Brickboards;

There's really a lot going on in the old Bosch distributor...centrifugal advance is just one thing. I'm compiling information and am looking for advance curve graphs for the following distributors: xxx003, xxx009, xxx078 (with vacuum advance), and xxx099 (also with vacuum advance), or links to the info. These are the distributor numbers I've seen fitted, and they all seem to have different control springs which means different curves... if there are others, I'd be interested too.

Thanks in advance for all responses.

This is completely pointless info, because:
1. I seriously doubt anyone has a stock standard engine.
2. You can NOT get vintage gas.

Back in the day, the fat spring was used to DELAY full timing at peak torque. Today, you can get fuel much better than 1960's fuel, so you can bend that fat spring tab in & gain midrange torque/power & economy.

The thin spring you can loosen until it pings, then tighten it up a little for more improvement.

There are still special cases: I have a K-Jet B20E with a race head & 11.7:1 compression. It needs & uses 10°@idle & 20°TOTAL. It was my old race engine with Twin 48DHLA's, etc. with monster cam. When it was my race engine it ran a locked distributor. 27° with the average leaded fuel I could get, 34° with some Toluene mixed in for track useage.

Vintage Cams: No one should be driving around with A, B or C cams when the vastly superior K has been around for decades. For example, KGT sells a K grind for B30A's.

This page might be useful...
http://homepages.ihug.com.au/~ovlov/technical/distrib.txt
Hope it helps.
Actually, I'd be nice to re-curve a dizzy...but there are no shops here which know how to do it. I guess soon I'll have to go with something programable.

This guy does it:

Anyone can rebush a distributor, adjusting the timing curve is the easy part.

Anthony;

Thanks for link. Unfortunately it doesn't include numbers for earlier engines. If you want to recurve, look for a race shop with a Sun distributor machine...then it's just a matter of fixturing up the dist and playing...it seems to me though that the timing curve, and cam, and mixture, and comp ratio, plus other parameters all work together, so if you really want to to some tuning, and engine performance mapping, you need to have the engine on a dyne, otherwise, it's very tough to correlate any improvement from timing alone.

Cheers

i have some old manuals, showing graphs for advance. Since I have no scanner etc, I can fax you a copy, if you can provide me a fax nbr.
brgds, jfc
67 131

J;

I have a pretty good library of manuals...from factory green to Autobooks, to Haynes, to Clymer, (order of preference) but they don't have advance curve graphs...please mention which manual does (title/publisher/ISBN No). I'd prefer a photocopy sent to:

Swem
P. O. Box 370193
West Hartford, CT 06137-0193

A fax probably wont be neat enough or have decent resolution. If postage is an issue, e-mail me with address and I'll send a SASE.

TNX again for your help,
Ron

Ron,
they come from an old french technical revue (on the 144), and cover basically B18 and b20. Bosch p/ns & engine allocation are mentioned, so no translation problem to understand the technical content. No info for B16 provided though, since never used on 144. I'll send copies to your address next week. Postage won't be an issue, I guess, but thx for offering anyway.
Brgds, JFC