Synthetic oil

I would avoid it. Synthetic oil works well with modern engines with tight tolerances and modern seals. It has great lubrication properties you don't need and a worn engine with ancient like Chicago Rawhide and rope seals will let a lot of that synthetic oil find its way to your clutch and garage floor. Stick with something like Valvolene VR1 that has zinc or any petroleum oil you like. That is my advice. Woodies are cool!
 
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John, I'm not saying that you can or can't, but sooner or later you are going to have to. I was at my auto part's store last month to purchase conventional motor oil. There were shelves and shelves of synthetics but only one small shelf with only one brand of conventional oil. When I asked the owner of the store about it he replied that it's only a matter of time before the conventional oil won't be a viable product for him to stock.
 
Dollar General always seems to have a good supply on hand. Plus, their prices are better the your FLAPS.

When I quit circle racing 20 years ago, I had a couple of cases of MOBIL 1 15-50 synthetic. I ran it in my 80K '51 for several years with no ill effects or more leakage.
 
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“ There were shelves and shelves of synthetics but only one small shelf with only one brand of conventional oil. ”
I’ve noticed this in my area also. I do look in the discount stores and can usually still find what I want……..Mark
 
belive it or not a heavy diesel oil is about the best you can get ie RX super 15w40 or CRB 50 in mono yes they have a high detergent level but they also have high zinc or equivalent due to the cam loads exerted by cam operated injectors and engine brakes [Jacobs brakes] just need to keep an eye on the change intervals Sorry they wont magically fix leaks due to age and wear
 
I have bought a small supply of Walmart's Supertech 20-50 conventional oil. It is not always easy to find. It is about 15 or 16 dollars for 5 quarts. Walmart has Castrol for approximately 25 bucks.
 
0w-20w SuperTech in my 21-studder for over 3yrs.. Also in my newer stuff. $18 a jug now. Before that, MotorCraft 5w-20w SynBlend for yrs.
 
Lot's of opinions here. Many valid points have been made.


In my opinion, synthetic oil of the correct viscosity will reduce friction and extend engine life. I switched my flathead to synthetic on the last oil change with the idea in mind that this engine should last the rest of my life without rebuilding. PERHAPS there's more leakage past seals, but, in my case, it would measured in drops per month.


I last replaced the oil 9 months ago, have driven 1000 miles since, have lost no more than 1/4 quart in that time, if that, so that's a win. In fact, it's better than than my last car with a 383 stroker Chevy crate motor which used a quart every 3000 miles.


All of the oils today are better than anything available in the flathead era. The only thing I might avoid is an oil with no additives, which would actually be pretty hard to find.


So, review the opinions and make your choice. It's likely that any oil of the right viscosity rated for modern cars will be a safe choice.
 
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I agree with SoCalCoupe above. I've been using Mobil 1 15W-50 in my '34 for over 10 years now with no leakage problem. I figured it would be a better lube for my Babbitt mains...
 
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JohnI said:
I have a 1934 Ford v8 woodie with 100,000 miles and no oil filter. Can I use synthetic oil?
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I'm a little late chiming in here but I'll give you my experience of what I use on my '35 original flathead that I drive about 300+ miles a month. After researching and trying different oils, I've settled and been using 20/50 Castrol from Walmart with great results here in the Florida heat. The Castrol oil is a great choice for the older engines. I've put about 7k miles and still going strong. Don't forget the MMO, Marvel Mystery Oil! 6oz each change added to the crank. I change every 1000 miles. I also add the same amount in the gas tank at the same time. Good luck
 
woodiewagon46 said:
John, I'm not saying that you can or can't, but sooner or later you are going to have to. I was at my auto part's store last month to purchase conventional motor oil. There were shelves and shelves of synthetics but only one small shelf with only one brand of conventional oil. When I asked the owner of the store about it he replied that it's only a matter of time before the conventional oil won't be a viable product for him to stock.
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I'm a little biased in that I worked for Mobil but what passes for synthetic today is not what it used to be. Synthetic used to be like Mobil 1, a non crude oil based polyalphaolefins (PAO) which are a chemically engineered synthesized basestocks. I only use Mobil 1 for modern cars and dino oil for my 41 Ford.

Mobil sued other companies calling their oil "synthetic" when it wasn't PAO but lost.

Lube oils are of a specific chemical structure, branched chain paraffins. Used to be lube base stocks came from "lube" crudes, in other words the lube oils were in the crude oil and just needed to be separated out. Lube crudes are becoming few and far between these days so the oil companies have been forced to manufacture the base stock from non lube crudes. What passes for "synthetic" these days is from crude oil. The lube cut from the crude unit is then hydrocracked to get a lube base stock. They make their lube oils sound "better" by calling them synthetic. "Synthetic" is a marketing term these days!

