Timing ( dumb question ) and heat riser valve.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Timing ( dumb question ) and heat riser valve.
OK, hopefully 2 fairly easy questions....
The heat riser valve on a non running engine, is it open or closed? The vac supply to mine is capped off at the mo and just want to make sure its open without vacuum applied or vice versa. The rod can be pushed in by hand from this position.
Second one, timing....if timing mark on balancer is aligned with timing tab, rotor is pointing pretty much to cylinder 1 lead, we are in the correct position to start getting the timing dialed in.
Thanks.
The heat riser valve on a non running engine, is it open or closed? The vac supply to mine is capped off at the mo and just want to make sure its open without vacuum applied or vice versa. The rod can be pushed in by hand from this position.
Second one, timing....if timing mark on balancer is aligned with timing tab, rotor is pointing pretty much to cylinder 1 lead, we are in the correct position to start getting the timing dialed in.
Thanks.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Can't help with the heat riser- I haven't had one in many years.
The timing mark- your picture shows that it is in the 0 degree position, but it could be either in the firing position for #1 or #6. Confirm by removing either the #1 spark plug and bumping the engine over until you feel compression at the plug, or by observing the rockers to see if both valves are closed. The common place for the rotor to point is the left front when #1 is on the compression stroke.
The timing mark- your picture shows that it is in the 0 degree position, but it could be either in the firing position for #1 or #6. Confirm by removing either the #1 spark plug and bumping the engine over until you feel compression at the plug, or by observing the rockers to see if both valves are closed. The common place for the rotor to point is the left front when #1 is on the compression stroke.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
With regards to the timing question, I had the marks lined up as per the picture and the rotor was pointing towards the no.1 tower or there abouts. If the distributor was installed a tooth out, what would the symptoms be?
She starts and runs fine but with a timing light on zero, the mark is about 2 1/2 inches down towards the drivers wheel. As I adjust the timing light higher ie advance it, the mark moves further away from the timing tab.
I thought the balancer may have slipped but im wondering if it's possible that I installed the dizzy off a tooth.
Would it run a tooth out or is that not a possibility.
She starts and runs fine but with a timing light on zero, the mark is about 2 1/2 inches down towards the drivers wheel. As I adjust the timing light higher ie advance it, the mark moves further away from the timing tab.
I thought the balancer may have slipped but im wondering if it's possible that I installed the dizzy off a tooth.
Would it run a tooth out or is that not a possibility.
Instructor
Joined: Mar 2013
Posts: 108
Likes: 1
From: Georgia
Jotto
Your dizzy will run a tooth off but you have to compensate by moving it counterclockwise to advance it or clockwise if it is a tooth off the other way. The problem is your vacuum advance will either be way back or too far forward. Make sure your vacuum hose is not on the advance when you set the timing.
Here is another problem. Let’s hope your timing chain hasn’t jumped a tooth. I have seen cars run like this but you will notice a big performance problem.
Your dizzy will run a tooth off but you have to compensate by moving it counterclockwise to advance it or clockwise if it is a tooth off the other way. The problem is your vacuum advance will either be way back or too far forward. Make sure your vacuum hose is not on the advance when you set the timing.
Here is another problem. Let’s hope your timing chain hasn’t jumped a tooth. I have seen cars run like this but you will notice a big performance problem.
Instructor
Joined: Mar 2013
Posts: 108
Likes: 1
From: Georgia
jotto
As for the heat riser, check the position with the motor cold and with it hot. I am pretty sure it just operates with a spring movement according to heat. If I remember right the vacuum line is to open it up when someone hammers down on the gas and the motor is still cold.
Just check it cold and hot and see if the position changes. If it does, you are good to go.
As for the heat riser, check the position with the motor cold and with it hot. I am pretty sure it just operates with a spring movement according to heat. If I remember right the vacuum line is to open it up when someone hammers down on the gas and the motor is still cold.
Just check it cold and hot and see if the position changes. If it does, you are good to go.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
I did try moving the dizzy to get the mark to line up but it died as its obviously too far out of whack.
When I connect the vac advance, it runs like cr*p. Without vac advance, idle is smooth but when connected it runs a little rough.
