454 Firing Order/Distributor alignment

[1970BannerBlazer]

Need help with understanding the correct firing order and distributor alignment for a 454. Is there ever a scenario where #1 on the distributor doesn’t point to #1 cylinder?

My internet searches say no.

This is my first 454, came installed in my 1970 Blazer. Was trying to diagnose some rough idle/backfire situation and noticed that the #1 on the distributor isn’t pointing at #1 cylinder like I have experienced on every other engine I have had.

I can’t upload a photo but here is how the distributor is setup now.

#3 points at cylinder #1
Then going clockwise it’s
6
5
7
2
1 in the back and points at the driver
8
4

Engine runs, just not great. The person I bought from didn’t really know what they were doing so I’ve had to fix a lot already.

Thoughts?

[Dead Parrot]

On a non-computerized motor, nothing in the distributor cares which post is called #1. As long as the timing is correct and the firing order is correct, it will work. Fairly common for the designated #1 to change when a distributor is pulled. The person doesn't note where the rotor is pointing before pulling and/or the motor gets turned while the distributor is out. Then when things are put back, they have to move the wires to match the new #1. Not having a long enough screwdriver to adjust the oil pump shaft before installing the distributor can also lead to #1 being moved.

One side effect of moving #1 is if the wires are a close match to the 'proper' #1 position, one or more of the wires may be stretched and touching things they shouldn't touch, like headers or exhaust manifolds with resulting burn through. Could be why there is a miss.

Park the truck where it is dark, let your eyes adjust to the dark, start the motor and look for blue sparks. Also check the distributor cap for blue sparks on the surface which indicate a bad cap.

[RustyPile]

The firing order of the wires is correct, they're just not in the "normal" position. Nothing wrong with that. Except for routing issues explained by Dead Parrot, you should be fine.. In fact, rearranging the wires and resetting the distributor might create additional problems for you.. Concentrate on correcting the bad running problem. Get that sorted out and then if your OCD acts up, Locate TDC #1, remove the distributor and reset the rotor to the "normal" #1 position. Pull all the spark plug wires and re-install them in their new location.. Hook up the timing light AGAIN and set the timing.

Me??? I don't like making extra work for myself.. I'd leave the wires and distributor in their present arrangement and concentrate on the run problem...

[AussieinNC]

Here is the method I have always used to install and time the distributor on any Chevrolet V8 Points or HEi based ignition system.

Firing order is 18436572, with odd numbered cylinders on drivers side starting at front of engine.

1/ Remove the coil lead into the distributor cap or remove the power feed plug for the HEI system.

2/ Remove the cylinder #1 spark plug.

3/ Have someone pulse the ignition switch over while yu hold you finger against the cylinder # 1 plug hole, to feel the compression build.

4/ When you feel compression building, manually turn the crank clockwise until the timing line on the balancer aligns with the timing tab.

5/ Remove the distributor cap and note where the rotor button arm is pointing.

6/ The rotor arm should be pointing at the # 1 cylinder location.

7/ If its not, at this point you have two choices, (a) remove the distributor and turn the rotor arm so that when installed it points to the #1 cylinder or (b) note which cap post the rotor end is pointing to and use that as #1 lead location. I prefer to use (a).

8/ Install the plug leads in the cap posts starting with #1 and in clockwise direction using the firing order 18436572.

9/ Reinstall the spark plug and coil lead or HEI power supply plug.

10/ Start the engine and set timing as specified. Remove and plug the vacuum advance hose. To advance the timing, rotate the distributor should be rotated slower anticlockwise.

11/ Once timing is correct, make sure to lock down the clamp bolt so the distributor cannot rotate.

12/ Make sure vacuum advance hose is reconnected to the distributor.

Hope this helps.

[GASoline71]

Sounds to me like someone tore it down far enough they had to "line up the dots" on the cam and crank sprockets. Like a cam swap or a rebuild. This puts the engine at TDC on the #6 cylinder. So instead of just turning the engine over to put it on TDC at #1 before installing the distributor. They installed the distributor and had trouble getting it to run. So they just moved the wires around on the cap.

Gary

[1970BannerBlazer]

Thanks all. I’ll keep it they way it is for now and try to track down the real issue.

The shaking is getting worse at very low throttle (1000-1200). When I first got it the shaking was very bad but I figured out that the builder didn’t use an externality balanced crank pulley or flex plate. Once we got those in the shaking diminished. Now it’s coming back.

