MCI Tach hookup question

[jmblake]

I am putting a tach on my MC-9 with a 8v71, My question is what or where do I hook the tach sender to on the alternator, is the signal generator already on the alt or do I need to add the signal generator to the alt. And if so where do you buy one and where does it go one the alt at. Any help would be appreciated Thanks Jason.

[RTS/Daytona]

For Detroit Diesel Delco gear driven 50DN

        The "R" terminal output is 12 volt pulses-
         Most 6V92 / 8V92-->(2.94 (53/18) gears & 6 pulses per rev=17.66 pulses/rev)
         Most 24 volt - 8v71->(2.75 (55/20) gears & 6 pulses per rev=16.5  pulses/rev)
         Most 12 volt - 8V71>(2.29 (55/24) gears & 6 pulses per rev=13.75 pulses/rev)     

Pete RTS/Daytona

[Lin]

Try Precision Speed in Phoenix.  They can be very helpful.

http://www.precisionspeed.com/

[jmblake]

Thanks Pete is the R terminal marked on the alt, I haven't crawled back in there to look yet so i don't know how many terminals there is. Thanks Jason

[RTS/Daytona]

I believe it is -

There will be f1 and f2 (field) and the big battery terminal +

and off to the side - pointing in the same direction as f1 & F2 will be the "R" terminal

[bcaddel]

I just put a tach on my 8v71 about a month ago and i ordered it from
http://www.precisionspeed.com/
Unfortunately I ordered one to install to the "R" terminal on my alternator. Come to find out all alternators don't have the "R" terminal installed. I called and talked to the folks at precision speed and they helped me figure out how I could get my signal pulse. There are numerous ways that you can get your signal if you engine is so equipped. Mine didn't have any of them and I had to drill a 3/4" hole in the cover of the flywheel and and tap it to screw in a signal generator. It works great but I would have never been able to get it done without their help. I sent the first tach back and they sent me a full cash refund.

I strongly recommend them as their knowledge and customer service is outstanding. Cost was about $160 for tach and signal generator.

[bcaddel]

Jim
I was told the Alternator will have a post with the letter "R" stamped on the case right beside it if there is in fact an "R" terminal on your alternator. There may also be a signal generator on your cam, blower, flywell or at least an threaded access hole where you can screw in the signal generator. If you don't see a terminal stamped with the "R" call the folks at Precision Speed. ( I am not associated with them in any way)

I love my tach and would not want to be without it contrary to what some here say about tachs.