TheSamba.com :: View topic - I set valve clearances at the 10° timing mark. Bug is not happy.

Sat Jan 09, 2021 2:03 pm

My problem is basically as the title suggests. I read online that for an 009 distributor, I should use the right-most timing mark on the pulley, aka the 10° mark. So I set all my valve clearances to .006 (1600cc dual port engine). Now the bug is not happy. It sputters cyclically when trying to start, and does not wind up starting. (It used to be that once the bug started to fire, it would start up and run decently). Did I mess up by using the 10° mark to set the clearances? I have read some conflicting info online about which mark to use and now I'm unsure what to do next.

Sat Jan 09, 2021 2:18 pm

The valves must be adjusted with the piston at TDC.

timing for a 009 distributor should be 28-32⁰ at full advance.

Sat Jan 09, 2021 2:28 pm

You need both the intake and exhaust valves to be closed when you check and adjust their clearance. 10° of advance would be an initial advance of timing for the idle of your motor. You're not adjusting your valves while the motor is running I'm fairly sure.

Sat Jan 09, 2021 2:37 pm

Igpoe wrote: You need both the intake and exhaust valves to be closed when you check and adjust their clearance. 10° of advance would be an initial advance of timing for the idle of your motor. You're not adjusting your valves while the motor is running I'm fairly sure.

What I'm trying to say is that out of the 3 notches on my pulley (which I understand to be 0, 7.5, and 10 degrees from center), I set the valve clearances by lining the crack in the case up to the right-most one, while the engine was off. I'm doing all this in the first place to get the motor starting/running well. Was it a mistake to use the right-most notch instead of the center one?

Sat Jan 09, 2021 2:43 pm

Sat Jan 09, 2021 2:47 pm

the_8th_dwarf wrote: Igpoe wrote: You need both the intake and exhaust valves to be closed when you check and adjust their clearance. 10° of advance would be an initial advance of timing for the idle of your motor. You're not adjusting your valves while the motor is running I'm fairly sure.

What I'm trying to say is that out of the 3 notches on my pulley (which I understand to be 0, 7.5, and 10 degrees from center), I set the valve clearances by lining the crack in the case up to the right-most one, while the engine was off. I'm doing all this in the first place to get the motor starting/running well. Was it a mistake to use the right-most notch instead of the center one?

Yes, you made a mistake. Your valve clearances were not set correctly, and thus one of the very likely reasons your motor is not happy.

Please read these instructions carefully, and if you are at all confused, ask any questions here before you start the job: http://www.vw-resource.com/valveadj.html

Here is an image of the pulley, to help you see where TDC (Top Dead Centre) is. BDC (Bottom Dead Centre) is 180deg.

You need to wait for your engine to be stone cold (ideally overnight) to adjust the valves. So read up, ask your questions, and re-adjust on Sunday.

Sat Jan 09, 2021 2:51 pm

Valve adjustment is done at TDC.

Ignition timing is different than valve adjustment.

Sat Jan 09, 2021 4:08 pm

the_8th_dwarf wrote: Was it a mistake to use the right-most notch instead of the center one?

It should not really matter. Something else is wrong.
Set the valve lash when the opposite cylinder is in overlap,
to make sure you aren't setting it AT overlap or 180 degrees out, ect.

Sat Jan 09, 2021 4:52 pm

modok wrote:
It should not really matter. Something else is wrong.
Set the valve lash when the opposite cylinder is in overlap,
to make sure you aren't setting it AT overlap or 180 degrees out, ect.

Forgive my ignorance but could you please explain what you mean by "valve lash" and "cylinder in overlap"?

Sat Jan 09, 2021 5:46 pm

If I may...

Valve lash is just another way to say valve clearance.

Valve overlap is when the exhaust valve is closing and the intake valve is beginning to open. Since the VW engine only has four lobes on it's cam to operate 8 valves, this means when cylinder #1 is on overlap #3 is on TDC firing. The same follows for all four cylinders, when #3 is on overlap #1 is TDC firing and so on.

That same four lobe cam is nearly round opposite it's peak. I have found by experience unless you have a wild hi-po cam in there setting the valves at 10 BTDC or 10 ATDC will not make a noticeable difference.
In other words don't fret too much over a few degrees and look for other causes for your issue.

Sat Jan 09, 2021 5:55 pm

the_8th_dwarf wrote: modok wrote:
It should not really matter. Something else is wrong.
Set the valve lash when the opposite cylinder is in overlap,
to make sure you aren't setting it AT overlap or 180 degrees out, ect.

Forgive my ignorance but could you please explain what you mean by "valve lash" and "cylinder in overlap"?

Valve lash is the same thing as what you call'd valve clearance in your opening post. Overlap refers to when both valves are supposed to be open (slightly), but that occurs at the end of the exhaust stroke as the intake valve already begins to open; and this occurs (for cyl#1) every other rotation of crank pulley reaching that 10° advanced mark. To make sure you are not setting valves at that overlap, pop off the distributor cap and make sure the rotor is pointing to the cylinder whose valves you are adjusting (instead of pointing 180° off).

