hello everyone and welcome in this video
we're going to be talking about why
companies like chevy and dodge are still
making push rod engines and you know
these engines tend to get a lot of flack
for kind of being outdated uh but there
are actually some really nice advantages
to them so we're going to get into five
of those different advantages looking at
a disassembled single cylinder pushrod
engine as well as looking at a 3d
printed chevy ls3 v8 pushrod engine okay
so the first advantage i want to talk
about is low end torque because pushrod
engines tend to produce good low end
torque and really all of this comes down
to airflow so pushrod engines are using
just two valves per cylinder that's the
case for the majority of them and while
this does create a challenge for higher
rpm at low rpm it improves your air
velocity so because the air flow is more
restricted at low rpm where that's not
as big of a concern it speeds up the
flow of the intake air now when you
increase the velocity of the intake air
that means the air and fuel tend to mix
better and as a result you have better
combustion and you produce more torque
the next advantage i want to talk about
is just the simplicity of the engine and
it's not always true that something that
is simple will be reliable or something
that is complex will be unreliable but
generally speaking if you can achieve
the same solution with a more simple
design it's advantageous from a
reliability standpoint okay so looking
at the engine here you can see there's
just a single camshaft and it's a very
short distance from what's driving it
the crankshaft so you could have a
geared relationship you could have a
belt or chain but it doesn't have to
travel very far to rotate that camshaft
versus if you're using a dual overhead
cam solution on a v8 engine now you've
got two camshafts above this cylinder
head two camshafts in this cylinder head
so four total and that means four drive
gears so two drive gears on each end and
it requires you using two separate
chains so one chain for this cylinder
head and one chain for this cylinder
head so you can see that this is a much
simpler solution than a dual overhead
cam head on a v8 engine now the camshaft
design leads us to our next two
advantages which are both size and
weight so as you can imagine just using
this single camshaft down low in the
center of the v rather than up here
imagine having two of these camshafts
now placed at the top of the cylinder
head so this cylinder head is
significantly smaller than on a dual
overhead cam v8 engine and as a result
not only is this engine not as wide as a
dual overhead cam engine but it's also
not as tall now having an engine that's
generally more narrow and shorter than
dual overhead cam engines gives you more
freedom within your engine bay and so
whether that's improving the suspension
design with more room or pushing the
engine further back in the engine bay
because there's the space to do it to
get that center of gravity towards the
center of the car there are advantages
of having this engine smaller in size
now the smaller size of these pushrod
engines often means that they weigh less
than a similar displacement dual
overhead can b8 engine not always the
case but usually these are on the
lighter end and also it's important
where that weight is so you've got the
camshaft down low you don't have the big
dual overhead cams up on top so the
center of gravity of the engine is lower
and also because the engine is shorter
in overall height it means you can place
it lower within the car so you can get
the center of gravity of the engine
relative to the car much lower with a
push rod design than using a dual
overhead cam design and finally our
fifth advantage of these push rod
engines is cost and so in an interview
in 2004 between car and driver and gm's
chief engineer for the small block
engines the engineer estimated that
their engines are about 400
less per engine versus a dual overhead
cam design and 400 may not seem like a
massive amount but when you start
multiplying that across tens of
thousands or hundreds of thousands of
engines you start to realize how much
money can be saved by using a simple
design like this ultimately the
advantages of this engine its low end
torque its simplicity its size and
weight and of course its cost help keep
it alive in today's cars so if you
enjoyed this video i will include links
to some other videos that you may find
interesting and if you have any
questions or comments of course feel
free to leave those below thanks for
watching