Engine Maintenance and upgrades

[leaningchimney]

I'm thinking about buying my first Stag and like most people am wary of the well documented engine problems. It seems as if modern upgrades to the cooling system such as high spec ali radiators and careful maintenance (regular flushing and correct antifreeze) are the answer here but any advice gratefully accepted. I was also aware of the timing chain weaknesses and a change every 25,000 seems a reasonable precaution and in fact with likely classic car mileages not really a problem and anyway we are all much more used to changing timing (belts) regularly these days anyway. What did surprise me though was I read somewhere that the oil should be changed every 3000 miles OR every 6 months whichever is the sooner. I can't remember where I read this, but whilst every 3000 miles seems sensible, every 6 months seems a bit excessive - is it THAT much of a problem for a Stag engine?

[richardthestag]

Hello

Pretty much everything you mention above is part of the original service schedule I think.

Search box on the top of the screen and also the technical pages will point you to areas of interest

oil changes are essential because of bore wash and contamination of the oil. this happens even more now because of cars that are used so infrequently. what is an extra £30 of quality 20/50 mineral lube a year compared to a rebuild which is likely to be in 4 figures for parts and machining alone if you are lucky.

Rover v8 is also 3k / 6 months

[jakesmig]

.........

Rover v8 is also 3k / 6 months

My basic Rover engine cost £84.00 from Ebay, new mains and big end bearings, a fast road cam, an Emerald ECU and gaskets raised that to circa £1200.00. It does about 5000 miles a year and gets an oil change before each MOT.

John

[flying farmer]

I think a lot depends on how you use the car. I try not to use any of mine for very short journeys any more as it is cold starts that cause the greatest problems with oil contamination through condensation and bore wash with unburned petrol.
If you are using it daily then I think 6 months is not unreasonable, but most of my Triumphs only get used once every two or three weeks so most of them get a change annually.
Neil

[Ian Durrant]

Factory oil change intervals were 6000 miles. 3000 miles became recommended for the Stag engine because of timing chain wear and as a way of lessening that, by Stag specialists. I first ran my stag in the mid 1980's, even commuting from Essex to Reading in it twice a week and I never changed oil at 3000 mile intervals, the chains never suffered. Mind you I had IWIS chains in it at the time. I did get a timing chain break but that was caused by a waterpump failure that left metal in the oil that contributed to the jack shaft seizing. Modern oils (even the good quality classic ones) outstrip the oils from 30 odd years ago by a wide margin, I'd stick to once a year *if* you don't do mostly short journeys in it and if you cover less than 6000 miles a year. If you lay your car up for the winter, then change the oil shortly before you lay it up, because you want a good amount of anti corrosion additive remaining to protect the bearings from acidic corrosion during the layup. Better yet drive the thing all year round so long as there is no salt on the roads, cars always get issues after a layup. The Stag engines issues were mainly down to poor quality control at he factory (sand in the castings) and as the cars became secondhand, by lack of a sensible maintenance schedule. Cars get run with antifreeze that is 6 years old and with the anti freeze available at the time it needed changing frequently (every year or two) so you got mixed metal corrosion because the anti corrosion additives were depleted, leading to aluminium and iron oxides mixed into a sludge that blocked radiators and caused overheating, warping the heads. Also having a very high mounted water pump the stag is very sensitive to coolant levels and again as the cars became second hand and owners neglected maintenance, low coolant levels made overheating almost a certainty. All IMHO

[davidf]

I only do my oil change once a year, but as mentioned above, the big problem is infrequent use, leading to oil draining away from bearing surfaces, and potentially, damage can occur in the first few seconds after starting, before the oil reaches the bearing surfaces.
Many years ago, I was presented with components from an engine which had not been run for months, but in which STP oil additive had been used. I actually could not hold a valve by its stem; it slipped from my fingers. By comparison, when I stripped my mini heads (as one had to do regularly in those days !!), the valve stems felt bone dry only days after running. Therefore, I always add STP at each oil change. About 60000 miles after building a new Stag engine, I could not measure any wear anywhere (crank shell thicknesses, piston ring gaps, ...)
I think modern oils do retain their properties for longer than oils of the '70s, but I guess it also depends on how 'tight' the engine is. If there is a lot of bypass of the piston rings, there could be a lot of contamination of the oil.
You can look at the oil on the dip-stick - if it is filthy black and runs off like water, it needs changing whatever the time or mileage. If it still has clarity and hints of its original colour, and feels like proper oil, then it is OK within a year.

