Olds 455 timing
February 9th, 2014, 07:12 AM
#1
Olds 455 timing
Olds 455 Timing
Have a 71 Cutlass w/455, edelbrock performer intake, G heads, holley 650 carb, HEI distributor, 160 thermostat. I am trying to get the timing set. I have read several post on how to do it but I am still a bit confused. I need a step-by-step "how to" on timing procedures for the olds 455. This is my understanding of how to do it:
Step 1: Align the engine balancer mark with the "0" on timing tab @TDC on #1 cylinder on compression stroke.
Step 2: Make sure distributor rotor is pointing to #1 spark plug wire. (Attach timing light to #1 spark plug wire)
Step 3: Start the engine, make sure balancer mark is still align with timing tab "0" with timing light.
Step 4: Set timing light advance to 32-34 and raise engine RPMs to 3000-3500.
Step 5: Rotate distributor (advance/retard) until balancer mark align with timing tab "0" seen with timing light.(total advance timing)
Step 6: Let engine idle and check with timing light, the number that aligns with timing tab "0" is initial timing (initial timing).
When I did the above procedure the car ran hot while running the engine up to 3000 rpm and backfired when I shut it off. Is this the correct way to set timing on olds 455? If I am wrong please advise me what to do. -Fred
Have a 71 Cutlass w/455, edelbrock performer intake, G heads, holley 650 carb, HEI distributor, 160 thermostat. I am trying to get the timing set. I have read several post on how to do it but I am still a bit confused. I need a step-by-step "how to" on timing procedures for the olds 455. This is my understanding of how to do it:
Step 1: Align the engine balancer mark with the "0" on timing tab @TDC on #1 cylinder on compression stroke.
Step 2: Make sure distributor rotor is pointing to #1 spark plug wire. (Attach timing light to #1 spark plug wire)
Step 3: Start the engine, make sure balancer mark is still align with timing tab "0" with timing light.
Step 4: Set timing light advance to 32-34 and raise engine RPMs to 3000-3500.
Step 5: Rotate distributor (advance/retard) until balancer mark align with timing tab "0" seen with timing light.(total advance timing)
Step 6: Let engine idle and check with timing light, the number that aligns with timing tab "0" is initial timing (initial timing).
When I did the above procedure the car ran hot while running the engine up to 3000 rpm and backfired when I shut it off. Is this the correct way to set timing on olds 455? If I am wrong please advise me what to do. -Fred
Last edited by Freddy B; February 9th, 2014 at 07:19 AM.
February 9th, 2014, 07:31 AM
#4
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Olds 455 Timing
Have a 71 Cutlass w/455, edelbrock performer intake, G heads, holley 650 carb, HEI distributor. I am trying to get the timing set. I have read several post on how to do it but I am still a bit confused. I need a step-by-step "how to" on timing procedures for the olds 455. This is my understanding of how to do it:
Step 1: Align the engine balancer mark with the "0" on timing tab @TDC
on #1 cylinder on compression stroke.
Step 2: Make sure distributor rotor is pointing to #1 spark plug wire. (Attach timing light to #1 spark plug wire)
Step 3: Start the engine, make sure balancer mark is still align with timing tab "0" with timing light.
Skip steps 1,2, and 3, make sure your vacuum, advance is disconnected. Start engine with timing light connected to #1.
Step 4: Set timing light advance to 32-34 and raise engine RPMs to 3000-3500.
Step 5: Rotate distributor (advance/retard) until balancer mark align with timing tab "0" seen with timing light.(total advance timing)
Once you have your timing set, run Rpms up to 4-4500 and make sure it does not advance anymore. You want to limit your total to 36*BTDC plus or minus 2 degrees.
When the vacuum advance is connected, it should be limited to 50* or less at 3000+ Rpms, should not climb over that at higher Rpms.
Step 6: Let engine idle and check with timing light, the number that aligns with timing tab "0" is initial timing (initial timing).
Initial timing at idle with vacuum advance disconnected should be around 18-21*.
When I did the above procedure the car ran hot while running the engine up to 3000 rpm and backfired whe I shut it off. Is this the correct way to set timing on olds 455? If I am wrong please advise me what to do. -Fred
Have a 71 Cutlass w/455, edelbrock performer intake, G heads, holley 650 carb, HEI distributor. I am trying to get the timing set. I have read several post on how to do it but I am still a bit confused. I need a step-by-step "how to" on timing procedures for the olds 455. This is my understanding of how to do it:
Step 1: Align the engine balancer mark with the "0" on timing tab @TDC
on #1 cylinder on compression stroke.
