Same Engine, Different Horsepower

[ovrszd]

Having lower engine torque output in lower gears is a way of being able to produce a machine wilt a low capacity driveline and still advertise high power. Auto manufacturers have used torque limiting strategies in the lower gears and on shifting for years for the same reason: keep the loads on the transmission and drivetrain down for reliability.

Electronics make many things possible.

My wife's Hemi Grand Cherokee comes off the throttle every time the auto trans shifts, regardless of where you have the gas pedal, even with it to the floor.

 

[finn1]

This is not accurate, it used the same DESIGN, NOT the same block.

The diesel block was beefed up internally, but it didn't have any more head studs and other important things like that, so it failed under the higher compression.

SR

. The Olds Diesel was based on gas engine tooling, but the block was significantly altered during the dieselization program.

Deere, International, Ford, and many others used a similar stategy, albeit successfully, to build both gasoline and Diesel engines on the same line, with the same architecture.

The Ford/International 6.9 was based on the International MV gasoline architecture, albeit wiith additional head bolts and a lot of beefing up. Those engines went 500k to a million miles when properly maintained.

Even VW Diesels were based on common diesel architecture.

 

[buickanddeere]

This is not accurate, it used the same DESIGN, NOT the same block.

The diesel block was beefed up internally, but it didn't have any more head studs and other important things like that, so it failed under the higher compression.

SR

The Olds diesel failed because the bean counters cheapened the engine from what the engineers wanted . The last year or two of production did have high nickel blocks, proper fuel filters and roller cam followers. By that time however the reputation was ruined.

 

[Sawyer Rob]

Two big failures killed the 350 diesel...

First, they used the same amount/size of head bolts, gaskets failed, so GM speced a higher torque, that caused head bolt stretching and gasket failed! Finally, they sized the head bolts to a larger size with higher torque, and that pretty much fixed that.

By then, everyone was pretty fed up with the 350 diesel, but the metric 200 trannys failed left and right too, and that was the last straw.

SR

 

[nova3930]

Having lower engine torque output in lower gears is a way of being able to produce a machine wilt a low capacity driveline and still advertise high power. Auto manufacturers have used torque limiting strategies in the lower gears and on shifting for years for the same reason: keep the loads on the transmission and drivetrain down for reliability.

Electronics make many things possible.

Ram trucks with the Cummins 6.7 have an aggressive torque limiting scheme in the ECM because if you give a 68RFE transmission the full torque the 6.7 is capable of from a dead stop, you will blow it all to pieces.

 

[Sawyer Rob]

A GM tech. guy stated that, that was true for the thousand pounds of torque option Cummins, then he went on to add, that the Duramax puts out 950 pounds of torque and GM does NOT de-rate/limit the engine/torque in any gear, including low gear.

SR