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MG MGA - oil

It's been asked before, but I don't believe it's been asked in a while. What kind of oil do you recommend. I recall reading something about using diesel oil because it has sulfur. Is there a sulfur additive to use with regular 20-50 oil?

I've been using really cheap oil during my restoration. Now that my engine appears to be reliable, I'd like to change the oil soon (it's mixed with bad oil) with something that's better for my engine.

Thanks,

Darian
Darian Henderson

Darian, I've noticed that the term "really cheap" came up a few times in some of your posts. "Really cheap" clock , "really cheap" oil, etc.

I don't think those should be the operative words for such vehicles as our MGAs.

However really good oil changed frequently is "really cheap" insurance for that engine of yours. : )
A. Tirella

"Really cheap" comes up often as the expensive stuff is very easy to find. I've already spent about $10,000 on my car, and in some cases (like when I had my cylinder head repaired) I went for the highest quality/expensive option, so I'm trying to keep the price down. I also don't see what the point of using high quality oil would have been when I had to change the oil several times in a two-month period.

Do you have any suggestions about what oil is "really good oil," or did you just wish to discuss the linguistic nuances of my messages?
Darian Henderson

Darian

It depends how you use the car. In your case, I think you are right to use a cheap Diesel oil to clear all the crud out and afford multiple oil changes in a short time. When all is settled in, however, a quality oil will allow you to go longer between oil changes and not damage the engine.

If you have an engine which loses / uses oil as fast as you can pour it in, then cheap is the way to go till the engine gets rebuilt.

But as I remember, you have some quite nice performance mods (an original Derrington head I think). If you are using this performance, then the quality oils will make your engine last longer.

As for clocks etc, there are clocks available from the UK people (mgbreakers.com is another that comes to mind) that will match the instruments on the A perfectly, and for much less than a MiG one....
dominic clancy

Thanks, Dominic. I've been pretty lucky about oil consumption. The engine was rebuilt and driven for only about 2000 miles before it was parked, and all appears to be well. A little oil leaks when I park the car after it's been driven, but oil consumption so far has been negliable.

The reason I started this thread was to find out if there is a special oil that is best for these engines, or if any quality oil will work. As I mentioned, I recall reading that these engines last longer with oil that has sulfur in it but that modern oil doesn't have this. Any truth to this?
Darian Henderson

Oil is tested to a standard latest is SM, so cheap or expensive oils should all perform to a minimum standard.

Expensive oils should outperform these standards when used in extreme conditions Cold ,high temps, long oil change intervals, high oil temps using a turbo.

Oils use anti wear additives to protect the engine, and flat tappet engines may require a higher level than used in SM oils.

Higher levels of these additives are usually used in Diesel Bike and Race Oils.

Oils tend to keep clean rather than clean by using additives, with Diesel oils this is to deal with high soot levels.

Mineral oils breakdown during use so synthetics will help keep engines cleaner and free from varnish and sludge.

Good oils are the best mix of oil bases and additives for the purpose, but in general the highest performance oil base will be an ester synthetic used in most race oils but it is also the most expensive option.
Paul Wiley

Considering the motor oils that were in use when our cars were built, I would think that just about any modern oil would be a vast improvement, bearing in mind things like the flat tappet additive issue with some newer oils. As long as you can navigate your way around that, and use a proper weight, I think you will be fine.

Synthetics are great and I run Mobil 1 in my modern vehicles, but they tend to find places that are vulnerable to leaks and exploit them. Since our engines are not necessarily the most oil-tight power units around, I would prefer to stick with a good grade of standard detergent oil.
Del Rawlins

The big oil debate has been over the elimination of zinc (ZDDP) additive in the oil and that with out it there are adverse affects to engines running flat tappets. Excessive wear and damage to lifters and cam shafts during break in. It is still listed in diesel oils as well as in Castrol 20W50 motor oil. I use Kendall 20W50 as it has the same amount of zddp as Castrol but is a $1 a quart less mainly because they don't advertise. I have been using there oil for 30 years with excellent results.

While Del is correct in that modern oils are better in most respects. But many additives like zinc have been removed because they can foul catalitic converters. Modern engines have been built with materials and designs that can live without the additives, our cars were not. You can also purchase an additive from your local GM dealership that contains the necessary additives, about $10. You can also find these additives in motorcycle oil but you will pay about $4 to $5 a quart.
J Heisenfeldt

Thanks, that's what I was thinking of but I guess it's zinc these engines need, rather than sulfur.

Much appreciated.