[StagJonno]

Not sure about your ali rad proposal - there's been many mentions about these recently, but I'm inclined to think this is smart marketing and attractive to "bling" addicts. A well-flushed standard rad should be OK. A lot of the cooling efficiency depends on the staggering of the tubes within the rad. If I were to upgrade the rad, I'd be looking first at the Tony Hart "Supergill". Many have fitted a TR6 front spoiler which is reported as improving cooling and also giving improved high speed stability.

Jonno

[Paul Kelley]

Pretty much agree with all points above re the engine. Nothing inherently wrong with the design (high water pump and long timing chains possibly excepted) so when put together properly and well-maintained they are good reliable motors. Original Strombergs need to be well maintained, kept topped up, and balanced. I use my Stag regularly and change oil and filter annually after 3-4k miles. Apart from the engine, IMO worth considering investing in new front axle stubs and rear hubs as a safety precaution. 40 + year old metal on any car may be subject to fatigue so this is an insurance/safety consideration as there are a few reports of wheels coming adrift. I don't wish to be alarmist, just pointing out it's not all about the engine.
PK

[Ritchie6]

I only do my oil change once a year, but as mentioned above, the big problem is infrequent use, leading to oil draining away from bearing surfaces, and potentially, damage can occur in the first few seconds after starting, before the oil reaches the bearing surfaces.
Many years ago, I was presented with components from an engine which had not been run for months, but in which STP oil additive had been used. I actually could not hold a valve by its stem; it slipped from my fingers. By comparison, when I stripped my mini heads (as one had to do regularly in those days !!), the valve stems felt bone dry only days after running. Therefore, I always add STP at each oil change.

I'd never considered using STP in my engine but it sounds as if it could be quite beneficial,especially as I don't use the car during the winter except for bringing it out onto the drive and running up to temperature a couple of times on nice days. I'm currently using Comma Classic Heritage 20/50 oil so would this be compatible with the use of STP?

Richard

[CJG]

I'd never considered using STP in my engine but it sounds as if it could be quite beneficial,especially as I don't use the car during the winter except for bringing it out onto the drive and running up to temperature a couple of times on nice days. I'm currently using Comma Classic Heritage 20/50 oil so would this be compatible with the use of STP?

Richard

Good point Richard after reading Davids post was considering this myself, i used to use it back in the seventies / eighties ok.

[garyf]

I bunged some of this stuff in when I done my last oil change.....Haven't got a clue if its to any benefit, seemed a good idea at the time

https://lucasoil.com/products/engine...oil-stabilizer

[CJG]

Hi Garry
Haven't used the engine oil stabiliser but did use the lucas auto transmission anti slip and conditioner in an 240 glt volvo , on the recommendation of an AA patrol mechanic and it did help with the snatching of the gear changes.

[Paul Kelley]

My old school (ex-Aston Martin) go-to mechanic (John Hoyes, Old Forge Motors, Harrogate) swears by Vivax superstar anti-friction oil from Highspeed Ltd in Keigthley. Details here: http://www.highspeed.co.uk/oils-greases/vivax.html#1 The picture shows a barrel of the stuff, you can buy 1 litre bottles! Been using it for about three years at annual oil changes, along with Valvoline VR-1. All I can honestly say is the engine runs really well and wear on chains in 10k miles is virtually zero. Whether that's the Vivax hard to say for sure.
PK

[davidf]

I'd never considered using STP in my engine but it sounds as if it could be quite beneficial,especially as I don't use the car during the winter except for bringing it out onto the drive and running up to temperature a couple of times on nice days. I'm currently using Comma Classic Heritage 20/50 oil so would this be compatible with the use of STP?

Richard

I use Halford's Classic (with STP) - it seems to be more similar to a 20/50 of the 70's than anything else. After all, the can has a picture of a Stag on it (amongst others of the time), so it must be right, mustn't it? Some on here have suggested it is actually the same oil as Comma Classic.

[Ritchie6]

I use Halford's Classic (with STP) - it seems to be more similar to a 20/50 of the 70's than anything else. After all, the can has a picture of a Stag on it (amongst others of the time), so it must be right, mustn't it? Some on here have suggested it is actually the same oil as Comma Classic.

Yes I believe that Comma Classic and Halfords oil are one and the same product. I certainly haven't had any issues using it and have very good oil pressure.I get my Comma oil from a local motor factors as I find Halfords to be expensive for many items.

Richard