Distributor Specs and adjustment questions

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Gypsie
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Distributor Specs and adjustment questions

Post by Gypsie » Mon Aug 20, 2012 1:46 pm

Ok. Questions for the group.

I recently bit the bullet and purchased a rebuilt distributor from a reputable builder (the Philbin Group).

I wanted to keep my original as a spare with points set and ready for a 'side of the road' swap, (I plan on setting timing and keeping the clamp attached and set as I have a Pertronix that I hear may crap out someday).

Before installation I checked part numbers on the dizzy body. My current distributor is a Bosch 0231 170 093.

What I purchased had these numbers on the side: Bosch 0231 170 034.
My cursory research reveals that this is for a Beetle. I called the rebuilder and queried about this discrepancy and he said "you should have no problem" I queried further regarding advance curve for both mechanical and vacuum, and he said that they test all devices by testing them on the bench and that if I have any problem I can bring it back. My concern is that by the time I discover a problem there may be damage done due to out of kilter advance (not so keen on that)

My question for the group is: Can this part number (Bosch 0231 170 034) be used for my 1980 Vanagon? I can see that the advance curve could be made to work with the proper centrifugal adv. spring tension and vac. can travel and presumably this has been spec'd by the builder though I am hesitant to install it if I will be blow torching valves or some other unforeseen conflict.

Below are the specs for my rig provided by old volks home:


Vanagon Federal 1980-1983 * 2000

Note: This Distributor also fits Type 4 (412) 1974
Distributor: VW 022-905-205S, Bosch 0231 170 093
Note: VW 021-905-205P, Bosch 022-905-205S, 0231 168 005
Can Use:
Points: 01 011
Condensor: 02 074
Rotor: 04 033
Dust Cover: 039-905-241, Bosch 1230 500 139 > 1230 500 147
Cap: 03 010
Distributor Cap Clip: 034-905-265, Bosch 1231 251 033
Parts Kit (Shims, Washers & Hardware): 059-998-211, Bosch 1237 010 007
Coil: 00 012
Vacuum Can: 07 060
Ignition Wires: 09 171
Spark Plug: W8CC
Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacuum hose connected. (Bentley Table on Page 28.3 incorrectly states with hose disconnected).
Advance/Retard Range: Vacuum: 8-12deg Adv @ 7.9 In. Hg; Centrifugal: 9-14deg @ 1600 rpm, 21-25deg @ 3400 rpm


I also am surprised to see that high rpm centrifugal advance is to be set to 21-25 deg as I have been setting to 28*, which (the old dist) still leaves it struggling at idle... If I set to 21-25 I am sure that the beast will not run at idle at all.

My desire to switch dist. is because I am having difficulty finding the balance between idle and operating speeds. When timing is set to operating speeds rpm (28* at 3000rpm) , it runs great on the open road and struggles at idle (down to 4* at 700-800 (i can't get the idle rpms up in this condition).
If I set timing at idle rpm (7.5* at 1000 rpms) the full advance is in the 36-38* zone, which is concerning to me as this makes head temps want to climb in the uncomfortable zone when on the open road. I am also surprised to see that the vac line is to be connected when setting at idle...?

Lastly, does anyone have experience with the idle speed adjustment procedure for a vehicle with an automatic tranny. My understanding is that the final idle speed adjustment is to be done with the throttle linkage at the throttle body (ie the throttle body is opened/closed a smidge by way of the throttle linkage and locked down when in the sweet spot. this has always been a curiosity to me as this is not a finite point (ie the throttle plate is fully closed and adjustments (idle speed screw) are made at this stage.
Rather, the throttle linkage has a spring that allows for kickdown at WOT. If the idle speed is adjusted with the tension that is placed on the spring on the throttle linkage there is the possibility of parameters changing with the temp changes in the engine bay area. Likely there is not much variable and this is the least of my concerns in this area. just curious if anyone had thoughts about this peculiarity.

Lots of items to ponder, I know, I am just hoping one of y'all will have some guidance.

Thanks for anything you have to offer.
So it all started when I wanted to get better gas mileage....

