Converting a Gas Tachometer to a 24V Diesel

[smcruisin]

I've used this site for years without participating, and I figured I need to start somewhere...so, here goes my first thread.

Does anyone have any experience modifying/rebuilding a tachometer from a gas (distributor?, s-p-a-r-k p-l-u-g??? what is that?) to Diesel application???

It is going into my '81 Canadian spec. 24V BJ-42 (3B).

I don't want to go the route of a Toyota Tach from a 60 or 70 series truck (bellhousing magnet & sensor arrangement) because I already have a really bling-bling military tach. It looks like an aircraft altimeter and has a 0-4500 rpm face.

I've been told that any alternator/starter/electrics shop worth its salt can rebuild my tach and alternator at the same time (something about adding a 'B' pole to the alternator and swapping out the back half of the tach). I'm just curious of anyone elses' experiences...

I'll double check with my brother what application the tach came from (I forget if it was a 4-cylinder aircraft or a 6-cylinder stationary generator)... Any electronics folk care to comment: If this tach came out of a 6-cylinder gasser, can it be rebuilt for a 4-cylinder diesel?

I'll post some pics of the gauge face tomorrow.

Thanks for your input...
Happy Trails,


Steve

 

[Gumby]

I don't think th eproblem would be from converting 12V to 24V or even from 6cyl to 4. Both of those would need to be done, but are doable. The question is how to make your diesel create 6 pulses per revolution. The gas tach counts coil discharges. Most diesel tachs I have seen, at least with mechanical pumps, are mechanicaly driven.

 

[drexx]

28Nov2005 (UTC +8)

My HZJ-80 I found out, doesn't have a sender. But I got a tachometer from a FJ-80 from Jeff in Davis (CA) recently. So what I'm planning right now is secure a magnet in the H55 flywheel and attach a cheap motorcycle igniter in it to count the rpm's, and wire it up to the tachometer. I figure that it'll cost me less than US$10 to do this, excluding the cost of the tachometer and the labor to do this.

I searched around ih8mud, but nobody has done this approach just yet. If they did, then I must've skipped a whole lot of readin' Hope I'm doing this right?

 

[crustyBJ60]

try this, or "search" is good too

https://forum.ih8mud.com/showthread.php?t=41271&highlight=diesel+tach

crusty

 

[beanz2]

28Nov2005 (UTC +8)

My HZJ-80 I found out, doesn't have a sender. But I got a tachometer from a FJ-80 from Jeff in Davis (CA) recently. So what I'm planning right now is secure a magnet in the H55 flywheel and attach a cheap motorcycle igniter in it to count the rpm's, and wire it up to the tachometer. I figure that it'll cost me less than US$10 to do this, excluding the cost of the tachometer and the labor to do this.

I searched around ih8mud, but nobody has done this approach just yet. If they did, then I must've skipped a whole lot of readin' Hope I'm doing this right?

Hey Drexx,

Herb Peyerl is in a similar situation as you now, maybe you can see how he did his. He's got an FZJ80 tach and IIRC his 1HZ also does not have a sender. Check out his swap on www. birfield.com forums. My first 1HZ also does not have a sender but I had a sender put on the alternator by a shop. But I am using a 1HZ tach.

Dave