Distributor 180* Off

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whc03grady
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Distributor 180* Off

Post by whc03grady » Tue Sep 05, 2017 10:10 am

Earlier this Summer I tried to help out a stranded couple in a '68? I think it was? bus that was running like crap. I couldn't get the engine timed...it backfired like crazy under load and I had to surrender to a mechanic. Nota bene: it backfired under load. It'd sit there and idle and rev okay, but if you tried to drive it, sputter sputter ka-POW!
Well a few mechanics and tows later the couple got to where they were going. The owner says she found a new mechanic who told them the distributor was installed 180* off.
Admittedly, this thing ran like shit but it did move down the road, more or less, and idled well enough most of the time. Would that have even been possible with the spark 180* out of sync with the strokes? I'm more inclined to believe this person is misunderstanding the mechanic than that an engine can provide any meaningful power whatsoever when it's firing at BDC of the opposite* cylinder's intake stroke. Can a car really get from Indiana to Oregon like this?

*opposite distributary-wise, not opposite engine layoutary-wise
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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Amskeptic
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Re: Distributor 180* Off

Post by Amskeptic » Thu Sep 07, 2017 9:45 am

A distributor that is 180* off can run just fine if the wires correspond. I think someone is grabbing at a cause. If the distributor were 180* off and the wires were not corresponding,
1432 would be
3214
and the engine could not develop any motive force at all.
Colin
BobD - 1978 Bus . . . . . . . . . . . 111,155 miles
Chloe - 1970 bus . . . . . . . . . . . 206,820 miles
Naranja - 1977 Westfalia . . . . . 108,000 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,885 miles

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asiab3
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Re: Distributor 180* Off

Post by asiab3 » Thu Sep 07, 2017 11:45 am

Those symptoms sound like plug wires in the wrong spot, but 180° off could not start or run at all. I had my bus up to 35mph in 3rd on two cylinders years ago, before I knew what the heck I was doing… If the cap was 180° off, with the wires were in the correct spots to compensate, the cap could be wobbling around and causing misfires. Either way, I'm glad they're back on the road.

In the future, I would recommend "The Metric Wrench" in Billings. I know it's kind of a drive from Livingston, but there's one old gentleman there who knows Air-Cooled engines, and they have some dealer parts stashed upstairs from back in the day.

Robbie
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

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whc03grady
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Re: Distributor 180* Off

Post by whc03grady » Thu Sep 07, 2017 12:14 pm

Amskeptic wrote:
Thu Sep 07, 2017 9:45 am
If the distributor were 180* off and the wires were not corresponding,
1432 would be
3214
and the engine could not develop any motive force at all.
My thoughts exactly.

I couldn't time it and couldn't understand why, but then again I unconsciously assumed the distributor drive is installed correctly on a recent rebuild and didn't look underneath it; it didn't cross my mind. Plus, I have a history with removing distributors.
This owner is insistent that the mechanic she took it to removed the distributor, removed the distributor drive, turned it 180*, put it all back together and it ran. The spark plug wires were correct throughout, meaning it was somehow running, shittily, 3-2-1-4? Impossible.
When she was here I implored her to avail herself to the IAC's in-person and virtual services but given our recent conversation on facebook, wherein she subtly implies I don't know what I'm talking about (when I say an engine can't run with the diz 180* off and the wires 'correct'), I don't think she'll show up here any time soon.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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sgkent
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Re: Distributor 180* Off

Post by sgkent » Thu Sep 07, 2017 12:27 pm

it could be that just two wires were reversed. In that case it would run but quite poorly. I use a sharpie on the dist cap to mark which wire is #1 then move around from there when verifying where the wires go - e.g. 1432.
Thank You -

Merlin The Wrench

Machine Work/Shop Recommendations: http://kentcomputer.com/77VW/machinework.pdf

Pointers on rebuilding an engine: http://kentcomputer.com/77VW/rebuilding_a_vw_engine.pdf

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whc03grady
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Re: Distributor 180* Off

Post by whc03grady » Thu Sep 07, 2017 1:26 pm

sgkent wrote:
Thu Sep 07, 2017 12:27 pm
it could be that just two wires were reversed. In that case it would run but quite poorly. I use a sharpie on the dist cap to mark which wire is #1 then move around from there when verifying where the wires go - e.g. 1432.
She was adamant that the mechanic removed the distributor drive gear, rotated it 180*, reinstalled everything, and then it ran fine. And that he didn't change the spark plug wires; "They were exactly where they would have been from the factory", she said.

So what she's saying is the spark plug wires were oriented for a properly indexed distributor/drive; that the distributor drive was 180* off; and that it ran, albeit poorly. I can personally verify the first and last statements. She just doesn't believe me that it's impossible for it to have run at all if the distributor was 180* off and the plug wires were in their normal positions. "Okay well, you explain what was going on to me then Because you couldn't figure out any other cause for the timing issue," she said.

I guess I shouldn't take it personally but I needed validation here that I'm not crazy. Also, it's sad to see a(nother) bus in the hands of someone who's being willfully ignorant. Maybe I should take solace in the fact that I'm 1 for 2 helping strangers with their buses this Summer.
Ludwig--1974 Westfalia, 2.0L (GD035193), Solex 34PDSIT-2/3 carburetors.
Gertie--1971 Squareback, 1600cc with Bosch D-Jetronic fuel injection from a '72 (E brain).
Read about their adventures:
http://www.ludwigandgertie.blogspot.com

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asiab3
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Re: Distributor 180* Off

Post by asiab3 » Thu Sep 07, 2017 9:33 pm

You're not crazy. The engine won't run without compression, and at TDC between the exhaust and intake stroke, both valves are open, albeit a tiny bit. There will be no compression at the point the engine needs to fire. There also wouldn't be any oxygen to burn, because the engine would have just exhaled almost all of the air in the chamber. And there would be no power stroke, since the intake valve would be fully open as the piston went down, even if the fuel could have combusted.

If the engine runs, and the distributor drive is moved, the wires move. End of story. There is a communication breakdown here, unless the mechanic was being less-than honest, and wrote her up for work not performed. I like to think that folks are more honest than that, but I've seen it time and time again where someone goes into a shop, and the coil is replaced because it's easier to justify high prices to customers when you have something shiny and new in a dirty engine compartment. It's hard to justify an hour labor for a valve adjustment, because the customer can't see the valve adjustment. But a shiny blue coil?

There's a ninety dollar bill.

Robbie

PS- It's her money, not yours, and she's happy with the outcome, right? Drive and let drive. :)
1969 bus, "Buddy."
119k miles with me.
296k miles on Earth.

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