Why do GM and Ford even make a v8 diesel?

[BlueSky94]

Over the years, I've owned straight 6 and v8 diesels. Can anyone tell me why GM and Ford don't follow cummins/cat lead and make a straight 6 diesel?

I dont' understand the merits of a v8 diesel and they are clearly not a reliable.

[Diesel Dude]

They do it to save space under the hood,they do it to sell you more parts and they do it because they are automobile manufacturers primarily and light trucks are like big cars.I would prefer a straight 6 in a light truck as well .Soon even Dodges will have v-8's in them.They just want to sell units and they dont care .Maybe Toyota will get smart and sell a 1-ton with a Hino six in it and take market share for those who prefer that type of configuration.

[More Power]

This topic comes up from time to time, and usually stirs up a hornet's nest. :D

What I ask is, what company is the most successful US diesel pickup manufacturer - ever, and what engine configuration do they use? Answer: Ford and the Powerstroke V-8.

Now, who offers an HD pickup with the best automatic transmission? A drivetrain consists of more than just 6 or 8 cylinders. smile.gif

MP

[DogDiesel]

MP ;)
What truck have I owned since I bought my first diesel? Chevy.
What engine is now in my Chevy? Cummins.
Why did I quit Ford? Cause I always fix my own vehicles and buy my own parts and Ford frustrates me fully with lack of commonality in parts.
I grew up in a Ford family, and drove only Fords until I drove my first diesel.
I fully understand the hornets nest... smile.gif
Wayne

[toyboxrv]

Despite what a lot of people want to believe, an inline 6 is not more inherently balanced than a V8. The V8 has a piston and rod going down with another elsewhere going up while a 6 does not. There is no cooling advantage to an inline. The 6.2/6.5 has an open intake, one that doesn't seal the intake valley and that doesn't help with cooling much. The longer inline 6 has coolant going by more cylinders before it gets to the back and returns in the head. A better design on the cooling system is more important the configuration of cylinders. I talked to a friend who balances crank at an engine shop about balance and he said all engines except boxers must have counterweights to offset the piston/rod assembly and that an inline 6 has no advantage over an V8. The side thrust on either engine is the same, no advantage there either. Larger, fewer cylinders will produce more torque, but rev slower and make less hp than more and smaller cylinders. The Cummins has a very long stroke to bore and gets its torque advantage from that more than from being an inline 6. All of the currently available diesels in the big 3 are excellent choices and I wouldn't mind having any of them, but I wouldn't make my choice based on inline vs V8.

[2dogs]

However just look under the hood and see which one you can see through to the ground smile.gif and which one is easier to work on. It's not a cramped engine compartment that happens on a V-8 in a little pickup compartment! Now if the pickups offered a Tilt Hood :D - like a real truck - then this advantage wouldn't be there - but that's not going to happen....

[joe hatfield]

Despite what a lot of people want to believe, an inline 6 is not more inherently balanced than a V8. The V8 has a piston and rod going down with another elsewhere going up while a 6 does not. There is no cooling advantage to an inline. The 6.2/6.5 has an open intake, one that doesn't seal the intake valley and that doesn't help with cooling much. The longer inline 6 has coolant going by more cylinders before it gets to the back and returns in the head. A better design on the cooling system is more important the configuration of cylinders. I talked to a friend who balances crank at an engine shop about balance and he said all engines except boxers must have counterweights to offset the piston/rod assembly and that an inline 6 has no advantage over an V8. The side thrust on either engine is the same, no advantage there either. Larger, fewer cylinders will produce more torque, but rev slower and make less hp than more and smaller cylinders. The Cummins has a very long stroke to bore and gets its torque advantage from that more than from being an inline 6. All of the currently available diesels in the big 3 are excellent choices and I wouldn't mind having any of them, but I wouldn't make my choice based on inline vs V8

not being an engineer i cannot argue your points, however having driven diesels of all types for the better part of 40+ years (190hp supercharged cummins, 220's, 262's all the way up the line to the vt1710 @800hp, along with cats from the 1693t, 3408 to the 3406's, detroits from the 6v53's to the 16v92,s and the 1st mack v-8's, boy what a horse!!)
i think that if your above statements were true, all the above manufacture's would still be offering them in the large trucks, they don't. i can't tell why they no longer offer v-series motors for those applications, but they don't. i can say after owning, operating and driving several of them, they don't tend to stay together well (with the exception of the 8v71, but they didn't have enough hp to hurt them) in anything other than industrial apps.
i do think that both gm and ford offer a great motor for the application (with the exception of the 6.0), however when i made my choice for a new truck it was made from a life time of driving diesel's and was a dodge (not that i liked that). if i could have my cummins/6 spd in a gmc, well enough said.
i still own a 93 gmc 6.5 td with 250k+ miles on it, however it has had 3 motors in it, keep in mind i work my trucks hard, but i take very good care of my vehicles/equipment. my son will continue to drive this truck for many miles (other than power he likes it better than my dodge smart kid). the above not intended to stirup the hornets nest, just my opinions, not based on engineering, but one very sore a**

[tanker]

I tend to go along with Joe, about the V-8's in the larger rigs now all are I-6's. Less moving parts, most have a long stroke, which relates to massive low end torque. I believe the V-8 Diesel's are more like driving a gas engine in the smaller trucks etc.
I'm dyed in GM blood since my first car (1952 Chevy coup). Had a 6.5 suburban and just loved that vehicle, now I have the 05 D/A crew cab. Had issues with the 6.5 :rolleyes: but the ride comfort etc were 2nd. to none. I could have bought a Ford, but with the new redesigned engine and transmission issues, I avoided the Ford. I considered the Dodge with the good ole Cummins, but the automatic scared me away, and I've done about all the shifting with a manual that I don't need that for pleasure driving. That put me back in GM's court with the Allison, which is 2nd to none, and with the Duramax being out for 5 years, I felt comfortable with this choice. Local service was another reason for the D/A, we have a 24 hour shop 6 miles from home. smile.gif

[rjschoolcraft]

Caterpillar builds a lot of V-8 diesels...they just don't find their way into on the road trucks that you guys are used to. The biggest engine that Cat builds is a V-8. In fact, they couple two of them together in some applications to form a V-16! The 797 Dump truck uses three of these big V-8's coupled into a V-24 arrangement. Bore is 6.7 in. and stroke is 8.5 in. Total displacement is 7143 in^3 with 3350 gross hp.

The choice really comes down to packaging, envelope size, power density and reliability. The sixes are inherently more reliable than a V-8 of comparable technology because of fewer moving parts. However, the package is difficult to work with in pick-up trucks. V-8's have inherently higher power density capability because it is a more efficient use of space.

Trade-offs.

[Tatraplan]

Swedish Scania are still putting V8's in their heavy trucks. The 16-liter V8 produces 580 hp in the trucks and up to 800 hp for marine applications.

http://www.scania.com/products/new_truck_range/engines/16l_v8_engines/580hp.asp

For my Chevy C20 the 6.2 V8 is not really strong enough to give reasonable performance. When i stuff the bed full of heavy things, the acceleration is virtually non existing.

What i need is a turbo (or two), but my old truck is probably not worth the cost of that kind of upgrade.

/Robert

[Tatraplan]

At the bottom of this page:

http://www.svempas.se/showe.html

There's a Swedish "showtruck" with a tuned Scania 14.2 litre V8 that produces 3000 hp and 6200 Nm of torque (~4573 Lbft). So V8's are still capable of generating massive power.

/Robert