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Want to make sure Im setting the total timing correctly.
I changed the springs on the MSD billet distributor to the two lightest silver springs and the largest black bushing to limit the advance.
I have the vacuum advance disconnected.
Set up the timing light for 34 deg advance. Attached the pickup to #1 wire pointed towards the spark plug.
Started the engine ran it to operating temp.
Set the engine to 2700 rpm. Adjusted the distributor to the 0 deg mark on the balancer to O TDC pointer. So 34 deg total timing.
Is this correct procedure.
Appreciate any feedback
What 427 is it? 390 horse? If so....set timing to 38 degrees total....the closed chamber stuff likes a little more timing.
Your procedure is correct though....although 3000 rpm is usually the desired rpm where the advance will max out.
What 427 is it? 390 horse? If so....set timing to 38 degrees total....the closed chamber stuff likes a little more timing.
Your procedure is correct though....although 3000 rpm is usually the desired rpm where the advance will max out.
Jebby
Yes 390 hp
063 heads
Howards roller cam
In .555 . Ex .555
Duration in 219 . Ex 227 @ .050
Lobe Separation 110
Also, max advance is not at any rpm you decided on. Max advance is when the weights finish overpowering the springs. Rev it higher and be sure it is not advancing more. Now, unless it is drag strip only, hook up the vacuum advance.
Also, max advance is not at any rpm you decided on. Max advance is when the weights finish overpowering the springs. Rev it higher and be sure it is not advancing more. Now, unless it is drag strip only, hook up the vacuum advance.
Where is the best location to hook up the vacuum advance?
lm running a quadrajet carburetor.
063 is a semi-closed chamber and I would go 38 degrees total with that cam.
Jebby
Also stock intake and Exhaust Manifolds
Have side pipes
Worried that i won't hear detonation.
Also.. I have the stock timing pointer which is difficult to read. Is the 0 degree mark the second pointer from the bottom?
Are the pistons stock? These were 10.25 to 1 and on the ragged edge of pump gas with a stock cam.......if you are worried, dial 36 in and leave it......I had original pistons in mine and it did not ping on 93 octane.
Here is a pic of the tab:
Are the pistons stock? These were 10.25 to 1 and on the ragged edge of pump gas with a stock cam.......if you are worried, dial 36 in and leave it......I had original pistons in mine and it did not ping on 93 octane.
Here is a pic of the tab:
Jebby
I have Wiseco forged pistons now .060 over Domed
Compression Ratio is 9.3 to 1
From: At my Bar drinking and wrenching in Lafayette Colorado
As Derek noted above, you can't set total timing at any one rpm that you decide on, unless you have actually verified that the full centrifugal timing has "pegged out" at 2700. You need to rev it up as high as needed to assure that the full advance has slammed in all the way in and is no longer advancing. At that rpm, whatever it is, set total timing to 38. You're giving up power and throttle response if you set it at 34, as Jebby has noted above. You will not get detonation with 38 total if your comp ration is 9.3:1. Once done, hook up vacuum advance to the manifold vacuum port on the carb - the long tube coming out of the choke area on the passenger side works well.
As Derek noted above, you can't set total timing at any one rpm that you decide on, unless you have actually verified that the full centrifugal timing has "pegged out" at 2700. You need to rev it up as high as needed to assure that the full advance has slammed in all the way in and is no longer advancing. At that rpm, whatever it is, set total timing to 38. You're giving up power and throttle response if you set it at 34, as Jebby has noted above. You will not get detonation with 38 total if your comp ration is 9.3:1. Once done, hook up vacuum advance to the manifold vacuum port on the carb - the long tube coming out of the choke area on the passenger side works well.
Lars
Thanks Lars, Should I remove the springs on the distributor advance weights so it advances sooner? (Lower RPM) I have the light springs on now. The freaking heat that 427 throws out from the flex fan makes it difficult to take timing readings, especially at 3000 rpms.. lol
Thanks Lars, Should I remove the springs on the distributor advance weights so it advances sooner? (Lower RPM) I have the light springs on now. The freaking heat that 427 throws out from the flex fan makes it difficult to take timing readings, especially at 3000 rpms.. lol
Thanks
Mike
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Agree! Not to mention the contortions to get induction clip thing on nearly invisible #1 spark plug wire without burning the sh*t out of the back of your hand. Do the cool kids trace the #1 wire all the way back to where it comes out of the shroud at back of engine near distributor? There's got to be an easier way than the way I did it yesterday, from the bottom maybe?
Last edited by Elcransonator; Feb 24, 2020 at 01:05 PM.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Agree! Not to mention the contortions to get induction clip thing on nearly invisible #1 spark plug wire without burning the sh*t out of the back of your hand. Do the cool kids trace the #1 wire all the way back to where it comes out of the shroud at back of engine near distributor? There's got to be an easier way than the way I did it yesterday, from the bottom maybe?
you can place the inductive pick ip anywhere on the spark plug#1 wire. Make sure the inductive pick up arrow is pointing towards the spark plug.
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by Z06CE
Thanks Lars, Should I remove the springs on the distributor advance weights so it advances sooner? (Lower RPM) I have the light springs on now. The freaking heat that 427 throws out from the flex fan makes it difficult to take timing readings, especially at 3000 rpms.. lol Thanks Mike
No, you cannot remove both of the springs without inducing an artificially over-advanced condition cause by the missing springs. However, you can remove one of the springs to get the timing to come all-in at a lower rpm for the purposes of checking the timing.
Originally Posted by derekderek
You have the lightest Springs. You are probably fine. Just run it up to 3k. Then goose it to 4k. No additional advance? Good to go.
Just "blip" the throttle a few times and verify that you are not getting any more timing than what you're seeing at 2700. If it doesn't move, you're good to go.
Lars
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by Elcransonator
Not to mention the contortions to get induction clip thing on nearly invisible #1 spark plug wire without burning the sh*t out of the back of your hand. Do the cool kids trace the #1 wire all the way back to where it comes out of the shroud at back of engine near distributor? There's got to be an easier way than the way I did it yesterday, from the bottom maybe?
Note that this topic thread is about 427 timing: The 427 plug wires lay right across the valve covers, and are easily accessible. You can time the engine off either #1 or #6 wire, and the inductive pickup can be located anywhere on the easily accessible, exposed plug wires:
No, you cannot remove both of the springs without inducing an artificially over-advanced condition cause by the missing springs. However, you can remove one of the springs to get the timing to come all-in at a lower rpm for the purposes of checking the timing.
Lars
I just used the light springs. Its at 38 degrees now.
Having wide open throttle issue now... see my other post
You have the lightest Springs. You are probably fine. Just run it up to 3k. Then goose it to 4k. No additional advance? Good to go.
I tested the vette
Engine has good throttle response until its at wide open throttle at full load. Looses power like its starving for fuel it backfired as well at wot. Fuel issue?
69 427 Total timing
Just "blip" the throttle a few times and verify that you are not getting any more timing than what you're seeing at 2700. If it doesn't move, you're good to go.