Plugs on the passenger side look very clean, like you wouldn’t have known I had been driving it for a year. Drivers side, #1 is a white lean, #3 dark rich, #5&7 look like the passenger side.

My next stop is the valve train.

[geezer#99]

First thing to do is check and maybe set the timing.
Get that squared away and then adjust the carb.

Any idea what your initial timing is set at?

[kwmech]

Set up is the same as a small block. Pull #1 plug and turn engine till you feel compression coming up. Line up the timing mark at tdc. Pull the dist and set it with #1 where it belongs and roll from there. Start it and set the timing to about 6 btc to start things out.

[Dead Parrot]

You have 6 plugs that look good. Two adjacent ones that don't. Test the intake runners and gaskets for 1 & 3 for vacuum leaks.

Check the #3 wire for cracks and burns.

Make sure all the ports on the carb either have hoses or caps.

Make sure the PCV system is working.

Re-double check that the 1 & 3 wires are not crossed as in 1 going to 3 and 3 going to 1. Easy to do when resetting wires and plugs. Depending on the crossed up cylinders, a V8 engine can run surprisingly well on 6 cylinders.

[geezer#99]

You’ll need to check rocker movement on #3 also due to your rich plug.

[cadillac_al]

Since the timing isn't set up normally, I would question the valve adjustment too. I would get it timed right and do a running valve adjustment and if it still doesn't purr I would do some carb tweaking.

[1970BannerBlazer]

Shakes worse at 1000-1200 rpm.
18’ advance, 33 all in.
All wires are new.
HEI Cap and rotor are new.
I run a carb spacer and it seemed like it was leaking.
Tightened down the carb and spacer (a ton) still “leaking”.
Might be leaking from the head to intake surface.
Opened up the valve covers. Non adjustable rockers. Looks stock.
I’m used to Mopar rockers.
All rockers bolts where tight as can be. (Seems like it’s either all the way down or nothing with these stock bolts.
All push rods could be twisted with fingers.
Few of the rockers were sitting quite a ways off the center of the valve.
But since the rockers don’t have a centering mechanism I don’t see what I can do about this.
Rockers had lateral play by hand.

[geezer#99]

Is that 18 initial checked near 700 rpm and with vac advance plugged off.
With 33 all in that means you have 15 mechanical timing.
What method did you use to limit the mechanical in the hei?

The adjustment for the rockers is the big nut right in the rocker valley. They’re supposed to be tight enough not to move once set but are never tightened down all the way.

You got pics of your rockers, pushrods and springs?

[RustyPile]

Originally Posted by 1970BannerBlazer

Shakes worse at 1000-1200 rpm.
18’ advance, 33 all in.
All wires are new.
HEI Cap and rotor are new.
I run a carb spacer and it seemed like it was leaking.
Tightened down the carb and spacer (a ton) still “leaking”.
Might be leaking from the head to intake surface.

Sounds like you might have some mechanical issues with the engine.
Opened up the valve covers. Non adjustable rockers. Looks stock.

Rocker arms ARE adjustable. The nut in the middle of the rocker arm is where the adjustment is made.

I’m used to Mopar rockers.
All rockers bolts where tight as can be. (Seems like it’s either all the way down or nothing with these stock bolts.
All push rods could be twisted with fingers.

The nuts are special nuts. The threads are slightly distorted so that they will not turn freely, must use a wrench. This is so that, once the adjustment is set, the nut won't back off.. The design does not require the nuts to be "bottomed out" on the rocker shaft. The proper adjustment 'preloads" the lifter and the pushrod won't easily turn by hand.

Few of the rockers were sitting quite a ways off the center of the valve.
But since the rockers don’t have a centering mechanism I don’t see what I can do about this. Rockers had lateral play by hand.

Guide plates are used that straddle the pushrod. This centers the rocker arms on the valve stem. Without these guide plates, the rocker arms will wander all over the valve stem. The rocker studs pass through the guide plates and bolt to the head..

Problems with any of the stuff I mentioned could be the cause of your bad running..

[nikwho]

Engine doesn't care where the distributor points. I would verify TDC and verify where the timing mark coordinates with your timing tab. Firing order is 18436572. Doesn't matter where you start.

Then, I'd adjust all of the valves. I typically twist the pushrod back and forth on the valve that I am working on. I slowly Tighten until I can JUST feel a change in pressure. You can also wiggle the pushrod gently up and down, and Tighten until the slack is out. I then will put an additional 1/2 turn of preload on the valve, and lock it down.