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satchmo
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Re: Distributor Specs and adjustment questions

Post by satchmo » Mon Aug 20, 2012 2:32 pm

Gypsie wrote: I also am surprised to see that high rpm centrifugal advance is to be set to 21-25 deg as I have been setting to 28*, which (the old dist) still leaves it struggling at idle... If I set to 21-25 I am sure that the beast will not run at idle at all.
Er, how about adding in the initial timing (7.5 degrees BTDC) to the quoted 21-25 degrees of mechanical advance. That should get you near 30 deg for total advance. Most folks would tell you to time it to 28-30 deg at 3500 rpm (advance hose off), and let the idle fall where it falls.

You are unlikely to burn anything up running your new dist as long as you have the timing set correctly. The advance curve of your new dist. may be shaped differently than your original (check the oldvolkshome web page for specs), but it may or may not be all that noticeable in driving. I think for off idle performance, the vacuum advance is probably more important than the mech. advance (hence the reason why so few people like the mechanical advance only 009 dist), so put more of your focus on the vacuum can than on the dist. body.

Tim
By three methods we may learn wisdom:
First, by reflection, which is noblest;
second, by immitation, which is easiest;
and third, by experience, which is bitterest. -Confucius

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SlowLane
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Re: Distributor Specs and adjustment questions

Post by SlowLane » Mon Aug 20, 2012 2:42 pm

Gypsie wrote: Bosch 0231 170 034.
My cursory research reveals that this is for a Beetle. I called the rebuilder and queried about this discrepancy and he said "you should have no problem" I queried further regarding advance curve for both mechanical and vacuum, and he said that they test all devices by testing them on the bench and that if I have any problem I can bring it back. My concern is that by the time I discover a problem there may be damage done due to out of kilter advance (not so keen on that)
I don't think you should have a problem. If you look at the advance curves published by Old Volks Home, they're all pretty much within the same ball park. The allowable variations for each distributor model overlap so much that you wonder why Bosch bothered making so many models. I really doubt that they were that finely spec'd. It's like saying you want a piece of rod cut to 25.405 mm +/- 2 mm.
My question for the group is: Can this part number (Bosch 0231 170 034) be used for my 1980 Vanagon? I can see that the advance curve could be made to work with the proper centrifugal adv. spring tension and vac. can travel and presumably this has been spec'd by the builder though I am hesitant to install it if I will be blow torching valves or some other unforeseen conflict.

Below are the specs for my rig provided by old volks home:

Vanagon Federal 1980-1983 * 2000
Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacuum hose connected.
Advance/Retard Range: Vacuum: 8-12deg Adv @ 7.9 In. Hg; Centrifugal: 9-14deg @ 1600 rpm, 21-25deg @ 3400 rpm


I also am surprised to see that high rpm centrifugal advance is to be set to 21-25 deg as I have been setting to 28*, which (the old dist) still leaves it struggling at idle... If I set to 21-25 I am sure that the beast will not run at idle at all.
The 21-25 deg value is not what you set it to, but is the amount that the centrifugal mechanism will advance by at 3400 RPM, compared to idle (or static). It's what you would see at 3400 RPM if you had set your idle advance to 0 degrees. If you set your idle advance to 7.5 degrees, you should then see 28.5 - 32.5 (ie 7.5 + 21 - 25) degrees total advance at 3400 RPM.
My desire to switch dist. is because I am having difficulty finding the balance between idle and operating speeds. When timing is set to operating speeds rpm (28* at 3000rpm) , it runs great on the open road and struggles at idle (down to 4* at 700-800 (i can't get the idle rpms up in this condition).
If I set timing at idle rpm (7.5* at 1000 rpms) the full advance is in the 36-38* zone, which is concerning to me as this makes head temps want to climb in the uncomfortable zone when on the open road. I am also surprised to see that the vac line is to be connected when setting at idle...?
It sounds like you just need to move the weight stops in a bit to give yourself less total advance at high RPM.
'81 Canadian Westfalia (2.0L, manual), now Californiated

"They say a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance."
- Terry Pratchett

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Gypsie
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Re: Distributor Specs and adjustment questions

Post by Gypsie » Mon Aug 20, 2012 4:12 pm

excellent feedback.

I am relieved that I will not have to get stinky about returning an uninstalled dist, as it sounds like the difference is minute enough to be inconsequential. It will be thoroughly run through it's paces once installed.

