benefits of 20w50?

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Interesting responses.
Allowing for the obvious "thicker" characteristics such as noise and fuel economy/performance. I have used 20-50 Racing Oil in some motors (mainly blown/turbo/nitrous applications) as the load on the rods/bearings when under boost was squeezing" the 30/40 weight oil out and causing bearing damage. The 50 weight allowed a more survivable film on the bearings under load. Hydraulic Pressure I believe it is called.
 
there is no oil consumption in my 2.5, i was just making sure that using the valvoline high milage is where i should be, i dont have any major engine problems and i am at about 90k on the motor.
 
Then you don't need to change a thing, jayno20. It got you this far ..it's probably going to take you another 90k too. If you want to have fun ..get a UOA on it and see how good you've been treating it all these years
dunno.gif
 
quote:
Originally posted by Coral:
Interesting responses.
Allowing for the obvious "thicker" characteristics such as noise and fuel economy/performance. I have used 20-50 Racing Oil in some motors (mainly blown/turbo/nitrous applications) as the load on the rods/bearings when under boost was squeezing" the 30/40 weight oil out and causing bearing damage. The 50 weight allowed a more survivable film on the bearings under load. Hydraulic Pressure I believe it is called.
Click to expand...
In hydrodynamic bearings the relevant terms are "Minimum Oil Film Thickness" and "Maximum Film Pressure". If you need 50 weight oil to get your bearings to survive, you either have larger clearances, more eccentricity or rougher surface finish than modern manufactured engines, or you're compromising the oil through excessive heat or fuel dilution, or are generally taking the bearings severely past the original design parameters. Run some numbers through the bearing design equations for clarity.
 
quote:
Originally posted by 427Z06:

quote:
Originally posted by Coral:
Interesting responses.
Allowing for the obvious "thicker" characteristics such as noise and fuel economy/performance. I have used 20-50 Racing Oil in some motors (mainly blown/turbo/nitrous applications) as the load on the rods/bearings when under boost was squeezing" the 30/40 weight oil out and causing bearing damage. The 50 weight allowed a more survivable film on the bearings under load. Hydraulic Pressure I believe it is called.
Click to expand...
In hydrodynamic bearings the relevant terms are "Minimum Oil Film Thickness" and "Maximum Film Pressure". If you need 50 weight oil to get your bearings to survive, you either have larger clearances, more eccentricity or rougher surface finish than modern manufactured engines, or you're compromising the oil through excessive heat or fuel dilution, or are generally taking the bearings severely past the original design parameters. Run some numbers through the bearing design equations for clarity.
Click to expand...
Well, he DID say it was a blown/turbo/nitrous application. Sounds to me like he was taking them a LONG way past the original design parameters
crushedcar.gif
 
quote:
Originally posted by 427Z06:

quote:
Originally posted by Coral:
Interesting responses.
Allowing for the obvious "thicker" characteristics such as noise and fuel economy/performance. I have used 20-50 Racing Oil in some motors (mainly blown/turbo/nitrous applications) as the load on the rods/bearings when under boost was squeezing" the 30/40 weight oil out and causing bearing damage. The 50 weight allowed a more survivable film on the bearings under load. Hydraulic Pressure I believe it is called.
Click to expand...
In hydrodynamic bearings the relevant terms are "Minimum Oil Film Thickness" and "Maximum Film Pressure". If you need 50 weight oil to get your bearings to survive, you either have larger clearances, more eccentricity or rougher surface finish than modern manufactured engines, or you're compromising the oil through excessive heat or fuel dilution, or are generally taking the bearings severely past the original design parameters. Run some numbers through the bearing design equations for clarity.
Click to expand...
Bearing clearances after coating usually run .002 give or take a tenth. We run anywhere from a 250 shot of nitrous to 9-10 lbs. of boost depending on the power adder obviously. Is not you average grocery getter. And yes we have fuel dilution on top of that.
 
quote:
In hydrodynamic bearings the relevant terms are "Minimum Oil Film Thickness" and "Maximum Film Pressure". If you need 50 weight oil to get your bearings to survive, you either have larger clearances, more eccentricity or rougher surface finish than modern manufactured engines, or you're compromising the oil through excessive heat or fuel dilution, or are generally taking the bearings severely past the original design parameters. Run some numbers through the bearing design equations for clarity.
Click to expand...
Do you mean the type of bearing material or the physical size? From what I see ,if he's running an American V-8,it's trimetal Clevite 77 type or maybe the newer King aluminum bi metal barings,that's all you got.
I always heard the term "oil wedge" used by engine builders.Need enough clearance and visosity to build an "oil wedge" that'll survive the pounding of high compression and torsional twisting of the crankshaft.
 
quote:
Originally posted by jayno20:
well gary allen i hope to get at least another 90k out of it, i treat it well... but what is a UOA?
Click to expand...
(we pause in our ongoing hydrodynamic film discussions for an on topic response to the OP
grin.gif
)


UOA is a Used Oil Analysis. It will tell you how your oil is holding up over your usage. It will also indicate, somewhat, if your engine wear metals are within statistical norms. It tells if your air and oil filtration is up to par ..whether coolant is present in the oil ..how the viscosity held up ..if fuel is present ..etc..etc.

Since you haven't got your feet wet on UOA yet, I'd recommend getting your first sample interpretted by Terry Dyson, a site sponsor. He'll lead you by the hand and spell out the whole shabang for you ...advise any corrective action, if needed, and recommend any alternative lubricants (weights etc.) that may serve you better. Not bad for (I think) an additional $10 to the normal UOA from Blackstone (also a site sponsor).

It's something that I'd consider doing once a year. An annual checkup, if you will.
 
quote:
Originally posted by jayno20:
i have a 2000 chrysler sebring with about 90k on it, i have been using 10w30 since i'ved owned it.. what benefits come along with using 20w50? is it better for the engine or what i've heard of a lot of people using it..
Click to expand...
I wouldnt think so, im using AMSOIL Series 3000 5W30 in my 2002 Tacoma V6 and im in the middle in moving from Cali to Texas only 250 miles to go. Im towing a 6x12 Uhual trailer in thrid gear all the way and with 1400 miles so far no oil burn.
 
20w-50 is fine for some air-cooled big twin motorcycle engines during hot weather riding. Otherwise, it's much thicker than ideal for the average passenger car. Perhaps in some very high engine oil temp applications (greater than 275 F), 20w-50 would be appropriate. OTHERWISE, go for the higher flow rates of thinner oils...higher flows cool better.
 
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