Motor oil

[Rusty_S]

True. I was thinking of running valvoline 10w30 maybe 5w40/10w40 in either convential or synthetic (have heard people tell me to not use synthetic that it wears the lobes evenly down and the old y blocks dont like that). It is either that or Penn. which is the easest to find locally.

[Rusty_S]

I did a search just now on JC Whitney`s site for Zinc looking for the Zinc bar for radiator anti corrision and I came across this.

ROUSH® HIGH ZINC PERFORMANCE MOTOR OIL

Its $10 roughly per quart for it but it comes in both 10w30 and 10w40

it is pure synthetic though as the bottle says but it has high Zinc concentration though.

They also have this

ROUSH® HIGH ZINC PERFORMANCE BREAK-IN OIL

Its also $10 roughly per quart but only comes in SAE 40 though.

[gangstakr]

I agree with 46yblock. Here in Texas, it gets pretty hot in the summer. My problem with thick oil is that it does a poor job of flowing when first starting up. You'll get plenty of oil pressure, but most of the oil the pump is pumping is going out the bypass, rather than thru the bearings, which is where you want it.

I'm trying to understand this. Will the motor smoke at start up when using say 10w-40? How would 10w-30 do at start up?

[Rusty_S]

Originally Posted by gangstakr

I agree with 46yblock. Here in Texas, it gets pretty hot in the summer. My problem with thick oil is that it does a poor job of flowing when first starting up. You'll get plenty of oil pressure, but most of the oil the pump is pumping is going out the bypass, rather than thru the bearings, which is where you want it.

I'm trying to understand this. Will the motor smoke at start up when using say 10w-40? How would 10w-30 do at start up?

My grandfather ran 10w30 in his 292 all the time I run 10w30 in all my cars as well and I never had a problem.

My oil gauge though the pressure is in normal but round 75 - 80 psi when cold but when warmed up round 50 - 60 psi but my shop manual for the car said thats normal for a 351 but I think the owners manual calls for 10w30 for here in tx as well for hot climates

[46yblock]

Originally Posted by gangstakr

I agree with 46yblock. Here in Texas, it gets pretty hot in the summer. My problem with thick oil is that it does a poor job of flowing when first starting up. You'll get plenty of oil pressure, but most of the oil the pump is pumping is going out the bypass, rather than thru the bearings, which is where you want it.

I'm trying to understand this. Will the motor smoke at start up when using say 10w-40? How would 10w-30 do at start up?

My understanding is that either 10/40 0r 10/30 will have the same startup lubricating characteristics. Neither should produce a smoking engine if all is well with rings and valve guides. The 10/40 may give a little better hot pressure than 10/30 if oil pump and/or bearings are worn. Exactly what that improvement in pressure actually means...is for someone else. At 180 true engine temp, with 10/30 I have 24 psi idle and 54-55 psi cruise.

[gangstakr]

Thanks guy's

[flipklos]

Finaly, after two weeks Shell got back to me on the rotella issue.

"Yes, Rotella T 15W-40 provides sufficient anti-wear protections
(1200ppm of zinc) for your older flat-tappet gasoline engine.
(Mono-grades contain about 1000ppm.)

Gasoline only engine oils for newer cars have about 800 ppm."

There you have it.

[46yblock]

That is good to know, thanks Flip. I have 3 gallons of 15-40 on the shelf. I'll save them for a summer change and add a dash of additive.

[Rusty_S]

Makes me wondering if thats why my lifters are making noise on my 78 351 since I am just using regular 10w30 vavoline oil. Might need to look into getting some additive hate to wear the engine out sooner than it should.

[wild.bunch]

I'm trying to understand this. Will the motor smoke at start up when using say 10w-40? How would 10w-30 do at start up?

What I'm saying here has nothing to do with an engine smoking at start up.

What it does refer to is that in the plain bearings of the crank and rods (and to a lesser extent, the cam), the oil is pushed ahead of the rotating journal and the journal essentially hydroplanes on it, just like your tires will do if you go thru a large pool of water too fast on bald tires.

Some of the oil is pushed ahead of the journal and the pressure also forces some out the sides, which eventually goes into the sump, just like some of the water in front of a hydroplaning tire will squirt out of the sides, but eventually enough pressure builds up that the only way for it to escape is to push the whole car up off of the road and go under the tire. It isn't intuitive that the forces would be so great that a car can be lifted off of the road or that the crank won't touch the bearing, but there is is. The latter goes on whenever an engine is running and the former happens all too often.

Your oil pump pushes oil thru the galleries of the engine and ensures that the oil that has been pushed out of the journal-to-bearing clearance space is replaced by more oil, so that a film of oil is constantly maintained and no metal-to-metal contact occurs.

The oil pump takes power to push oil down the galleries and into those clearance spaces. With a cold engine, the oil will, granted, flow out of the clearances more slowly than thin oil will, but it will also be subjected to more friction and heat by remaining under load a little longer and flow out. Meanwhile, the thick oil in the galleries is not hot -- it is still thick -- and the pump needs to push this thicker oil at a rate needed by the bearings.

However, there is a limit just how much the pump can push -- that is determined by the bypass valve in the pump. When the pressure gets to a certain point, the valve in the pump opens enough to ensure that the pressure in the system will not exceed an amount determined by the bypass spring.

The spring is calibrated so that more than enough oil is delivered by the pump, with plenty to spare: But remember that this calibration is dependent on assuming a specific viscosity of oil. The bypass does not measure the VOLUME of oil pumped, it measures the PRESSURE. if the viscosity is the same, the volume will be the same. But if the viscosity is different, a different volume of oil will be flowing thru the engine at the same pressure.

