Following last month's look at the new American engines from
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Renaultowned Mack, here we examine what Caterpillar and Detroit Diesel have in the pipeline—including Cat's 600hp firebrand. What the US does today...
Anew flagship 600hp engine joins the Caterpillar line-up as the company readies its products for 1998. Based on the existing 3406E, six-cylinder, 14.6-litre engine offered by Foden, the new engine displaces 15.8 litres and develops 2,0501bft (2,780Nm) of torque to make it the new King of the Hill.
That's not all Caterpillar has in line for this year: new ratings for the 14.6-litre 3406E will also follow.
The 12-litre C-12, due for its European debut later this year, offers a clutch of new ratings, widening the engine's power range and upping the top end to give the C-12 the industry's highest power density with a 430hp (320kW), 2.0701b (940kg) engine.
The C-10, already available from Foden, will go into 1998 with no changes and the same ratings that are currently available for those applications where the 10-litre pro vides the best fit. Further down the scale, Caterpillar is to launch a host of new electronic features this summer for the 7,2-litre 3126. already launched in Europe at TipCon. Foden and EIT are likely buyers of this engine.
• The big 600
The components in the new 600hp Cat are unique to this engine, though it will continue to carry the 3406E model designation. Upping the displacement has required an increase in both bore and stroke so a new crankshaft, piston and liner are needed to accommodate the increased displacement. To improve engine breathing there's a revised camshaft which is matched to a different turbocharger.
Caterpillar warns that driveline matching will be critical to the successful application of this engine.
The big Cat was launched in March at the Mid-America Trucking Show, though it will not be available until September of this year—and then only in limited quantities.
• New niches
For the coming year Caterpillar is "nicheing" engine ratings for different applications. This is happening in both the 3406 and the C-12 line up, but for the bigger engines there is a new-for-'97 mid-torque 500 and several dual-personality Multi-Torque ratings developed specifically for Paccar nameplates Peterbilt and Kenworth.
The fleet 500 is a marginally derated engine with peak torque down to 1,7501bft (2,370Nm) from the 500's usual 1,8501h1t (2,508Nm) peak torque. The horsepower peak remains at 515hp (384kW), but the slightly lower torque peak makes the selection of transmission far less critical with this new 500. In fact, Caterpillar says the new rating is ideal for the newly developed 10-speed constant-mesh transmissions in US over-the-road high horsepower applications.
• C-12 moves up in power
The medium-bore C-12 engine range, introduced last year in the US, will also be available in a wider range of ratings. At the bottom end, Cat is introducing an unusual 335hp (250kW) rating that actually boasts a peak horsepower of 420hp (313kW) with a 1,5501bft (2,101Nm) maximum torque. As can be imagined with such a roll-off of horsepower in the upper revs this engine has an amazing torque rise: 85%.
This is designed specifically for users who specify wide-step transmissions with deep reduction for low-speed crawler work. Because it has a well defined market, the engine also has preferred electronics settings similar to the high-performance 600hp 3406, such as hard cruise, manual retarder selection and monitoring in the shut-down mode, In deference to its likely applications, the 335 C-12 also has its PTO features activated.
At the other end of the spectrum, the C-12 is being boosted to a rated 430hp (321kW) for the 1998 model year, with the engine actually developing 455hp (339kW) at its 1600rpm peak power, with a maximum 1,6501bft (2,237Nm) of peak torque. Caterpillar claims that the 430, at 940kg, has the highest powerto-weight ratio in the industry.
The Cat 430 is being phased in to production through the summer. By year end it should he fully into production.
A new performance multi-torque rating is also introduced in the US this year for the C12, with full production set for 1998. It has a 380/430 dual-mode personality, giving it the 1,450Ibft (1,965Nm) torque curve in general driving mode and access to the new top rating's 1,6501bft (2,237Nm) torque curve when lugging in cruise control.
• Medium-duty Cats
Later this year Caterpillar will be making a full launch of the US 3126 engines for 1998. These 7.2-litre engines will have electronics updated for US 1998 emissions levels—also being addressed by Cummins with electronics for its medium-duty engines.
In Cat's case, a new generation of the ADEM electronic control unit will debut on the 3126, with a range of electronic control features which are more commonly found on larger engines.
Li by Steve Sturgess