Hours at 1000 RPM meter

I love this forum, been lurking for awhile. It's helped me out immensely so far. I got a 99XJ for under $1k last year. The poor thing waddled down the road while overheating when I first got it. Now it's a dedicated rural route mail jeep.

Which brings me to my question. I drive this jeep 6 or 7 hours a day, but only clock maybe 40 miles in that time so changing the oil by the millage obviously won't work in my situation.

I've seen meters on tractors before that produced an adjusted hours elapsed. Like hours at 1000 RPM. So if you ran your tractor at 2000 rpm for one hour, the meter actually clocked it as two hours.

I've been trying to find something like that for my XJ. But I'm not having any luck. Plenty of hour meters, and tach's out there. But that's not exactly what I'm looking for.

Any ideas or should the tach from my dad's kubota just mysteriously disappear some night? ;^)

Thanks,
Dean

You are looking for something called a "tach timer". Very common in planes, in general the reference RPM is 2300-2500RPM. The ones I have seen for small aircraft run over $3k.

I imagine that if someone had any skill with electrical engineering they could design a basic stamp micro-controller with an integrator function (area under the curve for RPM x time) for under $300.

You have a vehicle that you got for $1k and the motors are known to be very reliable if not bordering on bullet-proof. Why worry about this issue and not just change the oil every 3k miles or sooner if you are worried about it?

this is kind of a cool idea that i had never thought of. id actually love to know how many running hours are on my motor, like they do for boats.


keep in mind that the "Every 3k miles" rule is starting to become phased out, a lot of oils are now meant to run 5k, and tests prove that it is 100% safe.

You can buy a gauge that runs off of the ingition, just like on a boat. It will clock the hours that the ignition is turned on. However, it will not increase the time based on your RPM. But check around the Marine Stores to find one. They are very simple, basically a hot wire off of the ignition and a good ground.

Here you go:

http://www.sportsimportsltd.com/2--clamp-mount-hour-meter.html?gclid=CKGmoNOQ57ACFYMKKgod1XYbzw

Hobbs have been making hour meters, for aircraft, cince the dawn of time...

napa carrys hobbs hour meters as well.

You might also consider oil sampling to figure out the proper. Interval for oil changes

An hour-meter would be good to have, especially in a trail-only vehicle or vehicle that idles and/or runs at low speeds most of the time. I've thought about putting one in my heep for shits and giggles.

souske said:

You might also consider oil sampling to figure out the proper. Interval for oil changes

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This is really the key right here. Also, using oil that can be used for extended intervals also. The two places I know that do good testing are Oil Analysis Lab, Inc. www.oillab.com ( I worked there for a short while when I lived in Spotucky, before I moved back down to Cali) Good people, family owned. Also Blackstone labs.

grab the trip computer out of an XJ that has one IE limited trim. it has an "engine time" feature.

This seems way overcomplicated. As stated, you spent a grand on a jeep with a notoriously good track record for motors longevity....just change it every three months and forget about it.

JohnX said:

This seems way overcomplicated. As stated, you spent a grand on a jeep with a notoriously good track record for motors longevity....just change it every three months and forget about it.

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/\ This... Everything stated above sounds like a good idea but way over complicated... I would just run synthetic and change every 3 mo. and be done with it.


Oh and welcome to the forum man!! :thumbup:

I'm an EE and I like the idea because it's a neat gadget type thing... but the hour meter will probably croak before the motor :laugh2:

Do you run cool? As long as you reach ~200-210 degrees on a reasonably frequent basis to burn any condensation out of the oil, you should have no problems. I'd go with the 3 month interval from the old "3000 miles or 3 months whichever comes first" rule, personally.