? for diesel guru's

[msperos]

Why are most heavy duty diesel engines inline 6's but ford sticks with a V8. Who else makes a V8. I know that CATS over the road motors are inline's. Just wondering. Seems that an inline makes more torque and can deal with the loads on the crank better

 

[NIsaacs]

I think the main reason is the simplicity and longevity. All the big truck and engine manufacturers have built and used V- engines, however the only one with any success, was the two-stroke Detriot. All the others seemed to be short lived. However when it comes to huge power plants, they are all V-style. Can you imagine a straight inline 12 or 16 cylinder engine, it would be longer than a well rope. Also most huge power plants are of the stationary type, and are sized for HP and one set RPM, rather than variable torque output like the trucks need.



"NICK"

 

[BigEasy]

I think packaging has a lot to do with it as well. The powerjoke fits nicely in the Ferds, without going under the windshield like the Cummins/Dodge setup.

 

[JUeckert]

couple of reasons why over the road trucks use inlines. easier to work on,better packageing,and in most cases a little more effecient and also in most cases cheaper to replace or overhaul. cat,detroit cummins and mack all made v8 engines. all of them had certain engines that were a very reliable powerhouse,and some that were junky! but the same applies to the inlines also. back in the day,v8 engines were the engine of choice ,if you wanted max power,straight off the dealers lot. but the power option came with a higher price tag,and when it came time for repairs,that was more expensive also,more parts and labor! in certain heavy haul situations,the v8 is still the engine of choice. in off road and mineing applications that use very large equipment,the v engine is the most common engine,contrary to some opinions these engines last as long as inline engines in similar applications. as for ford an gm using v8 engines,in part its what was avilable at the time ,secondly ,when diesels first started really catching on in pickups,the v8 engines were more driver friendly,they had broader power bands,and turned higher rpms,which is what most drivers were use to. think about it,todays 5. 9 drives a lot different from the same engine of the late 80,s and early 90,s . its got a larger powerband,more hp and more rpms just like v8 engines,yet it still maintains a good amount of low end trq,and the inline simplicity,what could be better??

 

[Forrest Nearing]

straight 6's are traditionally "torque" engines... (although BMW and Toyota have made some pretty high hp I6 gas engines!)



diesels are "torque" engines...



straight 6's are naturally balanced and inline engine configurations are stronger than V shaped engines... the blocks are stronger, the cranks are stronger, etc.



when it comes to a 4 stroke diesel, inline is the only way to go IMHO.



FWIW, Cat motors you see in 18 wheelers are I6's.



Forrest

 

[fox]

A diesel works best with a good stroke length. This long stroke in a 'V' design makes the block very wide, thus it gets tight in most chassis.

A long stroke makes torque down low. A short stroke motor moves the torque higher in the rpm and that is not what makes a good pulling motor.

It also explains why the Power Stroke and Duramax will shift down long before the Cummins to get over a hill.

If you ever had an Old's diesel back in the early 80's and tried to compare it's torque to the Cummins you will understand. It wouldn't climb an overpass when the truck was empty without a down shift. A good Olds could go close to 100,000 miles before it was thrown away.

 

[Steve St.Laurent]

However when it comes to huge power plants, they are all V-style. Can you imagine a straight inline 12 or 16 cylinder engine, it would be longer than a well rope. Also most huge power plants are of the stationary type, and are sized for HP and one set RPM, rather than variable torque output like the trucks need.



"NICK"

They aren't all V's :-laf



http://www.bath.ac.uk/~ccsshb/12cyl/



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[Graphic man]

that may fit in my Dodge :-laf

 

[DennyDay]

Anybody got an ... ...

adaptor for a 01 auto 4x4?





Denny

 

[SRadke]

I6's have fewer moving parts and more main bearings. An inherantly better design for power and life. The size thing is a big factor as well. Have you ever seen a Cat 3408? That is one WIDE V8 to be squeezing in a truck.



-Scott