Oil Recommendations for 1948 MG TC? Confused

[Kam]

Hello All. I'm a bit new here. Hopefully this is the right section to ask in:

I have a 1948 MG TC and it seems that people are very adamant that these cars are picky as to the kind of oils they use. Unfortunately, across the internet, and across retailers, it seems that many people and sellers have different products that they claim is the "ONLY right way" to lube up the car, and this has me quite confused.

I am aware that my car requires .12 to .15 ZDDP added to the engine oil if it is not included already. After all, this is essentially a pre-war OHV pushrod engine design at its finest, and the stroke is longer than the bore Diameter. (Oh yesssss)

The things that I have found to be consistent about recommendations online is:

most people seem to think 20w50 is recommended for the engine oil weight and EP? 140 is recommended for the gear oil. Some sources I have come across claim that high sulfur gear oil needs to be avoided because of lots of little brass parts and things.

When it was new, the manufacturer recommended Woesely 40 wt oil.

As for the gear oil, EP 140 is what I hear to use.

Anyway, long story short, I see a great many oil brands which different entities online claim to be "The one"
Collector's choice
Abingdon Spares (Spectro oil "specially formulated for TC")
Miller's Oils
and so on.
It's confusing.

I'm on a little bit of a budget, not a shoestring tight one, mind, and I just want to know if anyone here has an opinion on what kinds of oil are best for a classic car like this. Is there anything I need to really watch out for? Is ZDDPplus good? What brands are to love and avoid? Etc.

Any thoughts would be greatly appreciated.

-kam-

 

[OneEyeJack]

Have you tried a forum dedicated to your TC?

 

[Trav]

http://www.penngrade1.com/Products/High-Performance/SAE-40.aspx

 

[Kuato]

Original 40 weight and ZDDP? How about Rotella T6?

 

[Kamele0N]

for oils with more zddp you can look at ATV/Motocycle (Jaso MA GL4 ) oils...

For gear oil...use GL4 (yellow metals safe)...sae40 engine oil corelates more to 75w90 or 80w90 than 140...

 

[Greasymechtech]

Any 5w40 or 15w40 diesel motor oil or 10w40 motorcycle oil. If you need a 50 grade for oil pressure, thinking a good motorcycle V-Twin oil is another option.

Differential or manual transmission gear oil?

Technology has improved lubricants. Don't get stuck on "must use ancient crud" as so many on collector car forums do.

 

[expat]

I have known several XPAG engines to run very happily on 20w-50.

What condition is your engine in?

What is your oil pressure?

I know of one owner that had his EXPAG rebuilt (and converted from a scroll type oil seal to a modern replacment). He swears by Rotella 15w-40. And he has a hot cam fitted (MGTD)

My gut feeling with these old cars, and their owners :
Oil is like religion, people pick an oil, have faith in it, and preach that faith till the cows come home.
But in reality, they have little more than faith to base their wisdom on.

Valve spring pressures for that engine should not be extream, I would not think huge amounts of ZDDP would be required (over what other flat lifter engines might require)
The rest is downt to your oil pressure readings as to the weight YOU might require.

As for gear oil, I would NOT use GL5 (been there, and lost thrust washers to pay for it)
I would use a good GL4 in what ever weight keeps the noise down.

 

[ShotGun429]

Brad Penn 15W-40 or Brad Penn 20W-50 We have experience in those engines here, DONT chance it with other advice. Edit: Before the hate starts: Yes the V-twin oils are also very good also, The Rotella,and Delo,and Desiel oils just Dont have the Zinc anymore this engine needs as It has been removed over the last 4 years.

 

[Doug Hillary]

Hi,
Kam - any modern known Brand 15W-40 HDEO will be a good choice

We used Castrol's XL-30/40 when they were first on the market!!'

When these engines were sold the 20W-50 viscosity wasn't even thought of. This was introduced in 1959 for the "A" series BMC engines in the first Mini

Can't remember the gearbox lubricant but engine oil was used extensively by Morris-MG in their products and typically it was the same viscosity as used in the engine!

 

[Kam]

I have spoken on TC forums and this is why I came here... because of different opinions causing more confusion than when I started

 

[fdcg27]

What about M1 15W-50 or even 0W-40?
These oils are pretty cheap at Walmart and a driver TC is certainly not a cheap car these days.

 

[Kam]

My engine is original to the car, never rebuilt, with 30,000 miles. It has not been run in a great many years, though it turns over well and still has "Decent" oil in it from the previous restorer. Eventually, I plan on doing a full tear-down and rebuild from the ground up, but at this time I am working on more pressing concerns in the major mechanicals, and if I can get her to run in her present state with a valve lash adjustment and some fettling with the carb, then I would like to refrain from doing the rebuild until everything else is in better shape.