Step 2: Make sure distributor rotor is pointing to #1 spark plug wire. (Attach timing light to #1 spark plug wire)
Step 3: Start the engine, make sure balancer mark is still align with timing tab "0" with timing light.
Skip steps 1,2, and 3, make sure your vacuum, advance is disconnected. Start engine with timing light connected to #1.
Step 4: Set timing light advance to 32-34 and raise engine RPMs to 3000-3500.
Step 5: Rotate distributor (advance/retard) until balancer mark align with timing tab "0" seen with timing light.(total advance timing)
Once you have your timing set, run Rpms up to 4-4500 and make sure it does not advance anymore. You want to limit your total to 36*BTDC plus or minus 2 degrees.
When the vacuum advance is connected, it should be limited to 50* or less at 3000+ Rpms, should not climb over that at higher Rpms.
Step 6: Let engine idle and check with timing light, the number that aligns with timing tab "0" is initial timing (initial timing).
Initial timing at idle with vacuum advance disconnected should be around 18-21*.
When I did the above procedure the car ran hot while running the engine up to 3000 rpm and backfired whe I shut it off. Is this the correct way to set timing on olds 455? If I am wrong please advise me what to do. -Fred
Hopefully this helps. If you sense any detonation at all, or engine runs on like you described above, drop timing down 2*. Make sure your running hi test fuel.
February 9th, 2014, 08:27 AM
#9
Scotty- just to verify the 8 degree initial timing was set before you set your total timing? I am trying to figure out were should my timing be before setting timing. Either TDC or 8* BTDC?
Last edited by Freddy B; February 9th, 2014 at 08:31 AM.
February 9th, 2014, 08:51 AM
#10
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0 on the balancer should align with 0 on the tab with your gun set to 34-36*. Vacuum advance disconnected. Note spark plug gap needs to be @ .045.
You are correct.
No, the 18-20* is where your initial should wind up after you set your total. Do not readjust your timing, just note where it is for future reference.
No the 18-21 with vacuum advance disconnected @ idle, your 8* is with a points distributor, he has an Hei.
February 9th, 2014, 08:51 AM
#11
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Location: The Hudson Valley
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You could make on if you wanted to, but there is none now. The distance from the Zero mark to 35° (as measured with a tape laid along the balancer) is 50.5mm.
With a dial-back timing light, you set the light to a number, and add that number to what you see.
So, set it for 36° and set the indicator to 0.
OR set for 20° and set the indicator to 16.
Whatever.
The initial timing is not important here.
You dial in the maximum mechanical timing first, then adjust the lower end by changing weights and springs, if necessary, then adjust the vacuum advance.
You should read some other threads on this subject, such as here, here, and here. Also here and here. And, of course, here and here.
This has been discussed before.
- Eric
February 9th, 2014, 11:52 AM
#12
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Location: Calgary Alberta
Posts: 641
Hmmm...nope I have an HEI dialed in by DUI. Set my timing with the balancer showing 8 degrees and rotor dead centre at the number one cyl. And Im all in at 3500 rpm. Maybe its my low end torque cam ? I will have to double check everything this spring. Too friggin cold right now
February 9th, 2014, 12:02 PM
#13
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A stock HEI will not sit that low at idle if it's set around 36° at 3,500.
- Eric
February 9th, 2014, 02:07 PM
#14
Here is the update. I got the engine to 32 degrees at 3000 rpm then timing light stop flashing. The initial timing is 11 degrees BTDC. When I connect the vacuum advance it starts to run rough with low idle. After shutting engine off its hard to start. Disconnect vacuum advance car starts. Does anyone know what the problem could be?
February 9th, 2014, 02:46 PM
#15
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Sounds like you have your vacuum advance connected to manifold vacuum, but your engine prefers ported vacuum.
I'd connect it to the proper port on the carburetor and see what happens.
- Eric
I'd connect it to the proper port on the carburetor and see what happens.
- Eric
February 9th, 2014, 03:04 PM
#17
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I read a lot of mixed reviews on whether the vacuum advance should be connected to the ported and manifold vacuum. I always have it connected to the ported but someone wrote an article in the 442.com about it should be connected to manifold. I would like to hear other peoples opinion on this. Hopefully it can help us out on this confusion.
February 9th, 2014, 03:22 PM
#18
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All I can suggest is that you vary your timing and see how much it seems to like at idle, then recurve your distributor to give you that range from Zero to Full advance.
I read a lot of mixed reviews on whether the vacuum advance should be connected to the ported and manifold vacuum. I always have it connected to the ported but someone wrote an article in the 442.com about it should be connected to manifold. I would like to hear other peoples opinion on this. Hopefully it can help us out on this confusion.
