Trouble with Timing Chain install 383

[roadrunnerh]

Ok fellas, I'm going nuts. I am trying to not repeat the same mistake twice.
Previously, I F'ed up 383 assembly. I had my timing marks at 12 and 12. Pulled motor, opened her up after running like crap.
Ok - now trying to get the ignition timing correct.

Currently, Heads are off, #1 piston at TDC, cam installed, crank and cam sprockets installed, chain off.
I understand that when the timing mark in the crank sprocket is at 12 O'clock
And the mark on the cam sprocket is dead on at 6 O'clock - the timing is set.

But wait, that could be 180* off!
I greased and dropped in a couple lifters for #1 cylinder.
After spark, the next valve to open should be exhaust, right?
After the cam timing mark passes the stationary straight up crank timing mark, the next opening valve seems to be Intake.
BB 906 Head configuration E-I-I-E-E-I-I-E no matter which way.
My first lifter (exhaust) should be first to open after spark which should occur when marks are cam 6 crank 12.

PLEASE HELP!

 

[rickseeman]

Dot-to-dot is all there is. I think you have overthought this.

 

[roadrunnerh]

What about #1 cylinder being TDC? Is it compression stroke TDC or is it exhaust stroke TDC?

 

[Hemirunner]

The cam rotates at half the speed of the crank. The cam will line up with the crank at both 12 and 6 and alternate as you turn the crank. As Rick says, dot to dot works. If it’s a performance application, degree the cam, but that’s another conversation. The 180 out doesn’t come into play until you’re trying to put the distributor in. The easiest way to do that is to watch the #1 intake rocker. Once that valve closes, keep turning until 30 degrees BTDC. Insert the distributor so the number one wire is set to fire. Good to go.

 

[roadrunnerh]

When marks are at 12 crank and 6 cam, you want the spark, right?
The intake valve just closed, now both valves are closed.
Spark
The next valve opening for #1 should be the exhaust, right?

 

[rickseeman]

Dot-to-dot. It doesn't matter what is firing or where the valves are what is at TDC or what opens next. Dot-to-dot.

 

[forphorty]

When marks are at 12 crank and 6 cam, you want the spark, right?
The intake valve just closed, now both valves are closed.
Spark
The next valve opening for #1 should be the exhaust, right?

With marks at 12 crank and 6 cam , #1 is on overlap , #6 is firing.

 

[R413]

Dot to dot on sprockets and the engine is ready to fire #6 plug.

So it's 180 degrees out for #1 at that point without turning crank.

You are making it way to hard on yourself

 

[roadrunnerh]

Thank you all very much for being patient with me.

I was always under the impression that when you establish timing, you want #1 cylinder in compression stroke and your distributor is pointing to #1 on cap.
1991, when I acquired a GTX, I installed a distributor not knowing where TDC was. I pulled plugs, felt compression in #1 with finger, installed distributor and knew I was in timing.

So the dots lined up doesn't occur at that point?

 

[Don67Satellite]

My easy explanation is you install the chain dot-to-dot, at this point your #1 will be at TDC, but on the exhaust stroke, so once you have that, then you rotate the engine until both dots are at 12 o'clock, that brings #1 to TDC on the compression stroke. Then you're not 180 out.

 

[roadrunnerh]

Thanks guys for your patience and for the responses, I truly appreciate them.
I need to step away from the flame at this point. Frustration level higher than enjoyment level, ya know? I'll have to get back to this project.

 

[PurpleBeeper]

I understand that when the timing mark in the crank sprocket is at 12 O'clock
And the mark on the cam sprocket is dead on at 6 O'clock - the timing is set.

But wait, that could be 180* off! NO IT COUDLN'T. THAT IS WHAT'S CONFUSING YOU. THESE GUYS ARE CORRECT. IT CAN'T BE 180 OFF DOT-TO-DOT. THE PIN IN THE CAMSHAFT THAT GOES INTO THE CAM GEAR OF THE TIMING CHAIN MAKES SURE OF THAT. YOU GOT THIS

 

[eldubb440]

rotate the engine in the direction it runs; watch the intake valve on #1

after the intake valve opens and shuts, keep rotating until the timing mark comes up, you're on the compression stroke..........

stop at about 15 degrees before TDC .........

line up your rotor with #1 on the cap and snug the distributor..........

it'll fire right up

 

[R/T Boy 67]

You seem confused by the relationship between the cam timing marks and the ignition timing. I would line up the cam dot to dot. The crank dot at 12 o'clock and the cam at 6 o'clock, then I would bolt the timing cover on and finish assembling the engine. Then follow the instructions in post #13, when it is time to put the distributor in.

 

[Kern Dog]

Put BOTH dots at 12:00.

 

[Mopar Hunter]

Put BOTH dots at 12:00.

??

 

[Kern Dog]

Put BOTH dots at 12:00.

??

The "Dot to dot" setting is with the cam at 6:00 and the crank at 12:00.
EVERY time that I have done this, the engine is on the #6 cylinder firing location. It took me awhile to learn that when I was younger.
I wrenched on many Chevys before I came back to Ma Mopar. The Chevy and Mopar engines do share a lot of similarities. They have the same firing orders, they have siamesed intake and exhaust ports, in the case of the LA and Chevy small block series, even more stuff is similar.
With the crank sprocket at 12:00 and the camshaft sprocket also at 12:00, you're at the #1 cylinder firing location. You need a straightedge to aim through the cam sprocket and to the crank hub to verify that they are both exactly at 12:00. Maybe some just default to the dot to dot and stab the distributor to aim toward #6 because it is easier and the end result is the same anyway.

 

[R413]

Put them close to each other at 6 cam and 12 crank. It makes it very easy to make sure they are lined up.

Now at this point put distributor to #6

Or read and follow post 14 and 13 for #1

Let not make this any harder than it is.

 

[Krooser]

Cam timing and ignition timing are two different things.

Get your cam timed right, assemble the engine THEN look at your ignition.

Don't confuse yourself even more than you are already...

 

[roadrunnerh]

Quick update, back at it today. Suspension and brakes done,



Here's the dot to dot.




moving along, Thanks for reading!