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Originally Posted by ag-ford-4x4
Im a fan of inline diesels. Not quite sure what the hell anyone was thinking with V8...
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a quote from a fellow poster on another site
From what I recall, in most cases, the I6 design is more efficient ONLY when used in narrow/constant rpm ranges. This makes them ideal for OTR, pump engines, and even light tow rigs that get on the road and just roll down the highway. The computer control of the CTD 600 goes a long way to improving this, but you can clearly see in torque graphs that it is no where near the width or range of the common V configs.
They tend to have "spiky" torque curves which make them less ideal for general purpose use such as daily drivers and even around town short haul delivery. The V config tends to have a broader operating rpm range and a flatter torque curve, although that often comes with a lower peak output for comparable displacement. They also generally have FAR less vibration issues, though that gap is narrowing as well in modern designs.
So, that "superior inline efficiency" only applies to applications where you can keep it on its peak most of the time. As soon as the torque drops (on either side) below the (often) table flat levels of the V configs, they become more efficient (assuming comparable displacement and design".
So, yet again, I maintain that it depends on the application. Do you really think that CAT, International, Detroit, Isuzu and all the rest continue to build V designs just because they are not as smart as you guys chanting the benefits of "inline"? That they just "don't get it", but you do? Do you think Navistar and GM/Isuzu built brand new from the ground up V configs for light trucks just because they lacked your wisdom in understanding the merits of inline design?
No, they build multiple configs for different applications because they each have characteristics that lend themselves better certain types of use. Don't you think maybe they analyzed the pros-n-cons of the various designs before deciding on a V config? If anything, I would say it's Dodge that's out of the loop. The CTD is a *FINE* motor and I love it for many reasons, but Navistar, Isuzu, Ford and GM all agree that for the usage of the light truck market, a V config is better. You CTD heads and all the fanatics chanting "inline is better because OTRs use inline engines" and "CTD is better in a light truck because it's a medium duty engine" (same applies similar statements about IN/NS medium trucks) are all drinking the cool-aid and not thinking about the TOTALLY different usage.
Hmm, lets see, the big players who designed new engines from the ground up for light duty trucks thought V designs would work better. Obviously economics played a part, but the "simpler", fewer moving parts, and your vaunted "more efficient" inline designs should have won there, don't you think? But Dodge, who grabbed a diesel pretty much off the shelf, quite likely based on economic inputs that had nothing to do with "best diesel possible for this application", and which happened to be an inline meant for a completely different class of use; somehow, that gets touted as being better than what was consistently chosen when starting with a more-or-less clean slate? Don't you see the obvious conflict here?
As for the "million mile motors", again, who cares in the light truck market? If your not a "hot shotter", horse fanatic or retired RV fanatic who lives on the road in their RV, *nobody* puts half that many miles on a light truck before the entire truck is literally falling apart. Those motors that run that long are almost invariably run OTR style where most of their miles are highway and spending almost ALL their time at operating temperature. Nothing at all like the usage of light trucks (even tow rigs) where there is much more start up, shut down, stop-n-go, and more often than not, spotty maintenance. If a "light truck" ever sees more than 400-450k miles, it is very rare in the over-all total numbers on the road.
Bottom line, the "medium duty" and "million mile motor" chants along with the "inline is better" arguments simply DO NOT APPLY in general to light duty trucks. They do apply in certain categories, and they are "good things" in some cases, but not across the board, and trying to act as if they do smacks of "its best because that's what I have" thinking and lacking of rational consideration
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Definately the first engine I have ever seen of that design.
These ringed heads and studs will sit on the workbench no longer.
New engine
