vaccum can on the distributor

[albert]

hi , fans , do you have a trick for to test the vaccum can on the distributor ,, i have vaccum pump ,and guage if that can help, but how pound of pressure on the vaccum it is nécessaire for to moove the small arm ( mi testor guaghe can go to _ 30 to + 150 ) thanks for your help ,,, maybe ray can know that ,,, albert

[raygreenwood]

Thats a good question. I do not really know the answer. Of course....this is what makes the difference between all the different canisters.....is how sensitive each one is. They all had different springs and some even had different volumes even if the outside of the can is teh same. This is because the phenolic spacer block inside...between retard and advance sides is thicker or thinner. Those with higher volumes are sensitive to lower vacuum levels. Also...arm lengths differed. I will have to see if I have written the levels for various can numbers down. Ray

[albert]

thanks ray for your reeplay , my problem is, if my vac.can is good , it is very important for the power on the motor, if the auto. advence work , i suspect on my 412-73 1700cc bad ,,vac. can . thanks,,,alb.

[albert]

oh , i have 3 spare vac.can , toomorrow i make test with my vac. pump . for to see at ?? pound that take for to geeve moovement on the arm and i make comparaison with the 3 and afther i w,l take the suction scale on the vac. line from the motor ,, this test geeve me a good idee ,with the comp.test ,if my motor is in top shape ,,

[albert]

hi,ray , i d,t, know if this information is good for the 412 , but in the ,,,cip,,, vw parts they show diagram for vaccum can with single vac. hose for type one ,,beetle ,,p.n. .043-905-205 zp,,, from 3.5 to 9 inchs of low pressure (vaccum ) for différent rpm ,, 800to4k i d,t have the exact p.n. for the 412 vac.can he have 4 dif. p.n. ,,,205p,,205 zp,,205 ab,,205 e ,,and they play of 5 degrées to 24 deg advence ,alb.

[vwbill]

Do you think you can compare them graphically or is the travel and pressure change too small?? Is this the vacuum can with one port or two? I have many cans too if you want me to check response per vacuum??? bill

[albert]

ho, bill, i loose the power afther 2.5- 3 k , rpm ,,, this problem start afther my rotor restoration , he has 2 vac. tube,, one for advence and one for reetard ,, in the pélican tech. description , he have 5-6 dif. model for the 1700 cc ,, and they geeve shart description for advence or reetard on différent ,,rpm,, and vaccum pound pressure ,, but my problem is what model no. is good for the 412-1700-73 ,, ,,,205 E+f 205 A+B 205 D 205 J on my 3 spare vac.can. i have 3 diff. p . no. thanks,,alb.

[albert]

yes that was my vac.can the problem ,, on the good vac.can harm he have no.917 ond i have the no. 831 in stock ,this no. is for différent application , this no, is not good , he take more pounds of suction ,,, alb.

[vwbill]

Hello Albert, which vac can did you need?? Are you still looking? Bill

[albert]

thanks bill, i find one in my spare stock , and the good parts .no. for the 412 -1700 injection d , is the no.917 you can see this no. on the small arm ,,he have 3 dif. no. for the vac.can on the 411-412 1700 d. inj. the vac.can is match with the dif. p.no. on the distributor , it is very important to match the good vac.can. with the good dist. that make big dif. on the auto. advence alb.

[raygreenwood]

Yes, it is quite important especially on the injected 412. The correct vacuum can makes a world of difference on throttle repsonse.
If you are using the vacuum retard, the arm # 917 is the very best as it also incorporates the adjusting lock screw.
The # 831 is a very common "bus" part that was used on lots of type 4 engines. It seems to require (from my notes) more vacuum....as Albert noted. Roughly 1.5 times what is normal for a # 917.
It can be used.....if a vacuum reservoir ....or larger area line is used ...to exert more volume on teh can. But that can leave a delay.

As for what else fits,....if you do not need the retard function....can # 1-237-121-579 works quite well and is a single vacuum advance.
Double acting # 883 works ok....but has too long of a stroke. If you install a limiting screw like teh #917...and readjust the retard stop, this works well.

I have also used the #811 advance unit with relative sucess.

Ray

[albert]

yes ray , the crazy vac.can change with the motor code ,,exp,,,an,,w,, ae,,ec,, the application is différent for différent région , exap.. california ,usa,, with the power réduction for the pollution law ,, and for many reason you can find a différent vac. can if it was destinate for north of usa or canada or calli. usa , and the différence for the 1700,,,1800,,ccc ,,, the most important we install the exact vac.can,, for the good motor sérial no. in accordance with the good rotor distributor ,,, all that parts are very important for the original power on the 411-412 ,,,alb.

[raygreenwood]

For the most part...the can must not be too "slow". The california and smog models needed a lot more vacuum to move the same distance. With that in mind....as long as the starting arm length is the same and the vacuum is the same or less than what you needed....all else can be adjusted. Ray

[MGVWfan]

Sorry I've been offline again, we had some really bad thunderstorms over the past month or so...I've discovered all the problems with my UPS now, I certainly hope !

I guess what we need is a magic decoder ring listing dizzy P/N to vacuum can arm number, with specs. I have some specs on degrees advance per dizzy for 1973, and I can measure some of the vacuum can distances on the cans I have.

Also try Brad Anders' 914 parts list for T4 D-Jet dizzy p/n decoding, the dizzies are about halfway down the list...

http://members.rennlist.com/pbanders/DJetParts.htm

Here we go. I hope this is useful sometime...

Dist
Bosch 0 231 172 007
VW 022 905 205E
Vacuum Can Arm # 831
(Fixed vacuum can arm stop)
I got this one off E-Bay, it's supposed to be from a D-Jet equipped 914.

Advance side
Arm starts moving at 5" Hg (120 mmHg)
Arm hits stop at 7.5" Hg (195 mm Hg)
Total arm movement 3/32" (2.4mm)

Retard side
Arm starts moving at 4.5" Hg (105 mm Hg)
Arm hits stop at 6.5" Hg (160 mm Hg)
Total arm movement 1/16" (1.6mm)

Dist
Bosch 0 231 172 019
VW 022 905 205P
NOTE - This dizzy is what's in my EA-code 73 412, and is listed as original to the 1973 1.7L Federal US 412 with manual transmission (and I have an automatic...hmmm) per the 1973 Mitchell manual. That year with automatic is supposed to have a Bosch 0 231 172 093 per the same reference (suspect number IMHO). The original vacuum can was bad, so I can't measure the distance specs for it, I'll dig up the old can to see what number was on the arm sometime. FYI, I have an arm # 831 can on there right now. It seems to run well, though I have nothing to compare it against right now.