Query on diesel engine

[Shutterbug]

very helpful thread... so when you say modern diesel engines nowadays don't need long warmup times... how about older diesel engines from the 90's?

[Archerfish]

very helpful thread... so when you say modern diesel engines nowadays don't need long warmup times... how about older diesel engines from the 90's?

Yes, this is very helpful. Thanks for the guy who started this topic, our experts here posted useful information and discussed a few things.

I also have the same question about older diesel engines.

[jick.cejoco]

very helpful thread... so when you say modern diesel engines nowadays don't need long warmup times... how about older diesel engines from the 90's?

No need to waste fuel, start and drive specially hybrids or electric cars. Oils, fuel, engine metals, engine controls have been improved, reformulated and re-engineered a couple of times since then.

[12vdc]

very helpful thread... so when you say modern diesel engines nowadays don't need long warmup times... how about older diesel engines from the 90's?

Old and new same principle of lubrication and combustion. At idling the oil pump delivers the oil from sump to the journals, galleries, no need to rev up. Some oil on top of the engine are retained after shutoff because of anti-drain-back-valve built-in the oil filter, this helps in faster lubrication on cold startups. Oil pressure in action can be seen after startup as the oil pressure indicator in the dash extinguish in less than 2 secs.

Just start the cold engine, drive slowly maintaining low RPM until you reach operating temp.

[Vodka]

Just start the cold engine, drive slowly maintaining low RPM until you reach operating temp.

i don't think maintaining low RPM is a good idea during warm up. someone posted about this like in the previous page.

[DiliKoAmericano]

i don't think maintaining low RPM is a good idea during warm up. someone posted about this like in the previous page.

I think what he means is dont use high rpms. And this is good avdvice. But yea u certainly dont wanna go the other extreme and change gears earlier than usual. U should drive normally, changing gears at the same rpm as u normally would, but using about 3/4 of the power you normally would, so a bit slower acceleration to the upshift point, until the engine is somewhere inside operating temp range.
Perhaps what these tossers should be saying when they sell the vehicles, is actually yo idle the engine for aminute before shutdown, as all diesels all have turbos now amd turbos need some nice cool oil flow to cool down so the hot oil doesnt sit in the stationary hot turbo and heat up to the point it breaks down.

[makelovenotwar]

How low is low RPM for the usual 2.5L - 3.0L diesel engines?
Less than 2k rpm?

[monty_GTV]

How low is low RPM for the usual 2.5L - 3.0L diesel engines?
Less than 2k rpm?

around 650-900 rpm. it fluctuates as the AC thermostat switches

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[makelovenotwar]

around 650-900 rpm. it fluctuates as the AC thermostat switches

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Oh, that's difficult to maintain while driving for me.
I live along the national hi-way so i'll be a nuisance if I drive with that rpm.

[monty_GTV]

Oh, that's difficult to maintain while driving for me.
I live along the national hi-way so i'll be a nuisance if I drive with that rpm.

i taught you are asking kapag naka idle.

while driving, less than 2k rpm cruising at 80kph

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[bigT]

I also agree what the Toyota staff said is incorrect, every time I start the engine and drive out, several years have passed, and nothing unusual about the engine has been noted.

[DiliKoAmericano]

I wouldnt listen to anything anyone sais in this country, and i dont mean that as an offensive remark to the amazing friendly people of the philippines, its just that there has been no international training and the country has been left on its own in the middle of the ocean. Everytime another country invests in you, its just to take more of your economy out of your hands.

For example.
I have visited every single motorcycle mechanic in cebu, and found that not a single one knows what the purpoae of the cylinder hone on their boring machine is for. They all have the stones wrapped in fine grit silicone carbide paper in am effort to make the cylinder borea smooth as glass.

[Archerfish]

I wouldnt listen to anything anyone sais in this country, and i dont mean that as an offensive remark to the amazing friendly people of the philippines, its just that there has been no international training and the country has been left on its own in the middle of the ocean. Everytime another country invests in you, its just to take more of your economy out of your hands.

For example.
I have visited every single motorcycle mechanic in cebu, and found that not a single one knows what the purpoae of the cylinder hone on their boring machine is for. They all have the stones wrapped in fine grit silicone carbide paper in am effort to make the cylinder borea smooth as glass.

Are you referring to this honing tool? We have that one for small sized engine with piston diameter of about 12 inches. I don't remember having a tool like this for a large engine with a piston diameter of 900 mm.

From what I know, it is used in the cylinder liner so as to avoid a mirror like finish. Otherwise, the oil won't cling or stick with the cylinder liner and so you have less lubricating effect.

