Tach options?

[aaronk25]

So my 1977 j needs a new tach. The tach's rpm needle failed as it wrapped all the way around and broke off on the idle stop....it's keeping time correctly but has no RPM indication. Which to me isn't a big deal as I never look at it any way as the JPI 830 is more accurate as it feeds if of the mags.

I know the 830 isn't TSO'd as primary but I'm fine flying with it but it just looks trashy to fly around with a tach with no needle as I've worked hard getting the plane up to snuff . It also equally bothers me that I have to pay to fix something that adds no additional level of safety but will probably continue to be a maintenance point! The current tach only lasted. 500 hours!

If it was upto me I'd pull it out and put a block off plate in the hole and record time off integrated Tach/Hobbs meter in the 830....but considering the log books would indicate a change from the tach to the JPI which isn't approved as primary for the plane, it probably wouldn't look good to a buyer as I'm looking at trading for a turbo plane .....even if I replaced the tach with new but left it in a box!

Any ideas? Anyone share the same frustration? Any ideas where to get this tach overhauled at a good price...

[scottfromiowa]

I'd rather talk about your honeymoon, but my EI digital tach is great and didn't break the bank.

[xftrplt]

+1 (on the tach).

[TTaylor]

+2 on the E.I. tach.

Sent from my Nexus 7 using Tapatalk

[aaronk25]

I'd rather talk about your honeymoon, but my EI digital tach is great and didn't break the bank.

I'll make sure to post some pictures!

[Oscar Avalle]

EI is great

[carusoam]

Old cables wear out, followed by needle oscillation, followed by needle getting knocked off it's axle...

If this happened to yours....

Have instrument shop remount the needle, get new cable, and continue on with the 830...

Then consider....

Replacement tachs are also available on eBay as well. I have one from a C if it would help?

A primary instrument is a requirement.

The 930 looks nice and it's legal/primary

There are some modern digital tachs that do the run-up math for you.

Ideas that came to mind,

-a-

[Oscar Avalle]

EI is great

[jetdriven]

U can borrow my old AC tach for your Mexico trip

[N201MKTurbo]

I have a UMA that has worked flawlessly for the last 5 years, although the "Hobbs" numbers are a little hard to read.

It's pickup mounts in place of the cable and the wire can be routed through the grommet the cable went through. Altogether a very easy install.

I had a Horizon on my old M20F and it worked flawlessly for 15 years.

I prefer the analog display of the UMA.

Mechanical tachs art just a PITA!

[aaronk25]

That's everybody, I can get a EI installed in time for the trip. It sounds like that's the tach thank makes the most sense based on everybody's opinion.

I flew a different 201 for about 60 hours that had one, works nice and the ability to check flight time with press of a button is nice. My panel equipment (396) has the capability but not without going to a different screen.

Thanks for the kind offers for usage of equipment!

Aaron

[Marauder]

Once you go EI, you won't go back! I converted all my gauges over.

From this:

To this:

[jetdriven]

Marauder, what do you use for fuel pressure?

[laytonl]

I have used both the horizon tach and the ei. My current airplane has the ei, but I like the horizon unit better because of the mag status lights. Lee

[jetdriven]

Keep in mind those digital tachometers count hours faster than actual flight time, so it devalues your airplane and engine faster as well.

[Marauder]

Marauder, what do you use for fuel pressure?

An EI FP-5L. It is legal as primary. It is the bottom gauge. Fuel flow/totalizer with pressure option, installed since 1995, had EI update it to LED backlight for $65 last year.

[aaronk25]

Can't they be set to 2500rpm per hour like original tach? The jpi allows the adjusting of cruise speed rpm

[Marauder]

Keep in mind those digital tachometers count hours faster than actual flight time, so it devalues your airplane and engine faster as well.

I have a JPI 830 in the panel and it runs faster than the EI. I spend a lot of time recording both tach time and actual engine running time. Good example was today. I showed 1.6 hours on the EI Tach but my Davtron clock showed 2:24 minutes actual run time with it reset at engine start.

[jetdriven]

IIRC the EI counts at 1300 RPM and the Horizon counts at 700 RPM, but both are going to add up faster than a recording tachometer because they aren't a ratio.

[SkyPilot]

I just ordered the Horizon P-1000. Hopefully it is good. I also ordered the cap for the engine to cover the hole from the tach cable.

[Jeff_S]

I have a Horizon tach as well and love it. The fact that it is measuring each mag independently and will show you any problems without even doing a mag check is pretty good. You can also isolate either mag if you want to do some diagnostics. Be very familiar with it's operation, however, to avoid freaking yourself out. When I first got it I hadn't really studied all the buttons, and in turbulence I accidentally pushed one of the buttons to isolate a mag and a red light came on. You generally don't like to see flashing red lights in the cockpit!

 

Also, since the readout is digital only, it can tend to make you a bit anal about staying "on the number" for your RPM. That's fine if you like fiddling with it all the time, but it's best just to get it close and then leave it alone.

[scottfromiowa]

Marauder, what do you use for fuel pressure?

I have fuel pressure as auxillary/primary in my fuel flow

[FlyDave]

IIRC the EI counts at 1300 RPM and the Horizon counts at 700 RPM, but both are going to add up faster than a recording tachometer because they aren't a ratio.

Mechanical tachs record 1 hour at a certain RPM. On my J that number was 2300 RPM. I cruised at 2500 RPM so I was racking up 1.08695652173 hours of tach time per hour of flight. As Jetdriven stated, the EI tach starts recording at 1300 RPM but then records time just as a hobbs meter would until the RPM drops under 1300 for more than 10 seconds (or there abouts).

I have the EI tach in my Bravo and have issues with reading the numeric display during the day. I sit fairly close to the panel and because of my viewing angle to the instrument I need the tach backlit during the day. Because the tack illumination circuit is connected to my panel light switch, I have to run the panel lights during the day to comfortably see the tach. Another issue - but I believe is specific to the Bravo - is that the panel lights come on only when the nav lights are on. So I have to run the nav lights during the day to see the tach.

[TTaylor]

Keep in mind those digital tachometers count hours faster than actual flight time, so it devalues your airplane and engine faster as well.

Not quite true, the correct answer is it depends.

It depends on which mechanical tach you have and how you fly. Mechanical tachs come in many flavors, some are 2300, 2500, or 2566. All record as long as the engine is running.

If you want to save on hours you need one with the highest ratio and fly at the lowest rpm. As has been noted already if you have a 2300 rpm model and fly at a higher rpm you are logging extra hours.

The electric generally don't record until a specific rpm is held continuously. As stated the E.I. is 1300 rpm. This means most of the time on the ground is not recorded. I fly now at 2400 rpm and I would guess the non-recorded ground time is just about equal to any time saved by a lower rpm on a mechanical tach.

[OR75]

i replaced my old cable tach with an electric needle UMA tach with bendix mag pickup

I prefer the needle classic type display ( rather than the EI led) .

Nice and rather unusual to have different quality options for a replacement part for a Mooney !!!