45 replies to this topic

[govig]

I've fitted a decat pipe too Magic. Any problems at MOT time?

[CMXCVIII]

I used it on a 600cc Scott Special trials outfit. Total loss lube system but such a glorious smell - the smell of five pound notes burning.........

Bob

Forget the smell - completely worth it for the sound of the yowling two stroke!

[FWIW, Bob, somewhere else on the forum, guys are enquiring about any lock-ups in Bristol. I needed a lock-up in Bristol in the '70s for motor bikes and knocked on a door in Clifton to ask about the derelict house next door. The lady who answered, typically kindly, said she had motor bikes and we could share her lock-up. She opened the door to show us and there in the gloom were a Honda 90 ... and her Silk 700S!!!! My next question was, of course, "Will you marry me?" ]

[Old Bob]

I used it on a 600cc Scott Special trials outfit. Total loss lube system but such a glorious smell - the smell of five pound notes burning.........

Bob

Forget the smell - completely worth it for the sound of the yowling two stroke!

[FWIW, Bob, somewhere else on the forum, guys are enquiring about any lock-ups in Bristol. I needed a lock-up in Bristol in the '70s for motor bikes and knocked on a door in Clifton to ask about the derelict house next door. The lady who answered, typically kindly, said she had motor bikes and we could share her lock-up. She opened the door to show us and there in the gloom were a Honda 90 ... and her Silk 700S!!!! My next question was, of course, "Will you marry me?" ]

Love it - a lady with style!

Bob

[jaydee]

• Does using synthetic oil damage engine seals?
  No. Synthetic motor oils are perfectly safe for all rubber seals.

Not correct. Not all the seals are the same rubber grade neither the oils. We're talking about 60 years old technology.
I have tryed both 0w60 and 20w50 fully synth (one is a racing oil from shell the other its millers) on a fresh engine they're great, if youre engine has done a bunch of miles, then steer clear from them.
Also, on a classic, where you've been using mineral for ages, the switch to a synth oil is not reccomendable.

Switching to a Synthetic on new and used cars

DO NOT USE a fully synthetic until the engine has covered a little more mileage (approx 10k) because the engine is still bedding in for some time up to this point. Then switch to a good synthetic.
What are the benefits? Less wear, less power loss in the engine, better fuel consumption.
Generally, the reference to synthetic oil for an engine can mean a Group 3 Mineral oil. But if it means a lubricant is formulated with a polyalphaolefin (PAO) base oil, then it is pure and is compatible with mineral base oils.
However, because the PAO base oil does not dissolve additives as well as a basic mineral oils, it is usually formulated with an ester co-base (usually di-ester and/or polyol ester). The additives are soluble with the ester and the ester is soluble with the PAO.
The PAO tends to cause seal shrinkage and the ester causes seal swelling, so the effects are offset when both base oils are present.
When switching to a fully synthetic on an older engine, or one with a higher mileage, it is the ester that can cause problems when one changes from mineral to synthetic. Ester base oil used alongside PAO base oil in lubricant formulation has excellent natural detergency. In other words, it will clean up deposits on component surfaces as a result of thermal and oxidative degradation of the lubricant. When one switches from typical mineral-based engine oils to a typical synthetic-based oil, the varnish layer will be removed by the ester in the synthetic oil and become suspended.
This suspended material can rapidly clog filters and can potentially block oil flow passageways and lead to component starvation. The same is true for gearboxes and other industrial machines. So think twice about switching to synthetic oils in applications where the engine or other machine has been operating for some time with mineral oils. It can be done but be aware of the potential for creating more harm than good.
This is also where oil seal leakage can be an issue as the beneficial layer of deposits on the seal are holding the oil in, but once cleaned off, the seal can initially shrink before settling again, so a short spell of oil leakage may result.

What site are you quoting that from?

Sorry for slow reply, but i have already posted it above ;)
www.kewengineering.co.uk

[jaydee]

Oils have improved out of all reasonable comparison since 1959 as have engines. It's very easy to be bamboozled by all the specs but just remember this : thin synthetics and semi synthetics have been designed for engines which in the main are OHC with very narrow oil galleries and for cars with catalytic converters and only have to lubricate the engine rather than an engine and gearbox. Whilst they are hugely better lubricants, they are not for the A series. Just use a good quality mineral 15w-50 or 20w-50 SF spec (15w-50 are usually SG) and change it often. Personally, I change the oil and filter every 2500 miles, it's only about £25!

The only problem I see with this simplification are minis with cats. The older high ZDDP oils (which damage cats) are best for the A series. Mine hasn't got a cat so it's not a big snag for me. In reality how much of a problem is it? You often see minis with 100k on the clock where the owner has put any old rubbish in and they still mostly survive maybe with a bit of a crunch 3rd - 2nd. Best not get too raveled up with this unless you have a high output A series. If you can afford it, use Valvolene or Morris' (others probably just as good), if not there's always Wilko. The main things is to change it much more often than we are now used to with modern cars. Do that and stop worrying.