[jick.cejoco]

I wouldnt listen to anything anyone sais in this country, and i dont mean that as an offensive remark to the amazing friendly people of the philippines, its just that there has been no international training and the country has been left on its own in the middle of the ocean. Everytime another country invests in you, its just to take more of your economy out of your hands.

For example.
I have visited every single motorcycle mechanic in cebu, and found that not a single one knows what the purpoae of the cylinder hone on their boring machine is for. They all have the stones wrapped in fine grit silicone carbide paper in am effort to make the cylinder borea smooth as glass.

Not all shops are that backward, not all not so backward shops are equipped or trained. There are decent techs but the shop they work for is probably not equipped and some shops with equipment don't have the tech smart enough to employ the equipment.

I had a shop foreman before who grew up and had been a "mechanic" for sometime who is older than me. I only respected him because of his age, but his theory, work practice was that of a caveman. If he didn't understand how things are supposed to work or too complicated for him, he would say " alisin mo 'yan, pampagulo lang yan" like the thermostat.
Some people don't want to admit incompetence, hence, they tell you to go backwards when it comes to technology- that's the " mechanic" attitude.
You want somebody who understands how things work, how they're supposed to work, knows how to make diagnosis at the shortest time? Ask a technician who makes use of simple physics, simple chemistry, simple geometry not just "oido" skills. Today's cars are not designed to be serviced by your favorite " mechanic" at your favorite talyer. Talyer was it when we rode calesas.

[oj88]

Are you referring to this honing tool? We have that one for small sized engine with piston diameter of about 12 inches. I don't remember having a tool like this for a large engine with a piston diameter of 900 mm.

Marine/ship engines?

[Archerfish]

Marine/ship engines?

Yes. The small sized engines are used for running the alternators while the large one is used to propel the ship.

On the topic of warming up the jacket water, those engines are always warm so it can be started anytime without delay. For generators, there is another "warm up". You wait for the exhaust temperature to reach about 250°C before you change over from diesel to bunker oil and then you load it up. That is, you now synchronize the generators. I might mixed up some procedures...

For the main engine, jacket water is maintained between 80 to 85. I think the alarm is set at 90. Recently, I heard that the cooling system is now similar to automotive design such that the the jacket water is now pressurized and so temperature is now maintained at almost the boiling point of water. I just don't know how it is done. That is, the equivalent of radiator cap for this marine application.

[jick.cejoco]

Otherwise, the oil won't cling or stick with the cylinder liner and so you have less lubricating effect.






The main reason the cylider bores of a piston engine are honed or deglazed, is to shorten the break-in period to make the piston rings and the bores match fit each other for better compression. Old mechanics call this "justar" or to mate or match the contour of the bores and the piston rings or the bearings against the journals that move around the rotating journals.

After break-in, the mating surfaces might have become smooth but still get sufficient oil film between the cylinder bores and the piston rings.

[Archerfish]

Otherwise, the oil won't cling or stick with the cylinder liner and so you have less lubricating effect.






The main reason the cylider bores of a piston engine are honed or deglazed, is to shorten the break-in period to make the piston rings and the bores match fit each other for better compression. Old mechanics call this "justar" or to mate or match the contour of the bores and the piston rings or the bearings against the journals that move around the rotating journals.

After break-in, the mating surfaces might have become smooth but still get sufficient oil film between the cylinder bores and the piston rings.

So the guy who told me about this mirror finish thing is wrong... or partly correct?

[jick.cejoco]

So the guy who told me about this mirror finish thing is wrong... or partly correct?

Picture angle grinding the valves and the valve seats, you use grease mixed emery lapping compound, the objective of lapping is to match fit the valve with the valve seat, ain't it right? After a couple of hours of engine operation don't the valve face and the valve seat contact are get shiny?
So, if the piston rings and the cylinder bores have developed fit wear, do you tear the engine apart again just because your 45-60° cross hatch hone pattern has disappeared,?

[Archerfish]

Picture angle grinding the valves and the valve seats, you use grease mixed emery lapping compound, the objective of lapping is to match fit the valve with the valve seat, ain't it right? After a couple of hours of engine operation don't the valve face and the valve seat contact are get shiny?
So, if the piston rings and the cylinder bores have developed fit wear, do you tear the engine apart again just because your 45-60° cross hatch hone pattern has disappeared,?

Yes, that lapping compound is used to "remove" uneven surfaces. And no, overhaul is based on running hours or something is wrong with it and not because the hone pattern is gone.

Thank you for clarifying it this way. A simple "yes" or "no" answer would have not satisfied my curiosity.