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burdenh
Samba Member
Joined: July 07, 2011
Posts: 22
Location: Greenville, NC
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 Posted: Fri Jun 20, 2025 8:53 am Post subject: valve adjustment question |
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Trying to do a valve adjustment on my 72 and trying to learn. Only done this once before. This first time I removed the distributor cap and rotated the engine clockwise until the rotor pointed to the slot on the distributor AND the notch on the pulley lined up with the split in the engine case. Then started the valve adjustment. This time when I rotate the engine and the rotor points to the slot on the distributor, the notch on the pulley does NOT line up with the split in the engine case. Turned the engine around several times and still cannot get rotor to point to the slot and the pulley notch to align with the split case on the engine at the same time. Does this mean the belt is loose? Does not seem to be. What is going on? Trying to learn.
Thank you. |
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Glenn 
Mr. 010
Joined: December 25, 2001
Posts: 79445
Location: Sneaking up behind you
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| Posted: Fri Jun 20, 2025 9:02 am Post subject: Re: valve adjustment question |
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The dimple on the pulley should be close, is it?
If so then rotate the engine so the dimple is at the case seam.
If not.. post pictures.
The belt has nothing to do with this, it just spins the generator and fan..
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
עַם יִשְׂרָאֵל חַי |
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Multi69s
Samba Member
Joined: January 24, 2006
Posts: 5552
Location: Lefty, CA
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burdenh
Samba Member
Joined: July 07, 2011
Posts: 22
Location: Greenville, NC
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| Posted: Fri Jun 20, 2025 9:23 am Post subject: Re: valve adjustment question |
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| When I rotate the engine to where the notch on the pulley aligns with the split engine case, the rotor is not close to the slot in the distributor. Also when I rotate the engine to where the rotor points to the distributor slot, the pulley notch is no where near the split in the engine case. No ignition work has been done since last valve adjustment. The car was locked in storage for about the last 5 months. Car seems to run fine, but starts to shake about 35 mph. |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 33056
Location: Hot Arizona
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| Posted: Fri Jun 20, 2025 9:32 am Post subject: Re: valve adjustment question |
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| burdenh wrote: |
| When I rotate the engine to where the notch on the pulley aligns with the split engine case, the rotor is not close to the slot in the distributor. |
So what - ignore that distributor slot !!!
When the notch or dimple on the top of the crankshaft pulley lines up with the seam in the engine case, the distributor ROTOR will be under either the position on the distributor cap that goes to either spark plug #1 or spark plug #3. If it's under spark plug #1: GREAT. If under #3, rotate the engine one full turn counter clockwise to get it under #1.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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bsairhead
Samba Member
Joined: October 08, 2008
Posts: 4479
Location: viroqua wi.
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| Posted: Fri Jun 20, 2025 9:51 am Post subject: Re: valve adjustment question |
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| If the valves on #1 are not loose at pulley TDC rotate another 360* |
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bhartwell59
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Joined: December 28, 2014
Posts: 829
Location: dallas, tx
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burdenh
Samba Member
Joined: July 07, 2011
Posts: 22
Location: Greenville, NC
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| Posted: Fri Jun 20, 2025 10:06 am Post subject: Re: valve adjustment question |
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| OK, thanks everybody! I have some things to try. I will let you know how it goes. Hubert |
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burdenh
Samba Member
Joined: July 07, 2011
Posts: 22
Location: Greenville, NC
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| Posted: Fri Jun 20, 2025 11:44 am Post subject: Re: valve adjustment question |
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OK, All is good with the valve adjustment. For some reason I thought the rotor had to point toward the slot on the distributor, instead of the #1 spark plug. Pretty dumb thought process. As Cusser implored, I ignored the slot in the distributor body, lined the notch on the crankshaft pulley with the split in the engine case and sure enough the rotor was pointing to spark plug #1. (Guess I am lucky; could have been spark plug #3.) I am an old man (82) but a rookie at this.
Thanks again for all the help.