I also am reminded by you two that the specs regarding advance refer to the distributor behavior specs and not ignition timing specs. doh! With these reminders I can correctly see that the maximum degree of centrifugal advance of the distributor is 21*-25* and that timing adjustment for optimal performance of the engine is to set the timing to the total amount of advance of plug firing to BTC. Thank you, gentlemen, for reminding me that to focus on one tree is to miss the forest. I am such a dolt sometimes.

I am interested in the distributor adjustment you refer to, slowlane. Are these weight stops accessible without dist. disassembly? I am interested in checking out my original dizzy and perhaps giving it a refresh without the $150 rebuild at Philbin though I will comfortably pull that sucker apart once I am assured that my newly rebuilt one will work properly.

I also found on the old dizzy that the felt wick under the rotor was missing. Can I just find a wad of felt to poke in there? I added a few drops onto the screw there presuming that it would seep down into the area needing lubrication even without the felt, though I would like to replace the wick.

I had a problem with the vacuum advance sticking recently as well. After I expressed my shock at finding my centrifugal advance (with no vac hose connected) at 3000rpm to be 42*. When I opined, at the Lab over a pint, that I did not understand how my timing could work it's way to this position when it was securely clamped down our Itinerant Madman immediately surmised that the vacuum advance was likely not releasing. Double Doh!! I pulled the dizzy and spritzed it out and tested using the tried and true method of applying vac pressure to the vac can and it advanced and released reliably a dozen times.

I will look into the max centrifugal advance being provided by the current dizzy because I do think that it is a bit more than 25* (maybe only a few * more) but an adjustment may be in order.
So it all started when I wanted to get better gas mileage....

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Amskeptic
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Re: Distributor Specs and adjustment questions

Post by Amskeptic » Tue Aug 21, 2012 7:56 am

Gypsie wrote:our Itinerant Madman immediately surmised that the vacuum advance was likely not releasing.
I will look into the max centrifugal advance being provided by the current dizzy because I do think that it is a bit more than 25* (maybe only a few * more) but an adjustment may be in order.
Please note:
The oem scale cut-out gives you an actual timing range of 25*-28*. It does not care about "the range of the weights being added to the initial timing set point".

Your engine should not give a fiddlef**k about running anywhere from 7.5*BTDC all the way down to 5*ATDC at idle, it does not care. Set to max 28* period down at sea level with compression ratio of 7.3:1 or above. You need to know that under load on a hot day, you must not fool around with a combustion pressure wave hitting the compression stroke too early, that is what causes temperature spikes that can spontaneously ignite all the gas vapor instantly (as opposed to the desired flame front travel) and you do not necessarily hear the pinging, and your two channel CHT gauge may not catch it either.

YOUR problem, Gypsie, is not timing. It is airflow/mixture at idle. Do you have the automatic transmission throttle plate, the one with the drilled hole?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Gypsie
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Re: Distributor Specs and adjustment questions

Post by Gypsie » Tue Aug 21, 2012 10:43 am

Amskeptic wrote:

YOUR problem, Gypsie, is not timing. It is airflow/mixture at idle. Do you have the automatic transmission throttle plate, the one with the drilled hole?
Colin

Oooh, now were getting somewhere. I happen to have a drilled throttle plate as I have drilled it after rebuilding because it was not idling at all even with the idle speed screw all the way out and ready to fall off. I was not aware that the automatic needed a drilled throttle plate. Is this something I missed in the Bentley?

How big is the hole supposed to be?

I did discover that my throttle linkage had come loose and had backed out about 15 mm. This was allowing the throttle plate to sit all the way down (at rest) when the pedal was released. It also made it so that the accel. pedal had to be almost floored to get up to speed and would go into kickdown before being at WOT. That was a simple fix though I am of the mind to think that the throttle plate should come to rest and idle adjustments are made from there.

The idle speed adjustment made by turning the throttle link adjustment in to pull the throttle plate open is still unclear in my head. I can see why a hole in the plate would help by adding some air (as if the throttle plate was open a smidge).

Trying to grok this....
So it all started when I wanted to get better gas mileage....

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Amskeptic
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Re: Distributor Specs and adjustment questions

Post by Amskeptic » Tue Aug 21, 2012 8:22 pm

Gypsie wrote:
Amskeptic wrote:

YOUR problem, Gypsie, is not timing. It is airflow/mixture at idle. Do you have the automatic transmission throttle plate, the one with the drilled hole?
Colin

Oooh, now were getting somewhere. I happen to have a drilled throttle plate as I have drilled it after rebuilding because it was not idling at all even with the idle speed screw all the way out and ready to fall off. I was not aware that the automatic needed a drilled throttle plate. Is this something I missed in the Bentley?

