Diesel V16 60L

What it is

Bore measures 159 mm, stroke 190 mm and the compression ratio is 14.5:1. Those figures, and the 60.4 litres they come to, match the Cummins QSK60. Nothing else here was copied from one. The 60 degree bank angle is the figure everyone quotes for this engine and it stays out of the claim, because nobody here checked it against a Cummins document. The torque on the dyno comes out of a Wiebe heat release solved against crank-slider geometry 240 times a second, with the plenum, the runners and the collector filling and emptying around it.

A real QSK60 breathes through four turbochargers and this model fits one, so a single 210 mm compressor wheel stands in for all four. Wheels in parallel buy flow rather than pressure: four 110 mm discs come to the area of one 220 mm disc, and 210 is where that landed. The first attempt went the other way, a small wheel at high boost, and it reached the published 1,900 kW while putting peak torque hundreds of rpm below the rated 1,400 and driving the compressor into its own choke wall. What ships is the opposite trade, a big wheel against a wastegate holding 2.20 bar absolute.

It idles at 600 rpm and stops at 2,100. A four-stroke sixteen fires eight times a revolution, so a 600 rpm idle is a firing rate of 80 Hz, low enough that you hear separate cylinders instead of a note. The governor holding that idle is proportional droop with no integral term, so the engine settles wherever fuel balances friction and nothing takes the standing error back out. The flywheel is 25 kg·m², well under the real thing, where a 400 kg disc a metre and a half across comes to roughly 112 kg·m². That gap says this model's combustion torque at idle is thin rather than that the flywheel is wrong.

Things to try

• Bore reaches 200 mm here and Stroke 250 mm, against 120 mm each on an ordinary preset, because Free Roam's wider table covers this engine and six others. Drag either one and the voice moves while you drag: cylinder volume sets how deep the exhaust pulse sounds.
• Flywheel is 25 kg·m². Put it at 40 and the climb from first fire to idle crawls, still under 400 rpm five seconds in. Put it at 12 and the same climb is past 600. The idle speed itself does not move, since the fuel rate alone decides that.
• Redline is 2,100 and the slider will take it to 9,000. Friction is charged on mean piston speed, and a 190 mm stroke is doing 13 m/s at the standard limiter, so every rev you add costs more than the one before it.

Seen in

Komatsu mining haul truck

Same layout

The QSK60's own market: ultra-class haulers such as the Komatsu 930E, plus standby gensets, locomotives and ships. This truck's badge names the make, not the model, so it stands for the class.

Photo: Giovanni Spoletini · Pexels

Caterpillar mining haul truck

Same layout

Same layout, different engine: the Caterpillar 3516 is a 16-cylinder V diesel of much the same size, hauling in the Cat 793 and running gensets everywhere else.

Photo: omid roshan · Unsplash