Hubert |
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Bobs67vwagen
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Joined: March 27, 2005
Posts: 298
Location: Eastern north carolina
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| Posted: Fri Jun 20, 2025 11:52 am Post subject: Re: valve adjustment question |
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| Hubert, just a thought-regardless of what some of the manuals say, adjust the valves to .006 and you will not have a problem. Do it with engine cold, not after it has been run-good luck bob |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 33056
Location: Hot Arizona
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| Posted: Fri Jun 20, 2025 11:58 am Post subject: Re: valve adjustment question |
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| Bobs67vwagen wrote: |
| Hubert, just a thought-regardless of what some of the manuals say, adjust the valves to .006 and you will not have a problem. Do it with engine cold, not after it has been run-good luck bob |
Yes, 0.006 inches. After engine has been sitting overnight -cold.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 16561
Location: North Florida, USA
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| Posted: Sat Jun 21, 2025 9:45 am Post subject: Re: valve adjustment question |
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| burdenh wrote: |
| This time when I rotate the engine and the rotor points to the slot on the distributor, the notch on the pulley does NOT line up with the split in the engine case. |
I'm wondering if by "slot on the distributor" you are referring to the large square cutout in the rim of the distributor where the distributor cap indexes? Rather than the small "notch" in the rim used for identifying where the #1 plug wire is installed?
Borrowing some pics from the gallery to illustrate this for anyone who comes across this thread looking for help...
Above is a pic of the crank pulley. The "notch" in the front lip (closer to front of car) is the timing notch. In this case the notch represents 5ATDC.
The "dimple" on the rear lip (closer to rear of car) is the TDC marking. It indicates when the crank is rotated so that #1 piston is at the top of its stroke. This could be the top of stroke at the end of the compression stroke (when a spark is needed at cylinder #1) or it could be the top of stroke at the end of the exhaust stroke. You cannot tell which from looking at the crank pulley alone. To know which stroke the #1 cylinder is in you need to look at the #1 valve positioning. At the end of the compression stroke both valves will be closed so the cylinder can build pressure. The rocker arms will be loose and NOT pressing on the valves. When it is at the end of the exhaust stroke the exhaust valve will be closing and the intake will just start to open. The #1 rocker arms will be applying pressure on one or both of the valve stems.
Above is a pic of the top rim of the distributor (I think this is from a T3 engine). Note the large cutout at the 10-o'clock position and the small "notch" at the 2-o'clock position. The large cutout is for positioning the distributor cap onto the distributor making sure it will fit only one way. The cutout has nothing to do with where #1 plug wire is installed. Different distributors will place this cutout in different locations.
The small "notch" at 2-o'clock is an indicator of where the #1 plug wire "should" be installed. Many people mistakenly believe that the "notch" is always correct and "dictates" where the #1 plug wire goes. Or they believe the notch must ALWAYS be in a certain position around the distributor. Neither is correct. It is possible (in most cases) to rotate the distributor 90deg in either direction and the notch will now represent where the #4 or #2 plug wire should be located, not #1.
Truth: The #1 post on the distributor cap is the one that will deliver a spark to the #1 spark plug when cylinder #1 is at the end of its compression stroke.
When installing the distributor into the case, it is the job of the mechanic to install it such that when the engine is at the end of the #1 cylinder compression stroke the notch is below the tip of the rotor; ensuring it can be used during future tune ups to located the #1 post on the distributor. I like to call it a "permanent pencil mark" which you can use to note where the #1 plug wire is installed on the cap. But like any other pencil mark, it can mislead you if placed incorrectly.
This is also why on any new ACVW engine, I mistrust the notch until I can confirm with #1 cylinder valve movement and crank pulley markings that when the #1 piston is at the end of the compression stroke the notch is below the rotor tip. Only THEN do I trust what the notch means. If the engine is running well, you can follow the #1 plug wire coming from the #1 spark plug and note which post it connects to and then confirm the notch is below this post. But I will admit, I have confused the #1 and #2 plug wires while tracing them below the generator stand opening and got them mixed up.
