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Michael Ambrozik
Samba Member
Joined: October 17, 2020
Posts: 631
Location: San Jose, CA
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 Posted: Mon Jun 21, 2021 3:45 pm Post subject: Re: Static Timing Questions |
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| You will also need a new exhaust with the risiers. |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Mon Jun 21, 2021 6:19 pm Post subject: Re: Static Timing Questions |
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| Michael Ambrozik wrote: |
| You will also need a new exhaust with the risiers. |
Sure, this one is here already! |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Mon Jun 21, 2021 6:20 pm Post subject: Re: Static Timing Questions |
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| busdaddy wrote: |
I think many get the static timing idea from Muir, it works well on early distributors, not so much on later more complex versions.
1.5 times the distance between that TDC mark and the 5 ATDC mark measured in the opposite direction from TDC is 7.5 BTDC.  |
So I think I understand the 7.5.
While timing, I guess I also need to verify at higher RPM? |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51128
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Mon Jun 21, 2021 6:49 pm Post subject: Re: Static Timing Questions |
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| Gadwood74 wrote: |
| busdaddy wrote: |
I think many get the static timing idea from Muir, it works well on early distributors, not so much on later more complex versions.
1.5 times the distance between that TDC mark and the 5 ATDC mark measured in the opposite direction from TDC is 7.5 BTDC. |
So I think I understand the 7.5.
While timing, I guess I also need to verify at higher RPM? |
Yes, the 7.5 is good for static timing, and most idle around there, but see what it advances to at ~3500 RPM with the hoses disconnected, it should stop between 28-32 degrees.
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Rust NEVER sleeps and stock never goes out of style.
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Frodge
Samba Member
Joined: October 04, 2006
Posts: 1991
Location: Dump
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| Posted: Tue Jun 22, 2021 4:58 am Post subject: Re: Static Timing Questions |
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| busdaddy wrote: |
If it runs now you won't improve anything by static timing it, you must use a timing light, and you'll also need a degree wheel if the light doesn't have an advance dial on it.
Driving with the timing off is dangerous, you can damage internal engine parts or over heat it without knowing until it's too late, get your hands on a timing light. |
You can statically time the engine of it has matching carb and vacuum advance distributor. I run the original solex and 205t and statically time mine for 20 years. I was told this can be done if you run stock by many old vw guys. If you start going to 009 or distributor like that you need to use a light. |
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MuzzcoVW
Samba Member
Joined: February 21, 2018
Posts: 1462
Location: Westfield, MA.
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| Posted: Tue Jun 22, 2021 6:40 am Post subject: Re: Static Timing Questions |
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| I would only use static timing for initial setup. I know there are many who only use static but it's just too much of a gamble. Timing light is far more accurate... and easier IMO. If you're off by a couple degrees at idle it really doesn't matter, but can be a huge issue at highway speeds |
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busdaddy
Samba Member
Joined: February 12, 2004
Posts: 51128
Location: Surrey B.C. Canada, but thinking of Ukraine
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| Posted: Tue Jun 22, 2021 8:14 am Post subject: Re: Static Timing Questions |
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| Frodge wrote: |
| busdaddy wrote: |
If it runs now you won't improve anything by static timing it, you must use a timing light, and you'll also need a degree wheel if the light doesn't have an advance dial on it.
Driving with the timing off is dangerous, you can damage internal engine parts or over heat it without knowing until it's too late, get your hands on a timing light. |
You can statically time the engine of it has matching carb and vacuum advance distributor. I run the original solex and 205t and statically time mine for 20 years. I was told this can be done if you run stock by many old vw guys. If you start going to 009 or distributor like that you need to use a light. |
That's comparing apples to oranges, your SVSA unit can time static, the OP's DVDA can not.
_________________
Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 15982
Location: North Florida, USA
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| Posted: Tue Jun 22, 2021 3:27 pm Post subject: Re: Static Timing Questions |
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| Gadwood74 wrote: |
So I think I understand the 7.5.
