TheSamba.com :: View topic - 90 degree difference? and petronix? and o-ring?

Tue Feb 09, 2010 6:14 pm

My distributor in my '69 camper seems to have developed a bit of shaft wobble and the rubbing block for the points wears unevenly. I think that might cause the point gap to vary and the points go out of adjustment quickly, but the engine runs well after a tuneup.

I purchased a new distributor several years ago and decided to replace the working, but tired, distributor today. I checked the point gap, oiled the felt, put a bit of dielectric grease on the rubbing block, swapped the wires to the new cap, and put it in. No start! I tried + and - a few degrees, No start!

I pulled the new distributor and compared it to the old. Between the two there is a 90 degree difference in the rotors when installed. I put the old tired distributor back in and put the wires back in the old cap and it started right up and ran well.

The part number on the old distributor is:
JUR4<-
Bosch logo 0 231 137 035
VW logo 119 905 205 T

The box for the new distributor is labeled:
Bruck VWC-043-905-205 SVDA repro distributor.
The distributor is stamped: 0113905205AN and it did not come with an o-ring and fits tighter than the old. The Cip1 ad states that their distributor, "Comes complete with cap,rotor,points and condenser. Ready to install." Their photo shows no o-ring. I pulled the old o-ring and put it on the new distributor, but it would not go in the hole.

I've installed the new distributor without the o-ring, swapped the wiring 90 degrees and after a few small + twists it stared up. I had already hooked up the dwell meter and timing light and, bang, dwell 24 degrees. Not a V8 and 24x2 is 48. Specs are 47 + or - 3. Pulled the vacuum line and ran it up to about 3,000 rpm, and, bang, right on the 28 degree mark I had filed on the pulley. A bit of a ticking noise so valve adjustment tomorrow and then test drive down to the tire shop to buy the proper Hankook tires for my new 15" wheels which fit over the front disk brakes.

That's the story. Here are the questions.

1. I believe the new distributor is correct for my engine and carburetor. I found a post by keifernet about the 90 degree difference between 009 and a SVDA and photos by Glenn of the two. Thank you both. But if both of my distributors are SVDA why is there the 90 degree difference?

2. Would my old distributor be usable with petronix? Petronix are pointless and the wobble might not be a problem.

3. Is my present coil usable with a petronix? It is blue and says Bosch but how do I know or measure the impedance?
This is from the aircooled.net website.
"IMPORTANT NOTE! You MUST make sure your ignition coil has the proper impedence, the Points Replacement Device WILL BURN UP if the coil has less then 2 ohms. Stock Bosch blue coils have 3 ohms of resistance INSIDE the coil (so they are compatible). If your coil or primary ignition winding has less then 2 ohms of resistance, the points replacement device in the distributor WILL BURN UP and leave you walking. There are 5 different "Bosch Blue Coils", and only one of them has the ballast in it (guess which one ACN sells?). You must measure your coil impedence to ensure compatability."

4. What would I carry for a spare if I went to petronix? The new distributor with points would be the spare if the old distibutor with wobble were not a problem for the petronix.

5. Why didn't the "ready to install" distributor have an o-ring? Do I need an o-ring? If so, where can I purchase it? Is it available online or can I find one at a good hardware store?

I did the search, read the Bentley, did the work and am ready for answers and opinions.

Aloha
tp

Wed Feb 10, 2010 1:50 am

Couple of things to be aware of....

Your old distributor (the 035 T) was not a SVDA, it was a vacuum only advance (no centrifical advance function). The 28 or 30 series carb you have may not provide a vacuum signature it is looking for. The SVDA from VW was used starting in 1971 with the dual port engines using the 34 series carbs. At least in buses.

Those chineese made Brucks have some QA/QC issues as the vacuum cans like to fall off. That can be a drag if you are stuck in the desert. Personally I prefer the "mexi-bosch" ones but that is just my choice.

You want to use a new distributor O -ring. I think you may be able to get that from a VW dealer still.

