Can anyone tell me where an 'engine hour gauge' on a 93, 28' 5.9 Cummins with 4-speed might be located?

I don't think this was standard equipment, Main engine hour meter is meaningless. generator engine hour meter is a different story and IMO required

Use the odometer. All engine stuff is measured in miles.

I found an hour meter inside the dash of our coach, under the removable panel. It registers 0.9 hours. It always seemed weird that there would be one if not used and tucked away inside the dash. I don't know if there is any value in an hour meter in an RV. The engine in my RV is also used in many generators. In that usage an hour meter would be a necessity.

Hour meters on a diesel are not worthless. Engine services are measured in hours of operation not miles because diesels tend to idle for long periods and are run, in the past, for twenty minutes before starting out and when cooling down. This is becoming much less common, but is still the method used by CAT. In a gasser it is common to change oil at 3,000 to 7,000 miles but you have to use good judgment- if your engine idles a lot this is reduced, and in many documents it says xxxx miles or once a year, whichever comes first. This is also carried on with your Allison transmission which specifies hours between fluid changes.

In aviation, everything is done by hours since they have no odometers. The official designation is tachometer time or "tach time."

The old hour meters were geared from the tach drive (like the odometer on a conventional speedometer.) They recorded hours at a varying rate depending on the engine rpm. At cruise rpm the tach recorded 1 hour for every hour run. At idle they ran slower, recording fewer hours.

The newer hour meters (known as Hobbs meters) are simply a clock that runs normal speed whenever the engine is running. An hour of idling will register 1 hour on the Hobbs but less on the old tach hour meters. The airplane rental guys love the Hobbs because you get more hours clocked to charge for. On my airplane, the tach hours are about 200 less than the Hobbs hours.

Boats also rely on hour meters for the same reason. All of our diesel maintenance on our 371 is based on engine hours as stated by the manufacturer. All diesels I know of have the manufacturer's required maintenance specified by hour intervals when possible.

I am in the process of installing hour meters on my new Honda generator and my snowblower tractor so I can more accurately determine service intervals.

Hour meters are far from useless, they are the gold standard.

Many components in commercial service (mechanical and electronic) are rated for "MTBF" or "Mean(average) Time Between Failures."

Maybe I should have been more clear! I was referring to Engines use in an RV or passenger service engines (light trucks etc.)! Some trucks, airplanes, boats, generators and tractors have a different operation MO and of course hours of operation there are important and in most cases of those applications, the only way to measure usage or service intervals or maintenance schedules is by hours of operation.

As stated, the method of hour measurement varies greatly and certainly not very accurate. I have owned heavy trucks, tractors and airplanes. I used various methods of determining maintenance schedules, mainly based on common sense.

I recently bought an sold several Kenworth T2000 tractors and all reference to usage of these units was logged miles. Hours, even though logged, was not a consideration of either the buyer or seller.

Tom, my Allison transmission maintenance guide specifies miles and or hours.

A goal never to be attained short of Heaven.

I have an engine hour meter on my coach. The odo is at 133,000 and hour meter at 3334 hours giving an average speed of about 40 mph.

Hey Guys,
Unless Barth installed an hour meter or you have a tachometer with an hour meter, there will be no way to measure hours on a mechanical diesel. The new diesels are electronic and by connecting my laptop via Cummins InSite software, I can read engine running time and ECU up-time. Unless you can calculate your average speed and apply some math to it, your are as-they-say, screwed! Use your mileage for any maintenance.
Billy T

You could hook up a Hobbs meter to any 12v source that is tied to the engine operation: alternator, etc (They are just a 12v clock, actually)

FYI there is a new hour meter that was designed for small engines but works well in every application...it runs off vibration! It's easy to mount and uses no electrical connections. The built in battery has a 6 year life and this thing really works. We also use them for onboard and portable generators as well as air compressors or most any moving, rotating mechanical unit that knowing the actual hours of operation could be critical to the care of the unit. We keep them in stock at Smith Auto Electric 800-822-0819 about $60.00 Thanks, Jim Thomas, owner.

quote:

it runs off vibration!

Very interesting, Jim.
But, when I am going down the road in the motorhome, with every thing vibrating to some extent, isn't the device going to think my genny is running when it is not? Is there a sensitivity adjustment? My Onan MicroLite 2800 does vibrate significantly when it is running.