While timing, I guess I also need to verify at higher RPM? |
I just helped a buddy install an aftermarket clone of the OE Bosch SVDA distributor. Ideally, we should have been able to set it to 7.5BTDC @idle just like the OE Bosch distributor and be done with the ignition adjustments. We set it to 7.5BTDC as part of the initial set up, but to be safe we also tested the max total advance w/o vacuum advance. This was to check how much the mechanical (rpm-based) advance was adding to the initial 7.5BTDC. We were looking for a total of 28-32BTDC, the safe upper limit for ACVWs. This would show that the mechanical advance was adding 21-25deg of timing advance. The total advance on this distributor reached 35BTDC. The aftermarket clone was providing too much mechanical advance! We set the total advance to 30BTDC and let the idle timing drop to 2BTDC. Going forward, the idle timing for this distributor will be 2BTDC... to make sure the total rpm-based timing never goes above 30BTDC.
Just trying to illustrate that just because it is a clone of the OE SVDA distributor it does not mean it can be trusted to have the same build tolerances. Checking that your distributor's mechanical advance maintains a safe upper limit will avoid damaging your engine with too much timing advance at high rpms under load. Mechanical advance does not take engine load into account. It only looks at the rpm and advances based on engine speed. Even race engines limit their rpm-based timing advance to no more than 35BTDC to avoid detonation. 28-32BTDC is the safe upper limit for ACVWs.
The other (more involved) way to fix this would be to disassemble the distributor and tweak the stop for the mechanical advance plate. By adjusting this stop you limit the amount of advance the mechanical weights and springs will provide; bringing it back into the OE spec of around 22.5deg. Without a distributor machine to test the timing outside the engine this would take a great deal of trial and error to adjust properly.
The earlier SVSA distributors had no mechanical advance systems. On the SVSA distributor the vacuum signal is the ONLY advance system in addition to the initial (static) timing. They advanced based on venturi vacuum and intake vacuum. Venturi vacuum goes up with increased velocity thru the carb. Intake vacuum goes down with engine load. This vacuum signal could adjust for higher engine rpms (higher air velocity thru the carb) as well as engine load (lower vacuum under load).
When checking the ignition timing at idle with the vacuum advance hose disconnected, the only timing setting involved is the static timing. So static timing and idle timing w/ the vacuum hose disconnected should always be the same. But I will point out that strobe timing at idle tends to be more accurate than static timing. So if you want to be sure your ignition timing is actually TDC and not TDC +/- 1deg, use a strobe timing light.
The SVDA distributor could ideally be static timed and it should be the same as idle timing with the vacuum advance hose disconnected. At idle below 1000rpm the mechanical advance "should not" yet be adding any advance. But unlike the SVSA distributor where you disabled all other advance mechanisms by disconnecting the vacuum hose, you have not "disabled" the mechanical advance, you are just assuming it is not working below 1000rpm. For this reason, static time to get it running and double-check at idle with a strobe timing light that the idle timing has not changed. Again, I have usually found that strobe timing is more precise than static timing.
_________________
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!}
Last edited by ashman40 on Tue Jun 22, 2021 3:53 pm; edited 1 time in total |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Tue Jun 22, 2021 3:50 pm Post subject: Re: Static Timing Questions |
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https://photos.app.goo.gl/6FncejCTsNEiMfuQ8
Just did this. Idle @7.5 (not too precise as the rpm varies). I think I set it OK!
It was way off before.
Goes up to 30 with a higher RPM.
However, as soon as I accelerate the engine is missing air or gas (struggle on acceleration). Wasn’t doing this before. Maybe a carb adjustment? I’ve initially set the 2 screws @ 3 turns. Tried to give a bit more on each (different scenarios) but didn’t help… spark plugs were new but maybe got dirty. Choke runs good.
Always a little something 😅 |
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Gadwood74
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Posts: 62
Location: Quebec
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 15982
Location: North Florida, USA
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| Posted: Tue Jun 22, 2021 6:17 pm Post subject: Re: Static Timing Questions |
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In the first video your idle rpms are above 1000. This means your mechanical advance could be on the verge of adding to the timing. You need to get the rpms in the 800-950 range at warmed up idle.
I can see the dot which I assume is your TDC mark as well as a line that you added which represents, what? 7.5BTDC? In the first video are you trying to show that with your timing light set at 7deg the 7.5BTDC mark lines up with the case split? That would mean your idle timing is 7deg + 7.5BTDC = 14.5BTDC. That is rather on the high side for idle timing. Have you tried setting your timing light to 7deg and rotating the distributor body until the TDC mark lines up with the case split? This would set your idle timing to 7BTDC (TDC + 7deg).