The fact that the 009 distributor is 90º "out of phase" is a 009 issue, not yours. It doesn't matter anyway. You want to install it so that the vacuum can clears any obstacles and still lets you time it correctly. You can always dance the ignition wires around the cap if needed.

Wed Feb 10, 2010 5:17 am

Thanks for the reply Randy

I did the wire dance, but there are more things that I don't understand now.

You said,
"Your old distributor (the 035 T) was not a SVDA, it was a vacuum only advance (no centrifical advance function). "

In another post you described how to set the timing,
"Remove the vacuum hose(s) going to the distributor can. Plug them with a golf T if you wish, but you don't have to.
Timing light hooked up.
Wind that bad boy up to about 3500 RPMs (the actual RPM doesn't matter) until all the centrifical advance it has to offer is "in". Make that point to be 28º BTDC on the timing scale by moving the distributor. Turn the engine off. Tighten up the distributor clamp." ...
and Busdaddy commented,
"Randy's post above applies to all combinations, distributor, carb or engine, follow it exactly and you're good to go."

I've seen other posts that referred to vacuum only distributors, but I thought all modern automobile distributors had centrifical advance. I consider a VW to be be modern when compared to a Ford model A which had an advance lever on the steering wheel with mechanical linkage to the distributor.
And when I did a tuneup didn't my old distributor advance to 28 degrees at 3000 rpm with the vacuum hose disconnected?

I understand that my carburetor may not have the correct vacuum signature for the new distributor and I've seen references to burned pistons using the wrong distributor. That would make me consider that the old distributor with the wobble and o-ring should be converted to petronix and the new distributor as a backup for SPF.

it's time to hit the search and books again
there is no shame in being ignorant, it is only a lack of knowledge
live, search, learn, and enjoy

Aloha
tp

Wed Feb 10, 2010 5:22 am

Tom,

From www.oldvolkshome.com....

Bus & Pickup 1969-1970 * 1600

Distributor: VW 113-905-205T, Bosch 0231 137 035 or 036
Can Use: VW 113-905-205M, Bosch 0231 137 021

Timing Set At:: 0deg TDC Static or @ 800-950rpm w/strobe w/vacuum hose disconnected and plugged
Advance/Retard Range: Vacuum (Advance Only): 17-19deg @ 1.3 In. Hg, 32-35deg @ 3.2 In. Hg

Also worth reading is this rap by andy.....

http://www.thesamba.com/vw/forum/viewtopic.php?t=185095

Wed Feb 10, 2010 2:21 pm

#2 Your current distributor works well and has the Pertronix? Use it. And don't use a worn out wobble distributor. The Pertronix unit uses magnets and with a wobble they probably would fire at the wrong time due to the wobble.
#3 Ratwell has good description of the various Bosch blue coils. Check the P/No to see what you have. However the wrong coil would be a Pertronix concern. Go to their website to find out what is needed and what is bad. Pertronix people are helpful. Go to them first. It's their unit and they are the experts.
#4 For spare parts to carry if you ever have Pertronix failure you need points, condenser, and condenser screw that will work in the distributor. No need for new parts. Old working spares are good enough. It would just be for an emergency fix anyway. !2 years with my dubs running the original Pertronix units and never a need for the spare points. Except to help a points guy broken down.

Wed Feb 10, 2010 4:10 pm

the current distributor is the 205T with a wobble shaft and fast wearing points

I just did a test drive with the SVDA
ok at first, a bit of acceleration hesitation, but then rough running, backfiring, and stalling at low rpm. difficult to restart, but it would run at high rpm and made it back home, pulled the SVDA, put the 205T back at the punch mark, did the wire dance and zipped around the block a few times. I have not found a new 205T online but found a restored 205T in the classifieds and I'll buy that. I called Pertronix and they said #1849 would work even with a wobbly shaft. I'll run the wobbly 205T with new points until the rebuilt arrives, install that, and use it until the points wear. buy pertronix #1849 and put it in the rebuilt and use the wobbly, but functional 205T, as the SPF backup., and I have a new SVDA to sell.

I have a plan.
Thanks for the help Randy and Desertbusman

Aloha
tp