The difference between PAO oil and "synthetic" oil is in impurities. The PAO oils are more pure. The biggest benefit is in cold places like Alaska as the PAO oils freeze at a much lower temperature.

I've tried to make this explanation to be understood by the non engineer. Don't know if what I wrote makes sense to old Ford owners or not?
 
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Originally Posted by mrtexas
I've tried to make this explanation to be understood by the non engineer. Don't know if what I wrote makes sense to old Ford owners or not?

[/FONT]

[FONT=&quot]MrTexas, thanks for the post. (Nice woodie BTW, I looked at your website.) I actually am an engineer but not a chemical engineer and understood your explanation of dino vs. PAO oils.[/FONT]

[FONT=&quot]Please let us know why you put dino rather than PAO oil in your flathead. I don't understand that. Not challenging your judgement, just want to know.[/FONT]

[FONT=&quot]You very likely know much more than I do but I recall that genuine synthetic oil (PAO) reduces friction and thus wear more than a dino oil. Do you think that's correct? Why/why not?[/FONT]

[FONT=&quot]I also recall that PAO has much longer hydrocarbon chains than dino oil which is the main reason that PAO can extend oil change intervals. However I think I know that additive packages in the oil are consumed meaning the oil has to be changed whether the lubrication capability has been degraded or not.[/FONT]

[FONT=&quot]I know that zinc is one of the important additives that's consumed and that zinc prevents flat tappet cam wear. However, it may not be terribly important for cars like flatheads that don't have aggressive cams with high valve spring pressures.[/FONT]

[FONT=&quot]Thanks again for your post; looking forward to learning something.[/FONT]
 
deuce_roadster said:
I would avoid it. Synthetic oil works well with modern engines with tight tolerances and modern seals. It has great lubrication properties you don't need and a worn engine with ancient like Chicago Rawhide and rope seals will let a lot of that synthetic oil find its way to your clutch and garage floor. Stick with something like Valvolene VR1 that has zinc or any petroleum oil you like. That is my advice. Woodies are cool!
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"and a worn engine with ancient like Chicago Rawhide and rope seals will let a lot of that synthetic oil find its way to your clutch and garage floor"

It's pretty much that ^.
A true synthetic oil has esters that will tend to flush out the sludge in an older engine... like the sludge up against seals that helps them seal.
If your engine is in newer/fresher shape there's much less of this situation, so you're pretty safe with using a true full synthetic engine oil. Getting past the lack of zinc though, may be an issue....
 
My engineering field wasn't motor oils, but I was interested since we had a lube blending and packaging plant on site. Additives came from somewhere else. The refinery just produced the base stocks. Somewhere else made the additives which can amount to 40% of total volume. Biggest advantage of PAO oils is low pour point(cold temperature when the oil won't pour anymore) meaning better in cold weather. Reduced friction, maybe a marketing claim. I figure with the cost of modern cars a few bucks more for an oil changel is money well spent.

My refinery actually made more industrial oils than motor oils. Interesting that the base stocks had to be distilled in a vacuum. Oil cracks when heated to more than 700F, so vacuum was applied when boiling range was over 700F which lube oils are.

Lube stocks are highly refined. The base stocks have the aromatics taken out by solvent extraction and the wax taken out by cold filtering. Dino crude oils already have the lube oils in them. The lube oils are produced by taking out the non lubes by processing.

Non PAO synthetics are made from crude oils not containing lubes. The lubes are produced by hydrocracking the base stocks.

Lube oils are branched chain paraffin hydrocarbons. Longer chain hydrocarbons would mean higher boiling point. Don't have a good reason for dino oils in the flathead!
 
Out of curiosity and my lack of knowing I guess, what does the zinc do for the older motors, that isn't needed in the newer ones? I guess I would assume it has something to do with corrosion? But maybe not.
 
Ron_r1959 said:
Out of curiosity and my lack of knowing I guess, what does the zinc do for the older motors, that isn't needed in the newer ones? I guess I would assume it has something to do with corrosion? But maybe not.
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Ron, I’m answering as a non-Chemical Engineer, so my explanation is totally in layman terms:
Zinc was added to motor oil to act as a cushion against the destructive friction of solid lifters against cam lobes. Modern engines having roller lifters are less vulnerable to that sort of friction, while earlier engines such as the Olsmobile V8 of the early 50’s are most vulnerable. A Ford flathead with stock cam has very low vulnerability to that friction, as it does not require strong valve springs. A flathead will normally need a complete rebuild before its cam lobes need grinding. Zinc additives burn off into the atmosphere, accelerating climate change, so that’s the reason it is no longer added in quantity to motor oil.
 
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