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ashman40
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 Posted: Wed Jul 06, 2011 8:02 pm Post subject: Retarded #3 timing on pre-doghouse distributors |
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I've been curious about this for a while now....
I read that in an effort to reduce temps on #3 cylinder, VW offset the distributor cam lobe a few degrees retarded for JUST #3 cylinder. This was prior to the doghouse oil cooler/fan shroud which took the oil cooler out of the way and allowed more cooling air to reach #3 cylinder.
According to this passage from vw-resource.com even the 009 distributors of that era retarded the #3 timing.
| VW-resource.com wrote: |
A problem occurs in mismatching the 009 distributor with the doghouse-type oil coolers. Up to and including 1970, the oil cooler was internal to the fan shroud, and this meant that the #3 cylinder (left front) got warm air for it's cooling and therefore ran hotter than the others. So VW altered the timing on the #3 cylinder only -- the cam in the vacuum distributors has #3 cut 2-3 degrees later than the other three cylinders, to reduce the heat load on that cylinder a little. The early 009 distributors also had this feature.
But since 1971 the engines have a doghouse oil cooler that sticks out the front of the fan shroud. After passing through this oil cooler, the hot air is dumped overboard through some extra tinware. The fan itself is a little larger to supply this extra air. You should be able to see/feel this cooler sticking out the front of the fan shroud (front is front of car), slightly left of center. When you're under the car you should be able to see the rectangular air outlet in the tinware just above the bell housing. If the shroud is smooth/straight right across the front of the shroud, you have the earlier type of "in shroud" cooler.
So with the newer type oil cooler, the #3 cylinder now gets nice cool air for cooling, and the retard on #3 is not needed. The double vacuum distributors therefore have no retard on the #3 cylinder (double vacuum distributors were only used on '71 and later engines). VW dropped the retard on 009 distributors about 10 years ago too. So some 009 distributors have the retard, some don't. You need to make sure you have the right one. The only way to tell is to time the engine on #1 as it should be, then look at the timing for #3 (turn the engine 360 degrees). If the points open at the same time, okay; but if the points are opening later (the timing mark is now more about 4-5mm to the right), it's the wrong 009 distributor for a doghouse cooler engine. |
So the question... has anyone actually TESTED one of these distributors to see if #3 cylinder is actually firing a few degrees later than #1? It would be a simple test... connect the strobe timing light to #1 plug wire and set timing. Then move the inductive pick up to #3 plug wire. If all four lobes of the distributor shaft cam are exactly 90-deg apart, #3 will fire at the same timing mark as #1 on the crank pulley. If #3 is retarded, the tiiming marks will have shifted.
I found a few threads on this subject and it has actually been described as "urban myth". So is it true or not? And has anyone actually seen the proof?
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AshMan40
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'67 Beetle #1 {project car that never made it to the road  }
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Cusser
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gt1953
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| Posted: Wed Jul 06, 2011 8:52 pm Post subject: |
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I am surprised that Glen has not responded witht the answer...I do have reason to think that is is retared by 3 degrees.
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ashman40
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| Posted: Wed Jul 06, 2011 9:24 pm Post subject: |
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| Cusser wrote: |
| Glenn has a Sun distributor tester, bet he knows. |
I'm sure I could "see" 3-deg using just a timing light... but I don't have access to dozens of different distributors 
It would be good if we could take an example from science where one person publishes a theory (found a specific VW distributor model with retarded #3) and that theory is validated by another (someone else with the same model distributor). Only then is the theory accepted as true.
A bit harder for 009s as you would need to find two OLD ones and confirm.
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candymustang65
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| Posted: Thu Jul 07, 2011 8:09 am Post subject: |
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Yes Im interested as to what Glenn has to say about it ?
My understandin of it as well is that number 3 is retarded on all dizzy's .
Why you line up the slash mark on the edge of the dizzy in the Vicinity of #1 when time-ing .
Same reason you Sync dual carb's like dual 2 barrel webbers to the Lowest cyl. wich is #3 almost every time .
What say you Glenn ?
I cant answer the question for fear of being wrong, even tho it has never stopp'ed me before ? 
Sean |
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Glenn 
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| Posted: Thu Jul 07, 2011 9:20 am Post subject: |
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I don't work on the aluminum models but if you want to send one to me, i'd be happy to test it.
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kreemoweet
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| Posted: Thu Jul 07, 2011 10:52 am Post subject: |
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Personally, I believe this story of retarded timing on #3 cylinder is a MYTH.
