061 dizzy vs 031

techi · 03-25-2013, 07:03 PM

Hi,

Is the advance curve of the 061 same as 031? I have seen postings indicating that the "061 is same as 031, except 061 has a vacuum retard"

I am using a bosch 050, brazilian distributor and when it is tuned for go low end take off, it seems to advance too much at high rpm. I have looked at the curves and it seems like the 031 has a higher advance curve at low rpm and top out at 26 degrees rather than 32 degrees, which seems to be more suitable for my 68, 912. I am running MSD and Petronix, and have webers but thinking to go back to original solex as well.

Thanks very much for assistance. I am already aware of the rsr 0012 and 022 and have looked at those curves. Someone recommended I need a 031.

JT912 · 03-26-2013, 06:16 AM

Here is a recent thread on 912bbs
Quick glance showed plenty of graphs. Not sure 061 specific.
009 Ditributer or 022 - Page 3

Jaems · 03-26-2013, 09:23 AM

The stock advance curves for the 022, 031, 0012, 050, and 009. After removing the vacuum retard on the 061 you can make it a 031. Using the old Sun Dial you can optimize the 061 and 031 advance curves for the 912 engines. The 031 works very well with the Weber's. Once you have them sorted out for the 912 engine.

techi · 03-27-2013, 02:32 PM

Thanks all for the input and graphs.

The statement ...."After removing the vacuum retard on the 061 you can make it a 031." is what I am trying to discipher.......Does this mean after removing vaccum retard the 061 has same advance curve as 031, or does the statement mean I can then send it to a shop to have it recurved to an 031? I can get the 031 springs and do the recurve myself on the 031(fun exercise) but I dont want to try unless first I understand what the curve looks like on the 061. I dont like to reinvent the wheel.

When I put in the 050, I put in the pertronix and MSD all together. It is a 68, 912 with stock cam, weber carbs and with the steel cyclinders to make it a 1.8L...It runs well, but noticed it starts and idles better at 5-8 degrees but the car doesnt seem to run as well at cruise (over advance timing). If I run it 3 degrees, startup and idle suffers but top end is better.

This makes me to believe the 031 would work best for my config. since it advances more at low rpm than other dizzys and tops out at 26 rather the 32degrees. I like to kinda know what I am doing before I change the config.

I have spent two days prior going through all posts, and trying to answer the question...what does a 061 advance curve really look like and unravel the statement above? [/B]

03-28-2013, 03:24 AM

Hi techi,

Below a diagram with the 022 advance curve from the Porsche factory 912 manual. It's for the 022, but all 912 engines are basically the same. The 061 was used in combination with the smog system, introduced in '68 for the US market. To realize a smooth running engine and a "stable" idling, a relatively complex system with vacuum advance lines for proper advance and retard was developed. The vacuum controlled idle "bottle"on top of your fan housing is part of that.

I'm not sure if this also will function correctly in combination with a big bore and Weber carbs.

Note: for my '68 an advance of 31 degr. at 3000 rpm and 5-7 degr. at idle works fine - stock engine with Weber carbs.

Otto

Jaems · 03-28-2013, 10:31 AM

The 031 was a replacement Distributor for the 022. It was standard on non US delivery 912's for 68 and 69. It was also available for non-road use in the US as a special package that could be ordered from the dealer separate from the car purchase.

The 061 was for all 912's that have the same or similar laws for smog control as the US did in 68 and 69 912's.

With Weber or Solex carburetors, any of the following distributors will work well with the 65-69 912 engines: 022, 031, and the 0012. The 061 if it has been converted. The non converted 061 for the 68 and 69 912 with all the smog hardware..

03-28-2013, 02:09 PM

Jaems,

Could you explain the difference in the advance curves from the curves you added to your previous post and the curve depicted in the Porsche factory manual as I added to my post?

Otto

Jaems · 03-28-2013, 05:25 PM

I don't have my factory workshop manuals handy. However, this graft that you posted is also in conflict with the factory spec book that states that at 2000 rpms you should be between 21-26 degrees. Where you grafts show only 16.8 degrees and stays the way until 2900 rpms. The factory may be using some different method than the ones that we are using in the US to determent advance curves.

JT912 · 03-28-2013, 06:14 PM

Distributor curves/advances have been discussed in depth on the 912BBS. Enough research and information to keep you busy reading for hours. I know the graph posted by Jaems is discussed in the link I posted. I know a member did real world graphs with the different distributors to show how the advance differered in relation to the crank speed.

WFBowen · WFBowen's Garage

What's important to note here is that the "genuine" Porsche distributors' advance curves are by no means linear. When you look at the weights in the mech. adv. mechanism, those odd shapes dictate not just how much advance occurs, but exactly when it happens. All things considered, for a basically stock engine, it's hard to beat a factory designed advance curve, but the distributor itself has to be in perfect operating condition. On the other side, I've spoken with some owners who absolutely love their RS0012 units.
As for the observed differences in the two advance curve charts, it might be that Otto's chart compares distributor shaft rotation speed with dist. shaft advance, while Jaems' is the more traditional crankshaft speed vs. crankshaft advance. I'm trying to grasp the algorithm for the difference in values, but the front of my head is really starting to hurt.
JMO
Bill

Jaems · 03-29-2013, 11:21 AM

I believe that WFBowen has it correct.

