Changed The Weight Of My Oil

[billybronco1]

So after reading about the controversial subject "what weight of oil to use" I decided to do my own experiment. Seems its a toss up between 10W-30 and 20W-50. Not sure the consensuses on full synthetic.

When I bought my car a few months ago I changed the oil, used the same as the previous owner 10W-30 full synthetic. I really didn't like the sound of the engine, light lifter noise, more noise under a load, oil pressure was about 25 psi cold and about 10 psi hot at idle.

So the other day I changed it to 10W-40 still full synthetic high mileage and a can of STP (another controversial item) results are 30+psi oil pressure when cold and 20 psi when hot. As far as the noise once the car was hot it was much quieter and ticking under a load was almost completely gone.

Part of the problem with this car is the previous owner ran it for years with no thermostats and it never got hot, at least I could not get it above 130 degrees. Now with new thermostats installed she is running between 180-200 degrees so the oil should work better.

I might consider 20W-50 in the spring. What weight/kind of oil do you use?

[Bill OH]

Mobil 1 10 W 20

[Kube]

Please stop using STP. It will cause more harm than good. Consider it "snake oil".

I'd personally rebuilt NUMEROUS engines in the past decades. It was always easy to tell what clients used STP by the amount of GUNK in the engine galley.
It (STP) held many "garbage" particles in place. In other words, the poopy never got to the filter.
If you are looking to quiet down an engine to sell to some unsuspecting person, use it. If you're looking to increase oil pressure temporarily, perhaps to fool some unsuspecting person, use it. Otherwise, stay far away...

[Kube]

You're going to get as many differing opinions on what oil to use as there are belly buttons.
I was taught in school (GM) that most critical is to use what the manufacture recommends and stay with the identical brand throughout the life of the engine.
Obviously with today's chemicals and yesterday's (flathead) engines, the factory recommendation doesn't apply apples to apples.
I might suggest you "test" different viscosities and see what works best with your engine and driving demands.
I'd start with a non-synthetic 20/50 in your (used) engine.
Synthetic in an old (used) flathead is a waste of money.

[flatjack9]

I agree with Kube for your engine, Personally I use 10W- 30.

[RalphG]

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My dad used to run #20 in the 52 Merc back in the days before multi grade oils. I ran 10w-30 for a while but last oil change I went to a 15w-40 diesel engine oil. Just because I had some on hand, not for any perceived benefits or advantages. Oil pressure is good cold or hot. Started up at 20 degrees yesterday. Not a recommendation, just how I do it.

[JSeery]

You have solid lifters in a flathead, so changing the viscosity of the oil is not going to change the valve clearance. Whether you can hear the lifters or not the clearance is still the same. I would also suggest a non-synthetic oil what ever viscosity makes you happy.

[1stford]

The oil topic seems to be a great one. Kinda like if you want to start a fight a Christmas dinner you just ask this question. After reading many posts on this site I moved to VR1 racing oil. It has zinc in it and I took the top 3 recommendations and then did eeny miny moe!

[billybronco1]

Well, I knew this would create a stir. I like how my engine sounds with the change and the increased oil pressure. The engine was rebuilt and has been using synthetic since the rebuilt about 3000 miles ago. The synthetic STP is no where as heavy as the original STP, it actually pours like oil. No oil filter on my car, just a lot of oil changes. In the spring if I go to 20W-50 I will opt out of using STP and see how things sound. We grew up using STP in every car and flatheads. I worked at a car garage as a teenager, some lady pulled in off the highway said her oil light was on for the last 8-10 miles. Found oil filter had fallen off and no oil in the pan. The customer had used STP in it, we filled with oil, she drove off, engine was fine. Made me a believer in the product.

[J Franklin]

Isn't STP "the racers edge"?

[Jeff/Illinois]

Originally Posted by Kube

.................I was taught in school (GM) that most critical is to use what the manufacture recommends and stay with the identical brand throughout the life of the engine.
...............

That is the same exact advice I grew up with, and also the mechanics in the local Ford garage where I was a Parts. Mgr. ALWAYS told people this exact same thing.

Customers that went by that rule were running 200,000 miles PLUS easily on their Ford FE big block engines and Windsor series small blocks and those engines purred like no tomorrow.

[BobR35]

I'm a little late on this discussion but with my newly acquizition ('35), I was told VR1 straight 40w from the previous owner. Of course the temp here is different but the OP hot is midway on the dial at idle and 3/4 driving hot. I'm sticking with what works. I used to be a STP fan back in the day when I didn't know anything!!!

