Confused cam timing / ignition timing?

[MylilBowTie]

I'm wondering how would you know if #1 is on compression stroke or exhaust. If the timing chain was taken off and the crank rotated so that the cam gear and crank gear isn't in sequence.

I seen where some line the timing chain up with #6 TDC and #1 TDC what way is better? There was also something about watching the lifters. I have an engine tore down and installing a new timing chain. Took the old off it was really really loose and in the process didn't think about it turned the crank from where it was. So now I'm kind of lost how to get it back where it needs to be.

[87 STEPPER]

Ya gotta start over!

Take off the timing chain cover and the cam gear and chain rotate the crank untill you have #1 cyl. @ TDC both valves should be closed and the piston on it's compression stroke align the crank mark the little dot on the gear with the cam gears little dot as you reinstall it and the chain.

Thats it your done. Now stab the distributor and it should point to #1 cyl.

Now if every thing is correct the timing mark on the balancer should be aligned to the timing pointer and the dist. rotor should point to #1.

I have no clue what your talking about timing an eng. off the #6 cly. iv'e never heard of that one! Not shure why anyone would do it that way theres no advantage to that!

Mechanical timing will not change weather it's done off the #1 cly or any other! what will change is figuering out how to tell if it's in timing like you just found out. you cannot use any of the factory settings or markings because they only apply to timing off the #1 cyl.

[Nolowrider]

This how I do it- Put both gears on (crank and cam) aligned the dots/marks (cam at 6 o'clock and the crank at 12). Install the chain and then rotate the entire assy 360* (both dots now at 12 o'clock)then drop the dizzy in with the rotor button pointed at the #1 lug on the dizzy. If you don't rotate the engine 360* and you drop the dizzy in, it will be firing on the exhaust stroke not the intake stroke. If you don't rotate it 360*, then drop the dizzy in pointing to the #6 lug rather than #1 and it has the same effect. Just remember that you are timed on the #6 and not the #1.

[Ric83]

Originally Posted by Nolowrider

If you don't rotate it 360*, then drop the dizzy in pointing to the #6 lug rather than #1 and it has the same effect. Just remember that you are timed on the #6 and not the #1.

Bingo, I think that is what he was talking about. I had to turn my dizzy 180 to get it to work properly or I would backfire trhu the carb.

[MylilBowTie]

I have the intake manifold off, valve covers, timing chain cover, oil pan, and the #1 spark plug out. I'm used to the cam gear at 6 and the crank at 12 on the compression stroke TDC with #1 piston. But I seen a post where it was actually timed on #6 at TDC? Or maybe it was that if #1 was on exhaust stroke it has to do with something about #6.

So if I did everything right #1 cylinder both lifters will be down in there bores (valves closed). #1 Piston will be at TDC cam gear will be at 12:00 and crank at 6:00? Then I'm done with the timing chain part and can start putting everything back together. I have the engine on a stand right now. I was looking it over really good before I installed it.

I'm going to see what I can get done. Thanks for the help

[swervin ervin]

Use this article to help you get everything right. It's a article I wrote on removing and installing a cam, but most of it will apply to what you are trying to do.

Oops. Forgot the link.

http://www.73-87.com/7387garage/drivetrain/cam2.htm

[piecesparts]

I am reading that you have a camshaft and crank that are NOT in time with each other. The timing chain is not connecting the two of them. Am I correct? If that is the case then you will have to align the timing of the gears on the camshaft and the crank. If you have the timing chain cover off, then you will see a dot or "dimple" on the crank timing chain gear and the same on the camshaft gear. Those marks NEED to be aligned with each other (crank at 12 o clock and the cam at 6 o clock), when you put the timing chain on the gears. This is done by taking the camshaft gear off of the camshaft and hanging the chain on the gear and then putting it around the crankshaft as you put it back onto the camshaft and tighten the bolts.

NOW, that you have the cam and the crank in "Time" with each other you can turn the crank to get the #1 cylinder up to the top of the stroke and both of the valves are closed (the rocker arms will be slightly loose). (Pulling all of the plugs out will make this effort easier) (Make sure the harmonic dampener is sitting at the TDC mark on the timing tab) Put everything back together and drop the distributor in with the #1 cylinder at the top and the distributor rotor should set pointing at the position the #1 cylinder wire will attach.

[MylilBowTie]

Yes I removed the camshaft gear and the chain that links the cam and crank together. I then turned the crank over not thinking about the timing chain not being installed. So I was thinking as long as the piston is TDC that I would be good to install the timing chain. Then I started thinking that I didn't know if it would be on a exhaust cycle or compression doing it that way. I know that the camshaft gear turns one revolution to the crankshafts every four.

So I started thinking and pretty much lost confidence that I knew how to get things back on track.

[MylilBowTie]

I got the camshaft gear and crankshaft gear in phase. The camshaft gear at alignment dot at 6 and the crankshaft gear at 12. I put a piece of tissue in the sparkplug hole of the #1 cylinder. Turned the crankshaft clockwise one revolution. The tissue blew out of the sparkplug hole. Both the lifters for #1 are down in there bores with the intake lifter a hair higher than the exhaust. Crankshaft gear is at 12 and the camshaft gear is at 12 also.

So sounds like I'm good to go far as the timing chain installation is considered?

[MylilBowTie]

Second thought with the ignition. When I install the distributor where do I want the rotor to point in relation to the sparkplug wire tower. Do I want them to be aligned center of the metal rotor contract with the center of the tower or just in the contact area?

[swervin ervin]

Now, at where you have the cam timing, if you drop in the distributor, you will have exactly zero degrees of ignition advance. Best way to get the ignition timing right is to install the balancer and once again rotate the engine, two revolutions. Well, almost two revolutions but on the second one stop the mark on the balancer at like 10 degrees BTDC on the pointer. Then drop in the distributor and line up the rotor with the #1 tower. This way it will have 10 degrees of advance and it should start right up with no wasted cranking.

Don't forget to check the ignition timing after you get it running with a light though.

Oh, btw. You have to rotate the crank two revolutions (720 degrees) in order to rotate the cam one revolution (360 degrees).

Mike

[MylilBowTie]

Okay I turned the crank over once with the alignment dot going one full turn. So who many times would I need to turn in now to set the timing? One more from where it is now? I haven't moved it since I installed the timing chain just a little bit ago.

[swervin ervin]

So you had it at 6 for the cam and 12 for the crank and you've now turned it once, right? If this is right, the dots on the gears will now be at 12 for the cam and 12 for the crank since you have rotated it once, which is TDC on #1, which is also exactly zero degrees of advance at the distributor. So now, rotate the crank one more full turn and then almost one more but stop the balancer mark at 10 degrees BTDC on the pointer and drop in the distributor. Line the rotor up with the #1 tower on the cap and you will be good to go. This will give you and initial advance of 10 degrees BTDC. It should start right up with no cranking. You can then set it to whatever you normally run it at with a light. Don't forget to plug the vacuum advance hose before timing with a light.