PS Has anyone used ZDDP additive?

Yes, but havent covered enough miles to write a review...
Only thing i can say is that after nearly 10k miles cam follwers were in great conditions (that with hi lift cam+1.3 rollers+160lbs springs), cant comment on the gearbox cause i didnt split and check.

[firstforward]

• Does using synthetic oil damage engine seals?
  No. Synthetic motor oils are perfectly safe for all rubber seals.

Not correct. Not all the seals are the same rubber grade neither the oils. We're talking about 60 years old technology.
I have tryed both 0w60 and 20w50 fully synth (one is a racing oil from shell the other its millers) on a fresh engine they're great, if youre engine has done a bunch of miles, then steer clear from them.
Also, on a classic, where you've been using mineral for ages, the switch to a synth oil is not reccomendable.

Switching to a Synthetic on new and used cars

DO NOT USE a fully synthetic until the engine has covered a little more mileage (approx 10k) because the engine is still bedding in for some time up to this point. Then switch to a good synthetic.
What are the benefits? Less wear, less power loss in the engine, better fuel consumption.
Generally, the reference to synthetic oil for an engine can mean a Group 3 Mineral oil. But if it means a lubricant is formulated with a polyalphaolefin (PAO) base oil, then it is pure and is compatible with mineral base oils.
However, because the PAO base oil does not dissolve additives as well as a basic mineral oils, it is usually formulated with an ester co-base (usually di-ester and/or polyol ester). The additives are soluble with the ester and the ester is soluble with the PAO.
The PAO tends to cause seal shrinkage and the ester causes seal swelling, so the effects are offset when both base oils are present.
When switching to a fully synthetic on an older engine, or one with a higher mileage, it is the ester that can cause problems when one changes from mineral to synthetic. Ester base oil used alongside PAO base oil in lubricant formulation has excellent natural detergency. In other words, it will clean up deposits on component surfaces as a result of thermal and oxidative degradation of the lubricant. When one switches from typical mineral-based engine oils to a typical synthetic-based oil, the varnish layer will be removed by the ester in the synthetic oil and become suspended.
This suspended material can rapidly clog filters and can potentially block oil flow passageways and lead to component starvation. The same is true for gearboxes and other industrial machines. So think twice about switching to synthetic oils in applications where the engine or other machine has been operating for some time with mineral oils. It can be done but be aware of the potential for creating more harm than good.
This is also where oil seal leakage can be an issue as the beneficial layer of deposits on the seal are holding the oil in, but once cleaned off, the seal can initially shrink before settling again, so a short spell of oil leakage may result.

What site are you quoting that from?

Sorry for slow reply, but i have already posted it above ;)
www.kewengineering.co.uk

That is a big site, where exactly is that information located?

[jaydee]

Yeah its quite big site with no search function, thats why i search through google
http://lmgtfy.com/?q...w and used cars

1st one, motor oil FAQ

Edited by jaydee, 05 November 2012 - 02:20 PM.

[Mini_Magic]

I've fitted a decat pipe too Magic. Any problems at MOT time?

Nope, because I put the cat back on for the MOT

[Noah]

Mineral,

Unless your pockets are about as deep as the grand canyon, Synthetic oil is inaccessible

[Artful Dodger]

Nobody using Castrol R and putting a smile on the faces of everyone you pass?

Bob

I though it was discontinued..

That's the trouble with progress - things get better but no longer seem as good!

Bob

I got a full sealed can from my dads racing days.. I'm going to be feeding a tiny bit into the fuel tank so you still get the lovely smell 8). But I don't have enough to run the engine on it, you can get castrol R, just not the same and you get no smell!!

[govig]

Don't put R in the sump without a full rebuild and even then will it be OK for the gearbox?

[Artful Dodger]

Don't put R in the sump without a full rebuild and even then will it be OK for the gearbox?

they used to run R on racing engines back in the day!

but they were more frequently rebuilt back then and the oil is different to what it is today.

im only putting it into the fuel tank so i can get the smell, without using it in the engine. il probably only put 3/4 of a thimble full in every tank or whenever i remember

[Mini_Magic]

So the answer is mineral 20W/50 oil is best for a road Mini.

Race Minis use all sorts of different oils, because they're rebuilt regularly and heavily modified.

[jaydee]

Don't put R in the sump without a full rebuild and even then will it be OK for the gearbox?

they used to run R on racing engines back in the day!

but they were more frequently rebuilt back then and the oil is different to what it is today.

im only putting it into the fuel tank so i can get the smell, without using it in the engine. il probably only put 3/4 of a thimble full in every tank or whenever i remember

Indeed thayll make a nice paper weight as they're one of worst oil you can put in an engine, but the tin looks retro and cool

[ianclark1275]

Milers CTV 20/50 without a doubt the best oil i have ever used. (Race car)

brewed in England

but like beer it is getting expensive (£40-50)


Road car - ive used all sorts, but like the Metal tin cans of the green stuff seem the best value. comma - (£15-20)

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