[J Franklin]

Don't know what VR1 is but Ford called for 20w oil when it was made. 40w seems a bit sluggish to me. Do you have an owners manual? if not get a hold of one and give it a thorough read.

[JSeery]

I would go with a multi-viscosity oil vs straight viscosity. Are you sure about the 40w rating? "W" stands for "winter" rating on the oil viscosity. Not something you would want to be using if it exist.

[Tinker]

The heavier oil would certainly quiet things. I used to run straight 30 in florida. So I guess my engine is ready for the strap yard. Last change was just 10w-30.


On a rebuilt motor I wouldn't think a thicker oil would be idealistic. Maybe once the bearings are worn. Just a thought. Flatheads are not a high oil pressure engine. It can be harmful but does have a gratifying gauge viewing.

[jrvariel48]

VR1 20W-50 here

[drolston]

Originally Posted by jrvariel48

VR1 20W-50 here

Definitely a good choice for break-in, but it does not contain enough detergent for year after year. I run four quarts of any good brand of 10w-30 plus one quart of VR-1 to boost the zinc a little.

[J Franklin]

What brand is VR-1?

[jrvariel48]

Originally Posted by J Franklin

What brand is VR-1?

Valvoline

[flathead 39]

Valvoline VR1 20w50. It's been VR1 since new motor in 2005.

[JSeery]

Originally Posted by Tinker

The heavier oil would certainly quiet things. I used to run straight 30 in florida. So I guess my engine is ready for the strap yard. Last change was just 10w-30.


On a rebuilt motor I wouldn't think a thicker oil would be idealistic. Maybe once the bearings are worn. Just a thought. Flatheads are not a high oil pressure engine. It can be harmful but does have a gratifying gauge viewing.

Wouldn't think you'd have enough temperature change to be an issue!

Car/trucks ran straight viscosity oil for years, modern multi-viscosity oil is just a better option IMO.

A lot of people don't seem to understand the oil viscosity ratings, there are two different temperatures they are tested at high temp (212 deg) and low temp (0 deg). The low temperature rating is indicated with a W for Winter.

As far as I know 25W is about the highest Winter rating that is used. To me using the term "weight" with oil is confusing because it gets mixed up with "winter".

[TomT/Williamsburg]

I have used conventional 20w-50 oil for quite a while now in my avatar, no oil filter of any kind, and I change it often. I add STP once in awhile too and I can remove my intake and show you a super clean lifter valley. An old Flathead racer once told me flatheads need heat to run efficiently, and run best between 2000-3000 rpm. I set my car up to run 2500 rpm @ 75 mph (running a 5-speed) and with temps from 170-180 degree temps no matter how hot it gets outside. I have also been across the country 3 times with many other trips in between and so far, no problems.

[FL&WVMIKE]

15w40 diesel oil is pretty good stuff. It has plenty of additives for long engine life, and should be thick enough to allow your engine to run quietly... without being too thick for warm up. I consider it perfect for old flatheads.

If it is still not thick enough to keep the engine quiet, consider a conventional 20w50. Just be careful with warm up, and allow the engine to get some heat before running it very hard at all.

[38 coupe]

Originally Posted by FL&WVMIKE

15w40 diesel oil is pretty good stuff. It has plenty of additives for long engine life, and should be thick enough to allow your engine to run quietly... without being too thick for warm up. I consider it perfect for old flatheads.

I agree with this. My understanding from reading a lot about engine oil is that oils intended for gasoline engines no longer are made to deal with contamination. This happened since electronic fuel injection has made flooded engines and the like a thing of the past. Diesel oil still is made to deal with contamination, which our carbureted engines will do. If you are running an electronically fuel injected engine this advice is irrelevant to you.

Also, please don't think that whatever was recommended in the 1930s is still relevant. Oils and rubber are two areas that have changed to unrecognizable levels from where they were when our Fords were built. I don't see anyone recommending going out and finding natural rubber inner tubes, so why are some still looking for oils that haven't been manufactured in decades?

[Holeshot]

I run whatever is on sale at wally world. Motor oil is motor oil.

[Bill OH]

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Correction: Not 10W20, but use 5W20, Mobil 1. I want quick flow on startup and good flow thru the bearings for not only lubrication, but also cooling of the bearings.

[Drbrown]

Its often an individual situation. My engine is stock with about 30,000m after a rebuild. There's a pressure relief ball/spring in the valve chamber which allows for some adjustment in maximum oil pressure. MY engine runs at 70 lbs cold and about 20-25 lbs hot. Pressure when hot varies slightly depending on driving in winter vs. summer. The engine has NO oil filter, change the oil every 1000m, so it stays relatively clean change-to-change. It doesn't burn oil. I use a detergent 10w-30 year round.

