DOHC respect
DOHC basic respect 101:                                


Double over head cam respect , that is what you have ,when you learn that most are INTERFERENCE, ENGINES. Not a complete list is here.
So, if your engine stalls, don't just keep cranking away, and bend over all those head valves or worse. THINK  ABOUT what you have there!

CAM drive failure:
The timing belts snaps slips or? shreds? oops.
The cam chain jumps off the sprocket, by only one hydraulic chain tensioner failure (ignoring its cry, was your doom and very $$$$ thin wallet)
DOHC +VVT , IS DOUBLE TROUBLE, you can Google and read about that for weeks, (lots of sad owners, world wide)
Some DOHC are safe, like Mazda's  fabulous 1.8L liter engines. But all Honda's smash.

DOHC 101:

Interference engine 101.

VVT:

Short and sweet,  it's not new information .
The FSM or all cars (chapter on your engines, covers this topic 100% read it) It may be at alldata.com  too.

Why does DOHC do this and SOHC engines not. (mostly)
EASY:
DOHC engines are designed from maximum performance per liter displacement.  (this ,magic timing gets more exhaust out of the cylinders, and makes compression more effective during the intake stroke)
As does valve overlap.
This means it may have 4 or more valves per cylinder and a 2nd cam, and VVT and now the key part, to get max pumping efficiencies
This tricky timing, makes the piston chase  the exhaust valve closed, closely, so close in fact, that if the cam drive fails, the piston will hit the valves and bend them.
 (some are lucky and it just stalls, and no bend, pure raw luck)
Luck happens, like walking across a turn pike , blind folded?  (getting killed), what is the point of  discussing pure luck, as so many do.  Silly to the extreme , IMO.
The comment, gee my chain can't fail, below 200k miles design limits, really? with oil filthy oil , running 20k on oil changes for SYN oil hype,  and did you know the hydraulic tensioner on many engines don't last 200k?
See VVT failures (cause and effects) Google that when bored.
No matter what, the savvy mechanic, hand turns the crank (wrench) and does a cylinder leak down test to make sure the valves are not hitting and that they are not bent leaking like mad.
Cranking it willy nilly only bends more valves, or far worse, there is no limit to the damage caused, if you try harder.

Some engines not inference can bend valves, if the lash is set wrong, or that and engine overheated.
They have like 0.020" clearance, and if lash is wrong, off by that amount , bam you bend valves.
So there are lots of ways to mess up a soup sandwich, no?  (a comedy of errors by DIY mech.'s can happen (timed wrong and lash way off?)
Keep in mind cold engines work different that hot or too hot.  (thermal expansions , and pure physics)
That is all I have on this topic, but I do respect all DOHC engines. (leak down tests done or valve drive noise big time)
Keep in mind 2, that some engines,world wide run a differnent cam profile and are different than yours (height of lobes and timing) So, respect them all, and win.
Respect means.