I use the "EOIC" (Exhaust opening, Intake closing) method. To set lash on Intake, Rotate the engine until the exhaust pushrod on the #1 cylinder begins to move upward. Look for any rocker arm movement. This is the start of the exhaust valve opening. At this point, you can adjust the intake because the intake valve will be closed, ensuring that the intake lifter is on the base circle of the cam. Then, after I adjust #1 intake, I rotate the engine (clockwise from front, counterclockwise from drivers seat) and look for exhaust rocker deflection on #8 exhaust valve, then adjust #8 intake. I repeat this for 4, 3, 6, 5, 7 and 2, in that order.

Then I move on to adjust tye exhaust valves. To set lash on exhaust, rotate the engine again until you see the #1 intake valve open to full lift and just begin to close. Again, watch for the first sign of rocker arm movement. You then can set lash for #1 exhaust. Then I move on to 8, 4, 3, 6, 5, 7 and 2.

If your in a rush, there's other ways that allow you to adjust more valves at a time, but this is very simple, and accurate. Actually, you can adjust any four stroke engine valves this way! I adjust valves on my KTM motorcycle the same way!

Once I verified TDC, set timing and lashed all of the valves, I would get a can of ether (starting fluid) and spray it around anywhere you suspect may have an intake leak! If there's a vacuum leak where you spray, there will be a sudden increase in engine RPM.

If this doesn't resolve your issue, you may have a leak in your intake manifold. So, you might have to pull your intake and re-seal that up.

If you have to pull the intake, I'd go ahead and inspect the tappets one at a time, to verify that you aren't starting to flatten a cam Lobe. The one time I've flattened a cam, it started off feeling/sounding like a bad tune, and I couldn't get it to run without a bunch of timing advance.

Good luck!

[1970BannerBlazer]

Originally Posted by nikwho

Engine doesn't care where the distributor points. I would verify TDC and verify where the timing mark coordinates with your timing tab. Firing order is 18436572. Doesn't matter where you start.

Then, I'd adjust all of the valves. I typically twist the pushrod back and forth on the valve that I am working on. I slowly Tighten until I can JUST feel a change in pressure. You can also wiggle the pushrod gently up and down, and Tighten until the slack is out. I then will put an additional 1/2 turn of preload on the valve, and lock it down.

I use the "EOIC" (Exhaust opening, Intake closing) method. To set lash on Intake, Rotate the engine until the exhaust pushrod on the #1 cylinder begins to move upward. Look for any rocker arm movement. This is the start of the exhaust valve opening. At this point, you can adjust the intake because the intake valve will be closed, ensuring that the intake lifter is on the base circle of the cam. Then, after I adjust #1 intake, I rotate the engine (clockwise from front, counterclockwise from drivers seat) and look for exhaust rocker deflection on #8 exhaust valve, then adjust #8 intake. I repeat this for 4, 3, 6, 5, 7 and 2, in that order.

Then I move on to adjust tye exhaust valves. To set lash on exhaust, rotate the engine again until you see the #1 intake valve open to full lift and just begin to close. Again, watch for the first sign of rocker arm movement. You then can set lash for #1 exhaust. Then I move on to 8, 4, 3, 6, 5, 7 and 2.

If your in a rush, there's other ways that allow you to adjust more valves at a time, but this is very simple, and accurate. Actually, you can adjust any four stroke engine valves this way! I adjust valves on my KTM motorcycle the same way!

Once I verified TDC, set timing and lashed all of the valves, I would get a can of ether (starting fluid) and spray it around anywhere you suspect may have an intake leak! If there's a vacuum leak where you spray, there will be a sudden increase in engine RPM.

If this doesn't resolve your issue, you may have a leak in your intake manifold. So, you might have to pull your intake and re-seal that up.

If you have to pull the intake, I'd go ahead and inspect the tappets one at a time, to verify that you aren't starting to flatten a cam Lobe. The one time I've flattened a cam, it started off feeling/sounding like a bad tune, and I couldn't get it to run without a bunch of timing advance.

Good luck!

Thanks for this. Yesterday I tried the “running” method for adjusting the lash. That didn’t work so well. Engine ended up dieing. So I moved to hand rotating and working through the exhaust/intake process.

This stock setup is interesting. I see the guide plate for the push rod. The bolts have no lock mechanism on them.

