Opinions on older diesel trucks

[4570Man]

Why do you like them better, then?

An inline 6 engine is undeniably better. The vast majority of all heavy duty diesel are inline. An inline motor has a less complicated timing chain setup and an inline motor has crank bearings between every cylinder where V motors have 2 pistons per lobe. An inline motor does typically allow better access in the engine bay for service.

 

[4570Man]

Here’s a 2017 Cummins engine bay vs a 2018 powerstroke. You could pull some shrouding off the Cummins and actually have decent access. The powerstroke is just a mess for working on anything. Any of the emission compliant trucks have a lot of crap crammed under the hood. If you went back to the 5.9-6.0 era days the difference was even more drastic. You could take a nap in a 5.9 engine bay. The 7.3 and 6.0 trucks aren’t a lot less crowded than the new trucks. And I’m not down on powerstroke. The Powerstroke does claim slightly better power numbers. I think the Cummins torque curve is better but I don’t have a graph. The Cummins exhaust brake blows away powerstroke exhaust brake. My Cummins makes a solid effort at slowing down. Dad’s powerstroke exhaust brake mostly just makes noise and annoys me. It would be lucky to maintain speed without gaining anymore downhill.

 

[Snobdds]

An inline 6 engine is undeniably better. The vast majority of all heavy duty diesel are inline. An inline motor has a less complicated timing chain setup and an inline motor has crank bearings between every cylinder where V motors have 2 pistons per lobe. An inline motor does typically allow better access in the engine bay for service.

What makes a small block chevy so good...bearing surface. They have huge bearing surfaces on the crank, and connecting rods relative to their size.

That is true with a V based motor as there are 4 extra bearing surfaces to spread the load on to. There is more bearing surface to support more rotational loads better.

There is better thermal transfer in a v than with a inline, meaning cooling capacities can handle higher HP and Torque. Like the powerstroke that reversed the head design to put the exhaust in the middle of the motor with a very small path to the turbo. The turbo has a better ability to turn heat energy via the exhaust to compressive cycling.

A long engine is simple. But it lacks efficiencies due to it's long design.

 

[deserteagle71]

Gas engines are easier to work on, cheaper to maintain, and cheaper to buy.

We're talking about "older" diesel trucks - the theme of this thread. So the only part of the above statement I can agree to is the "cheaper to buy". Around here, if you find an older Dodge/Cummins with the 5.9 or Ford 7.3 Powerstroke that hasn't been abused you'll have to pay just about what the truck cost new if you wanted to buy it. A gas-powered truck 20+ years old sells for $5k or less. Nobody wants them.

I have two, 2004 Dodge Cummins trucks. Don't know how anything could be easier to work on than that Cummins - lots of room around it in the engine bay. That is, if it needed to be worked on. If not abused these engines last half a million miles and nothing needs to be done to them other than oil changes. Granted, it takes 3 gallons per oil change versus 6 quarts but that's peanuts.

 

[tacticalturnip]

My dream pickup would be an 03-07 (Classic) GMC of Chevrolet HD crew-cab, short bed, 6.6 diesel in that gorgeous blue-gray they had available back then. Ugh, I had four trucks and SUV's of that generation, but never anything larger than a 1500HD and no diesel.

They're good trucks, but do they love to rust around the rear fender.

 

[not2old]

What makes a small block chevy so good...bearing surface. They have huge bearing surfaces on the crank, and connecting rods relative to their size.

That is true with a V based motor as there are 4 extra bearing surfaces to spread the load on to. There is more bearing surface to support more rotational loads better.

I used to think that one of the reasons that the 1800cc motor in my 1967 Volvo 123GT was bulletproof was because of the bearings. At 109 cubic inches it had exactly the same main bearing surface as a 327 Chevy.

 

[Rustyiron]

There's something about the longer *stroke of a straight 6 that offers a different torque curve from a V configuration. If I said more than that I'd be guessing but I'd like to find that video? or explanation again. I found it very interesting without any specific brand favoritism entering into the fray, just science and physics.
There were some positives about a "V", but again I don't remember enough to repeat them.
* edit; one thing I just remembered is the longer stroke required a longer "throw" on the crank therefore applying power for more degrees of it's rotation per ignition/stroke. There might have been a mention of the additional "leverage" that a longer distance between the main crank bearings and the rod bearings. Makes sense to me.

 

[deserteagle71]

There's something about the longer *stroke of a straight 6 that offers a different torque curve from a V configuration.

Absolutely. Anyone who's driven trucks with the old Ford 300 cubic inch straight 6, or the Chevy 292, can tell you that. And it is why I still drive a Jeep Wrangler with the straight 6 engine and manual transmission. Just can't stall those engines even if the tach is only reading 500 rpm - they just keep pulling. When Jeep went to the V6 in 2007 most found to their sorrow that low end power went away, so to keep from stalling the engine it was better to buy the automatic transmission instead of the manual. Lugging the manual transmission version just resulted in stalling.

Note that the 4.0 straight 6 is making over 200 lb-ft of torque at idle:

The 3.6 V6 doesn't get to over 200 lb-ft of torque till nearly 2500 rpm!

But once rpms were up, the V6 could produce better power. And at least with the Jeep, it was easier to meet the new emissions standards with a high-revving V6 than it would have been with the old straight 6.

 

[Rustyiron]

It's interesting comparing the 2 that the torque and hp of the V6 cross at about 5200 rpm at nearly the same hp of the 4L six. It's also interesting how the approximately 4000 rpm range that the torque is pretty flat.
I had a CJ with the straight 6 and it was a very sturdy and dependable mill and I also like the low end grunt.

 

[Hay Dude]

I am at work currently and not at the service shop. It would require quite a bit of effort to drive there JUST to snap an "easy" picture to prove to you what I say is true. To be honest, I couldn't care less whether you believe it or not. It changes nothing either way. But if you spend a little time poking around the WWW, I think you will see the 6.2 is pretty legendary for it's reliability and long life.

Well, just get a picture of a 6.2L work truck with 1 million+ miles on it when you get a chance. I didn’t say right now. lol
I’ll check back on the thread once in a while.

I agree if a guy is towing really heavy a diesel is the way to go, it will do it easier and with less fuel consumption. What I like about a diesel is you have that pulling power in the low RPM's verses a gasser peaking RPM's under heavy loads.

Yeah, that’s one advantage. There are others.

I no longer tow heavy. 10K is probably my limits these days and will probably rarely exceed that need again which is why I say I hope I never need to own another diesel. I do not like them and don't want to own one. My Nephew lives 3 miles from me and has offered his Duramax to me whenever I need it.

Ok, I thought you said you don’t want one because in your previous post you said “Gas engines are easier to work on, cheaper to maintain, and cheaper to buy. I also think they sound much better than a diesel does too because I love the sound of a v8 gasser, and despise the sound of a turbo whining.”

Your son's friend has an opinion and that's great. Does he know that the Ford 6.7 puts out 50 pounds more torque and 75 more HP than the Cummins does? He would probably think the Cummins is even weaker.

I drive a cab & chassis, so does my son’s friend. Do you know the cab & chassis ratings are different than the pickups?
I have plenty of hot rod clowns in Fords & Duramaxes in my area making 2X the HP my stock rig makes, but not ONE of them will tow what I tow. The reason is because there’s a LOT more to towing than HP & TQ.

I have owned a few diesels from the 5.9 to the 7.3 and the 6.0. I also had the 6.7 as a company truck when I worked in mining. I have always liked an inline engine more than a V engine.

You got that right.