Your last generator Maintenance Run

   / Your last generator Maintenance Run #3,711  
I could use some education about the lubrication of Small Diesel Engines.

It came to light that Onan had a 5 psi oil pressure switch that would prevent the motor from starting until it saw oil pressure. It wasn't working and would prevent the engine from starting, so I bypassed it momentarily on starting, not realizing what they were attempting to do. If I install a new controller, I had no intention of doing anything like that.

How do the cylinders get lubricated anyway?

Ok get ready for another long rambling post.

That’s called a rolling prelube and ensures the bearings get an oil film if not before firing, it least after very few rotations.

Turning the engine over with just compression doesn’t cause much wear but once it fires and gets up to speed there is a lot of wear on a dry bearing. 80-90% of the wear on most engines happens at startup.

Most newer digital controllers either have this feature by default or at least the option to enable it. Basically it won’t enable the fuelling until oil pressure is achieved or a certain number of rotations are completed.

Cylinders are lubricated by the oil that intentionally gets past the oil ring. Piston cooling nozzles are just for cooling the pistons, not for lube. A common belief is that the less oil a new engine uses, the better. In reality an engine that uses too little oil will wear out the cylinders prematurely. There is such a thing as too much oil but it’s always a lot more than most people realize. On a 15L engine that has a a 45L pan, you could expect to use about 4-5L per day and up to about 12L in a 24hrs before any investigation is required.

On another note, with all the wind and rain here the pst few days, power went out about 3AM Saturday morning... so I rolled over and went back to sleep. We have a gas stove so coffee and toast with the camping toaster wasn’t a problem in the morning but by 9AM and no crew dispatched figured it was time to start the OLD Emerald up. I run the fuel pump first to fill the carb then it fires after only a couple seconds. (17k hours I’m not worried about rolling prelube anymore) Ran about 6 hours getting two freezers and 3 fridges cold again, recharging phones and running the water pump. Was just about ready to shut it down until dinner time when the power came back.
 
   / Your last generator Maintenance Run #3,712  
Thanks. Most informative as usual. I tried making a prelube pump on that set years ago, but it was a failure. I don't remember why.

Isn't oil stuck in the main journals for some time?

A little while I saw a video about Locomotives. They NEVER changed the oil, ever, just added buckets every few thousand miles.
 
   / Your last generator Maintenance Run
  • Thread Starter
#3,713  
Ok get ready for another long rambling post.

That痴 called a rolling prelube and ensures the bearings get an oil film if not before firing, it least after very few rotations.

Turning the engine over with just compression doesn稚 cause much wear but once it fires and gets up to speed there is a lot of wear on a dry bearing. 80-90% of the wear on most engines happens at startup.

Most newer digital controllers either have this feature by default or at least the option to enable it. Basically it won稚 enable the fuelling until oil pressure is achieved or a certain number of rotations are completed.

Cylinders are lubricated by the oil that intentionally gets past the oil ring. Piston cooling nozzles are just for cooling the pistons, not for lube. A common belief is that the less oil a new engine uses, the better. In reality an engine that uses too little oil will wear out the cylinders prematurely. There is such a thing as too much oil but it痴 always a lot more than most people realize. On a 15L engine that has a a 45L pan, you could expect to use about 4-5L per day and up to about 12L in a 24hrs before any investigation is required.

On another note, with all the wind and rain here the pst few days, power went out about 3AM Saturday morning... so I rolled over and went back to sleep. We have a gas stove so coffee and toast with the camping toaster wasn稚 a problem in the morning but by 9AM and no crew dispatched figured it was time to start the OLD Emerald up. I run the fuel pump first to fill the carb then it fires after only a couple seconds. (17k hours I知 not worried about rolling prelube anymore) Ran about 6 hours getting two freezers and 3 fridges cold again, recharging phones and running the water pump. Was just about ready to shut it down until dinner time when the power came back.

Thanks CM !

Hold for Pre-lube, (IT's switch) makes sense now...... (back to that topic in a minute.....)

Startling consumption #'s CM ! (I believe you, they're just higher than I was expecting). How does that effect emissions ? Thinking HC #.

I think (?) you posted about oil auto-fill systems before.... with those kind of #'s, they don't look optional now......

Old 17k faithful is serving you well......... How are you doing re. Flooding near you ?

I wasn't heavy into diesels back when, but I do recall when turbos started appearing on light-duty gas motors........ Turbo Timers were a popular aftermarket option back then, and electric pre-lubers too.

Oil has gotten better since then, but still...... I wonder how many people today idle a light-duty turbo after suddenly pulling off an expressway to grab a coffee stop..... I'd guess only a minor fraction.

Rgds, D.
 
   / Your last generator Maintenance Run #3,714  
Thanks CM !

Hold for Pre-lube, (IT's switch) makes sense now...... (back to that topic in a minute.....)

Startling consumption #'s CM ! (I believe you, they're just higher than I was expecting). How does that effect emissions ? Thinking HC #.

I think (?) you posted about oil auto-fill systems before.... with those kind of #'s, they don't look optional now......

Old 17k faithful is serving you well......... How are you doing re. Flooding near you ?

I wasn't heavy into diesels back when, but I do recall when turbos started appearing on light-duty gas motors........ Turbo Timers were a popular aftermarket option back then, and electric pre-lubers too.

Oil has gotten better since then, but still...... I wonder how many people today idle a light-duty turbo after suddenly pulling off an expressway to grab a coffee stop..... I'd guess only a minor fraction.

Rgds, D.
A big issue with those older turbos was that they were only oil cooled and the oil back of the time had a hard time resisting coking up when it sat in a hot turbo.
With water cooled turbos and better oil, those problems are significantly reduced if not completely eliminated.

