How engine hours are count?

[ylop]

Does that mean power to the engine control panel but key in off position , or key turned ? Key in the run position is when the hr meter should run rather than when there is live to ignition but off.

On at least some Volvo engines there is no key. The panel has on switch (which can turn the panel off but not the engine).

If you switch the panel off when engine is not running then engine hours and panel hours are going to be the same. If, like @Daydream believer , you leave panel on so that the engine can be started by simply pressing start (or glow then start) then the OPs question becomes relevant. If the panel is mounted at knee height and various people helm you may not even have a consistent approach.

Whether you use the hours to determine oil changes or at point of sale/purchase to estimate life it would be very misleading to count panel on hours rather than tuning hours, if you regularly use as DDB does. Imagine a boat used for 26 days a year. The skipper sails 0900-1700 each of those days. He is blessed with the weather so only uses the engine for 30 min at start and end of the day. By end of the season his engine has done just 26h of running. Now imagine like DDB (and I am sure many others, for either seaman like or laziness reasons) doesn’t turn the panel off between 0930 and 1630. If his logged hours record all of that: 208h a season, but the records don’t show mid season servicing you might be worried if you come to buy it… so I think the OP’s question is a useful one, even if only to know that the hours number might be nonsense - and therefore it’s of zero value to fix the inevitable lcd display fault.

 

[lustyd]

Pretty sure the VP engines count when the alternator is running, not the panel.

 

[Daydream believer]

Isolated in the cabin

On at least some Volvo engines there is no key. The panel has on switch (which can turn the panel off but not the engine).

If you switch the panel off when engine is not running then engine hours and panel hours are going to be the same. If, like @Daydream believer , you leave panel on so that the engine can be started by simply pressing start (or glow then start) then the OPs question becomes relevant. If the panel is mounted at knee height and various people helm you may not even have a consistent approach.

That is how it worked on my boat with the MD2020.Leaving the panel on or off did not record hours unless the engine was running. It was available for instant use when needed
I religiously log every trip & when the engine is running. So I actually have the meter & my log as a check. I do this because the old Volvo meter gave up the ghost at around 1250 hours & it was another few hundred hours before I fitted a meter following advice on how to, from this forum.
There are instructions on how to change the display inside the rev counter as it seems that the volvo hour meter is inclined to fail regularly. I did not fancy that option.
My engine died without warning at circa 5000 hours. 25/05/23 Rest in peace

 

[Lucky Duck]

On at least some Volvo engines there is no key. The panel has on switch (which can turn the panel off but not the engine).

If you switch the panel off when engine is not running then engine hours and panel hours are going to be the same. If, like @Daydream believer , you leave panel on so that the engine can be started by simply pressing start (or glow then start) then the OPs question becomes relevant. If the panel is mounted at knee height and various people helm you may not even have a consistent approach.

Whether you use the hours to determine oil changes or at point of sale/purchase to estimate life it would be very misleading to count panel on hours rather than tuning hours, if you regularly use as DDB does. Imagine a boat used for 26 days a year. The skipper sails 0900-1700 each of those days. He is blessed with the weather so only uses the engine for 30 min at start and end of the day. By end of the season his engine has done just 26h of running. Now imagine like DDB (and I am sure many others, for either seaman like or laziness reasons) doesn’t turn the panel off between 0930 and 1630. If his logged hours record all of that: 208h a season, but the records don’t show mid season servicing you might be worried if you come to buy it… so I think the OP’s question is a useful one, even if only to know that the hours number might be nonsense - and therefore it’s of zero value to fix the inevitable lcd display fault.

I have had two boats with panels like that for both Volvo and Yanmar engines.

Switching the panel on causes the oil pressure, etc alarms to sound until the engine starts so assuming nobody sails for hours with that noise going on I don’t see how they can be used as described.

 

[ylop]

I have had two boats with panels like that for both Volvo and Yanmar engines.

Switching the panel on causes the oil pressure, etc alarms to sound until the engine starts so assuming nobody sails for hours with that noise going on I don’t see how they can be used as described.

Not how my Volvo MD2020 works. There's an "alarm test" switch (same switch as glow but pushed in opposite direction). Turning the panel on is silent - I frequently do that perhaps 30 minutes before I actually start the engine, because I turn the power on to get the fuel tank level as part of my pre-departure checks. In some ways that irritating alarm would be better as you can accidentally leave it on draining the engine battery - since Bavaria thought it would be most useful at gnome height!

