Topping up oil when engine still running

[tmorris1]

Originally Posted By: gfh77665
Originally Posted By: tmorris1
Put your oil in the microwave to warm it up if you are worried.


MW's heat by the excitation of water molecules. Unless your oil has a significant amount of water in it, (and I hope it does not!) the MW won't do much good.

You are right, but it fits with this thread

 

[PimTac]

Originally Posted By: tmorris1
Originally Posted By: gfh77665
Originally Posted By: tmorris1
Put your oil in the microwave to warm it up if you are worried.


MW's heat by the excitation of water molecules. Unless your oil has a significant amount of water in it, (and I hope it does not!) the MW won't do much good.

You are right, but it fits with this thread




Do you reheat your food in the same microwave? I’m not sure this is anything I would even attempt let alone recommend.

 

[Vdubuk]

Depends on the vehicle and where the oil filler cap is ...ive an air cooled flat four with a high necked oil filler cap that can be removed with no oil splashing out.

 

[Snagglefoot]

In resonse to Berniedd from page 1:

Hey, this is fun. One rev, (from revolutions per minute or RPM) is defined as 360 degrees of rotation. As you say, there is a compression event in pistons #1 and #4 in 180 degrees. There is then an air compression event in #2 and #3 in the second 180 degrees. That makes four compression events in 360 degrees. Multiply 4 x 600 = 2400. One rev is 360 degrees, not 180 degrees.

 

[ZeeOSix]

Think of 2 pairs of 2 pistons moving together as one big piston. Therefore, in this 4-cyl example there are 1200 "air pulses" per minute from piston movement when the engine is idling at 600 RPM.

 

[gathermewool]

Originally Posted By: Shannow
Nope, but blowby and crankcase pulsations (especially if a 4 cyl) will blow it up into your face.

Ask me how I know.


This. Don't do it!

I usually leave the oil fill cap loosely on top of the fill neck, but not threaded in at all, while changing the oil, so that nothing accidentally falls into it.

Well, I forgot to thread the cap back on after topping off the oil, and it made a nice little mess when I started the engine to circulate the oil and fill the filter.

 

[Snagglefoot]

Haha, OK, but each compression event comes from two different sources. Nomenclature! It’s therefore dominated by the definition of “event”.

 

[ZeeOSix]

Originally Posted By: Snagglefoot
Haha, OK, but each compression event comes from two different sources. Nomenclature! It’s therefore dominated by the definition of “event”.


The "air pulses" seen at the open oil filler cap is only a function of the pistons moving up and down. Two pistons moving together is causing one pulse cycle that is larger in volume than one piston would cause. If you had 4 pistons moving in unison the pusle cycle would be the same, but 2 times the volume of 2 pistons moving together, and 4 times the volume of 1 piston moving up & down.

 

[Snagglefoot]

Originally Posted By: Snagglefoot
Haha, OK, but each compression event comes from two different sources. Nomenclature! It’s therefore dominated by the definition of “event”.


So if your your wife hits you with in the head simultaneously with two frying pans, to you it’s one event but to the pathologist it’s two events.

 

[FCD]

Take the oil cap off most 4 cylinder engine when running hot and you will notice quite a bit of crankcase vapours coming out of the oil filler cap.

 

[ZeeOSix]

Originally Posted By: Snagglefoot
So if your your wife hits you with in the head simultaneously with two frying pans, to you it’s one event but to the pathologist it’s two events.

From your head's perspective it's one hit that's twice the force as a single frying pan hit. Your head felt one hit, not 2. Just like 2 pistons moving together causes 1 air pulse cycle, not two. A 4-cyl at 600 RPM makes 1200 air pulses inside the crankcase every minute.

 

[Snagglefoot]

Originally Posted By: ZeeOSix
Originally Posted By: Snagglefoot
So if your your wife hits you with in the head simultaneously with two frying pans, to you it’s one event but to the pathologist it’s two events.

From your head's perspective it's one hit that's twice the force as a single frying pan hit. Your head felt one hit, not 2. Just like 2 pistons moving together causes 1 air pulse cycle, not two. A 4-cyl at 600 RPM makes 1200 air pulses inside the crankcase every minute.


We are most concerned about the pressure pulse as it exits the filler cap hole. Most likely the cap is not centred on the valve cover but is to one side of the valve cover. Therefore the distances to the filler cap hole from the two pistons in question are not identical and the pressure pulses hit the filler cap hole at two distinctly different times. Though they overlap they are two distantly seperate events.

From the heads perspective, the human brain is distinctly two seperate halves, and the damage and result of the damage will be distinctly different from each other. The head will feel the effect of two dfferent distinct hits.

Gotta walk my dog.

How about those Bluejays!

 

[PeterPolyol]

Originally Posted By: Shannow
Originally Posted By: Garak
I think I added a couple times to the LTD back in the day, with it running, but not even close to warm, with oil that was as cold as what was in the sump. Nothing was doing much flying.

