rev up your engines, today I'm gonna talk about timing belts versus timing chains
inside your car's engine, now for most internal combustion engines the
crankshaft which the Pistons are connected to spins around and that's
connected to the camshaft which opens and closes the valves, and there's
various ways you can connect it, now a long time ago in my grandfather's day
the early engines they didn't even use timing belts or timing chains, they had
timing gears, the bottom crank had a gear and then gears went to the camshaft
which spun the camshaft and then push rods open and closed the valves, now that
was a solid reliable system, you had gears connecting them, but that two main
disadvantages, one it costs a lot of money to make good gears to put that
together and the gears themselves had a tendency of making whiny noises that
people didn't like, so then instead of having gear on gear to spin it
they decided to use a timing chain and these engine designs the crankshaft
sprocket teeth on it, then a timing chain, then another sprocket with teeth that
ran the camshaft all the old American v8 engines were made that way and some of
them are still that way, you can see these are thick hardy change this one
came off a 350 Chevrolet they're really strong they lasted off a long time but
of course it costs money to make hard steel sprockets and expensive chains
so they gave the idea of the timing belt instead of a timing chain, the pulley on
the bottom of the crank and the pulley on a camshaft was connected using a
rubber base timing belt and contrary to what people might try to tell you, the
only reason they went to tiny belts it's cuz it's cheaper to make them when you
have a sprocket that uses a timing chain it has to be really strong steel, but the
sprockets that run these rubber base timing belts they can be a lot softer
because they're just pulling rubber they're not steel, so most of the
manufacturers switched over the timing belt, now with a car like this Toyota
that's well designed a 94 Celica, those rubber timing belt sometimes could last
hundreds of thousands of miles they'd tell you to change them every one
thousand or 90 or so, they were pretty reliable in the Toyota engine and
there's one big advantage of this design almost every Toyota engine ever made is
a non-interference engine, so off the timing belt breaks the Pistons don't hit
the valve and do any damage, but when you take cars like many of the Nissans, they
were a faster engine racing design, so the Pistons went higher and the valves
came lower, so if those rubber belts ever broke when you're driving on the highway
the Pistons hit the valves they break the engine and destroy the
engine, I've seen many people in the past few decades with these timing belt Nissan's
have the belt brake ruined the engine and they said, you're telling me that this
$30.00 belt broke made out of rubber and it destroyed my engine, I'll never buy
another Nissan, well then respond to this Nissan was one of the early companies to
go from timing chains on their cars, to timing belts and then back to timing
chains, so that they wouldn't have this problem and unfortunately for Nissan and
the people who bought them, a lot of those early switchover that went from
timing belts to timing chains had problems with the timing chains cuz
Nissan made them kind of poorly, but the idea was correct and now many
manufacturers have switched back to timing chains and the main reason for that is the
higher design capacity of smaller engines, they're making smaller engines put
out more horsepower, putting variable valve timing and other things inside and
that strains the timing belt so much that the rubber timing belts would have a
tendency of breaking too often and to get added horsepower to these smaller
engines, a lot of the manufacturers had used to make non-interference engines
are now making an interference engine but since they have a sturdy steel chain
that's driving it, they don't have the problems of a rubber belt snapping, take
this matrix it's twelve years old, it's got a timing chain inside the engine
never had a problem, as quiet as can be, and runs just as good as it did when it
was brand new, because really steel chains, they beat
the heck out of a rubber base timing belt
any day of the week if the chains are made correctly, and I know some guys maybe
motorcycle guys are gonna say, but Scotty chains need lubrication well guess what
timing chain is inside the engine, it's coated with the engine motor oil it is
inside the engine, so as long as you change your engine oil regularly this
chain is lubricated with nice clean engine oil and
it can last a really long time, rubber hey it falls apart it's over time, it's going
to stretch over time and yeah a chain stretches a little over time but it
takes a lot more time and mileage to stretch solid steel than it does rubber
and sure costs a lot more money to manufacture a chain and build an engine
that way but hey, they're not giving away modern car so you're paying enough money
you really want one that's got a solid timing chain in it, because I doubt
they'll ever go back to making gear driven cams, that just costs way too much
money and as I said earlier it does make a reasonable amount of whining
noise and people want quieter cars, they don't want louder ones, now of course the
rubber base timing belts were really quiet, but in a modern engine they just
wouldn't hold up, with all those extra cams and variable valve timing and GDI
direct injection, there's a lot more pressure, a rubber belt can't take it but
a chain can, so if you're shopping around for a new car hey, I'd make
sure it had an engine with a timing chain and not one of these flimsy rubber
base timing belts, so if you never want to miss another one of my new car repair
videos, remember to ring that Bell!