Oil for Leyland E170

Last time I posted on HCVC the crew helped me out in identifying the engine in an old carvel hulled boat I just bought. It was a Leyland E170 (about 7l and 95hp).

I'm about to do a service on her and would like advice on what oil to use in her. There are a couple of empty containers of 15w-40 in the engine room but I

Dargo,

I have just been down this track with a 1915 Willys Overland. Talked to the aces at Prolube and they said putting multigrade oil in old engines is an invitation to trouble even though the modern oils lubricate better.

First problem is modern multi-grade oils have high detergent content which is great with modern oil filters but the filters on old engines such as your Leyland are really only to stop logs and dead sheep floating through.

As a result, the detergent scours the engine to remove every bit of rubbish collected over the years in little corners and, not being caught by modern fine filters, sticks it nicely in the bearings or just clogs up oil galleries like cholesterol does with your arteries.

The other problem with such efficient cleaning oil is it will seek out (clean out) every little leak and suddenly you have a total loss oil system'

Prolube highly recommended straight 30 grade oil for our Willys Overland and it works great.

Some years ago I had a boat with a Gardiner engine and went down the same path. Once again straight oil was insisted upon by the Gardiner overhaul specialists. They said they very strongly wanted me to use not just straight 30 grade but straight 30 grade DIESEL oil which has a much different sulphur content to car oil helping fuel pumps, valves and reducing wear in bores.

The only variation was to up the weight of the oil if the rings were worn and it was giving blue smoke to 40 or even 50 if it was bad.

Lang

Dargo - Lang is correct, the newest oils have very high detergent levels, and can strip all the beneficial carbon buildup from inside your engine.
This loose carbon can block filters .. or create wear, if it goes through a lubricating system that has poor or inefficient filtering.
In addition, with the beneficial carbon being stripped, this will increase oil consumption and create oil leaks where none existed before.

If you have good quality filters fitted (10 micron or better), then these will trap the carbon. However, many old engines before the 1930's had very little by way of oil filtering.
Decent filters did not appear in general use, until the late 1920's/early 1930's.
The Purolater Co. produced the first aftermarket filter in 1923, and it was fitted as standard to the new Chrysler Six, heralding a major advance in engine design and lifespan.

The bottom line is, don't change your oil type from one that has been used previously, to a much newer one.
If the engine has been run on a multi-grade oil with a certain API rating, it will be O.K. to use that same, multi-grade oil, again.
It's when you change to an oil designed for the latest pollution control engines, that's when the problems can commence.

In addition, take care when swapping brands .. as different brands of oil, have different levels of additives, and you can possibly develop an oil-burning problem by going to a different brand .. which has a higher level of "slippery" additives .. that encourage greater amounts of oil to stay on cylinder walls, after the oil ring has wiped the oil layer off.

Old engines are "high-tolerance" engines. They have greater clearances, turn slower, produce less power, and can cope with a wider range of imperfect operating conditions.
New engines are "low-tolerance" .. they have much tighter tolerances, turn faster, produce much more power, and can't cope with "out-of-specification" conditions, unlike the old engines.
As a result, somewhat different oils are needed for the two types of engines, because each engine operates under different internal conditions.
An oil designed specifically for the latest design, tight tolerance engine, will not work properly in an old engine with high clearances .. and vice-versa.

Diesel oils have to have higher levels of detergents, than petrol engine oils .. because diesels produce a vast amount of carbon, and other by-products of combustion, that would overwhelm the much lower level of detergents in petrol engine oils.

However, in recent years, the levels of detergents .. and the addition of newer and stronger detergents, to cope with pollutants being forced into the oil of diesel pollution-control engines, rather than out the exhaust .. has seen oils appear on the market, that are not suitable for older diesel engines.

I posted this oil advice (below) on a previous thread .. I'll post it again here, for explanation and reference ..


Multigrade oils contain serious amounts of synthetic additives called long-chain polymers .. up to 30% by volume. These are also known as viscosity index improvers (VII's).

These long chain polymers can best be visualised as long curly chains of molecules, that have the curious ability to lengthen when cold, and tighten up when hot.
This ability makes their fluid viscosity, thicker when hot, and thinner when cold.

This is the opposite of oil's viscosity, which is thick when cold, and very thin, when hot.
When oil gets cold and thick, its ability to penetrate into bearing surfaces is reduced, as well as its ability to be pumped.

When oil gets really hot, it gets so thin, that it can't lubricate properly. The coating of oil on wearing surfaces gets so thin, that metal-to-metal contact starts, and you have bearing seizure or galling.

The argument used against VII's and multi-grade oils, is that VII's are not lubricants in themselves, and that by occupying 30% of the oil volume, that is 30% less oil to do the lubricating.

However, the fact that the VII's enable the oil to stay thick when hot, and to thin out when cold, enables the oil to do its job much more effectively. Thus, less oil is needed.

Multigrade oils work just fine as a replacement for single grade, 30 weight oil. However, the thing to be careful of, is that many modern oils have a substantially increased level of detergents.

These high detergent levels are necessary for modern, emission control engines, because pollutants that go out the exhaust of older engines, are being forced down past the rings, and into the oil, of the emission-control engines.
However, in old engines, there are beneficial build-ups of carbon on pistons, rings and seals, that assists with compression sealing, and oil retention, both in cylinder bores and behind oil seals.

The sudden introduction of a new brand of high-detergent oil, will often strip this beneficial carbon from old engines, and they will often commence to lose power, burn oil, and leak oil.

Thus, you are well advised to ensure that the oil you buy, meets the API recommended service classification for your engine.
The API classification letters start with an "S" for petrol engines, and with a "C" for diesels.

These API classifications are upgraded to new classifications every few years. In general, the new API classification is "backwards" compatible with the older classifications.

However, since about the early 2000's, the newer API classifications aren't recommended for older engines, due to substantially increased levels of detergents, and reduced levels of the anti-wear additive, zinc dithiophosphate (ZDDP).

The ZDDP is removed from current emission-control engine oil, because the zinc compounds can wreck catalytic converters. However, ZDDP is needed in older engines for camshaft lobe and lifter lubrication, where severe sliding pressure is applied.
Many new emission-control engines have roller lifters, so the ZDDP isn't needed.

Always make sure that the oil you buy is compatible with the API service classification, that was in use when your vehicle was new.

www.aa1car.com/library/API_ratings.pdf

Cheers - Ron.

For pre-1950 engines, use Penrite Shelsley Light, Medium or Heavy oil where the manufacturer recommended SAE 30, SAE 40 or SAE 50 oils. Have a look at the Penrite website at www.penriteoil.com.au for the "good oil" on Penrite!

Thanks for the info Lang, Ron and Bugly - much appreciated !