When I adjust the lash out of the rocker and then turn 1/2-3/4 more I can see the rocker compressing the spring a tad. Isn’t the compression supposed to come from the hydraulic lifter? I was doing this on a cold engine so maybe there wasn’t any lifter pressure to be had?

Also, when I provide the 1/2-3/4 turn I can feel the bolt tighten down all the way. The previous owner had them cranked down hard. But I stopped once I felt the bolt start to bottom out.

Fun times. I promise I’m not an idiot when it comes to this stuff. Usually.

[nikwho]

Hmmm, shouldn't feel anything bottom out. The stock rocker arm nuts are slightly out of round, to keep them put, where they're set. You should not be compressing the lifter at all when simply tightening down to zero lash. You are only removing slack, so that the gap between the tappet and the rocker arm never let's the pushrod come off of the tappet or the rocker arm come off of the pushrod. Only the 1/2-3/4 turn for preload should compress the tappet spring.

[geezer#99]

When adjusting for zero lash don’t twist the rod. Wiggle the rocker until all the slack is out.

[nikwho]

There's some concerning things posted in this thread. About rockers being tightened all the way down. Can you post some pictures of your valvetrain? Basically of your rocker arms. If the rocker arms were tightened all the way down, you likely have bent pushrods. Before spending further time trying to set valve lash, I would remove all pushrods, and roll them on a clean, true surface, and look for bends! If you are working with bent pushrods, you're never going to get it right, until they're replace.

[1970BannerBlazer]

Originally Posted by nikwho

There's some concerning things posted in this thread. About rockers being tightened all the way down. Can you post some pictures of your valvetrain? Basically of your rocker arms. If the rocker arms were tightened all the way down, you likely have bent pushrods. Before spending further time trying to set valve lash, I would remove all pushrods, and roll them on a clean, true surface, and look for bends! If you are working with bent pushrods, you're never going to get it right, until they're replace.

You called it. #1 intake was bent. No others. I took this video of them running. https://youtu.be/hFUf48FE2Bg

#1 exhaust is off center. Next startup #1 intake was clacking. I watched the bolt as it started to back out. No other clacking.

Guess I’m ordering a set of stock pushrods.

[AussieinNC]

This engine has the NON adjustable rocker arms !

The "nut" is actually the bolt that holds both the rocker arm in place and the guide plate.
The bolts MUST be tight against the cyl head or they will back out!
It does not have the stud and locking style nut as found on earlier engines.

I would also be looking very closely at the pushrod guide plate groove to make sure its not worn excessively.

Is that engine a roller cam engine?

The reason I ask is if the roller lifter set has been installed "backwards" the pushrods end up off center and usually push the rocker off of the valve tip, and or bend pushrods.

[1970BannerBlazer]

Originally Posted by AussieinNC

This engine has the NON adjustable rocker arms !

The "nut" is actually the bolt that holds both the rocker arm in place and the guide plate.
The bolts MUST be tight against the cyl head or they will back out!
It does not have the stud and locking style nut as found on earlier engines.

I would also be looking very closely at the pushrod guide plate groove to make sure its not worn excessively.

Is that engine a roller cam engine?

The reason I ask is if the roller lifter set has been installed "backwards" the pushrods end up off center and usually push the rocker off of the valve tip, and or bend pushrods.

I have no idea about the engine build. Came with the truck. And from the looks of things so far, I’m willing to bet things are wrong.

Early on I figured out that they didn’t use the proper external balanced balancer and flex plate. Intake bolts were barely tight.

I plan to run the engine until it fails but try my best to keep it running.

[AussieinNC]

I reviewed the video closer and enlarged the image...the engine is a flat tappet cammed Mark V engine...454, non adjustable rockers.

Replace the bent pushrod/s and make sure the guide plate is not wollowed out where the pushrod runs....

Slowly tighten the center bolt holding the rocker in place then start the engine and allow it to run for 5 mins...it should smooth out and idle correctly.

The balancer / flexplate issue is not really a big issue so long as the vibration is not too bad.

Longevity may be an issue, but in street driver you may not even feel the imbalance.

[1970BannerBlazer]

I’m measuring my pushrods as:
Intake: 5/16” x 8 3/16”
Exhaust: 5/16” x 9 5/32”

Does this sound correct?

The openings on the guides have been altered/cut. The current opening range upwards of 1/2”

[AussieinNC]

Replace the guide and both pushrods.

Those measurements sound correct.

I would be checking the other bank as well for misaligned rockers....the guides are usually the culprits...