VR signal from pulley modified with holes for trigger

david_594 · Post by **david_594** » Wed Nov 12, 2008 1:23 am

Hate to hijack another persons thread, but I feel like this one atleast has the attention of the aircooled crowd.

What does everyone think of this as kind of a baseline map for my 68 bus? Its a bone stock dual port with low compression(7.3:1) pistons. Initially the stock dizzy was spec as follows:

Idle advance: 7 deg BTDC
Advance/Retard Range: Vacuum: 2-5deg Adv; Centrifugal: 12-16deg @ 2200rpm, 22-25deg @ 3800rpm

I'm not trying to turn it into a screamer or anything. I just want proper timing for fuel economy(#1) and power(#2) on 87 octane. Plus my current distributor isnt proper for a bus nor advancing right, so this seemed like more fun than simply buying a new one.

DannyP · Post by **DannyP** » Thu Nov 13, 2008 12:21 am

David, looks pretty good. Drive it and tweak it, that's what I did. Certain areas on mine had too much advance, so I backed it off, some areas not enough. I am on configuration file 11, just minor small changes to my initial map. I changed the low speed, 1000-2000, and some of my part load areas. I have a 10:1, 2165cc type1 w/dual Weber 44IDF and a killer cam, heads, valvetrain, and exhaust. Engine by Jake Raby, puts out 180 hp and over 140 ft. lbs. Max advance is 32-33 degrees at full load.

DannyP · Post by **DannyP** » Thu Nov 13, 2008 12:28 am

Alexander, I hear you. My car is topless so pretty much done for this year also. Spring will be here soon, right?

david_594 · Post by **david_594** » Tue Dec 09, 2008 3:45 am

So to make sure I do this right before I go drilling my pulley full of holes....

First off, is the timing wheel on this pulley the proper orientation relative to the notch for the woodruff key in the crank?

Second, I would want to drill my holes on the the x5 degree lines (5, 15, 25, 35, etc) correct?

And then on the right side where the black arrow is, that is where I would want the "missing tooth" to be assuming I can position the sensor right at the TDC mark?

Not that it really matters, but this is the actually pulley that I am using: http://www2.cip1.com/ProductDetails.asp ... 26-105-260

Alexander_Monday · Post by **Alexander_Monday** » Tue Dec 09, 2008 2:10 pm

Assuming Type 1 VW ( and I would guess Type 3, but don't own one ) TDC should be 90 degrees clockwise from the woodruff key. I can't tell exactly because the picture is at an angle, however it appears correct.

Yes, the holes should be on the 5 degree lines to make the "teeth" on 10 degree lines.

Yes, assuming you wanted the sensor at TDC, the "missing tooth" should be 90 degrees clockwise from TDC, but if you are using a conventional generator or alternator TDC will not work because of the belt. Take the advice of someone that has messed up and had to machine a new woodruff key slot in one to "move" the "missing tooth". Mount your VR sensor, sensor cable, pulley, and all accessories ( alt, belt, header, full flow lines, etc. ) that are near it to make sure the VR sensor will go where you want it before you machine the "missing tooth".

The first spot I had picked, and built a mount for, while the engine was on the stand would not clear the header once I put the engine in and installed the header. The sensor is now between the belt ( that is, in the space clockwise from TDC between the crank pulley and the alternator pulley where you do not trap the belt with the sensor and bracket). My bracket is mounted to one of the studs that hold the alternator stand on. Need to get off my but and take some pictures to post in the powered by gallery.

Also, I used a distributor and coil for initial fire up so I could quickly adjust timing while the engine was held at 2000 rpm for the cam break in procedure.

There is more information about how I made it on The Samba ==> http://www.thesamba.com/vw/forum/viewtopic.php?t=318526

dr.occa · Post by **dr.occa** » Tue Dec 09, 2008 6:19 pm

i know others have already commended you on this Alex but i didn't think it would hurt to also offer up my "high 5" for this different take on the trigger wheel. it makes for one less part to source while at the "grave yard/car morgue".

Alexander_Monday · Post by **Alexander_Monday** » Tue Dec 09, 2008 6:25 pm

Thank you, however to be truthful my motivation was necessity.
I have a trigger wheel from a ford, but thinking about trying to adapt it to this kind of pulley made my head hurt.

dr.occa · Post by **dr.occa** » Tue Dec 09, 2008 10:07 pm

Alexander_Monday wrote:Thank you, however to be truthful my motivation was necessity.
I have a trigger wheel from a ford, but thinking about trying to adapt it to this kind of pulley made my head hurt.

necessity=the mother of invention

Alexander_Monday · Post by **Alexander_Monday** » Mon Dec 22, 2008 3:37 pm

Just thought I would post an installed picture.
Ignore the timing marks, they are off 130 degrees now due to the new keyway I made to relocate the sensor.

alexander · Post by **alexander** » Tue Dec 23, 2008 10:48 pm

dr.occa wrote: necessity=the mother of invention

you hear this alot, but does anyone know who the father is? i would for invention to have to go through life as a bastard.

alexander.

alexander · Post by **alexander** » Tue Feb 17, 2009 11:19 am

........ but on a more serious note, i am just putting the finishing touches on an EDIS8 installation, in which i borrowed alexander's idea of drilling holes in the harmonic damper. what a brilliant idea! many thanks

alexander
(no relation)
sydney, australia.

Alexander_Monday · Post by **Alexander_Monday** » Tue Feb 17, 2009 1:12 pm

Occasionally one of my hair-brained ideas works.

(A blind squirrel occasionally finds a nut)

Glad you took the chance to try something out of the box and were successful.

Dean924s · Post by **Dean924s** » Tue Feb 17, 2009 11:55 pm

I am going to see if I can make this idea work on my 924s. I think I have a spare balance around. How did you all drill them? I assume that it was with a drill press. Any other tricks you can pass along? I just have to see if I can find a way to mount the sensor down there. It would be much better to hide it in under the plastic cover that encloses the timing and balance belts on these motors.

Alexander_Monday · Post by **Alexander_Monday** » Fri Feb 20, 2009 2:41 am

Actually I used an 18V cordless drill!

I took my time, made a jig ( out of spare stuff I had laying around ) to hold the pulley and the bit at the same time. I rotated the pulley in the jig between each drill and clamped it back down. I drilled the holes so that the width of the holes was the same as the space between them, and offset them 5 degrees so the spaces between them were centered on the 10 degree intervals. I made the bit guide with an adjustable depth stop so the holes would be the same depth. I measured the weight of the pulley with a digital scale between each drill so I could be assured I would still be balanced, then I drilled the 2 holes deeper that are 180 degrees ( actually 175 in each direction ) from the missing hole. I took out an extra 1/2 of the weight removed from each of the other holes from each of the 2 holes so balance would be retained. Since this is a high rev engine, I spun the pulley up with a drill ( slowly increasing the speed a little at a time for safety

) just to make sure it was still balanced. I fully expected to ruin the pulley, however it came out better than I could have ever hoped for with such crude equipment. Take your time ( took me all evening to do the drilling ), measure over and over between each drill just to make sure, keep the bit sharp.