It was one of those toothpaste tube oil additions.


LTD was an 8 ?

Try it on a 4...

Just charted the Delta in crank case volume for 4, 6, and 8 cylinder engines (the percentage is the percentage change in crankcase volume as a percentage of cylinder volume) for 4, 6, and 8, 3" stroke, 5.7" rod length.



A 4 cylinder at TDC has two all the way up, and two all the way down. At 90 degrees, has the maximum rod angularity (think ladder sliding down wall), so has a significant change in crankcase pressure as the cylinders are all "more down" than they would be sinusoidally.

Sixes, along with perfect primary balance show the benefit of three phase electricity, and the 8 is marginally more lumpy.

Just saying.
Nice visual!


Once tried pouring oil into my running 6, but the cam gear is under the fill hole and oil was getting slung out

 

[CR94]

Originally Posted By: Shannow
... Nope...it's twice per rev.
For much the same reason 4-cylinder in-line engines have unavoidable (except by balance shaft) secondary imbalance at a frequency of twice/revolution.

Whether you get oil in the face with the cap off also depends on whether the engine is OHC or pushrod, and whether the cam chain is directly under the filler hole. It was on my Mazda, which I once drove about three miles with the cap off, with very messy results.

 

[ZeeOSix]

Originally Posted By: Snagglefoot
Gotta walk my dog.

How about those Bluejays!


Is your dog's name "Strawman"?

 

[Shannow]

Originally Posted By: Snagglefoot
Originally Posted By: Shannow
Originally Posted By: Snagglefoot
If your 4 cylinder car is idling at say 600 rpm, there are 2400 air compression events per minute from the underside of the pistons. That’s 40 per second. Kinda drafty.


Nope...it's twice per rev.


Nope. Once per rev. Watch carefully.

https://www.youtube.com/watch?v=OGj8OneMjek


So you've gone from 4 times per rev (2,400 per minute at 600RPM), to once per rev, and are still wrong.

Max crankase volume is twice per revolution, one at tDC, and the other at 180. watch your video carefully, and youll see that. Minimum crankcase volume as around 90 degrees and 270 degrees, so the "pumping event" is twice RPM.

Check my chart, and count them.

 

[George Bynum]

Originally Posted By: gfh77665
Originally Posted By: tmorris1
Put your oil in the microwave to warm it up if you are worried.


MW's heat by the excitation of water molecules. Unless your oil has a significant amount of water in it, (and I hope it does not!) the MW won't do much good.
From physicsforums.com,

Before I answer let me tell you that I am a microwave scientist and have worked microwaves and microwave ovens for nearly 50 years - I also teach this stuff. 1. microwaves heating oil: while a much poorer microwave absorber than water, oils still do absorb microwave energy and heat, especially if the quantity of oil is large - say 4 ounces or more. Also, oils have a specific heat capacity of about 0.5, which is half that of water (1.0) and that means that for a given amount of microwave energy absorbed oil will heat twice as much as water. But be extraordinarily careful heating oil inside a microwave oven because oils can easily reach temperatures of over 400 F! This can cause serious burns. So, it is best not to heat them inside a microwave oven.

Reference https://www.physicsforums.com/threads/microwave-oven.316981/

 

[Garak]

Originally Posted By: Shannow
LOL, never experienced THAT..and hope I never do.

Yes, it wasn't pleasant, and I've been able to avoid repeating that in close to 30 years. An oil burning car in our winters sometimes just requires a bit of planning.

 

[CR94]

Originally Posted By: George Bynum
... But be extraordinarily careful heating oil inside a microwave oven because oils can easily reach temperatures of over 400 F! This can cause serious burns. So, it is best not to heat them inside a microwave oven. ...
For the same reasons, rewarming fatty food in an otherwise microwave-safe polypropylene container tends to damage the container.

 

[Snagglefoot]

Originally Posted By: Shannow
Originally Posted By: Snagglefoot
Originally Posted By: Shannow
Originally Posted By: Snagglefoot
If your 4 cylinder car is idling at say 600 rpm, there are 2400 air compression events per minute from the underside of the pistons. That’s 40 per second. Kinda drafty.


Nope...it's twice per rev.


Nope. Once per rev. Watch carefully.

https://www.youtube.com/watch?v=OGj8OneMjek


So you've gone from 4 times per rev (2,400 per minute at 600RPM), to once per rev, and are still wrong.

Max crankase volume is twice per revolution, one at tDC, and the other at 180. watch your video carefully, and youll see that. Minimum crankcase volume as around 90 degrees and 270 degrees, so the "pumping event" is twice RPM.

Check my chart, and count them.


Hey Shannow, maybe we can discuss it over a beer some day. Everything boils down to semantics and definitions. Time to move on. SF