Tractor Chat - subject is tachometers

[Save Old Iron 1,565]

Seeing there has been a surge of interest lately in tachometers on tractors, I thought I might ask the group what importance do you place on having a tachometer. If you feel knowing engine speed is important, what are the RPM range(s) that concern you the most? and under what conditions?

Of course 3500 to 3600 governed speed is important and I imagine folks may possibly want to know what speed the tractor is idling at,

but beyond that,

what other speeds, if any, would be of interest. I'm just doing a little market research for building a digital tachometer that could either read RPMS with digits, use an LED bargraph display or just light up an dashboard LED if the engine over revs past expected governed speeds.

Thanks

[AMC RULES 37,102]

If...when working it, you're supposed to run the engine WFO...isn't the need for a tach just for the cool factor?

[MalMac 1,331]

There is only one attachment I know of that is not supposed to run at the 3600 RPM. When I had a Mighty Mac when I first used it at full throttle I thought that thing was getting ready to leave the launch pad. I call the manufacturer of the Mighty Mac and talked to one of tech/engineers there. They said they the shredder should not be operated at anything above 2800 to 3000.

[sorekiwi 761]

My 520 is the only tractor I have with a tach.

About the only thing I look at it for is to check where the governor is set. Occasionally I'll look at it if I hit a thick patch of grass that bogs the motor a little,but I dont know why I'm interested in that useless little snippet of information :scratchead:

[Martin 2,131]

for me, putting one on the c125 was more for info than anything else. ive never had much luck with the handheld ones checking governed speed, the 520 one was a $25 install for me including the purchase of the gauge. the c125 has a blank spot to the left of the dash for an hourmeter, which is really useless for me since i keep up on maintenance more than enough, and if i did put one in where do i set the hours at? who knows what hours this tractor has on it. and its not a total rebuild anyway.

it was good info to see where my high rpms are at, which was set 200 rpm low fyi. i like to run my engines by ear and from installing the tach i can say i never spend anytime much below 2000 and most of the time at 2800 to 3200.

i guess they arent really a needed item, the way the engines are run governed, for me it just fills the blank spot on the dash with something i wanted and was a learning experience installing it.......

[littleredrider 409]

I'd like to have one. The governor on the ranger pulls the throttle cable, the lock doesn't work for crap. Also to be sure that it's running at optimum RPM.

[krazy_horse 59]

I would like a small hand held portable tachometer to check the idle and max. rpms.for our small engines

[Foozerush 40]

SOI- when I first joined RS, I believe a read a thread about tach on a WH, it was square and digital and had some diffrent gagues incorporated on it. if I remember and I think I posted I would be interested in one for my 416-8, I don't remember if it was you who posted info about it, but yes a tach on my tractor would help me know where the RPM's are on the ole Onan, like Sorekiwi said to know that useless tidbit of info just makes me feel better inside..... lol... Plus it would be a helpful tool to use to teach my son what operating rpm is best for the job at hand. When I am mowing with it, depending on grass height, I judge the throttle speed by how far the grass is flying out the deck... With a tach, I could just tell my boy to keep engine @ whatever rpm I tell him. So mark me down for a future sale.....

[joel_400 59]

Actron/sunpro makes a timing light with a tach feature available at advance auto parts for about 90 bucks if i'm not mistaken. Same one i bought from a tool guy, works great for checking rpms and ignition timing on just about anything. I even found with the adjustable advance feature at 20 degrees the keyway is straight up...

Joel

[jay in nc 210]

if you have a 110 generator wouldn't you need to know the rpm.s to keep from burning up tools ? Jay

[JackC 617]

I like to check the tach on my 520HC before I engage the 48" deck to be sure I have the RPMS up over 3,000.

I also like to see if the governor is keeping the RPMs up when I hit tall grass.

I also use the tach to check and set the idle speed.

The more instrumentation the better for me.

I like to see what the engine is doing rather than just relying in sound.

There is also the cool factor.

If I had a choice I would pick an analog display over digital for the older wheel horses.

If the display is digital and if for wheel horses, then the instrument should display RPM in digits and the case should have the same size and look (face and trim) as existing wheel horse gauges.

A digital tach in a wheel horse style case (with the case matching the model series) with installation instructions would be neat to have available.

[Ken B 3,134]

Most small equipment dealers sell a small digital tach/hr meter for about 40-45 bucks. I have had the same one for about 4 yrs. now with no problems with it. I just attach it to the dash with a small piece of velcro to whichever tractor I want to use it on. It does work great, not as cool looking as the tach on my 520 or what Martin now has on his C-125 though. If you could build something that has hrs. also that would be very cool. I find that to be just as important as the tach itself, very handy for oil change intervals and how many hrs. are on a freshly rebuilt motor. If you could make one a tad on the larger side so us guys with crappy eye sight that would be swell. The digital that I have is a little harder for me too read while cutting the grass not having my reading glasses on. I'd be on board for one, maybe two.

[Callen 64]

SOI,

How about a tach with 2 temp readouts for twins, similar to this? http://aimsports.com...ic2T/index.html

IMO being able to monitor both cylinder temps on the Onans may help to prevent some of the valve seat problems.

[JackC 617]

Two temp sensors for the twins and the ONANs in particular is a great idea.

[Philipp 1]

Very interesting topic, I frequently use my analog tachometer, it's a real help.