[miniceptor86]

That’s it? Only two pages?

[tubman]

Yep. I think most people on here are smart enough to know that anything available today is light years ahead of what was around when these engines were new. It really does come down to personal choice. (My criteria is cost.)

Just don't use non-detergent.

[Ford Freak]

I use 20W50 from Family Dollar.

[Jack E/NJ]

Bill OH>>>use 5W20, Mobil 1. I want quick flow on startup >>>


Absolutely. I used to use Motorcraft 5w20 synblend for this reason. But when Walmart 0w20 synthetic debuted at $15 a jug, I switched. 20psi ice cold. 20psi luke warm. 20psi scalding hot. Better than Ice cold 20w multivisc that pumps about as well as ice cold molasses.

[tubman]

WOW! I would have never thought of using 0W20 in a flathead, even a fresh one. If it worked for you, I might try it.

[woodiewagon46]

As far as oil additives are concerned, don't waist your money. A test with 75 New York City taxi cabs showed that additives such as STP, etc. had no significant help with engine wear after 4.5 million miles. The test involved 20 different brand's and types of oil and all were rated about the same. Synthetic proved no difference than conventional oil against wear.

[backrodebob]

same here vr1 20w50

[Zax40]

Not to open a can of worms, but does anyone have experience with the Lucas 20w50 with zinc?

https://lucasoil.com/products/hot-ro...w-50-motor-oil

[Jack E/NJ]

>>>Not to open a can of worms, but does anyone have experience with the Lucas 20w50 with zinc?>>>


With a name like Lucas, I'd be wary & worry. 8^)

[JayChicago]

Originally Posted by tubman

Just don't use non-detergent.

I'm using detergent oil. Last couple oil changes I slowly emptied the drain pan and examined the residue in bottom of the pan. Seeing bits of sludge and lots of tiny silver flakes. This is scaring me!

This 51,000 mile original engine runs strong and sounds fine. Only driven 400-500 miles between oil changes. Can't believe what I am seeing is normal wear in that short time. Thinking it is old sludge and bearing wear being released into the detergent oil. Previous owners probably used non-detergent oil. I'm worried releasing that old stuff could cause a blockage/damage. What do you all think?

[Jacques1960]

Rotella 15-40 because, as someone else said, I have it (tractor, marine diesel, gen set, etc)

[Jack E/NJ]

JayC>>>Seeing bits of sludge and lots of tiny silver flakes>>>Only driven 400-500 miles between oil changes>>>


How many times have you changed it and saw these tiny flakes? Are they magnetic?

[JayChicago]

Jack
I saw the flakes last year but thought maybe my drain pan had been contaminated on the shelf in the garage. But then saw it again this year.

The tiny silver flakes are not magnetic, do not stick to a magnet. The flakes are all flat, like the finest, thinest silver leaf.

OK, here some weirdness: When I lift or poke at a flake with a tweezers, it will seem to disappear, seems to dissolve in the oil residue. Maybe its my old eyes. But with handling the flakes seem to disappear. What the Heck???

[Jack E/NJ]

Maybe oil additive or gasket material separating out? If a blob of residue with disappearing flakes is dissolved in gasoline, does anything separate and drop to the bottom? If not, probably not metal.

[39-Ford]

Hi. I have a stock 1939 Ford Tudor. I was running standard non synthetic 10W-30. I had the same issue, as you. I run 20W-50 and my oil pressure is much higher a crusing speed. And idle on a hot engine. My oil pressure would really drop at idle.

[Mart]

Originally Posted by JayChicago

I'm using detergent oil. Last couple oil changes I slowly emptied the drain pan and examined the residue in bottom of the pan. Seeing bits of sludge and lots of tiny silver flakes. This is scaring me!

This 51,000 mile original engine runs strong and sounds fine. Only driven 400-500 miles between oil changes. Can't believe what I am seeing is normal wear in that short time. Thinking it is old sludge and bearing wear being released into the detergent oil. Previous owners probably used non-detergent oil. I'm worried releasing that old stuff could cause a blockage/damage. What do you all think?

Look, I'm no expert, but the one rule (urban myth?) is NOT to change to detergent oil in a vehicle that has run non detergent. It will start to loosen the sludge and release it to recirculate it around the engine.

I just came in from the garage after taking the pan off an unknown engine. The sludge in then bottom of the pan was 1" thick in places. The oil pickup was 95% blocked.

I'm glad I pulled the pan and was shocked when I saw what was inside.

From that experience I can't help thinking the unwritten rule is probably correct.