All it will do is incite a bloody civil war, which will consume all in its path, and out of which will arise no victors.
Every engine is different, especially if it has been modified (CR, cam, heads, etc.), and different engines will have different preferences.
Going from ported to manifold may cure rough running and overheating at idle, or may create an engine that wants to pull you through the intersection when you're stopped at a red light.
See which way it runs better.
- Eric
February 9th, 2014, 04:38 PM
#19
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You're connected to ported vacuum, then.
All I can suggest is that you vary your timing and see how much it seems to like at idle, then recurve your distributor to give you that range from Zero to Full advance.
It will do nothing of the kind.
All it will do is incite a bloody civil war, which will consume all in its path, and out of which will arise no victors.
Every engine is different, especially if it has been modified (CR, cam, heads, etc.), and different engines will have different preferences.
Going from ported to manifold may cure rough running and overheating at idle, or may create an engine that wants to pull you through the intersection when you're stopped at a red light.
See which way it runs better.
- Eric
All I can suggest is that you vary your timing and see how much it seems to like at idle, then recurve your distributor to give you that range from Zero to Full advance.
It will do nothing of the kind.
All it will do is incite a bloody civil war, which will consume all in its path, and out of which will arise no victors.
Every engine is different, especially if it has been modified (CR, cam, heads, etc.), and different engines will have different preferences.
Going from ported to manifold may cure rough running and overheating at idle, or may create an engine that wants to pull you through the intersection when you're stopped at a red light.
See which way it runs better.
- Eric
February 16th, 2014, 03:02 PM
#21
Here is an update and I am worse off than before. I changed the springs in the distributor with every set in the kit. I set the total advance to 32-34 degrees @ 3250 RPMs my initial was 11 degrees. When I connected the distributor vacuum to the ported vacuum on the carb my RPMs went to 1750 and my balancer was reading 40 degrees advance. Should the RPMs increase when the ported vacuum is connected? Car also hesitates when starting and then begins to crank, what could this be? Any help would be appreciated.
February 16th, 2014, 04:42 PM
#22
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Sounds like too much advance when turning over. Your advance canister sounds faulty. Try an adjustable vacuum advance canister which is what a lot of the aftermarket HEI use. (Mine is adjustable)
February 16th, 2014, 05:53 PM
#23
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Your engine should not increase in rpms when you connect the vacuum at idle. So you are connected to the wrong port. I would leave it disconnected for now. Which Holley carb are your running? Drop your timing down 2 degrees and see if it starts easier.
February 16th, 2014, 06:17 PM
#24
My engine does start really slow. The initial timing it is about 20* ATDC. I have the advance connected to the ported connection on my holley 750. I will try and retard the timing 2* and see what happens
February 16th, 2014, 06:29 PM
#25
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If your carb is a 3310 vacuum secondary carb, the port you need to connect to is on the passenger side front, midway up. Not the port on the bottom front right. If your battery is low it will be slow to start.
February 16th, 2014, 06:42 PM
#27
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Your engine should not increase in rpms when you connect the vacuum at idle.
==========
Correct
Any chance you plugged the DISTRIBUTOR half of the VA vacuum while setting timing, and left the vacuum SOURCE at the carb open and sucking air? The dist'r canister need not be plugged for any reason except to keep bugs and crud out- if there is no hose [vacuum] on it, it just sits there and does not alter the timing at all.
So you are connected to the wrong port.
=============
Or, the throttle is open so far that the port is exposed to the vacuum. Often required due to late timing... in order to get idle, with late timing, the throttle blades get propped open more.... NOT a solution. In fact, some factory carbs [and many modified carbs] have HOLES in the throttle plates, so that the plate must/can be closed more to get proper idle, so that the ported vacuum port is NOT exposed to vacuum at idle. This is common with lots of cam.
Faltering starter indicates a spark way too far advanced for starting. This happened to me on the high compression 403. Retarded timing to get better starter action led to overheating and very poor vacuum- like 5" and no power brakes, idle drops off and engine dies. I had to get the adjustable vacuum can and the spring/ weight kit for the advances, and figure out what it wanted and how to attain that. Long story, with photos, lost in the Great ROP Crash of '13. Dammit.
I ended up with manifold vacuum on the HEI. This means less advance while starting, then quite a bit more as soon as vacuum occurs [engine is running] which led to NOT overheating, DOES idle nicely, and GREATLY improved throttle response and top end power. Please note that 1965 Oldsmobiles were plumbed with manifold vacuum to the distributor. It is a perfectly viable alternative.
