- Hi, I'm Kyle Smith with Hagerty. Today we are going to
be adjusting a timing on a 350 Chevy small block that happens to be in this
1972 Chevrolet pick up. So today we just need
a couple simple tools, one will be a standard
9/16 open inch wrench, and the other is our one specialty tool that we've needed and that
will be our timing light. And then of course the
wires associated to it. And we'll go into how to use
this one here in just a moment. There's a couple reasons you might need to reset the timing on a give an engine. The first is if you've recently
disassembled the engine or remove the distributor. You want to make sure
everything is back in sync prior to starting it for the first time, or even starting it for the
first time in a long time. The second being if you've
made changes to the distributor or the overall engine set up, such as changing the fuel
that the engine will run on or going from a point style ignition to an electronic ignition style set up. On this engine that were working on today it is an HEI ignition so it
is an electronic ignition so we're not dealing with
points or the well set up today. So, there's two safety considerations that I'll be taking in today. One, I will be wearing safety glasses just in case something were to fly off of the engine while it's running. The second is I have to be
mindful of the mechanical fan. This does have a standard metal flex fan and for me to get my hand caught in that would be a very bad day. If you have electric fans you
still need to be cautious, but less so, most of those
are fairly well guarded, but it's just something
we need to keep in mind. So we'll go ahead and
remove the air cleaner just to make it a little bit easier, both for me to reach the distributor, and for you to see what I'm doing today. So this is a fairly fresh
restoration that we're working on and when we put the
engine in the truck and we got everything initially set up we set on the safe side
which is slightly retarded so it should start, and run, but it's probably going to
run a little bit rough. We'll go ahead and fire
it up and let you guys hear what it sounds like now that it's running just a little bit retarded. (engine rumbing) So you can hear this one, it's
missing just a slight bit. It's running just a little bit rougher than it truly needs to. As we get the timer closer and closer to where it needs to be, it's going to run smoother and smoother, have
a lot better idle to it. So at step one here and the first thing that we're going to do is
actually remove something, and that is the vacuum advance, so you can see here
where the vacuum advance is located on the side of the distributor. There can be many different styles but what it comes down to,
is there should only be one vacuum line running to the distributor, so it will be very easy to spot. So you'll see it's a small vacuum hose that goes to a port on the carburetor, you want to remove this and plug the line so that we don't have a vacuum leak going into the carburetor. The reason we want to
remove the vacuum advance is so that we don't have
any mechanical advance or vacuum advance taking
the distributor over while we're trying to
set that base timing. The vacuum advanced functions while the engine's at higher RPM, or when you lay into the
pedal as you're driving, gives it just a little more
advance so it's peppier. Our next step, or our
second step in this process, we're actually going to
take our 9/16 wrench, we're going to loosen
the distributor hold down that's tucked right here at
the base of the distributor. Most standard Chevy small blocks are going to have the
same 9/16 size wrench. I'm not sure of exactly what it is on Ford so check your service manual and make sure you've got the correct one. This is the last bolt you want
to round off on an engine. As you loosen it up, you'll
want it to where the distributor still holds tight while it's running, but you'll want to be able to move it just a little bit by hand. So you can see as I'm
moving that back and forth, it's still holding in it's place, it's not fully rotating, but
it allows me to move that. Step number three brings
in our first specialty tool and that is our timing light. So there's three connections
that we need to make on this one so it will do it's job. The first one is going to
be this inductive pick up which senses when there
is power going through the number one spark plug wire. So on a small block Chevrolet, on the driver's side, all the
way to the front of the engine is going to be cylinder number one. This is the odd numbers and
those are the even numbers. So we'll mark cylinder
number one spark plug wire and put the inductive pick up on there, and then we have to power the timing light with our standard two leads, so we will go the negative terminal and the positive terminal on the battery. So there are many different timing lights available for sale. This one does have the
option that you can adjust exactly where you want the timing to be, and then you adjust so the timing marks line up at zero degrees. I prefer to use this marked to zero, so it's just flashing exactly when the spark is going through
that spark plug wire, and then I use the marks on the engine. It really depends on how
your engine is set up, or what your preference is, there's many different ways to do it,
this is just my method. So what we are actually going to be using to time the engine is these
teeth marks right here that come off of the timing chain cover, and then there will be a mark on our harmonic balancer or
the main engine pulley. As the timing light flashes with the spark going to the number one cylinder, it's going to show where the mark is on the harmonic balancer
against those marks coming off the timing cover. Those marks are going to tell us exactly where the timing is set. So whether it be 10 degrees before or advanced or after or retarded, we'll be able to rotate the distributor to adjust where that mark is hitting, where that spark is
arriving in the cylinder. (engine roaring) So what I was adjusting that to and our actual timing marks, I wanted about 12 degrees
before top dead center or 12 degrees advanced. We were looking at the
timing marks coming off of that timing cover to
the marks on the balancer and you can hear the engine
smoothed out significantly, just by bringing that
into where it needs to be. Look it up in your factory service manual where you need to adjust it to or consult a professional engine builder if it's a custom application. At this point you might
be thinking to yourself, "Why is timing so
important and shouldn't I "just go one direction over the other? "Or even, why don't I just
align it at straight up "to where the spark is
arriving at top dead center." Now there's a couple things
to discuss with that. So when were looking
at it too far advanced or too far retarded for when
the cylinder is getting a spark can both have negative consequences. One, however, is worse than the other. If you retard the spark too much, the engine will struggle to
run, even if it runs at all, and that's simply because the piston is already on its way down
through the combustion stroke, when that cylinder is being ignited. That means it does not have
sufficient time to burn all the air and fuel, it's
not maximizing the potential of that compressed air and fuel. On the opposite side, if you
have it too far advanced, what's happening is, you are detonating all of the compressed air and fuel before the piston has
reached top dead center and that means essentially, the engine is now fighting itself, it's a quick way to end up with holes in pistons or some really nasty cylinder heads, especially if you have aluminum heads. Something to be cautious
of, because often times you need to run on the advanced side for a smooth running engine, but too much, is very much dangerous. So now we're going to go ahead and disconnect our timing
light and then we will tighten down the hold
down for the distributor and reconnect our vacuum advance, and then we'll see how it runs. (engine rumbling) Looks like we've got it
running nice and good, idling nice and smooth. If you have any questions,
please leave them in the comments below, and
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