Darian
Darian Henderson

Darian,
Check out the NAMGAR website for an article on oil for running in an MGA engine. The basis of the article is that modern multigrade oils do not have enough ZDDP (zinc dialkyl dithiophosphate) in them, and therefore the flat tappets (lifters) or camshaft lobes can be damaged during run-in. Diesel rated oils tend to have higher levels of ZDDP. After run-in, ie, after 1000 miles, a good 20W50 or 15W40 should do.
However, you may have done damage already by using "really cheap" oil! Of course the gearbox needs similar engine oil, while the diff needs Hypoid 90.
Regards, Peter.
P. Tilbury

I had read in a very recent issue of NAMGAR's MGA that Castrol's GTX 20W-50 also no longer contains ZDDP, or was going to phase it out. The label on a quart of Castrol GTX 20W-50 I had purchased a few months ago does not explicitly indicate it contains ZDDP. It says only, "delivers ... - advanced anti-wear additives to help extend engine like."

The same MGA article mentioned that two oils that still contained ZDDP are Valvoline VR1 20W-50 Racing Oil and Pennzoil LongLife Gold 15W-40. I purchased some of both from Advance Auto Parts. On the Valvoline label the list of features states, "Ashless anti-wear additives and ZDDP provide ulimate wear protection." On the Pennzoil label the list of features doesn't explicitly list ZDDP, but it does state, "Protection for Diesel and Gasoline Engines" and "- Excellent Wear Protection Helps Extend Engine Life." Based on the label on the Valvoline I bought a case to keep my MGA happy.

Steve
Steve K

From what I've been reading ZDDP is most important for the initial break-in of our engines. What if the engine has already been properly broken in with non-detergent oil and has 20k+ on it? Is the lack of ZDDP still highly detrimental to the tappet/camshaft wear? If Castrol really has eliminated ZDDP are we going to see a rash of engines in the next few years with badly worn camshafts if people keep using it assuming it's still the best oil for their MG?
Mark J Michalak

ZDDP is not the only anti wear additive and an oil can be Z free. However the current SM tests are aimed IMO at light use road cars with a fully protected cam (well run in).

Most oils use ZDDP including synthetic as its cheap and effective and the restrictions only apply to energy conserving oils (thin oils).

If you wish to check additives go to LN Engineering site.
GM EOS has now been withdrawn from market and low ZDDP is a US/Canada issue as UK oils are still SL.

IMO the current SM tests allow more cam wear when used for high performance so I would avoid low ZDDP oils and Castrol US are marketing a higher ZDDP oil in US, aimed at older car market although synthetic probably only a higly refined mineral.

As ZDDP is cheap its not cheap expensive oil debate just what's good or a cat may not be good for a flat tappet.

The P works the Z can determine temp range and S in fuel can help or hinder the chemical reactions as can detergents in oil.

Paul Wiley

While the level of ZDDP is more critical during break-in, I would think that if it was required in the engine for only a short time that it would not have become a standard ingredient in motor oils.

As you might imagine, owners of all manner of classic and race cars are concerned that the formulation of oils for contemporary cars may adversely affect their flat tappet engines. A quick search shows that this is indeed a topic on very many classic car forums.

While searching and reading just now I came across a response someone had received from Castrol when they inquired about the levels of ZDDP in Castrol's various motor oils. Within that response, the Castrol reprsentative indicated that this October Castrol is launching a new synthetic oil for classic cars with high levels of ZDDP. Here's the link to the Castrol website that describes their new 20W-50 product for classic cars.

http://www.castrol.com/castrol/genericarticle.do?categoryId=82915470&contentId=7032644

And here's the link to the BB that pointed there.

http://www.chevelles.com/forums/showthread.php?t=128203&page=5
Steve K

Can someone explain the difference (wear wise) between the MGA camshaft acting on the flat tappets , and a modern car (eg VW Jetta) camshaft acting on the flat surface of the inverted buckets that operate the valves. Surely, it is the same situation ?
Art Pearse

To demonstrate Art's comment about flat tappets on a modern engine, such as the VW Jetta. My Jetta, a couple of years old has flat tappets, and modern oils are recommended by VW.
What modern engine has curved tappets?

Image of VW Jetta head attached.

Mick


Mick Anderson

Another image attached.

Mick


Mick Anderson

While the oil manufacture may not list all the contents on the bottle, look at there websites. Last I checked both Castrol & Kendall listed the amount of ZDDP in there oils.
J Heisenfeldt

This thread was discussed between 21/09/2007 and 24/09/2007

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