_________________
AshMan40
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'67 Beetle #1 {project car that never made it to the road  }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!} |
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burdenh
Samba Member
Joined: July 07, 2011
Posts: 22
Location: Greenville, NC
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| Posted: Sat Jun 21, 2025 1:07 pm Post subject: Re: valve adjustment question |
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| Ashman40, Thank you, thank you for your detailed pictures and clear explanations that even a novice like me can follow. Very, very helpful. The willingness of people on this forum to share their knowledge and expertise is inspirational and pivotal to people like me keeping their chariots going. |
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nbvolks
Samba Member
Joined: April 06, 2020
Posts: 377
Location: MA
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| Posted: Sun Jun 22, 2025 5:04 am Post subject: Re: valve adjustment question |
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| ashman40 wrote: |
| burdenh wrote: |
| This time when I rotate the engine and the rotor points to the slot on the distributor, the notch on the pulley does NOT line up with the split in the engine case. |
I'm wondering if by "slot on the distributor" you are referring to the large square cutout in the rim of the distributor where the distributor cap indexes? Rather than the small "notch" in the rim used for identifying where the #1 plug wire is installed?
Borrowing some pics from the gallery to illustrate this for anyone who comes across this thread looking for help...
Above is a pic of the crank pulley. The "notch" in the front lip (closer to front of car) is the timing notch. In this case the notch represents 5ATDC.
The "dimple" on the rear lip (closer to rear of car) is the TDC marking. It indicates when the crank is rotated so that #1 piston is at the top of its stroke. This could be the top of stroke at the end of the compression stroke (when a spark is needed at cylinder #1) or it could be the top of stroke at the end of the exhaust stroke. You cannot tell which from looking at the crank pulley alone. To know which stroke the #1 cylinder is in you need to look at the #1 valve positioning. At the end of the compression stroke both valves will be closed so the cylinder can build pressure. The rocker arms will be loose and NOT pressing on the valves. When it is at the end of the exhaust stroke the exhaust valve will be closing and the intake will just start to open. The #1 rocker arms will be applying pressure on one or both of the valve stems.
Above is a pic of the top rim of the distributor (I think this is from a T3 engine). Note the large cutout at the 10-o'clock position and the small "notch" at the 2-o'clock position. The large cutout is for positioning the distributor cap onto the distributor making sure it will fit only one way. The cutout has nothing to do with where #1 plug wire is installed. Different distributors will place this cutout in different locations.
The small "notch" at 2-o'clock is an indicator of where the #1 plug wire "should" be installed. Many people mistakenly believe that the "notch" is always correct and "dictates" where the #1 plug wire goes. Or they believe the notch must ALWAYS be in a certain position around the distributor. Neither is correct. It is possible (in most cases) to rotate the distributor 90deg in either direction and the notch will now represent where the #4 or #2 plug wire should be located, not #1.
Truth: The #1 post on the distributor cap is the one that will deliver a spark to the #1 spark plug when cylinder #1 is at the end of its compression stroke.
When installing the distributor into the case, it is the job of the mechanic to install it such that when the engine is at the end of the #1 cylinder compression stroke the notch is below the tip of the rotor; ensuring it can be used during future tune ups to located the #1 post on the distributor. I like to call it a "permanent pencil mark" which you can use to note where the #1 plug wire is installed on the cap. But like any other pencil mark, it can mislead you if placed incorrectly.
This is also why on any new ACVW engine, I mistrust the notch until I can confirm with #1 cylinder valve movement and crank pulley markings that when the #1 piston is at the end of the compression stroke the notch is below the rotor tip. Only THEN do I trust what the notch means. If the engine is running well, you can follow the #1 plug wire coming from the #1 spark plug and note which post it connects to and then confirm the notch is below this post. But I will admit, I have confused the #1 and #2 plug wires while tracing them below the generator stand opening and got them mixed up. |
When adjusting the valves are you doing the adjustment with the dimple or the notch aligned with the seam in the case? |
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Glenn
Mr. 010
Joined: December 25, 2001
Posts: 79445
Location: Sneaking up behind you
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| Posted: Sun Jun 22, 2025 5:12 am Post subject: Re: valve adjustment question |
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Dimple
That notch is 5* ATDC
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
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