2023 GM Duramax Diesel 3.0L I6 - Test Drive Impression

[HEMIMANN]

Yes, Vee layout, aluminum heads, and chain driven OHC... everything a Cummins should not be.

While at Cummins, I was too busy with the big engines to get into the Chrysler / Nissan half ton engine design details. I didn't know they did all this cost reduction stuff. Then again, Fiat put the EcoDiesel into Ram instead, so both flopped.

 

[tjfdesmo]

While at Cummins, I was too busy with the big engines to get into the Chrysler / Nissan half ton engine design details. I didn't know they did all this cost reduction stuff. Then again, Fiat put the EcoDiesel into Ram instead, so both flopped.

Cummins shopped that 5.0 to everyone trying to get some sales volume. I remember watching a promo video where they were hawking it for school bus use. Swing and a miss...

 

[HEMIMANN]

Well, the V block architecture isn't new to Cummins - every engine above 750 hp is a V engine. Then again, they weren't built in USA, not sure if they were designed by Cummins, either. V28 was India, QST30 was Komatsu, K & QSK series were Daventry, England. I think the brought QST30 to USA for some volume.

By contrast, Caterpillar grew organically, not by acquisition.

 

[tjfdesmo]

Well, the V block architecture isn't new to Cummins - every engine above 750 hp is a V engine. Then again, they weren't built in USA, not sure if they were designed by Cummins, either. V28 was India, QST30 was Komatsu, K & QSK series were Daventry, England. I think the brought QST30 to USA for some volume.

By contrast, Caterpillar grew organically, not by acquisition.

When I think of Vee diesels I think of all the failed big truck V8s, including the "Triple Nickel" Cummins. The Mack E9 was just OK, and the 3408 CAT was probably the best of the Vees, but was known for breaking cranks. The old two cycle Detroits, as usual, were the exception to the rule, and ran in any configuration.

 

[HEMIMANN]

When I think of Vee diesels I think of all the failed big truck V8s, including the "Triple Nickel" Cummins. The Mack E9 was just OK, and the 3408 CAT was probably the best of the Vees, but was known for breaking cranks. The old two cycle Detroits, as usual, were the exception to the rule, and ran in any configuration.

Cat 3208 was a disaster - a cheapo 'me too' vocational motor that always overheated cylinder - number 7? I think.

I never hear of 3400 series breaking cranks. The original GM 350 was the crank-breaker ~20,000 miles with a brittle grey iron crank. I see the little Duramax has a forged steel crank. Not too worried about aluminum block and head - if they put enough stiffening ribs in them. Older diesels had aluminum pistons for years and years - it's not the material, it's how it's applied that counts.

Thinking about chain cams, I guess any non-gear OHC drive needs replacing every 100,000 miles, right? Belt, chain, whatever. Maybe OHC helps diesels meet EPA emissions easier? Dual phasers?