It's been going around for decades. People have been asked time and time
again to point to ANY official VW literature which makes this claim, and no
one has ever been able to do so, that I know of. People have been asked
time and time again to make the accurate measurements necessary to
demonstrate this alleged fact, and no one has ever been able to do so, that
I know of. It seems very unlikely to me that VW would choose to deal with
the enormous complication in machining and assembly that would result,
for the very dubious benefit of a 2 degree (no one seems to have a precise
figure, naturally) retarded timing. I say it's bunk.
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Glenn
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| Posted: Thu Jul 07, 2011 11:59 am Post subject: |
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I've seen it, it's no myth.
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kreemoweet
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| Posted: Thu Jul 07, 2011 12:24 pm Post subject: |
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Hmm, yes, well I stand corrected. I found this on page 59 of the 66-69
Type I Bentley service manual:
"....On some engines No. 3 cylinder fires 4 degrees of crankshaft
rotation later than No. 1 cylinder."
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KTPhil
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| Posted: Tue Jul 19, 2011 9:12 am Post subject: |
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| kreemoweet wrote: |
Personally, I believe this story of retarded timing on #3 cylinder is a MYTH.
It's been going around for decades. People have been asked time and time
again to point to ANY official VW literature which makes this claim, and no
one has ever been able to do so, that I know of. People have been asked
time and time again to make the accurate measurements necessary to
demonstrate this alleged fact, and no one has ever been able to do so, that
I know of. It seems very unlikely to me that VW would choose to deal with
the enormous complication in machining and assembly that would result,
for the very dubious benefit of a 2 degree (no one seems to have a precise
figure, naturally) retarded timing. I say it's bunk. |
From the "Volkswagen Service Manual 1300/1500" published by
Delius, Klasing & Co, using Volkswagen photographs.
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Max Welton
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Cusser
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KTPhil
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| Posted: Tue Jul 19, 2011 9:41 pm Post subject: |
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| Cusser wrote: |
| So the myth of the the "several degrees retarded myth" is exploded ??? |
Yes, but with it gone, it will be mythed. |
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GüteAndTite
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69 Jim
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| Posted: Wed Jul 20, 2011 12:39 am Post subject: |
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| It's easy enough to see if it's there with the use of a caliper on the cam. |
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Glenn
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| Posted: Wed Jul 20, 2011 3:52 am Post subject: |
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| 69 Jim wrote: |
| It's easy enough to see if it's there with the use of a caliper on the cam. |
Or test it on a Sun Distributor tester.
I've seen 1st hand an 009 with a 3* retard on #3. It was a Bosch German unit. I've also tested a few early 70's units with the retard.
It's no myth, but since I really only work on the cast iron models, I never bothered to document it.
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runamoc
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| Posted: Wed Jul 20, 2011 7:55 am Post subject: |
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Glad I was able help 
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candymustang65
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| Posted: Wed Jul 20, 2011 8:22 am Post subject: |
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My understanding is that it is no Myth also but I was led to beleive that retarded dizzy lobes on #3 extended well past the older distributor's intoo the Dog house era ?
Laughin at Glenn with the Sun tester .
I havent seen one of those in year's ?
Cant remember the Name of the bigg machine's they use to have in full service gas station's > ) Oscilliscope's or somethin ?
Was a combination Tach, Dwell, Timeing light , Vaccum Gauge , volt ohm meter with a osciliscope screen for valves looked like something you would see in a hospital .
Huge roll away tool box sized engine analyzer's ?
Grey Lab coat and and an American Muscle Car on the rack ?
Ethyl out front with a girlie calendar in the back of the shop .
Yupp now Im old and have to pump my own gas ?
Provided I can, even get Elvira to turn on the right pump # ? LMAO
Sean |
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Cusser
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Paul Windisch
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| Posted: Wed Jul 20, 2011 12:09 pm Post subject: |
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He's actually right this time. We had one of the oscilloscopes he's talking about in high school auto shop. It had leads so you could watch the ignition pulses on all cylinders simultaneously to help determine misfires. It had lots of stuff it could do, as he said, timing, show dwell, advance curve, all kinds of stuff. They were very useful to have around. The one we had in school was a Sun as well. They have pretty much been replaced by hand held scan tools now, such as the Tech 2 we use at the dealer, which is now being phased out by a wireless diagnostic port with which we use a PC.
The scope was called an engine analyzer, and looked just like this:
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