50 w oil

[sparks]

Does anyone see any problems w/ using strait 50 oil in temps above 50 degree's. I have been told that single viscosity oils have better lubricating properties. Kendall 50 or Brad Penn 50 is what I was going to try. I know alot of people stand by the oils they use but, Is there really any FACTS to back up
claims. Is a single weight much better than a multi-weight oil? I would think a strait weight would be better .

[Bob In Ct]

Bad idea. Mobil1 15w-50 would be a much wiser choice. Redline also makes a higher viscosity multi-weight. Both products have the higher ZDDP levels most of us desire.

Flow rate should also count for something. Getting cold 50W through a filter, tons of plumbing and an oil cooler puts quite a strain on one's oil pump gearing.

My $0.02.

Bob

[sparks]

Within a few minutes or so they both have the 50w properties ,no ?

[strictlypersonl]

The only time I would use a single-weight oil is for an industrial engine or a compressor. Multi-viscosity oils work much better than 30 years ago, and with the tight clearances in a street engine, you risk running dry until the oil gets up to working temperature. Cold 50W will also strain the oil pumping system at low temperatures because of the ultra-high backpressure from restricted cold flow.

[sparks]

I would think that in some of our older engines and designs that the clearances are not that tight? I would also think that putting in additives to make the oil change its properties w/ different temps(even if only slight) might take away from its main purpose.

[FWB]

stick with the brad penn 20-50 , the 50 and 70 weight as stated in the literature from brad penn is for racing apps where superchargers and nitro fuels are used, the washing down of the walls in those applications requires the heavier weight to keep viscosity.

[Bobcat]

Sparks ... stay away from the 50 wt for the street . I used it all the time in my race engines , but down here , our summer temps reach 100 degrees + in July and August .
I use Brad Penn multi viscosity oil . Unless the have large clearances or are racing for more than a 1/4 mile ... 50 wt is too much . For what it`s worth , a friend of mine used to build engines for the Penske team and is still involved with NASCAR . He told me that most of the teams run a multi viscosity oil . To really get picky , they use a light oil in the engine , rear end and tranny for qualifying and then go to a heavier oil for the race ... but it`s still a multi viscosity oil .

[StreetSnake]

This may be a little off topic but I currently run the XP4 oil in my 427W. It was recommended by my engine builder (Eric @ Performance Engineering). It is a 10-50. Do you guys have any thoughts on this oil.

[fkemmerer]

Originally Posted by sparks

Does anyone see any problems w/ using strait 50 oil in temps above 50 degree's. I have been told that single viscosity oils have better lubricating properties. Kendall 50 or Brad Penn 50 is what I was going to try. I know alot of people stand by the oils they use but, Is there really any FACTS to back up
claims. Is a single weight much better than a multi-weight oil? I would think a strait weight would be better .

There are much better choices than straight 50W. Check out the 15W-50 oil from Synergyn. This is a really excellent motor oil that will give you 50W performance at high temps, superior lubricating properties, and reasonable lubrication on colder startups. More information can be found at:

http://www.synergynracing.com/

- Fred

[sparks]

part of my thought was that since my motor has some miles on , I thought that maybe tolerances mite not be that tight. Thus the 50w.?

[Tim Brewer]

Your tolerances arn't going to change much until 70k miles or so, probably longer if you change your oil a lot like most all of us do. Using 50 weight oil is a good way to shear off a dist. gear.

[sparks]

%Question, since the flow rate of sae50 compared to 20w-50 is nearly identical at temps above 40deg.,how could shear a dist. gear any more than a 20w50 could ? Doesnt viscocity = resistance to shear? not the thickness of the oil? Just tryin to learn the facts.

[olddog]

Sparks my memory is not as good as it used to be and I have forgot things and I misconstrew things from time to time. Here is how/what I remember.

A multi-viscosity oil say 10W-40W for instance, means at a cold temp the viscosity behaves like a 10W oil would at that same cold temp, and that at operating temp the oil behaves like a 40W oil would at operating temp. This I am fairly certain is a good practical explanation.

To get this characteristic, they start with a 10W oil and partially polymerize the oil, which is attaching strings of molicules together. I believe that a multi viscosity oil actually outperforms a straight weight oil in some load tests because is it easier to squish the single molicules than a chain. I'm not 100% sure this is absolutely accurate, but the general gist is ballparkish, I think.

I would bet more engines have failed to too high a viscosity oil than too low. Viscosity when plotted against temp is very exponential. Typically you see it plotted on a LOG LOG scale graph. Some of the drag racers pushing 35 psi boost into a 4.6 ltr ford and getting 1500 hp at 10+ K rpms were running 0W-5W oil to keep the lifters from pumping up.

Light oils seem offer very good protection. Personally I would not run any more than 10W-40W in anything I have ever owned. I would bet a 10W-30W verses a 15W-50W oil dynoed in the same engine would show significant hp loss with the heavy oil. Every bit of that loss is extra load on the dizzy gear.

At 70F a 50W oil would be darn hard to pump. I wouldn't try it.

[Dwight]

Bob the oil guy http://bobistheoilguy.com/

and a second link to an oil article

http://www.animegame.com/cars/Oil%20Tests.pdf


enjoy the reading

Dwight

[Ron61]

I have ran the Mobil 1 / 15-50 oil in my 69 Big Block for years and had no problems. It is nice on freezing mornings to see the oil pressure go right up instead of having to sit and run the engine for 5 minutes as the gage slowly creeps toward operating pressure.

Ron

[madmaxx]

a 20w50 has the same viscosity as a straight 40w. Look up mobile on the web and go to properties of oil. The correct oil is 10W30. If you want to impress people with saying you use "racing oil" ,50wt, that is fine but in the depths of your garage put in 10W30 and you will not have a lubrication failure. 10W30 has the same viscosity as 20W at temperature. The greater the range of viscoity, like 20W50 is horrible because the additives (polymers) needed for that range are higher than say a 10w30. By the way the polymers take up volume in the oil but provide zero lubricating properties, so inside you little bearing you 75% oil and 25% mushy polymer.

[sparks]

Thats one of the things i read about. So wouldnt sae50 be best. For summer use,above 50deg...

[StreetSnake]

Madmaxx,

So are you saying the xp4 which is a 15-50 is a poor choice?

[madmaxx]

Yes, because
#1) huge viscostiy range which requires a larger volumen of modifiers
#2) Viscosity to heavy, does not lubricate as well when cold, does not disaapate the heat as quickly when hot.

Roush recommend 10W30 in their $15K engines, good enough for me

[sparks]

Well, I did a little test. Drilled 2 1/4" holes in a glass jar lid. Filled up one jar w/20w50 and the other w/sae50 oil. When turned upside down they both flowed out at the Same rate. Oil temp was around 65deg...