timing question

[PlayingWithTBI]

just put a new timing set distributer and full tune up on my 98 5.7. Timing marks are lined up and rotor points directly at cyl 1 on the cap. I couldnt get it to start. it was acting like it was out time. i quadruple checked everything. still couldnt figure it out. Knowing it was set exactly how its supposed to be but acting like it was 180degrees out. I went ahead and turned the distributer 180. Crazy enough she fired right up and purred like a kitten. Can somebody explain this? I talked to some other mechanics and said they had run into the same thing before

Crankshaft turns 2x for every turn of the camshaft and thus distributor. Timing marks on the balancer could align to TDC #1 or in your case TDC #6. Common mistake for novice engine builders too. They line the chain up dot to dot and drop the distributor in on #1 then proceed to make fireballs. Dots on the timing set line up, TDC#6, both at the top TDC#1.

As @L31MaxExpress said, but in a different way; When you install your timing set, you line up the crank sprocket and cam sprocket dot to dot. install the timing chain, and you're good to go - with that part. We're not going to get into degreeing the cam in this exercise.

Then turn the crank one revolution (360°) so timing mark on the balancer points at TDC again on the timing cover indicator (crank and cam gears' dots will be vertical). Now stab the distributor pointing at #1.

 

[Hipster]

Just gotta make sure your on compression stroke on number one. I normally pull number one plug and put my finger over the hole and feel for compression building if you get lost in the process, stop turning when balancer marks are lined up. 4 stroke = 2 revolutions to complete one combustion cycle, one TDC is the compression stroke, the other is TDC exhaust stroke. You basically put the dist. in on number one TDC exhaust stroke the first go.

intake, compression, power, exhaust. 4 strokes =2 revolutions =1 combustion cycle

 

[Hipster]

*

 

[Road Trip]

I've got to do this on another engine I've got this week. Its a used motor i'm dropping into another truck of mine. I dont want to make the same mistake again. This motor is sitting on my shop floor and I'd like to have all this done before I go and put it in.

@Schurkey & @PlayingWithTBI & @Hipster are giving you good guidance. Since a picture is worth a
thousand words, thought I'd add the picture that goes with their explanations:

Cam dot at 6 o'clock + Crank dot at 12 o'clock = #6 in firing order (ie: 'dot to dot')
{now turn crank 1 full 360° turn}
Cam dot at 12 o'clock + Crank dot at 12 o'clock = #1 in firing order

You must be registered for see images attach

SBC firing order:
1-8-4-3 (1st crank rotation)
6-5-7-2 (2nd crank rotation)

Note: Cam sprocket is exactly TWICE the size of the crank sprocket, so it takes (2) crank revs = 1 full cam rev.

NOTE: With 2 people, it's super easy to have the 1st mechanic turn the crank over while the 2nd mechanic holds their
thumb over #1 spark plug hole. When pressure is felt, #1 piston is starting on the compression stroke. Continue to
turn the crank until the timing marks line up, and stab the distributor.

NOTE: When working solo it's sometimes hard to do both, so a time-honored
mechanic hack is to use a "TDC Whistle". They work 100%:

You must be registered for see images attach

(Mr. Gasket TDC Whistle part #8016 MRG -- out of stock in several places, supposedly some here: (Amazon)

So a pro working solo would buy this tool and enjoy 100% confidence of installing the distributor correctly 1st time every time.

An amateur on a tight budget who already owns a compression tester with a hose might take the hose off of their compression gauge
and place a balloon over the end, secured with a rubber band. Thread it into #1 cylinder start turning the crank over...balloon starts to fill
= starting the #1 compression stroke.

****

In other words, when the mechanic is shown the dot-to-dot picture in the instructions in order to get the cam & crank phased properly,
that's all that's being accomplished on that step. And as long as the engine isn't turned while all the other parts are reinstalled, then
stuffing the distributor with the rotor lined up with the #6 cylinder and you are good to go.

But in the real world, just as soon as the timing chain is installed the motor is then spun by hand plenty in order to adjust the valve lash.
*Then* the intake manifold is installed, and *finally* the distributor goes in. Given all this, in my decades of working on SBCs, I've never
once lined up a distributor on #6. Instead, once it was time to install the distributor I always always felt for compression on #1 while either
myself or a buddy rotated the crank with a breaker bar.

But with the TDC whistle you can work solo & get this right every time super easy.

