The Stovebolt Site Forums The Shop Area Engine Shop Thicker Grade Oil

I have sworn by 10W30 in all my vehicles since day one. I have had it for 10+ years in my 1956 era 235 however I am starting to get more lifter clack and someone suggested I go thicker. I even find the oil visibly thin on the dipstick as it will drip off the end as I am replacing it in the tube. What would be the best grade in this case?

This may be a silly question but how long has it been since you adjusted the valves? They will loosen up over time.

That said, you're probably aware of the new oil formulations now. The 10W30 you used 10 years ago isn't the same as what you get today, it has much less ZDDP (zinc) in it. A lot of the guys around here are going to Shell Rotella or some other brand of heavy duty diesel oil, but even that has a new formulation you want to stay away from. The "old" CI-4 spec is what you want but Wallyworld doesn't carry it anymore, at least around here.

I use Castrol GTX 20W50, it has one of the highest ZDDP contents of any of the "dino" based oils.

Valvoline still has the higher ZDDP levels, too. I've been using Valvoline 30wt Super HPO in mine.

Adjust the valves? Never! They are hydraulic and I never considered doing that. Should I have?
As to the lifter noise it is most noticeable on start up after sitting overnight. Takes about 10 minutes for them to quiet down and then once they are warm there is only a faint tick from them.

Well, with hydraulics it's usually a set-em-and-forget-em deal but it sounds like you have a problem with leakdown. They shouldn't leak down overnight and take 10 minutes to quiet down. I've got hydraulics on mine and I can leave it for a week and they won't leak down much and any noise disappears as soon as the oil pressure comes up. Could be your oil is diluted with something, gas or water. Can you see or smell anything in the oil?

Has it been awhile since the last oil change? If it's been awhile (say 6 months or more) I would try that first using a good quality oil.

Good luck, hope it's nothing too serious.

Try some 15w40 Heavy Duty oil like the big rigs use.

I have heard the term leak down before pertaining to the noise. The oil does not smell of anything foreign and is changed every 1000 miles or so and I always use Quaker State.

The clatter could also be your pistons slapping the side of the cylinders. THey are probably getting loose.

Leaking down isn't as much of an issue on old engines as the problem of taking 10 minutes to pump back up. Sounds to me more a problem of needing to run a can of chemtool in your oil for a few hundred miles then changing the oil. Also run a filter if you don't already.

The engine has about 25,000 miles on it since rebuild. It does have one of those old style oil filters which I know are not the greatest. I don't think its pistons as it is a definite lifter clack. The oil is very clean but I think perhaps too thin. As mentioned when I pull the dipstick and hold it for a few seconds the oil drips off the end. Almost like no viscosity if that is the right term.

I used Lucas Oil treatment for the first time a few months ago. It makes the oil look like honey. I'm not referring to the color, just the way it acts - sorta stringy if you touch the dipstick with your finger and pull it of, as if it has more "grab." I've always been suspect of oil additives, but decided to try it since I have yet to hear anything bad about it. I ended up putting it in my lawn equipment too, and some 90wt in the differential.

You might consider trying some of this to see if it helps. Run your typical grade/weight, but substitute one qt of the Lucas for your oil.

Bill

Run a quart of engine flush at the next oil change, and refill with either straight 30 weight detergent oil or 15W40 diesel-rated oil. The engine flush will clean out any sludge in the lifter check valves from running QS oil, and the 15W40 has a slightly thicker basic viscosity to keep the leakdown to a minimum. The original reccomendation for these engines was straight 30 weight in the summer, and 20W in the winter. Variable-viscosity oils didn't even exist until the mid-1950's.
Jerry

Since you have been changing oil every 1000 miles, just step up to a 10W40 at the next oil change (same brand)it might help. Stay away from real heavy oils, its hard on the cam and distributor gears, plus your 25000 engine doesn't need it. I run 5W15 in my 250 with just a slight lifter tick after a week or so of setting, as long as it quits in reasonable amount of time, I don't worry about it. You could have a bit of dirt in one of the lifters so a little motor flush or even a quart of ATF right before a change won't hurt. If it gets worse, pull the valve cover and see if everything is still in place. Have someone start the engine while you try and find which one is noisy. It could be just a bad lifter, most new ones are imported in now, so its not unheard of for one out 12 go bad.

The lifter should be able take up any wear on the cam in just a second or two, so I wouldn't worry aboutcam wear to much, you don't have enough spring pressure to really worry about the Zinc levels in the oil. Its the new high lift cams with heavy springs that eating cam lobes.

A really good high Zinc level oil is Brad Penn racing oils. You can find them on the web. Most dyno shops and a few of the cam makers now recommend Brad Penn oil, it has the highest Zinc level out there. It is the old green Kendell oil.
Joe

I have been using some Lucas in my transmission. I am also leery of additives but after a lot of research I decided to try it. No problems yet in that component.
I have had the valve cover off after I had used the 'broomstick stethoscope' on the valve train. Nothing seems amiss.

I always use straight 30w as recommended in the old manuals. Multi garde oils are too thin

". . straight 30w as recommended in the old manuals"

It depends on the year of your manual (and engine).

Workinonit,

Not so on the "thin"! There is lots of interesting reading on how multi-grade oils work. Google it and you might change your mind.

Stuart

The first number / letter combination (e.g. 5W) indicates how well the oil will flow to lubricate critical engine parts at low temperatures. The lower this number, the more easily the oil will help your engine to start in cold weather.
The second number (e.g. 30) indicates the oil's ability to lubricate the engine at high temperature. In this case, the higher the number the thicker the oil. A multi-grade oil, SAE 5W-30 in this example, satisfies the requirements of both cold start and high temperature viscosity grades.
So in a nut shell, you get a thinner oil that provides the protection of a thicker oil at 100 degrees by the use of chemical additives. The old manual I refer to is from Chevrolet 1941-46

Keith,

Great post. The viscosity of the multigrade oil is measured once at 0&deg F and again at 210&deg F. The idea to remember is that when the oil is measured at 210&deg and comes out as a 30 weight (your example), that this oil didn't get "thicker", it is merely measured on a scale calibrated for 210&deg.

If a straight 30w oil was measured at this same temp with this same scale, it would measure as maybe a 10 weight oil.

So the gist of this is that with VI improvers, the oil doesn't get thicker at elevated temps....it just doesn't thin out like a single grade.

Stuart

The brand of oil that you are using could be the problem.. Quaker State is a Pennsylvania crude which is parafin based. I have taken engines apart that have been maintained with QS and they had a silver sludge build up. Change to some other oil and don't go to a higher weight, you will not gain anything. Cold start with thicker oil can result in noiser lifters as the cold thicker oil has a harder time squeezing thru the clearances.

I have heard such comments about Quaker State over the years but mainly from other oil companies. Also some talk about a higher water content which causes bubbling when hot. This is all Greek to me but its what I heard.
My preference for Quaker State is based on experience. I am driving an 81 Malibu with about 395,000 miles on it. The oil has been changed regularly at about 3000 mile intervals and has always been QS. The only thing I have done to the engine is change the valve stem seals. I rebuilt the carb but that is not relevant.
I see that Pennzoil is also a Quaker State (or vice-versa) product. Do you have any recommendations to brands other than those?
Thanks.