The pump is a positive displacement pump: every time it turns, a given volume is discharged from the output. This is true, whether the pump is the spur gear or gear rotor design: Both are positive displacement. But when the oil is thick, more of the oil goes out the bypass and less to the engine and bearings.

The point here being, that you want to ensure enough oil is flowing thru the galleries to the bearings and if most of it is going out the bypass on a cold start, you have something to think about.

I would like to mention something about viscosity. Consider:

Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.
Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best.

Very few manufactures recommend 10W-40 any more, and some threaten to void warranties if it is used. It was not included in this article for that reason. 20W-50 is the same 30 point spread, but because it starts with a heavier base it requires less viscosity index improvers (polymers) to do the job. AMSOIL can formulate their 10W-30 and 15W-40 with no viscosity index improvers but uses some in the 10W-40 and 5W-30. Mobil 1 uses no viscosity improvers in their 5W-30, and I assume the new 10W-30. Follow your manufacturer's recommendations as to which weights are appropriate for your vehicle.

This is a nice little summation that gets to the point without being to scientific about the issue. However, despite whatever testing goes on, I do note that on very hot days, 10W-40 will not hold the same oil pressure at idle that straight 30 will. There is, perhaps, a 5 psi or so difference, and that's why I run straight 30 in the hot summer.

Thank goodness this whole discussion has been able to continue without it turning into something like the 30 Years War, which is what usually occurs! For some reason, people seem to get religiously zealous and dogmatic about motor oil, of all things. It's pretty easy to profit from each other's knowledge and experience when that doesn't happen!

[indianajo]

I've owned 292s since 1966 and ran 20-20w per manual when it was available, went to 30 weight when 20 disappeared, have been running 20-50 since it became available. The old 20 weight would thin out on long road trips, trip the oil pressure light, although no apparent damage occurred and I didn't need lifters or cam at rebuild. Rebuilds were always due to weak rings or burned exhaust valves. I've never changed the cam in 40 years. I did run an external top end oil line for 7 years due to plugged heads, but SD rated oil opened up the flow in 73 due to better detergents.
My 292's have need the crank turned only at the 300000 mile area, and that was only .0018 clearance. These were not truck 292's with the steel crank, they were car 292's with the cheap crank. My small blocks (302's) and big block (360) that run 10w-40 have needed the crank turned every time I open them, usually .002 to .003 bearing clearance. Draw your own conclusions, I don't know if 302 crank metallurgy is inferior to the 292, or 10w-40 oil causes more wear. I'm running 20w-50 in the 302's now, except the one that doesn't leak has mobil1 15W-50. 20w-50 starts okay down to 8 degrees F, then I need to pour gas down the carb to get fire on the first crank.

[wild.bunch]

20w-50 starts okay down to 8 degrees F, then I need to pour gas down the carb to get fire on the first crank.

I drove my F100 with 239 and later 272 to work every day, over 30 miles one way from the mountains southwest of Denver into Lakewood at one point and Littleton at another.

During winter in the Colorado mountains at 8600 feet, 8* F sounds like a Hawaiian heat wave. It was so cold that I had to start the engine with the clutch pushed in and not let it out unless I was fully prepared with the brakes, or else letting off the clutch would send the truck thru the garage. The oil in the T98 4 speed was thick enough that, with the transmission in neutral, the truck would take off when the clutch was let off, and it was a tough chore for the starter to turn it over, due to the thick oil in the transmission. Things were fine when the clutch was pushed in.

Having said this, it always started with no trouble in the coldest of weather (surely a lot colder than 8* F, I can assure you!) and I never had to pour gas into the carb -- just set the choke, pump the pedal a couple of times, and push the button. Matter of fact, down in Littleton in the parking lot (not so cold, but much colder than any 8* F), many were surprised at how quickly my Y Block would start -- pretty much as soon as I hit the button. Up in the mountains on a cold morning, it might require a couple of "rar -rars" before it caught.

If you need to pour gas down the carb at that temp, you have another problem.

Furthermore, I sure hope you keep a fire extinguisher handy when you're doing this. You are one step away from the old Burma Shave commercial:

He lit a match
To check his tank
And now they call him
Skinless Frank"

[Midnite Cruiser]

On all this cold start debate-
If the 312 has sat for more than a few days, I crank with the starter button on the dash before pumping the gas pedal and/or pulling the choke. I can get a little pressure built with the starter motor churning the oil pump before I add any fuel.
Had not heard that bypass valves might be open and make all this useless, but maybe this fires up the battle over oil filters- old threads really beat up Fr#*m's for this....................

[flipklos]

Millions of frams in use in the past 30 years. I have yet to see a piece of concrete evidence stating they destroy engines. I use frams and my oil pressure pops up withing a second at 40 degrees and climbs slowly at -30.

Same story with a motorcraft. Why should I pay a buck more for the same effect.

Dont want to argue this guys. Use what you want.

[wild.bunch]

Had not heard that bypass valves might be open and make all this useless

All the bypass valve does is open at a certain pressure, which is set by the spring. Clearly thick oil is going to take more pressure to move a given volume thru a given clearance. The bypass valve is opened by pressure, not volume.

...maybe this fires up the battle over oil filters...

Is there any point in "battles?" Cut them open and see for yourself, regarding what's inside. Whatever anyone does or doesn't do, doesn't put a penny in my pocket or take one out. I own no stock in any oil filter manufacturing company.

If a person knows about oil filters, they cannot be taught what they already know. If they don't, they can listen to others and/or look for themselves, whatever they consider the best action for them. If someone asks, I'm willing to share what I think. Whoever wants to, can listen or ignore as they please. What's there to get shook up about?