For normal use (mostly shredding and trailer-work) I never run the Kohler up to 3600 rpm (it's an 8 speed) because it makes lots of noise, and the 16 hp has plenty of torque. (And I know that the manual says that I have to operate him at full throttle.

Of course when I'm mowing with a bagger things are different.

Also measuring fuel consumption at different rpms is easy with the tachometer (but I completly forgot them)

Here's an interesting site from a very interesting man: http://kirkengines.com/index.php#AnalogTach

[JackC 617]

SOI, how about coming up with an instrument that displays the temperature of a single cylinder or a twin cylinder engine?

There might be a lot of interest for the twin cylinder ONAN owners in particular. I would like to be able to monitor the temperature of the back cylinder compared to the front. Being able to set an alarm if a certain temperature is exceeded would also be helpful. That kind of instrument could prevent at least a few engine failures. Almost every car and truck has one. Why not the tractors?

[Wheel-N-It 2,968]

For me SOI, I would like RPM's and hours.

Are you thinking of surface mounting or a round recess type? It will be easy enough to cut a hold in the dash, so that would be preferred. I have a freshly rebuilt K-341 that I sure would like to have a new hour meter for to replace the original. It is the round recess type. I would likely purchase one of a combination type rpm/hour meters, and two rpm only meters.

[dsholler 54]

Instead of a tach, how about an auto-pilot

Just an observation as a boat owner. Single function instruments are not very popular these days. Since it does not add to the setup to put more logic in the display head, everything is set up to use whatever sensors you have installed, and even combine the inputs (GPS plus Maps plus depth sounder allows you to follow a depth contour). I do not know if the same issues apply to the tractor, but if the issue is about overworking the engine, you want to have something that will show you things like the relationship between RPM, governor setting, temperature and fuel flow. The other thing is that most instruments sold these days have task or problem specific displays. I am not familiar with the Onan twin, but I gather that it might be more useful to know the temperature difference between the two cylinders at the heads, to show whether the rear one is getting appropriate cooling flow. Or you could calculate mowing efficiency based on run time with mower engaged and the distance traveled during that time combined with fuel use.

Of course, this is complete overkill, but it would be very cool. :cool:

[WheelHorseSteve 48]

SOI - I have two tractors (and two empty round gauge spots) waiting for whatever you come up with! I have long had an interest in a tachometer... but like the idea of temperature as others have said. The Kirk Engines one is attractive... but just pricey enough to keep me from pulling the trigger. Now... if it had some sort of temp indicator / warning too? ... now we're talking.

[roscoemi 245]

I'll take a tach, or a tach hour meter combo analog style for a single.

[JackC 617]

"I'll take a tach, or a tach hour meter combo analog style for a single."

Kirk engines sells a tach for singles.

http://www.kirkengines.com/

[Save Old Iron 1,565]

any thoughts on indications for

Distance traveled

MPH

Exhaust gas temp

Tilt of tractor - for safety reasons

Battery Recharge - not amps or volts but amount of energy withdrawn - gauge would indicate "power units" as in 50 amp/ minutes, etc. Units of energy used during engine cranking are measured and replaced as tractor is charging - but you now know how many units need to be replaced before you shut the tractor off - extending battery life from undercharges.

How about computer controlled carb settings - on the fly high and low speed needle valve adjustments

Fly by wire throttle and choke - or heck, just automatic choke from engine temp sensors

Don't like your ignition switch? how about an ENGINE START pushbutton instead of an ignition switch ?

Trans temp warnings.

Oil temp warnings.

Maybe INTERACTIVE sensors - high oil temp may throttle back engine automatically.

Think big thoughts - the future in lawn care will be here soon enough.

More to follow. Keep the ideas coming.

[baerpath 517]

I'd be interested in one that shows rpm (5000) for the pullers, EGT's and intake air for the gassers.

For the diesel add in cooling oil temp fuel preassure and amperage

Duane

[JackC 617]

"but you now know how many units need to be replaced before you shut the tractor off - extending battery life from undercharges."

That would be very useful.

[sorekiwi 761]

Time to drag this one out of the archives:

In theory all this stuff would be great, but in reality I'm not sure that us average Wheel Horse owners really want the complexity that a system like this requires.

I have a reasonably recent background in very high performance vehicles, with inputs logged from over 75 sensors. Anything you can imagine from the simple engine parameters to throttle positions to brake pressure readings to atmospheric pressure readings to counting how many times the fuel injectors have pulsed so you can gamble on one more lap around Indianapolis Motor Speedway befor you run out of fuel. Add a few math channels to combine different sensor readings and you can look at graphs all day.

But looking after all those sensors is a huge PITA.

I think one of the attractions of our Wheel Horse hobby is the relative simplicity of the machine. Look at the number of people who finally get their 520H and freak out when it has one of its infamous 9 pin connector issues.

That said, I think an hour meter is very useful. A tach not so much for me (but I can see why others might like it). The distance travelled/speedo idea is a good one I hadnt thought of - I'm not so interested in speed, but I think a count of distance might be a useful thing to know. A bicycle type speedo would be an simple and cheap method of doing this.

The Tiny Tach has been available for years in the form of just a basic tach and with a Tach and an hour meter. I have no doubt that Chuck could design a better or cheaper box to do the same thing. With the added bonus of educating us to how it works and what to check when it doesnt.

Edited October 5, 2012 by sorekiwi