tach idea for mk1

[BruceM31]

Has anyone tried to use a electric vacuum pump to run the brake booster, and remove the mechanical vacuum pumo and replace it with a gas distributor for tach signal?  I havn't done any heavy research yet, but was curious if this could work.  I imagine the whole in the block is the same size between gas and diesel. 

If anyone has some insight on this it would be great!

Bruce

[Rabbit on Roids]

it wont work.
diesel IM shafts and gas IM shafts spin opposite directions.
and the gears that go on their respective accessories are also cut to spin there respective direction.
and the hole in the diesel block is either too big or too small for a gas dizzy.

[BruceM31]

  damn

[burn_your_money]

Can't you press the gears off? or even just use a gasser IM shaft?

[Vincent Waldon]

This just seems like an awful lot of trouble.  

Ford hall effect transducer mounted somewhere near the cam sprocket, little extra metal lug attached somewhere... hook up a gasser tach... done.

Or Dakota digital converter box.

Or an actual aftermarket diesel tach from VDO.

[maxfax]

Vince, you hit the nail on teh head as usual..   

I tried this once..  I think the reason I gave up was that the gear from the vac pump wouldn;t fit the gasser distributor...

That and I couldn;t scavenge an elec vac pump, and a new one was gonna cost as much as just buying a regular diesel tach...

Check out this thread http://www.vwdiesel.net/forum/index.php?topic=20437.0   
He has a slick idea there, although Merc diesel tachs that still work are kinda scarce...

[Rabbit on Roids]

Can't you press the gears off? or even just use a gasser IM shaft?

the diesel IM shaft is driven from the smooth side of the timing belt.
the gas IM shaft is driven from the toothed side of the belt.
diesels spin CCW
gassers spin CW

[burn_your_money]

the diesel IM shaft is driven from the smooth side of the timing belt.
the gas IM shaft is driven from the toothed side of the belt.
diesels spin CCW
gassers spin CW

Would that matter though?

[maxfax]

The t-belt wouldn;t fit if you used the gasser sprocket and IM shaft, plus I don't think you'd be catching as many teeth on the IP if you could get the belt routed around the IM shaft sprocket..  If you swapped the diesel pulley on there then the oil pump would be turning backwards....  I think...

[Kantdrivefast]

run a mk2 diesel cluster with a tach in a mk1

Fairly straightforward although you will need to do some modification to either the cluster mounts or the cluster itself. I did both, but were I to do it again, I would just alter the cluster mount.

Things you will need:

-Mk2 Cluster, CE1 or CE2 doesn't matter. CE2 was great and one plug makes rewiring much more central.
-Speedometer cable from a Mk2 manual car... Probably best if it comes from the same car as the cluster.
-www.a2resource.com for the pinout codes on the cluster pigtail.
-A Bentley Manual would be a great help, but you'll be fine without one.
-Good wiring and crimping pilers, you will need them.
-Lastly, take your time. I did fine without a bentley but its not exactly perfect. Theres enough info on the back of the Mk1 cluster to lead through the wiring. My coolant and oil lights and buzzers freak out after driving for a bit, but I think its caused by a lack of a coolant sensor in the overflow tank.