Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 01-03-2010, 06:54 PM   #21 (permalink)
EcoModding Lurker
 
Join Date: Nov 2009
Location: MD
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Christ View Post
Too much oil doesn't prevent the cylinders from moving at all... it just makes it alot harder. While oil doesn't compress, it does move. As one piston is coming down, another is going up, so the fluid is getting forced elsewhere in the crank case. The last thing that would happen from that is a seized piston. More likely what happened was that the flickering oil light was from a failing pump, and intermittent pressure, but without seeing the engine first hand, my guess is as good as the stuff in the cat box.
Christ, you can't be serious! If you really think that when a piston comes down and meets a volume of oil nothing will happen because there is another piston going up, you are in for a shock. Go ahead, add an extra gallon of oil to your car and rev it up. Let us know how much the repairs will be. I know for a FACT that overfilling WILL destroy an engine. At the speeds that the piston is traveling, the oil may as well be concrete.

Underfilling or overfilling by a small amount (~a quart) will not hurt an engine, but I doubt it will help anything either. The nominal dipstick oil level is just that, nominal. It is meant to accommodate all expected engine operating conditions, so it is not an exact, calculated setting. IMHO reducing the oil level in the engine to improve FE is more foolish than removing the seat belts to shed weight for the same goal. I have never met the OP, but I'm going out on a limb and suggest they drop 15lbs and forget about reducing the crankcase oil level. The impact on FE will in all likelihood be the same.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-16-2010, 09:03 AM   #22 (permalink)
Basjoos Wannabe
 
ShadeTreeMech's Avatar
 
Join Date: Apr 2009
Location: Arkansas
Posts: 870

The Van - '97 Mercury Villager gs
90 day: 19.8 mpg (US)

Lyle the Kindly Viking - '99 Volvo V70
90 day: 25.82 mpg (US)
Thanks: 174
Thanked 49 Times in 32 Posts
My van's motor lets me overfill it by a quart with no ill effects. It seems to like it, as far as that goes. And as far as whether less oil will allow the engine to heat up faster, there's plenty of heat to go around.

I'd be more comfortable with a lower weight of oil, or as i do, add a quart of Marvel mystery Oil to the crankcase to help keep things clean in there. It likely lowers the viscosity somewhat as well.

I've also loved to second guess the design specs of a vehicle, and sometimes i have to realize much smarter people than I said "you need 5 quarts of this oil to make the engine last longer."
__________________
RIP Maxima 1997-2012


Quote:
Originally Posted by jamesqf View Post
I think you missed the point I was trying to make, which is that it's not rational to do either speed or fuel economy mods for economic reasons. You do it as a form of recreation, for the fun and for the challenge.
  Reply With Quote
Old 04-16-2010, 10:21 AM   #23 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,525 Times in 1,126 Posts
...anybody familiar with the technical term "hydraulic lock"?
  Reply With Quote
Old 04-16-2010, 02:39 PM   #24 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,762

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,555 Times in 2,218 Posts
Yeah. Why?
__________________


  Reply With Quote
Old 04-16-2010, 02:44 PM   #25 (permalink)
...beats walking...
 
Join Date: Jul 2009
Location: .
Posts: 6,190
Thanks: 179
Thanked 1,525 Times in 1,126 Posts
...why? rhetorical emphasis only.

...being basically "incompressible," nasty things *happen* when rotating parts "hit" liquid oil in the crankcase.

...sorta akin to a "metallic bellyflop" for each cylinder as the engine turns.

...as mentioned earlier, that's why crankcase "windage" trays are often (but not always) used in high-rpm engines -- to keep metal and liquid oil totally separated, and metal and oil vapor/foam as far apart as possible.
  Reply With Quote
Old 04-16-2010, 08:26 PM   #26 (permalink)
Hyperlurker
 
daring4's Avatar
 
Join Date: Mar 2010
Location: Glendale, AZ
Posts: 87

D-max - '04 Chevy Silverado Ls

Notch - '65 Volkswagen 1500 S

MTCHBX - '05 Scion XB
90 day: 40.41 mpg (US)
Thanks: 12
Thanked 2 Times in 2 Posts
It would take a crap load of oil to hydro-lock an engine from the bottom of the pistons! When one comes down some are going up, hydro happens when one or more cylinders fills with a liquid on the compression stroke. Over filling the oil pan might reduce mpg's and power from the oil splash, but seriously you will not lock up an engine from a lil overfill.
  Reply With Quote
Old 04-16-2010, 08:34 PM   #27 (permalink)
Hyperlurker
 
daring4's Avatar
 
Join Date: Mar 2010
Location: Glendale, AZ
Posts: 87

D-max - '04 Chevy Silverado Ls

Notch - '65 Volkswagen 1500 S

MTCHBX - '05 Scion XB
90 day: 40.41 mpg (US)
Thanks: 12
Thanked 2 Times in 2 Posts
Engines wouldn't be designed with oil squirters on the rods to spray on the pistons if they couldn't handle it. It's how they cool the pistons. Oil mist is not much different than air, the bottom of a crankcase is not an area of high compression.
  Reply With Quote
Old 04-16-2010, 08:36 PM   #28 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Of course the crankcase won't hydro-lock... but if you overfill the crankcase, there is a good chance that oil will leak past the oil control rings and pump into the combustion chambers, which could cause a hydrolock condition on some engines.
__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 04-16-2010, 08:48 PM   #29 (permalink)
Hyperlurker
 
daring4's Avatar
 
Join Date: Mar 2010
Location: Glendale, AZ
Posts: 87

D-max - '04 Chevy Silverado Ls

Notch - '65 Volkswagen 1500 S

MTCHBX - '05 Scion XB
90 day: 40.41 mpg (US)
Thanks: 12
Thanked 2 Times in 2 Posts
I hate to tell Christ thats he's wrong but combustion pressures produce pressure in the crankcase not a vacuum. Oil won't be sucked through the rings into the combustion chamber. Air/fuel is much more easily pulled in through the open intake valve. Pull off your PCV valve at idle and see if it sucks or blows out the hole. 20 bucks says it blows.

If your oil control rings let that much oil in, burning 2 quarts per tank, then you have bigger fish to fry. But they wont let enough in to lock the engine. Thats all I'm trying to get at.

Darin
  Reply With Quote
Old 04-16-2010, 08:50 PM   #30 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Well, bud, you can keep believing that, but I've actually seen engines ingest oil when the crankcase was severely overfilled. A quart high, not a chance, but when the oil change specialists at Meineke decide to drain the transmission and refill the engine during an oil change, and now there's nearly 12 qts of oil in the engine, well, that's going to cause a problem.

__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Effect of gear oil viscosity on transmission efficiency (Metro owners take note) MetroMPG EcoModding Central 44 12-08-2014 11:22 PM
Pick Your Poison - Whose gas to buy? SVOboy General Efficiency Discussion 84 11-22-2010 10:19 PM
Oil change recommendations? rjacob EcoModding Central 48 08-02-2010 05:04 PM
Alberta Oil Sands Gone4 The Lounge 8 02-19-2008 07:58 PM
Book report: The Last Oil Shock by David Strahan AndrewJ The Lounge 0 01-16-2008 11:55 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com