EMD 16-645-E2 engines. 2Strokes, the only GM product I willingly work on. Probably my favorite engine of all time.... it is just so well designed to be serviced in place. I feel we can sail around the world with just a few parts.
4 exhaust valves per cylinder, no intake valves. The center spring is for the injector which is still controlled by a manual rack because tier 0 is the best tier.....
The rockers you see have three springs each (so 6 exhaust springs for four valves). The center spring is a stabilizer for the bridge. The excessive clicking you hear in the video are from the rockers. Despite being an overhead roller cam the rockers have what we call "poppers" on the valve tip end. They are essentially hydraulic lifters of sorts and with a lil rpm they fill with oil and take up valve lash. Of course these engines currently have 50,000 hours since the last overhaul so they don't really pump up until they've been running for awhile. Engines themselves were installed in place in 1976 and have only had overhauls every once in awhile, typically dictated by lube oil consumption. With a fresh build they will consume 7 gallons of lube oil a day each, we typically rebuild them when they start consuming 40+ gallons a day. Seems like a lot, but at full steam we burn upwards of 4,000 gallons of #2 a day. Realistically at cruise we burn 2500-3500 depending on what we are towing.
and yeah, doing a valve adjustment on a V16 when you have to set the gap on 7 things per cylinder is a little tedious.
intake ports look a little like this:

I just did the valve cover seals, they don't use gaskets, they use a 16 ft long rubber cord... doesn't seem like a big deal until you do 8 of them

