Tachometer

MEverard · March 05, 2011, 01:40:48 PM

I have a PD 4104 with a 6-71 engine. I would like some help finding the right tach for me. I don't have the 50DN gear drive alternator that came stock on that motor. I have a Prestolite/ Leece Neville, 130 amp, 14 volt, model #A0012670LC Regulator, that is belt driven. Any ideas where and what I should buy? Will I be able to monitor at the alternator, or will I have to put a pickup at the flywheel?

Any help is greatly appreciated.

Mike

luvrbus · March 05, 2011, 01:51:16 PM

Your 6-71 should have a place for a tach drive spend the bucks and buy a pulse generator for the tach alternator driven tachs are a joke

NeoplanAN440 · March 05, 2011, 02:48:33 PM

if your alternator has no " W " Terminal to drive a tach, just take out one phase at the diode block and you are set!!!!

Oonrahnjay · March 05, 2011, 06:21:22 PM

My engine has no pulse generator and no place for one. Also, the alternators are belt driven. Is there a good option for me to add a tachometer? Thx, BH

TomC · March 05, 2011, 07:37:50 PM

Usually off the blower drive there is a tach generator drive. At least on my 8V-71, I had one that I used a pulse generator to create the needed speed pickup for the Isspro tachometer with engine hour meter. Works well. Good Luck, TomC

Oonrahnjay · March 05, 2011, 08:39:13 PM

Quote from: TomC on March 05, 2011, 07:37:50 PMUsually off the blower drive there is a tach generator drive. (snip)

My engine doesn't have a blower, a blower drive, or a tach generator drive. That's the problem! (It's not a DD.)

JackConrad · March 06, 2011, 04:50:31 AM

Quote from: Oonrahnjay on March 05, 2011, 06:21:22 PM
My engine has no pulse generator and no place for one. Also, the alternators are belt driven. Is there a good option for me to add a tachometer? Thx, BH

Our tach runs off the R terminal on our belt driven alternator. As long as the belt(s) are properly adjusted, the tach should read accurately. Jack

MEverard · March 06, 2011, 06:15:35 AM

Thanks for the information guys. I will continue my research.

Mike

Geoff · March 06, 2011, 06:29:12 AM

I have two magnets on my front pulley and a sensor with two wires going up to the Isspro dash tach. 100% accurate.

TomC · March 06, 2011, 08:37:29 AM

Bruce-I'm surprised your Leyland engine doesn't have a mechanical tach drive. I know my Caterpillar does-although it uses the magnet built into the flywheel to power the tach. Maybe look again at the back of the injection pump or even off the front of the camshaft cover. Good Luck, TomC

Oonrahnjay · March 06, 2011, 11:03:17 AM

Quote from: TomC on March 06, 2011, 08:37:29 AMBruce-I'm surprised your Leyland engine doesn't have a mechanical tach drive. (snip)

Yeah, Tom, these things are the Kings not only of old technology but also "olde worlde" technology. I have flat surface on the belt-drive end (ie. the end opposite the crank output shaft) -- it should be easy to install a pair of magnets on that and use a pickup on a little bracket. The injector pump is stacked on the end of the air compressor shaft - no place for a tach drive.