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914World.com _ 914World Garage _ 2.0 distributor advance/retard question
Posted by: Robson51 Mar 5 2020, 11:48 AM
I am working on a 2.0 and have read a bit about the distributor vacuum advance/retard. It seems like the vacuum advance is just to get through a rough spot at part throttle, and does not affect the total amount of advance.
I understand the retard was there for emissions only.
So my question is this-
What happens if I run the car with both disconnected? I would love to get a 123 set up, since the car is running fuel injection, but it's not in the budget right now. How will it run?
Thanks-
Rob
Posted by: IronHillRestorations Mar 5 2020, 12:42 PM
You want them both connected. You can run it with both off, but you'll lose some performance somewhere in the RPM range, it will probably be a little boggy
Posted by: Bleyseng Mar 5 2020, 01:15 PM
I run it with just the vacuum advance hooked up and nothing connected to the retard. My engine isn't stock thou and isn't boggy at all.
Posted by: GregAmy Mar 5 2020, 01:30 PM
Just curious: why do you want to remove it? Are the pots damaged?
Posted by: Bleyseng Mar 5 2020, 01:54 PM
If the advance weights inside are spotlessly clean it will run fine. Most 914 dizzy weights are gummed up with 50 year old grease. Time the engine to 3500 rpms to the 27 BTDC mark on the fan.
Posted by: bbrock Mar 5 2020, 04:06 PM
I'm curious why people disconnect their vacuum retard when they have them? I've read articles from Jake Raby that say the retard improves emissions "a lot!" and can also smooth low idle. I know there is a tendency to think anything emissions related robs HP but I fail to see why vacuum retard would do that. Am I missing something?
Posted by: Robson51 Mar 5 2020, 04:30 PM
Just curious: why do you want to remove it? Are the pots damaged?
PO only had advance hooked up. The more I looked into it, it almost seemed like it's basically a centrifugal distributor with vacuum only to help it through some rough patches.
I just thought I would ask.
Posted by: Robson51 Mar 6 2020, 02:26 PM
If the advance weights inside are spotlessly clean it will run fine. Most 914 dizzy weights are gummed up with 50 year old grease. Time the engine to 3500 rpms to the 27 BTDC mark on the fan.
Good point. Just took a closer look at it and it's dirty and sticky. Sometimes I'm surprised this car ran at all.
Posted by: Gatornapper Mar 8 2020, 06:47 AM
Don't want to hi-jack this thread, but had a weird thing happen to my 0 231 181 009 dizzy re: centrifugal advance. Last Thursday, engine was running perfectly with Pertronix 1847V ignitor that seemed to fail.
I put points in the dizzy, and now the centrifugal advance does not work at all. Did nothing but pull the dizzy, put in points, all centrifugal advance gone. Yesterday put in Hot-Spark ignitor which of course changed nothing.
Will rebuild the dizzy next week and see internally what stopped the weights from working.....but no idea what would bring the change....no, did not drop the dizzy.
Meanwhile, put a new Hot-Spark ignitor in my old 0 231 178 009 and its CA is working fine. Just prefer the advance curve in the 181...
Oh - and as I'm running Webers, I'm not using, nor do I need, the vacuum advance/retard......
GN
Just curious: why do you want to remove it? Are the pots damaged?
PO only had advance hooked up. The more I looked into it, it almost seemed like it's basically a centrifugal distributor with vacuum only to help it through some rough patches.
I just thought I would ask.
Posted by: bbrock Mar 8 2020, 09:49 AM
Don't want to hi-jack this thread, but had a weird thing happen to my 0 231 181 009 dizzy re: centrifugal advance. Last Thursday, engine was running perfectly with Pertronix 1847V ignitor that seemed to fail.
I put points in the dizzy, and now the centrifugal advance does not work at all. Did nothing but pull the dizzy, put in points, all centrifugal advance gone. Yesterday put in Hot-Spark ignitor which of course changed nothing.
Will rebuild the dizzy next week and see internally what stopped the weights from working.....but no idea what would bring the change....no, did not drop the dizzy.
Meanwhile, put a new Hot-Spark ignitor in my old 0 231 178 009 and its CA is working fine. Just prefer the advance curve in the 181...
Oh - and as I'm running Webers, I'm not using, nor do I need, the vacuum advance/retard......
GN
Just curious: why do you want to remove it? Are the pots damaged?
PO only had advance hooked up. The more I looked into it, it almost seemed like it's basically a centrifugal distributor with vacuum only to help it through some rough patches.
I just thought I would ask.
My first thought is that the screw for the points is too long and preventing the plates from rotating properly to advance.
Also, carbs can benefit from vacuum advance too. Here's a good article on distributor choices: https://www.aircooled.net/vw-distributor-options/
Posted by: Gatornapper Mar 8 2020, 07:38 PM
Brent -
I believe the rotating plates are only moved by the vacuum advance/retard, which I am not using. and that plate seems to move nicely........
The centrifugal advance mechanism is weights and spring beneath the plates that actually move and advance the whole 4-lobe timing cam in relation to the dizzy drive shaft.
Very simple and I'll dive into taking the dizzy apart tomorrow......
GN
My first thought is that the screw for the points is too long and preventing the plates from rotating properly to advance.
Also, carbs can benefit from vacuum advance too. Here's a good article on distributor choices: https://www.aircooled.net/vw-distributor-options/
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