As set forth above, though, no two are identical... so do what your lady likes best, right?
==========
Correct
Any chance you plugged the DISTRIBUTOR half of the VA vacuum while setting timing, and left the vacuum SOURCE at the carb open and sucking air? The dist'r canister need not be plugged for any reason except to keep bugs and crud out- if there is no hose [vacuum] on it, it just sits there and does not alter the timing at all.
So you are connected to the wrong port.
=============
Or, the throttle is open so far that the port is exposed to the vacuum. Often required due to late timing... in order to get idle, with late timing, the throttle blades get propped open more.... NOT a solution. In fact, some factory carbs [and many modified carbs] have HOLES in the throttle plates, so that the plate must/can be closed more to get proper idle, so that the ported vacuum port is NOT exposed to vacuum at idle. This is common with lots of cam.
Faltering starter indicates a spark way too far advanced for starting. This happened to me on the high compression 403. Retarded timing to get better starter action led to overheating and very poor vacuum- like 5" and no power brakes, idle drops off and engine dies. I had to get the adjustable vacuum can and the spring/ weight kit for the advances, and figure out what it wanted and how to attain that. Long story, with photos, lost in the Great ROP Crash of '13. Dammit.
I ended up with manifold vacuum on the HEI. This means less advance while starting, then quite a bit more as soon as vacuum occurs [engine is running] which led to NOT overheating, DOES idle nicely, and GREATLY improved throttle response and top end power. Please note that 1965 Oldsmobiles were plumbed with manifold vacuum to the distributor. It is a perfectly viable alternative.
As set forth above, though, no two are identical... so do what your lady likes best, right?
Last edited by Octania; February 16th, 2014 at 06:44 PM.
February 16th, 2014, 06:53 PM
#28
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As Octania stated, your idle speed may be set too high and the carb is no longer in the idle circuit. Leave it disconnected and capped until you get you timing squared away. It's not needed other than it increases fuel economy at cruise.
February 16th, 2014, 07:18 PM
#29
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well, almost
On my high compression 403 with a lot of cam, it was VERY necessary to have vacuum advance immediately after starting, in order to have proper idle, vacuum for brakes and carb functions, and avoid excessive heating.
For setting the max timing for 5 minutes, no, it's not necessary.
Speaking of brake vacuum, OP- attach a vacuum gage while setting your timing and whatnot- it reveals a lot about the engine's condition. Google for sites on how to interpret vacuum gage readings.
On my high compression 403 with a lot of cam, it was VERY necessary to have vacuum advance immediately after starting, in order to have proper idle, vacuum for brakes and carb functions, and avoid excessive heating.
For setting the max timing for 5 minutes, no, it's not necessary.
Speaking of brake vacuum, OP- attach a vacuum gage while setting your timing and whatnot- it reveals a lot about the engine's condition. Google for sites on how to interpret vacuum gage readings.
October 19th, 2023, 10:34 PM
#30
There is no mark on the balancer for 36°BTDC.
You could make on if you wanted to, but there is none now. The distance from the Zero mark to 35° (as measured with a tape laid along the balancer) is 50.5mm.
With a dial-back timing light, you set the light to a number, and add that number to what you see.
So, set it for 36° and set the indicator to 0.
OR set for 20° and set the indicator to 16.
Whatever.
The initial timing is not important here.
You dial in the maximum mechanical timing first, then adjust the lower end by changing weights and springs, if necessary, then adjust the vacuum advance.
You should read some other threads on this subject, such as here, here, and here. Also here and here. And, of course, here and here.
This has been discussed before.
It looks like you have an older car, Scotty. HEI distributors have a different advance curve.
- Eric
You could make on if you wanted to, but there is none now. The distance from the Zero mark to 35° (as measured with a tape laid along the balancer) is 50.5mm.
With a dial-back timing light, you set the light to a number, and add that number to what you see.
So, set it for 36° and set the indicator to 0.
OR set for 20° and set the indicator to 16.
Whatever.
The initial timing is not important here.
You dial in the maximum mechanical timing first, then adjust the lower end by changing weights and springs, if necessary, then adjust the vacuum advance.
You should read some other threads on this subject, such as here, here, and here. Also here and here. And, of course, here and here.
This has been discussed before.
It looks like you have an older car, Scotty. HEI distributors have a different advance curve.
- Eric
October 20th, 2023, 03:45 PM
#31
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October 20th, 2023, 04:49 PM
#32
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mrrjay243289 and Donaldbabineau Do you realize that this post is almost ten years old?
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