How big is the hole supposed to be?

I did discover that my throttle linkage had come loose and had backed out about 15 mm. This was allowing the throttle plate to sit all the way down (at rest) when the pedal was released. It also made it so that the accel. pedal had to be almost floored to get up to speed and would go into kickdown before being at WOT. That was a simple fix though I am of the mind to think that the throttle plate should come to rest and idle adjustments are made from there.

The idle speed adjustment made by turning the throttle link adjustment in to pull the throttle plate open is still unclear in my head. I can see why a hole in the plate would help by adding some air (as if the throttle plate was open a smidge).

Trying to grok this....
I personally do not know of any Volkswagen after 1971 using the throttle linkage to set the idle. As a matter of fact, any throttle link adjustment is just to synchronize full throttle with kickdown. Stock cam?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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Gypsie
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Re: Distributor Specs and adjustment questions

Post by Gypsie » Wed Aug 22, 2012 7:41 am

In the area (of several manuals) speaking to throttle link adjustment, the final adjustment is for idle speed, though I still am at a loss for why this would need to be adjusted because the throttle link adjustment begins with the throttle link being at rest and adjusted to the point of contact against the link bushing. The override spring (for kickdown) pushes against the throttle bushing from the other side. The adjustment appears to speak to the possiblilty of impacting the idle speed when you adjust the throttle linkage and that it may require 'correcting'.

When I purchased the van it had a lockdown screw on the throttle linkage (as if it were a manual tranny) thereby eliminating the kickdown. ??? I figger that (since the rig is set up for an auto tran, someone got all ..uh...creative in some repair or other.

I have a Webcam 107i (very close to stock but a little different).

Volkswagen Type 4 8v
Part #: 00-612 (00-370 ; 00-372)
Grind: 107i vs (Stock)
---------------------------- Intake------------ Exhaust
Valve Lash (Inch):------------ HYD------------------HYD
Valve Lift (Inch): -----------.430(.333)------------.430(.313)
Valve Lift (mm):------------ 10.92(8.46)----------10.92(7.95)
Advertised Duration:--------255°(224°)----------255°(230°)
Duration @ 0.050":--------- 225°(196°)----------225°(196°)
Lobe Center: ---------------- 108°(108°)---------108°(108°)

Intake Opens 4.5° (-10°)BTDC Exhaust Opens 40.5° (26°)BBDC
Intake Closes 40.5° (26°) ABDC Exhaust Closes 4.5° (-10°) ATDC

Valve Timing Is Checked With Zero Valve Lash @ 0.050 Inches Of Valve Lift.
Comparison Chart:
http://www.vwparts.net/mm5/merchant.mvc ... webcamt4ch
So it all started when I wanted to get better gas mileage....

VWnBlood
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Re: Distributor Specs and adjustment questions

Post by VWnBlood » Tue Sep 08, 2015 6:15 pm

Late bay 76, my question is are all these 3 distributors interchangeable for my late 76bay ; 021 905 205p
022 905 205s
0231 168 005
* 0231 170 093
* This is the 1 I'm considering buying since I'm not having any luck finding the
021 905 205p... I just don't want to buy it if it's not a a stock replacement. Thanks

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Amskeptic
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Re: Distributor Specs and adjustment questions

Post by Amskeptic » Thu Sep 10, 2015 6:23 am

VWnBlood wrote: are these 3 distributors interchangeable ;
a) 021 905 205p
b) 905 205s
c) 0231 168 005
d) * 0231 170 093

* This is the 1 I'm considering buying since I'm not having any luck finding the
021 905 205p... I just don't want to buy it if it's not a a stock replacement. Thanks
I see four listed.
Go look at the vacuum and centrifugal advance ranges for each of the above. You want each to get you to 28* @ 3,400 rpm, and each needs to offer an additional 10* of vacuum.

I am not going to blithely answer your question above. Get what is available out there and you can definitely make it work, but check the advance right out of the box. The vacuum can must rotate the breaker plate counterclockwise and hold vacuum. The centrifugal advance must allow you to wind the rotor clockwise and it must spring back when you release it.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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