I have not gotten the engine up and running quite yet. My goal is to have this done by the end of the month, but I want to flush out the engine oil completely and put in fluids that I know to trust before then.

Seems like GL4 is the consensus here. I'll use that. Most people on TC forums claim that you MUST USE 140w for the diff, trans, and steering box. Can I get good GL4 in that weight, or is that information incorrect? If I can't get GL4 140, should I do something like 75w90 gl4 in the transmission and 140 in the steering box and diff?

 

[Kam]

Does anyone have experience with ZDDP plus additive? Is adding this to a modern oil with good properties the same as buying a specialty oil with ZDDP or is it worse, or is it better?

 

[CT8]

Did what ever oil in 1948 oil have 12 to 15 ppm zinc additive? Those are beautiful cars.

 

[gallydif]

Hey it would be great if you could post some pictures of your car

 

[Kam]

Sure thing.
She's not much a looker right now, but we're getting there. Been working on the suspension rubbers lately, and cleaning up things, rustproofing, etc. Haven't gotten to do much detail work as I'm fighting to get as MUCH as I can done on the major mechanicals before the cleveland wint'ry chill sets in.

 

[Kam]

So after looking online for myself, I've decided to go for Brad Penn 20w50 for the engine oil, and to try GL4 140w in the transmission, steering, and diff, and if the transmission doesn't behave the way I want it to, to go to GL4 75w90 for it.

Seem reasonable?

 

[SR5]

Doug Hillary says use a name brand HDEO 15W-40 ( eg Delo, Rotella. etc) and that would do me. He should know with his long history in testing and designing oils.

I can understand why you would go to the 20W-50 high zinc Brad Penn race oil path. You may also like to consider the Valvoline high zinc VR-1 20W-50 "road legal" race oil too.

Nice car, and a great project you are working on.

How common were MG cars in the USA? They were well liked in Australia back in the day. Any electrical issues?

 

[BrocLuno]

OK, so I'm going out on a limb here, but oils have progressed exponentially since that car was originally built. It's sort of precious jewel and I would not simply subject it to older style traditional oils. I might not go full synthetic, but I might consider a blend ... But first choice would be dino oil for now (see below).

Just for your basic enjoyment and to add a few lashes to the back, you might want to read this guys blog: https://540ratblog.wordpress.com/ He makes some valid points on things like rod bolts and some lubricants. Not bad background for some subjects...

He and I differ on a few areas such as using synthetics for cars that sit for prolonged periods because of syn's propensity to drain off capillary spaces due to its lower surface tension. That means it will clatter more on cold start until pumped oil makes it around the system.

Your car/motor has plenty of internal clearances compared to modern machining methods and fitment. In addition, the metallurgy was not anywhere near what it is today. And you have carbs, which almost no matter how well tuned, will lead to some oil dilution from fuel washing the cylinder walls.

So you are fighting many factors to try to prolong the machine. That's a good fight, but not an easy one as parts become more scarce, etc. Good on you for doing the job

I would use a conventional dino based oil because we do not know how all the old oil seal technologies would react to synthetics... If the MG Owners Assoc says they are having no issues, maybe in the future...

The motor does not have many miles, but I'll bet it has been started many times and never reached full operation temperature... That leads to condensation which leads to acid formation and that's not good. So I'd change the oil now and just get it out of the sump... You might then fire it on a squirt of petrol to get the new oil into the surfaces and let it be while working on it...

ZDDP is not necessarily your answer to anti-waer capability. There are many oils out there that have really good ant-wear capabilities and not a whole lot of ZDDP. The question comes down to which one is the most logical for your current situation?

I suspect the Castrol GTX 20w-50 will get you though the interim until you get around to the engine rebuild... It will meet your current budget requirements and it's a fine oil. The viscosity range will make life a bit easier on the old starter when cold and still fill/cushion all the spaces when hot

On the tranny. Use whatever oil you wish. GL-4 for sure (or other yellow metal safe oil). But if you notice hard shifting and resistance to gear change when running, consider Red Line MTL. I can tell you from experience that it is yellow metal safe and about as slick as you could want. Many, many classic "euro" car drivers and owners have made the switch (me included in an old BMW) and it was like night and day - good stuff, not cheap ...

There is every likelihood that doing your due diligence like you are will net you best practices for overall lubrication. Don't write off new lubes, they are mostly superior to what was only a dream back in the day. But take your time and ask all you want of everyone. Take it all with a grain and watch out for snake oil salesmen

 

[Ramblejam]

Originally Posted By: Kam
Seem reasonable?


I always find it entertaining to see people talk about GL-4 oils and "yellow metals". When pushed on the matter, you'll find that 99% of the time, they're just parroting something they heard. Better yet, ask them about modern dual-rated GL-5/MT-1 products and that same compatibility...

The transmission here is synchronized, no? Manual transmission fluids would be a better fit, offering superior shifting performance than whatever gear oil you select.