Need to verify TDC to get this sorted. Supposed to have a test here tomorrow to check car is road legal etc but may have to cancel if I dont get this sorted before hand.
The heat riser is disconnected....
Need to find out if its normally open or closed so i can either leave as is or wire open.
TIA.
When I connect the vac advance, it runs like cr*p. Without vac advance, idle is smooth but when connected it runs a little rough.
Need to verify TDC to get this sorted. Supposed to have a test here tomorrow to check car is road legal etc but may have to cancel if I dont get this sorted before hand.
The heat riser is disconnected....
Need to find out if its normally open or closed so i can either leave as is or wire open.
TIA.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I did try moving the dizzy to get the mark to line up but it died as its obviously too far out of whack.
When I connect the vac advance, it runs like cr*p. Without vac advance, idle is smooth but when connected it runs a little rough.
Need to verify TDC to get this sorted. Supposed to have a test here tomorrow to check car is road legal etc but may have to cancel if I dont get this sorted before hand.
The heat riser is disconnected....
Need to find out if its normally open or closed so i can either leave as is or wire open.
TIA.
When I connect the vac advance, it runs like cr*p. Without vac advance, idle is smooth but when connected it runs a little rough.
Need to verify TDC to get this sorted. Supposed to have a test here tomorrow to check car is road legal etc but may have to cancel if I dont get this sorted before hand.
The heat riser is disconnected....
Need to find out if its normally open or closed so i can either leave as is or wire open.
TIA.
open for normal use.
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Instructor
Joined: Mar 2013
Posts: 108
Likes: 1
From: Georgia
Don't cancel yet, just start from the beginning. Pull the #1 plug and have someone bump the motor over while you have your finger over the plug hole. Air will start pushing by your finger. This will be your compression stroke. Then bump it very slowly to the top dead center. Check the dizzy. It should be pointing at the #1 plug hole position.
If not pull the dizzy up and readjust. You may have to take it out and turn the oil pump with a long screwdriver in the bottom of the hole. A big flat head screw driver will work just fine. Most of the time this is what prevents the dizzy from sitting all the way down.
After that put the #1 wire where the dizzy is pointing and check all your wire to make sure they are not cross-wired.
If not pull the dizzy up and readjust. You may have to take it out and turn the oil pump with a long screwdriver in the bottom of the hole. A big flat head screw driver will work just fine. Most of the time this is what prevents the dizzy from sitting all the way down.
After that put the #1 wire where the dizzy is pointing and check all your wire to make sure they are not cross-wired.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Thanks....But....is there any vacuum applied during normal use?
Checked all wires, all in correct place. With balancer mark lined up with tab, rotor was pointing to the no 1 tower.
Will double check tomorrow to make sure it was on compression stroke and pointing directly to no 1. Will post pics tomorrow....
It is an 81 but I replaced dizzy and carb as the original carb needs to be rebuilt. just waiting on the it and tools to arrive. 
Don't cancel yet, just start from the beginning. Pull the #1 plug and have someone bump the motor over while you have your finger over the plug hole. Air will start pushing by your finger. This will be your compression stroke. Then bump it very slowly to the top dead center. Check the dizzy. It should be pointing at the #1 plug hole position.
If not pull the dizzy up and readjust. You may have to take it out and turn the oil pump with a long screwdriver in the bottom of the hole. A big flat head screw driver will work just fine. Most of the time this is what prevents the dizzy from sitting all the way down.
After that put the #1 wire where the dizzy is pointing and check all your wire to make sure they are not cross-wired.
If not pull the dizzy up and readjust. You may have to take it out and turn the oil pump with a long screwdriver in the bottom of the hole. A big flat head screw driver will work just fine. Most of the time this is what prevents the dizzy from sitting all the way down.
After that put the #1 wire where the dizzy is pointing and check all your wire to make sure they are not cross-wired.
Will double check tomorrow to make sure it was on compression stroke and pointing directly to no 1. Will post pics tomorrow....
Cruising
Joined: May 2013
Posts: 13
Likes: 0
From: Atlanta Georgia
newbie here, on my 82 I had to unplug 1 wire(tan wire with black stripe)from 4 wire connector from distributor not the entire 4 wire connector tan wire disables electronic spark timing and sets the timing correctly after timing is ste reconnect tan wire