Hot Rods Motor oil for a Mercury flathead

Whoever built my '50 Merc 8CM installed a cam with a bit of a lope, along with (2) 94's. I do not know if it has hardened valve seats. When I replaced a broken valve, I noticed the valve springs were very stiff. (There was no damage to cylinder or combustion chamber, thank God.)
I will never race this car. Just want to cruise.
So, what oil do you folks run? Something with ZDDP(?)? I'm currently running 15-40 diesel oil because of the additive package. I need to change it because of contamination caused by leaky power valves.
Any thoughts or references are appreciated.
Matt

 

I haunt the local "Dollar Stores" and look for the oldest oil I can find for "spark" engines that's on sale. That is oil with an API Rating of "SX". ("X" being another letter, usually "K" through "P". The earlier that letter is in the alphabet, the more ZDDP is in the oil.) Flatheads traditionally have lower spring pressures because the valve trains are much lighter and they are not fighting the "rocker arm differential" factor, so they do not need a lot of zinc. (zinc didn't become common in motor oil until the fifties with the advent of OHV engines with their higher spring pressures). You may have a different case than normal (" I noticed the valve springs were very stiff"), but how did you determine it? It's probably a normal 75 lbs, which is "very stiff" to your bare hands.

In any event, for a flathead built correctly, regular old car oil should be fine as long as it's a detergent oil. Your diesel oil should be OK also, though lately there have been reports of the deleterious effects of excess zinc. In any event, you're only wasting money on it.

 

VR1 or Torco.

 

We get tired of motor oil articles, but over on the Ford Barn somebody linked to a new piece from Hemming's. I'm gonna go with it.

 

The oil that was used when that flathead was new probably had less zinc than the basic store brand 10-30.

the higher zinc and other additives showed up past the flattty era.

so use oil.
Oil is good

 

This is what I use in my '57 F100

 

Valvolene 20W50 or Castrol 20W50 is what I've been using for the last 60 years.
Jump over to Fordbarn and read the most recent oil thread.

 

Straight 30w non detergent is all I ever run and never any issues.

 

Sorry man, but the idea of running non-detergent oil in anything other then an air compressor is the worst advice I have seen in my entire time on this forum.

O/P: Please do not follow this advice.

 

We take care of several car collections, classics and old race cars, quit using Rottella over 15 years ago, VR 1, 10-30, 20-50 depending on application . Valvoline conventional 10-40 is good also, today's diesel oil is for diesels only, no ZDDP additives are used in anything. Dedicated break-in oil when required.

 

That’s the only kinda oil that has been in this car since it was bought brand new by my great grandfather in 1951 and its still on its original motor so apparently I know something ……
Oh and the car was a daily driver from 1951-1975 then it was a weekend cruiser after my dad and I restored the car and started showing it. Now it’s back to a daily driver again

 

I highly recommend oil

 

But but but the experts say that’s impossible

 

What’s the saying, ignorance is bliss

 

I run oil. All kinds
Every weight, brand and detergent type
Worked out just fine

 

lostin51–I see NO valid reason in running non-detergent oil in anything in these modern day times. I would bet money(and most likely win) if u ventured to remove the oil pan on your original flathead;it would be full of schmegma(made up word for nastiness and terrible looking gunk). I prefer any DETERGENT straight 30 wt oil in a relatively moderate climate or possibly 20-50 in a colder climate conditions. Either weight oil should be appropriate for every day useage, but DETERGENT BASED OIL WOULD BE MY CHOICE over non-detergent any day and everyday!!

 

I won’t use 20/50 in anything unless it’s an emergency

Ran a quart in my “test” engine and nothing happened
All the old guys used it around here. Drained ot out a couple times in modern engines when these same old guys tried to use it.

 

Hello,

It is not worth it to get all excited over motor oil. It is basically the same thing, except for cost and additives. Why does any oil need additives? 30 wt. oil like the simple Valvoline from the 1960 archives is just as good for any motor today. A the 70s-80s rolled around, folks were jumping on the band wagon of the multi-grade oil, 10-30, 20-50 grades.

It was a good run for the companies to sell tons of different oil. Due to “worries” about their motors running hot or cold. So, how does the multi-grade oil make those changes and send out the lightweight guys to do battle when it is cold? Or vice versa.

The new motors from the factories use ow-2ow. What happened to the 10-3- or 20-50 0ils that were so important to use back then when they first came out to the public? Someone is making a lot of money dictating what oils to use for all of us driving what ever cars we drive or drove.

It was nice to have a can of 30 wt Valvoline for emergencies due to whatever on longer road trips.

As a matter of fact, due to teenage costs and no continuing income, the long distance road trips with the flathead 1940 Ford Sedan Delivery was using up oil like gangbusters. No visible leaks, no drips or spots on any grassy parking areas or concrete driveways. Two flathead expert mechanics were stumped after looking at my motor. Why isn’t is showing leaks or blowing smoke out of the pipes cold or hot?