I talked with one of my old friends, that was factory trained, and has been building Porsche engines since the early 60's both racing and street. Not discounting the RS0012 (which will not working in all 912 engines) the 031 is considered the best all around distributors for this engine. My friend has discussed this with other Porsche engines builder over the years. The 022 was the first dist. for the 65-67 912 engine and if you want to keep it original. But for optional performance the 031 is a little better. There are three types of 031's. You want the types 1 or 2. The type 3 is poorly made and not made in Germany.

Don Marks, before he passed away, optimized my 031's (I have two of them) for my engine with the Webers and cam combo. The car runs about as perfect as you can get with the 912 engine. The Weber's are also optimized for my engine.

03-29-2013, 01:51 PM

Jaems, the graphic was taken from page L32, fig. 37 from the English '66 912 supplement for the 911 factory service manual. Just standard Porsche factory info.

As Bill suggested, I also think the advance is related to the distributor shaft, because in the related text the Bosch tester is recommended for testing the curve of the distributor. The dynamic curve will differ and will result in more advance than shown in the manual. The 022 works fine on the 912 engine, but I agree with many that the 031 can result in a "better" engine performance. At the other hand the electronic distributors like the RS0012 and European 123-Ignition have their own advantages, in comfort and performance, and have their admirers.

Otto

Jaems · 03-29-2013, 03:01 PM

Otto H. Wegkamp:

The RS0012 is just a 009 that has been converted and curve for the 912. It is not an electronic dist. per se, anymore than a 022 or 031. I have a 031 with CD that is pointless and one that has points ignition. The performance was the same on the dyno. I use the pointless in the car and the points one as a backup. About the only thing I had to do in the last 10 years, is to adjust the valves when I change the oil and filter.

By the way are you familiar with the group? I have had this for years

04:27 AM

Jaems,

I thought the RS0012 was an electronic distributor. I was wrong on that. I also have a 031 (and 061) used with Bosch points and with electronic points replacement. As you say, adjusting once and drive for many years. I also have a full electronic replacement, a 123ignition. This one is available with software to program any curve you like, but also in versions with something like 8 preset curves, varying from standard VW bug application to 356/912 use. I experienced no difference between the 031 and the 123ignition.

Ignition systems are a bit like wine to me. Some differences can be pointed in an objective way, like a clear difference in performance between a 009 and a 031. But the difference between a standard well adjusted 031 and one with electronic points replacement is more or less subjective to me.

Regarding to the Holland Touring Club badge/pin: These badges - and also pins and flags - were souvenirs here in the Netherlands during the fifty's. The Holland Touring Club was not a real club in the sense of a community of drivers. The initiative was supported by the "Royal Dutch Touring Club", the ANWB (including Dutch roadside assistance). Some badges have the ANWB logo in stead of the HTC logo at the right bottom. I could not find the exact relation between the ANWB and badge. Probably the Dutch tourist information service could have had something to do with it.

The mill depicted is a classic Dutch windmill, a so called "Zuid-Hollandse Poldermolen". On some badges the designer added some tulips to it. These badges are quite rare and collectors pay around $150 for them. So nice to have, but no one will change it for another rare Danish 912 ...

Did it come with your car? Possibly the PO had a holiday here in the Netherlands - from Danmark to the Netherlands was just a one day drive.

Otto

Jaems · 03-30-2013, 02:20 PM

Otto,

I found this badge many years ago at a swap meet - Paid a dollar for it.

I have several badges from my earlier years, when I lived in Denmark. The first picture are those that are currently on the car. The section is my trophy case with some more badges and steins.

03-31-2013, 04:12 AM

Jaems,

Great collection! It's Always nice to have some memories you can really touch. The top Nürburgring-badge is very desirable compared to the cheap plastic stickers they sell there these days. Take care of them.

Otto

Matt Monson · 04-14-2013, 02:52 PM

I'm going to bump this thread since you guys seem to know dizzys. I was cleaning house today and came across my box of spares that didn't go with my 912e when I sold it.

There was an 009, an 050 and an 048. Never seen the last one before. Is the 048 an efi specific version designed for the type IV with injection?

C. Clark · C. Clark's Garage

VW I think......

04-15-2013, 08:37 AM

Matt,

If you are talking about Bosch 0 237 520 048, the unit is indeed from a bus T4 2.0 engine. If I remember well, there is an other 048 type used for Mercedes. Don't know what model.

Otto

Matt Monson · 04-15-2013, 08:52 AM

Given that the 912e uses a type IV I suspect this may be the original distributor off the car? Or were they a different model?

Mostly trying to figure out if I should keep it or sell it. I have my '67 912 plus two 914s, one on Webers and one on the original injection. If it works with the injection might be worth keeping.