Edit - I see 61SNRF beat me to your answers!

Wait, if you set ALL valves with the crank pulley's 10° notch at case split, then no wonder your bug's not happy 'cuz only one cylinder (either #1 or #3) will be set correctly! You need to rotate the crank so that the distributor rotor points to the cylinder whose valves you are adjusting.

Sat Jan 09, 2021 8:06 pm

MrGoodtunes wrote:

Wait, if you set ALL valves with the crank pulley's 10° notch at case split, then no wonder your bug's not happy 'cuz only one cylinder (either #1 or #3) will be set correctly! You need to rotate the crank so that the distributor rotor points to the cylinder whose valves you are adjusting.

I think this is the culprit

Sat Jan 09, 2021 9:49 pm

dirtkeeper wrote: MrGoodtunes wrote:

Wait, if you set ALL valves with the crank pulley's 10° notch at case split, then no wonder your bug's not happy 'cuz only one cylinder (either #1 or #3) will be set correctly! You need to rotate the crank so that the distributor rotor points to the cylinder whose valves you are adjusting.

I think this is the culprit

Sorry if I didn't make this clear; I set the #1 valves to the 10° mark, then rotated 180 degrees for valve #2. Back to the 10° mark for #3, and finally another 180 for #4

Sat Jan 09, 2021 10:16 pm

There is obviously some disagreement here as to whether the 10° setting is causing the issue of your bug not running right- I tend to agree with the posters who said it really wouldn't make that much of a difference, but just for kicks and sniggles go set it again (engine ice cold) using the left most mark on your pulley for cylinders 1 & 3 which as you stated should be 0° TDC, and 180° opposite that for cylinders 2 and 4.
I am also wondering if perhaps it's possible you might have accidentally been 360° off when doing your adjustment? i.e. you may have been on TDC for cylinder #3 when you thought you were on TDC for cylinder #1, since they both would use the same mark on the crank pulley. As a reference here is a photo I took a while back of the way your #1 and #2 valves should be oriented when you are on TDC for #1. You should see cylinder #1's intake and exhaust valves and #2's intake valve in the CLOSED position, and #2's exhaust valve OPEN:

Sat Jan 09, 2021 10:57 pm

I'm pretty certain I got all the right cylinders. I followed the spark plug wires and double checked the rotor position constantly as I was doing this. Probably gonna snow tomorrow but I'll see if i can't just get out and change the clearances anyway - I hate wasting weekends without making some progress on this thing

Sat Jan 09, 2021 11:14 pm

the_8th_dwarf wrote: I'm pretty certain I got all the right cylinders. I followed the spark plug wires and double checked the rotor position constantly as I was doing this. Probably gonna snow tomorrow but I'll see if i can't just get out and change the clearances anyway - I hate wasting weekends without making some progress on this thing
We are getting the snow from Tejas Monday
here in Mepho...

Make sure your Distr cap doesn't have any
hairline cracks... hope you figure it out...

This is how I have timed my Bug:

Sat Jan 09, 2021 11:40 pm

I'm not saying you are doing anything wrong, rather providing an alternate method, which can be used to double check your work, OR can be used if the engine does not have a distributor, does not have marks on the pulley, or if the distributor is set wrong, or (in my case) if it's so coated in oil and dirt you don't particularly want to even touch it, for your own sake as well as for fear of introducing dirt into the distributor.....which could cause a problem similar to whatever your problem is. Not that it has.....tho it could.
You can fondle your distributor all you want and it "should" not cause a problem if you do it right, but that's another issue entirely.

But point is....
If the valve lash (as it's called in the USA) of each cylinder is adjusted by placing the opposite cylinder in overlap(the point both valves are open at once), then you know that the lash IS set correctly no matter how many other parts of the engine are wrong.

Sun Jan 10, 2021 6:02 am

What, set the valves at 10°? One of the most wrong things I've ever read on the samba since I joined.

Sun Jan 10, 2021 6:57 am

You honestly need to identify the actual Top Dead Center TDC on number 1 cylinder. So how is that accomplished. Remove valve cover for number 1 2 cylinder. Remove number 1 spark plug. Rotate engine to what you think is TDC on number 1. Both valves on number 1 closed, insert a plastic straw into number 1 spark plug hole. Now rotate slightly one way and the other while monitoring the straw. It will go down a lil and up a lil. When the straw is at the top and does not go down that is your TDC. Mark Pulley. Now proceed with valve adjustment.

Sun Jan 10, 2021 9:13 am

For reference here is a cam lobe profile chart...

Notice in particular how large the base circle radius is. This should qualify my statement of why you can turn the engine so it is 10* before or past TDC and the lifter will still riding be on that base circle allowing a good valve lash adjustment.

Here's a pic with both lobes...