Distributors

[koho60]

I just put a 009 in my 72 T2 and am not quite sure were to set the advance. I set it at 35 btdc. I run 92 octane and am not getting any pinging. Is this still to high or should I retard it a tad?

Also, Is there any place I can get my stock vacuum advance distributor checked or repaired? The diaphram is still good it just will not advance right.

Mahalo
Jeffro

[NeverHadaBeetle]

Did you say 35 or was that a typo???? I assume you are talking about total advance before BTDC at about 3,000 RPMs. Sounds close to the total advance others claim to run, but I have never tried this method.

[koho60]

Do you know of any place to test my old distributor?

[NeverHadaBeetle]

You can test the distributor while on your engine, but you have to have a strobe timing light and a tach. All distributors are different, but basically you check the total advance of the distributor as you increase RPM up to about 3,000-4,000. This tells you how much total advance your distributor has at a specific RPM. Some distributors advance more than others and there are specs available for most of the common distributors, but I don't know where. I have seen them somewhere on a website, but I can't remember where. Check the archives at type2.com and search under "total advance timing" which should yield some info. I would ballpark total advance for most distributors at 35 degrees at about 3,500 RPM, but this is just a guess. I would think less than 30 degrees at 3,5000 would not be enough, but as I said there are specs for each of them so this is just a guess. Some people swear by this method for setting timing, but I never use it personally so I can't give you any specifics. Any reputable shop could check the total advance of your distributor or you could purchase a tach and timing light for less than $50 and do it yourself.

[Karl]

http://www.oldvolkshome.com/ignition.htm

Depending on the distributor, you can have 42-44 degrees of advance.
Initial + centrifugal + vacuum advance = total advance.
Using your 72 bus dist. as an example:

Bus & Pickup 1972 * 1700
Distributor: VW 021-905-205E, Bosch 0231 173 005
Vacuum Can: 07 101
Timing Set At:: 5deg ATDC @ 800-950rpm w/strobe, vacuum hose(s) connected
Advance/Retard Range: Vacuum: 8-12deg Adv, 11-15deg Ret; Centrifugal: 13-16deg @ 2000rpm, 23-26deg @ 3600 rpm

15 degrees vac retard + 12 degress vac advance + 26 centrifugal - 5 after degrees = 48 degrees of total advance.

And you are replacing it with a distributor that only gives you 35 degrees of advance and you lose in-town part-throttle drivabilty? Why are you doing this?!?

[koho60]

OK!
Thanks for the feedback. I live on the big island of hawaii and after driving up and down the same roads again and again I know what speed I should be going at any given point. I started to notice that I was losing MPH on the way home. I checked my timing via a strobe light. I noticed that my timing would advance to 35 BTDC and then retard to about 15 BTDC on it's own. I replaced all hoses and same problem. I had a 009 and put it in and my bus ran great. I would rather have the stock vac advance but I think my 205 is bad. I would like to have it tested.

Mahalo
Jeffro

[Type2meister]

Hey Jeff,
I replaced my 009 with the stock vac advance that was pulled out years ago. Apparently the advance plates were frozen so the entire distributor was taken apart and rebuilt. It seems to run nicer with the stock distibutor, lacking the "flat spot" and climbing the hills a little better in 3rd and 4th. I do have to upgrade the main jet to a larger size though. Maybe I'll ask a question re: that!