But for me the cost of 30 wt Valvoline was ruining my reserve pocketbook account for more longer road trips and also for daily driving. So, I went to reclaimed oil of suspicious sources. It was in a large 55 gallon tank with a crank handle. Filling up a gallon container was the weeks worth of oil for emergencies. It was so much less than the 30 wt Valvoline and allowed me many more miles of trips for the cost of oil used.

So, what weight was it? Who knows and supposedly it was 30 wt. but most oils back then were 30 wt. Where was it from? Again, who knows, but it was still 30 wt. Rumor had it that the station owner changed oil on cars that requested an oil change. Every 3000 or so miles as directed by the puppets at the car dealers. He may have dumped the last of the drips of the many oil cans upside down in a large container and then funneled it into the 55 gallon can as needed. Ha… suspicious detective work. A mixture of 30 wt oils or what ever was put into the oil change jobs all in one barrel.

Jnaki

Did it damage the motor? Probably not, it ran just the same, cold or hot and no funny noises coming from the motor at any time. Even when going up steep coastal highways in first gear loaded with several surfers, surfboards and gear for a week. The motor just purred and took its time doing what it is supposed to do, being underpowered and all, and get me to a specific destination when I wanted to go or arrive safely… ha!

So, detergent or non detergent oil, it does the same and runs in the motors we all use. YRMV

Note:

When we finally got our 327 powered 1940 Ford Sedan Delivery project fixed and running great, the motor was a user of 30 wt. Valvoline. It did not leak or use any extra oil for any road trips. The cost was a little higher for the same oil from the late 50s and early 60s, but that was consumer economics. But, luckily, we did not need any extra oil, except for the can stored away for emergencies, which we never had, leaks or repairs… Yikes!

We have since gone through 10-30, 20-50, 5-30, and every other number ratio possible. Now, the stock factory cars include 0-20 wt synthetic for its favorite money maker item. That is another “could be” game being played on all of us, these days. Formulated, offer benefits, superior to regular oils, etc… the list goes on…

 

Modern engines use the 0w stuff cause they have tighter tolerances but mostly to help MPG and cut emissions
Variable timing engines often use oil pressure to actuate “phasers” that advance/retard timing. Some used oil pressure to take the slack out of the timing chain.
So using 20/50 in that newer ride can cause issues especially cold

but that old flathead is probably ok using whatever the owner feels comfortable with.
I’ve personally never used 20/50 in anything besides topping off at gas stations due to that being what they had.
Guys use it and their experiences seem to be good. I don’t doubt it.

The newer 0ws is kinda just history repeating itself. They just added the Ow to it
There’s even a 0w/16 now.
I’d run the 0w/30 or 40 in my old ride if it came to it.

 

For a motor that is almost 75 years old and never been into I’d expect to have something in the oil pan But I promise you until it gives up the ghost I’m not going to crack it open to see.

Until our next monthly “What kinda oil do you put into old motor” thread I bid thee farewell

 

@mdogg1950, does your Mercury engine have a filter
If it does then running a detergent oil is your best solution
if you don’t have a filter you should run a non detergent oil,

detergent oils will carry dirt and debris around while it is circulating and need a filter to collect it

 

haha, Time for this gem again!



Any good oil around 30 weight will be fine man. Dont over complicate it. There is a split between Rotella and Conventional. Either will be fine honestly. Just run detergent oil to suspend particles, and frequent changes if running no filter.

 

Wal-Mart used to have SA oil, said right on the can "Not for use in engines made after 1930". Pure oil no additives. Probably the change every 500-1,000 mile stuff. Oil that is pre-SM has zinc.

 

I love it!!!

Okay since I like rubbing salt into a good wound for kicks and giggles and I want to get a good laugh out of @anthonymyrick here is the oil that I use in my flathead. If I remember correctly my dad bought cases upon cases of this stuff on close out for like .25 a quart at our local grocery store 30 something years ago. Now my ex wife would say that the honey out of a teddy bear bottle tastes better than out of a regular bottle so does that apply to oil? Just like my boy Anthony says “oil is oil just run it”

 

This. Mike

 

This is actually partially correct, but exactly the opposite of what really happens. As stated, the additives keep the "dirt and debris" in suspension so it is removed with the old oil during an oil change. If you are not running a filter, it is even more important to use detergent oil to keep the crud in suspension so it is drained out with the old oil. Non-detergent oil, with none of these additives, just lets the crud drop out and settle into various nooks and crannies in the engine, usually in the valley and oil pan.. This why it is important to change oil more frequently if you do not have a filter; the additives can only "hold on" to so much "dirt and debris" until they get overloaded and ineffectual (just like non-detergent oil).

As someone posted earlier in this thread, non-detergent oil is NOT to be used in engines built after 1930. It has nothing to do with running a filter or not, which is not even mentioned in the API specifications.

 

This statement needs a little clarification. API specifications "SM" and above do not specify a minimum level of ZDDP as did the earlier specs. They are silent of the subject of zinc, but most actually contain some zinc (around 500 ppm).. As the specifications advance, the level of zinc decreases.

BTW, the API specification currently in use is "SP".

 

misspelled dick cheese....

 

Reportedly SM & up has little or no zinc to reduce emissions by request of the OEMs where roller cams don't need it.