I do this because the old Volvo meter gave up the ghost at around 1250 hours

They all do! Useful to know its actual running hours it counts - it might actually be worth the hassle of fixing!

 

[Lucky Duck]

Not how my Volvo MD2020 works. There's an "alarm test" switch (same switch as glow but pushed in opposite direction). Turning the panel on is silent - I frequently do that perhaps 30 minutes before I actually start the engine, because I turn the power on to get the fuel tank level as part of my pre-departure checks. In some ways that irritating alarm would be better as you can accidentally leave it on draining the engine battery - since Bavaria thought it would be most useful at gnome height!

Apologies, that does sound familiar. The (current) Yanmar one definitely makes a noise!

 

[mattonthesea]

Wow. Thats dedication..
There seems to be some overly complicated methods of triggering the hour meter?
I just connected mine to the wiring going to the ignition switch so turn the key to on, hr meter counts. A few hrs out means oil change a few hrs early ?
Cant see the need for minute accuracy. My engine is so old that the hr meter is more for novelty factor and working out how many litres per hr over a tank full of fuel.

Well yes dedication, but with no means of assessing fuel level (except full and empty!) the engine hours becomes very useful; even if badly calculated

BTW when I finally got around to it I wired the counter to the ignition.

 

[Rappey]

On at least some Volvo engines there is no key

Ive seen that on a boat i was having a coffee on. Nice idea, press start and it does just that. Press stop and same.. far to easy -
I have to set throttle to "plenty" ,turn key to on, hold glowplug button depending on time of year for 20 - 60 secs then crank. When very cold or not run for a while it starts maybe on one cylinder and at some point the other 3 join in, and then my diesel runs as well as morris intended
Now to stop it i have to go inside, open engine compartment lid and place the palm of my hand over the air inlet.
I can always tell how many times ive started the engine by the amount of oil rings i have on the palm of my hand !

 

[Rappey]

but with no means of assessing fuel level (except full and empty

Thats not good. ive a project boat which had the same problem. I drilled a hole for 15mm copper pipe in the top of the tank and used chemical metal to glue it in place. Wow that stuff is strong. Now i can drop in a hardwood dipstick in to measure it. Ive got a copper end feed stop to close pipe..

 

[MikeBz]

We have a Tek Tanks gauge but it’s rather vague/variable so I don’t really trust it. The tank has a drain tap at the bottom with a length of clear plastic tube attached, and another tap at the end of the tube - I use it as a sight tube by holding it vertical and opening both taps.

 

[Moodysailor]

Our hours meter (Perkins Prima M50) is driven off the tacho drive from the alternator, which makes me wonder if it is revs dependent. As an aside I still haven’t worked why they are intermittent - works fine when at the pontoon, in gear under load for some time, but stops or becomes intermittent within minutes of casting off!

The tachometer (rev counter) is fed from the "W" terminal on the alternator, these can be a bit intermittent at times.
The hour counter is fed from the panel switched +12V (blue with red trace) on that generation VP engine - when the panel is switched on, it's recording hours.

 

[MikeBz]

The tachometer (rev counter) is fed from the "W" terminal on the alternator, these can be a bit intermittent at times.
The hour counter is fed from the panel switched +12V (blue with red trace) on that generation VP engine - when the panel is switched on, it's recording hours.

On ours the hour counter only counts when the rev counter works, not just when the panel is on. I’ve checked the supply to the panel and that is fine, ie there is 12V there whether or not the rev counter is working & the hour meter is counting.

 

[MontyMariner]

When I bought my boat it had the hour meter incorporated with in the tachometer but it worked intermittently.
I bought a 12v liquid crystal hour meter and wired that into the ignition so it only started counting when the ignition was on. Another benefit was that it had a total hours and a trip display which I zero when I fill up with fuel so I can instantly see how many hours I've done on the tank of fuel.

 

[Moodysailor]

On ours the hour counter only counts when the rev counter works, not just when the panel is on. I’ve checked the supply to the panel and that is fine, ie there is 12V there whether or not the rev counter is working & the hour meter is counting.

Ah, OK, thanks for clarifying - it's been many years since I worked on one. It may take a signal from D+ or elsewhere as a run signal then. Either way, W on the alternator provides the rpm signal.