To summarize, step #1 is to phase the cam to crank using the 'dot to dot' guidance. Then when it's time to install the distributor,
now we execute step #2 to locate TDC on the compression stroke on the #1 cylinder.
With enough practice feeling for compression just becomes second nature...

Hope this proves helpful --

 

[Hipster]

@Schurkey & @Hipster are giving you good guidance. Since a picture is worth a
thousand words, thought I'd add the picture that goes with Schurkey's explanation:

Cam dot at 6 o'clock + Crank dot at 12 o'clock = #6 in firing order (ie: 'dot to dot')
{now turn crank 1 full 360° turn}
Cam dot at 12 o'clock + Crank dot at 12 o'clock = #1 in firing order

You must be registered for see images attach

SBC firing order:
1-8-4-3 (1st crank rotation)
6-5-7-2 (2nd crank rotation)

Note: Cam sprocket is exactly TWICE the size of the crank sprocket, so it takes (2) crank revs = 1 full cam rev.

NOTE: With 2 people, it's super easy to have the 1st mechanic turn the crank over while the 2nd mechanic holds their
thumb over #1 spark plug hole. When pressure is felt, #1 piston is starting on the compression stroke. Continue to
turn the crank until the timing marks line up, and stab the distributor.

NOTE: When working solo it's sometimes hard to do both, so a time-honored
mechanic hack is to use a "TDC Whistle". They work 100%:

You must be registered for see images attach

(Mr. Gasket TDC Whistle part #8016 MRG -- out of stock in several places, supposedly some here: (Amazon)

So a pro working solo would buy this tool and enjoy 100% confidence of installing the distributor correctly 1st time every time.

An amateur on a tight budget who already owns a compression tester with a hose might take the hose off of their compression gauge
and place a balloon over the end, secured with a rubber band. Thread it into #1 cylinder start turning the crank over...balloon starts to fill
= starting the #1 compression stroke.

****

In other words, when the mechanic is shown the dot-to-dot picture in the instructions in order to get the cam & crank phased properly,
that's all that's being accomplished on that step. And as long as the engine isn't turned while all the other parts are reinstalled, then
stuffing the distributor with the rotor lined up with the #6 cylinder and you are good to go.

But in the real world, the motor is then spun by hand plenty in order to set all the adjustable valve lash set up...then the intake manifold
is installed, and *finally* the distributor goes in. Given all this, in my decades of working on SBCs, I've never once lined up a distributor on #6.
Instead, I always always felt for compression on #1 while either myself or a buddy rotated the crank with a breaker bar.

But with the TDC whistle you can work solo & get this right every time super easy.

To summarize, step #1 is to phase the cam to crank using the 'dot to dot' guidance. Then when it's time to install the distributor,
now we execute step #2 to locate TDC on #1 cylinder. With enough practice feeling for compression just becomes second nature...

Hope this proves helpful --

Guess I need to pillage some balloon's from one of the grandkid's. On the other hand, my thumb is always with me. lol

 

[Road Trip]

Guess I need to pillage some balloon's from one of the grandkid's. On the other hand, my thumb is always with me. lol

Sounds like you & I were shown the ropes pre-OSHA...can't imagine that today they would approve of the use of
thumbs in such a manner. :0)

 

[Schurkey]

Pull a valve cover and look at the rocker arms.

Either the valves for #1 are both fully closed (TDC-Compression) or they're both supposed to be open just a little bit on overlap (TDC-Exhaust.) IF they're open slightly on overlap, and the hydraulic lifters bleed down...the valves could be closed.

Not my favorite method due to the ambiguity of a mild cam and leaky lifters.

 

[Hipster]

Either the valves for #1 are both fully closed (TDC-Compression) or they're both supposed to be open just a little bit on overlap (TDC-Exhaust.) IF they're open slightly on overlap, and the hydraulic lifters bleed down...the valves could be closed.

Not my favorite method due to the ambiguity of a mild cam and leaky lifters.

I've always found that way a bit tricky myself.

 

[Hipster]

Sounds like you & I were shown the ropes pre-OSHA...can't imagine that today they would approve of the use of
thumbs in such a manner. :0)

I've been through a few Osha invasions in bodyshops. Turns into an all-day affair from hazmat records down to extension cord inspections.

 

[Erik the Awful]

I know I'm a little late to the party, but a while back I made a video just for this question.

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