In the second video you have your timing light set to 30deg and the 7.5BTDC line is jumping around the case split. This would indicate your total timing is around 37.5BTDC. This is too high. Rotate the distributor body until the TDC dot lines up with the case to bring your total timing to 30BTDC.
Was this taken with the vacuum hoses disconnected and plugged? This should have been done with all distributor hoses disconnected and plugged. The vacuum advance could have been adding timing advance if still connected.
Your timing marks seem to be jumping around even at idle below 1000rpm. Also, your strobe light pulses are not consistent. This suggests your timing light is not getting consistent pulses from the inductive pickup. Try moving the inductive pickup to the spark plug end of the #1 plug wire at the right side of the engine. Sometimes the pickup can detect stray pulses from other nearby wires. This is why you should not connect the inductive pickup near the distributor cap as all four spark plug wires are very close to each other here.
_________________
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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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Tue Jun 22, 2021 6:35 pm Post subject: Re: Static Timing Questions |
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First attempt in timing an engine! Still have homeworks to do...
So if I set my timing light to 7deg, this means that my TDC mark needs to be aligned to the case split, right?
Or if my timing light is set to 0, my 7BTDC line should align the case split.
Not easy to set idle at 800-950. Always have the feeling the damn thing will die!!
It was taken with hose connected, I'll redo with the hose disconnected (and nipples plugged). And I'll move the inductive pickup near the spark plug.
Only the advance hose is there, I've deleted the retard hose and plugged the front nipple on the carb.
I'll get there... I'm learning big time here. |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 15982
Location: North Florida, USA
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| Posted: Tue Jun 22, 2021 11:34 pm Post subject: Re: Static Timing Questions |
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| Gadwood74 wrote: |
So if I set my timing light to 7deg, this means that my TDC mark needs to be aligned to the case split, right?
Or if my timing light is set to 0, my 7BTDC line should align the case split. |
When you set your “advance timing light” to zero degrees it means the strobe will flash the instant it detects a spark on the (#1) spark plug wire. This is how typical/traditional timing lights work. If the 7BTDC mark on the crank pulley lines up with the case split under the strobe light it means the spark is coming 7deg BEFORE TDC. This method works great as long as you have markings for the timing you are checking/looking for.
When you set your “advance timing light” to 7deg it means the strobe light will now pulse/flash 7deg delayed. Most ignition timing is done with the spark firing some degrees BEFORE TDC. By delaying the strobe pulse by 7deg and lining up the TDC mark with the case split you are actually setting the ignition timing to 7BTDC. The spark at the spark plug is happening at 7BTDC but the advance feature of the timing light is delaying the timing light strobe pulse by 7deg. Under the strobe light the TDC mark lines up with the case split.
This feature is very useful as it allows you to check/adjust the timing to ANY BTDC value from 0deg to the max value of your light (60deg or 90deg in some cases). You do not need to add extra marks to the crank pulley nor do you need a degree crank pulley with 360 degree marks. Just set the desired BTDC degrees and check/set the timing using just the TDC timing mark.
| Gadwood74 wrote: |
| Not easy to set idle at 800-950. Always have the feeling the damn thing will die!! |
This suggests you have a problem with the engine. You should troubleshoot this and fix it if possible.
| Gadwood74 wrote: |
It was taken with hose connected, I'll redo with the hose disconnected (and nipples plugged). And I'll move the inductive pickup near the spark plug.
Only the advance hose is there, I've deleted the retard hose and plugged the front nipple on the carb. |
Thanking the readings with the vacuum advance connected basically means that all your readings are invalid.
At idle you are trying to confirm the initial timing setting with no other advance systems adding to the value.
At high rpms, you are trying to confirm the initial timing + max mechanical advance never takes you above 28-32BTDC. If vacuum advance is adding to this you won’t know how much is coming from the mechanical advance.
My advice is to set your max total advance to 28BTDC.
Set your advance timing light to 28deg.
Disconnect and plug the vacuum advance hose.
With the engine warmed up, rev the engine up until the timing marks stop advancing.
While maintaining this high rpm, loosen and rotate the distributor body until the TDC mark lines up with the case split. Your timing is now set to 28BTDC.