Aaron Z
 
   / Your last generator Maintenance Run #3,715  
Thanks CM !

Hold for Pre-lube, (IT's switch) makes sense now...... (back to that topic in a minute.....)

Startling consumption #'s CM ! (I believe you, they're just higher than I was expecting). How does that effect emissions ? Thinking HC #.

I think (?) you posted about oil auto-fill systems before.... with those kind of #'s, they don't look optional now......

Old 17k faithful is serving you well......... How are you doing re. Flooding near you ?

I wasn't heavy into diesels back when, but I do recall when turbos started appearing on light-duty gas motors........ Turbo Timers were a popular aftermarket option back then, and electric pre-lubers too.

Oil has gotten better since then, but still...... I wonder how many people today idle a light-duty turbo after suddenly pulling off an expressway to grab a coffee stop..... I'd guess only a minor fraction.

Rgds, D.

Actual oil consumption is always more than people think, especially when they just bought or rebuilt an engine. It does have a significant impact on emissions and is the main reason for the constantly advancing oil specs. Lubrication hasn’t changed all that much over the years, though ability to handle temperature extremes has. If you use an outdated oil in a modern engine your not likely to cause a mechanical failure but you won’t pass a detailed emissions test.

Auto fill systems are still the standard on prime units that aren’t shut down regularly however the burn off systems that used to work with them as a continuous oil change system aren’t allowed any more. If you pull out a few CC’s per hour it goes into a waste tank now.

Turbo timers saved the turbo by allowing the oil (and exhaust stream on diesels) to cool the impeller before shutting down. If you shut down right after running with significant load that impeller is red hot and the heat transfers into the bearing. More and more turbos use ceramic coated sleeve or ball bearings and seals now and can withstand heat soak much better.

We are on the side of the hill so no worries about flooding, though we have a creek coming down the mountain through the property that would generate significant power right now. Since we do live on the mountain, our 2.0 ecoboost Escape gets a minute or so to cool as does the 5.9 in my pickup... no point testing the theory of better materials.
 
   / Your last generator Maintenance Run #3,716  
Actually there is a guy on YOUTUBE that does some reasonably well done comparitive tests on all kinds of stuff. Someone sent him a can of rather old engine oil. I don't remember how old. 50s/60s? Modern oil beat it hands down in a number of important ways.

I'm still glad that a bunch of my engines don't have turbos.
 
   / Your last generator Maintenance Run #3,717  
A little bit off topic. My newest, a Briggs and Stratton Generator uses the cheapo rectifier excitation system instead of the AVR system. No load voltage is 145V and full load voltage is 105. My old Yamaha, Homelite and Walenstien all hold within a volt of two of 120V.
The AVR use six wires . Two DC to the brushes for the rotor. A pair wires to the excitation supply winding in the stator. Then two voltage reference wires however they don't appear to measure 120 or 240V. one line to neutral then another mid winding tap on the stator power winding at approx the 18V point to neutral. The 18Vac is sent to the regulator and controls level of excitation.
It is either use an 16 or 18V door bell transformer to drop 120V to a proper reference voltage . Or try and find a regulator that references to 120V for control BUT still takes it's excitation power from the excitation winding in the stator .
 
   / Your last generator Maintenance Run #3,718  
That’s weird. My 6,000 watt briggs and Stratton portable shows no load at 124 volt. I never looked at the 250 as I only use it for air compressor and skill saw work.

Edit. I just looked at my parts diagram and it shows the AVR. I GUESS MY MODEL has it. There such a cheap part, why wouldn’t they use them across the board. It’s a $40 part.
 
   / Your last generator Maintenance Run
  • Thread Starter
#3,719  
Turbo timers saved the turbo by allowing the oil (and exhaust stream on diesels) to cool the impeller before shutting down. If you shut down right after running with significant load that impeller is red hot and the heat transfers into the bearing. More and more turbos use ceramic coated sleeve or ball bearings and seals now and can withstand heat soak much better.

We are on the side of the hill so no worries about flooding, though we have a creek coming down the mountain through the property that would generate significant power right now. Since we do live on the mountain, our 2.0 ecoboost Escape gets a minute or so to cool as does the 5.9 in my pickup... no point testing the theory of better materials.

Materials and oil have become better across the time span we're talking about, for sure. That said, thermals still rule mechanical systems.....

Water cooling obviously helps turbos, but, you still need coolant circulating to really deliver btu xfer.

IIRC, you can spec out a 3.5L ecoboost to tow 5 tons. It won't necessarily immediately seize the turbo that day, but I know if I was cruising down the interstate at 75mph with that load and pulled in for a coffee, I'd be idling for a while before shutdown.

On my briggs gens, the general recommendation is to run 2 minutes unloaded, Start and Shutdown.

Many switching supplies wouldn't have an issue with what B&D's gen is doing, but incandescent bulbs might not be happy. I don't think my older Briggs has an AVR, I should meter it the next time On.....

Rgds, D.
 
   / Your last generator Maintenance Run
  • Thread Starter
#3,720  
That’s weird. My 6,000 watt briggs and Stratton portable shows no load at 124 volt. I never looked at the 250 as I only use it for air compressor and skill saw work.

Edit. I just looked at my parts diagram and it shows the AVR. I GUESS MY MODEL has it. There such a cheap part, why wouldn’t they use them across the board. It’s a $40 part.

High volume electronics is not a fun place to work...... to add $40 in cost, you'd probably have to sell a non-redundant body part, and one or two spare kids to get that released to production.....

Rgds, D.
 

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