
Originally Posted By: OVERKILL
Originally Posted By: bdcardinal
The 6.2 is extremely reliable. We literally don't see them for anything except maintenance. When the 6.2L was available in the Raptor up until 2014 that was the truck to get.
20.gif


Now the 5.0 Coyote is the engine to get in the F-150 is you want to avoid turbos.

Something to keep in mind, the 6.2 has 2 plugs per cylinder. One up top under the coil like where the 2V and 3V mod motors had them and then a wire going down to where a plug would have been on a pushrod engine. People for some reason miss that and freak out when they see 16 plugs billed out.

Also there is supposedly a new actual large displacement, 7.0L, V8 being run around and tested to be used in Super Duty trucks in the 2020 range.


Yes, I recall that when Hurricane was originally drafted that displacement >7.0L was part of the plan.


Supposedly the new 7+L is a pushrod engine where the 6.2L is a SOHC. The pushrod design makes it physically smaller to maybe, fingers crossed, fit in a F-150 somewhat similar to a LSx style engine.


OK, now that's funky. I didn't think Ford would go back to pushrod given their effort to entirely eliminate them from their product portfolio
21.gif


I fully expected just a longer stroke version of the 6.2L
crazy2.gif
 
Originally Posted By: OVERKILL
OK, now that's funky. I didn't think Ford would go back to pushrod given their effort to entirely eliminate them from their product portfolio
21.gif


I fully expected just a longer stroke version of the 6.2L
crazy2.gif



I laughed when I read the story. They are basically copying the LS platform but making it larger. Which is funny since the LS platform is the ultimate iteration of the SBF. Some of the pictures of the heads looked similar to the older NASCAR Roush-Yates castings.
 
Originally Posted By: bdcardinal
Originally Posted By: OVERKILL
OK, now that's funky. I didn't think Ford would go back to pushrod given their effort to entirely eliminate them from their product portfolio
21.gif


I fully expected just a longer stroke version of the 6.2L
crazy2.gif



I laughed when I read the story. They are basically copying the LS platform but making it larger. Which is funny since the LS platform is the ultimate iteration of the SBF. Some of the pictures of the heads looked similar to the older NASCAR Roush-Yates castings.


Well yeah, that was the running joke when the LSx hit the scene: You could bolt a set of Ford heads on the bloody thing it was so similar to the SBF
lol.gif
Even had the same cylinder firing order as the 302HO/351W. And of course all the much heralded "advantages" of having more head bolts and the like that were crowed about by the SBC crowd just sort of disappeared....
21.gif


Oh Ford...
 
Torque and the 6.2L variant of the Coyote also has a cast iron block to handle more abuse. Not sure if Ford is using 4/6-bolt mains to provide a rigid bottom end.

And the bigger engine can turn at lower RPMs for longevity. Toyota did this trick with the 3rd and 4th gen Prius, same 1.8L displacement as the Corolla but instead of pegging the 1.5L 1NZ-FXE from the 1st and 2nd gen cars, they used an Atkinson-cycle version of the Corolla's motor that provided more torque at lower RPMs.
 
Originally Posted By: nthach
Torque and the 6.2L variant of the Coyote also has a cast iron block to handle more abuse.


The 6.2L is not a variant of the Coyote. It was an engine design that pre-dated the Modular, and then came back after being shelved for quite some time. It was originally called "Hurricane" but renamed to "Boss" after Katrina.

The 6.2L was always designed to be big. It was somewhat loosely modelled after the 7.0L 427SOHC and that engines reputation.
 
Originally Posted By: OVERKILL

Well yeah, that was the running joke when the LSx hit the scene: You could bolt a set of Ford heads on the bloody thing it was so similar to the SBF
lol.gif
Even had the same cylinder firing order as the 302HO/351W. And of course all the much heralded "advantages" of having more head bolts and the like that were crowed about by the SBC crowd just sort of disappeared....
21.gif


Oh Ford...



Cadillac actually used that firing order before Ford....1963 390 & 1964-1967 429 along with the later 368, 425, 472, & 500 engines.

I kinda agree on the cylinder heads....Valve layout is the same but reversed, Though Cadillac used the same valve layout as the LS on the 368/425/472/500 engines along with 4 head bolts per cylinder.

If anything, It seems GM had these design attributes in their engineering toolbox already....Then sprinkled some modern Valve Angles & Port designs in for better efficiency.

It's always been my opinion that the extra head bolts on small block Chevies was more detrimental than just running 4 per cylinder, Anybody that's been around 400 blocks can attest to that.
 
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