Let the rpms drop to idle. Tighten the distributor clamp.
Rev the engine once more until the timing marks stop advancing and make sure the TDC mark still lines up with the case split (timing light still set to 28deg).
Let the rpms drop to idle.
While at idle, adjust the deg setting of your advance timing light until the TDC mark lines up with the case split.
Read the deg# from your timing light. This is your idle timing. This idle timing represents a max total advance (initial + mechanical) of 28BTDC.
If you want to advance the ignition timing you can add up to 4deg to take the max total advance to 32BTDC, but no more. Many engines will run fine with 28BTDC and start to encounter detonation at 30BTDC and above. So don’t feel the need to squeeze out every last degree of timing.
_________________
AshMan40
---------------------------
'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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Gadwood74
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Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Thu Jun 24, 2021 8:44 am Post subject: Re: Static Timing Questions |
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Well, I've done timing again w/o the advance hose (and nipples plugged) on idle at 850, tdc mark on engine split with timing light at zero.
Was trying then to see what was the advance at higher rpm , Strobe stops flashing at higher rpm. Is is clipped just near the spark plug number one... So couldn't read this well.
Tried the car again, ran like crap again (with the hose plugged back of course)
I may put back the retard hose and time 5 ATDC? |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Fri Jun 25, 2021 7:47 pm Post subject: Re: Static Timing Questions |
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Just a thought… can it be related to fuel pressure? I see I have a fuel
Pressure regulator in the engine bay…
When I set timing to where it should, the engine runs very bad…
I’ll change the fuel filter this we at least, even if it looks clean from the outside.
The car use to run quite well w/o the advance vacuum, but timing was completely off specs. Only the retard hose was connected. Since I’ve changed the vacuum can, fixed timing on it and connected the advance vacuum, the car won’t accelerate normally…. Anyways, getting a bit discouraged, but like everything else, we’ll find a solution someday… ideally before end of summer. |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Tue Jul 13, 2021 3:50 pm Post subject: Re: Static Timing Questions |
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Update
Distributor was bad. Now the car runs better, but still has a lot of hesitation. Still run with an EMPI carb so can be an issue.
Engine may have been affected by running with way too much advance. So I guess we’ll need to check valves, pistons etc. next winter. Hopefully crank will be good, but someone realized (from a picture in another thread) that it is a GEX… so I better be prepared for bad news. |
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LanceO
Samba Member
Joined: May 22, 2011
Posts: 54
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| Posted: Thu Jul 15, 2021 2:07 pm Post subject: Re: Static Timing Questions |
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| Gadwood74 wrote: |
Update
Distributor was bad. |
How'd you figure it out - trial and error? |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Thu Jul 15, 2021 2:17 pm Post subject: Re: Static Timing Questions |
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| LanceO wrote: |
| Gadwood74 wrote: |
Update
Distributor was bad. |
How'd you figure it out - trial and error? |
My mechanic told me simply. Apparently timing was not « normal » while trying to set it. I was not there watching him doing it so not too sure what this represents… and now I probably have burned valves because of the way the engine was adjusted. But runs way better that it was, I’ll be OK for the rest of the summer (I hope). |
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LanceO
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Joined: May 22, 2011
Posts: 54
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| Posted: Thu Jul 15, 2021 2:20 pm Post subject: Re: Static Timing Questions |
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Interesting.
I'm still having an idle prob (alongside this stupid spark plug insert issue), and one old VW guy is blaming on the carb and another old VW guy (both are local) thinks it's timing. If it's timing, then I'm starting to wonder if it's the distributor and not my timing setting. |
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Gadwood74
Samba Member
Joined: May 04, 2018
Posts: 62
Location: Quebec
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| Posted: Thu Jul 15, 2021 2:23 pm Post subject: Re: Static Timing Questions |
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| LanceO wrote: |
Interesting.
I'm still having an idle prob (alongside this stupid spark plug insert issue), and one old VW guy is blaming on the carb and another old VW guy (both are local) thinks it's timing. If it's timing, then I'm starting to wonder if it's the distributor and not my timing setting. |
We have 2 local guys here. One would use anything else than a 009 and the other would never use a 009…. Funny.
One thing for sure, they both say my EMPI 34 carb is junk and can be the source of many problems and symptoms. But Solex are hard to find so…. |
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