Using Flushing Oil in a Classic Engine?

[jtay2024]

Hi All,

Another quick question for the oil specialists on here! I am planning to do a thorough clean out / service of my Dads classic land rover. (2.0l petrol 1950s).

I have a quick question. Having recently done a load of experimenting with pinking (which I'm pretty sure turns out to be carbon build up). I am planning to run a good dose of Redline SI-1 and give it a good long drive to keep the temp up and burn off as much carbon as possible (seems to build up badly when pottering about with the choke out all the time).

Anyway, after that tank full of fuel, I'd like to also do a thorough oil change. I am wondering what peoples thoughts are on using a flushing oil to clean out the gunk possibly do anything for the rings?

It'd likely be this stuff. I have used it successfully on a more modern engine which saw my diesel oil stay clean for a significant length of time rather than going black instantly.

https://www.opieoils.co.uk/p-147366-comma-x-flow-flush-out-mineral-engine-oil-flush.aspx

Is it worth a go? Or would I be better just changing it, then doing a short change interval on regular 20w-50 classic oil?

Cheers

 

[Lubener]

A couple short oil changes are safer than a engine flush which might free up some debris, blocking an oil passage and destroy a bearing in the process..

 

[wings&wheels]

unless you have a known problem and are using the flush as a last-ditch effort, I would just stick to a good classic oil.

 

[ATex7239]

Flushes and cleaners fit into two categories for me… I’m going to do this preemptively so it doesn’t ever get that dirty or it is a sludge monster and try this before an engine replacement.

In that middle ground is where I think people can get in trouble.

 

[atikovi]

Having recently done a load of experimenting with pinking (which I'm pretty sure turns out to be carbon build up). I

Engine knock is caused by carbon on the piston tops and valve faces or any space in the cylinder that doesn't have something sliding against it. Oil doesn't lubricate any of those areas and a flush won't do anything to address that. You need a cylinder cleaner that you either pour down the throat of the carb or add to the gas tank.

https://www.amazon.com/ACDelco-10-3...lpcontext&ref_=fplfs&psc=1&smid=ATVPDKIKX0DER

 

[FCD]

As long as the engine is not too filthy that Comma flushing oil should be ok, but i'm not sure how that would fix the pinging, to remove carbon build up what i've done is water decarbonisation, using distilled water in a spray bottle and spraying it down the carb while revving it between 2000-3000rpm, it works.
As far as what oild to run in it, i would go for a 15w40 HDEO such as Shell Rimula R4X or Mobil Delvac MX

 

[cheesepuffs2]

You may find that the sludge being cleared away could expose some new leaks.

 

[jtay2024]

unless you have a known problem and are using the flush as a last-ditch effort, I would just stick to a good classic oil.

Flushes and cleaners fit into two categories for me… I’m going to do this preemptively so it doesn’t ever get that dirty or it is a sludge monster and try this before an engine replacement.

In that middle ground is where I think people can get in trouble.

It was more as a "preventative" lets clean it up kind of thing. I was thinking that if I was to use the fuel system cleaner, it may contaminate the oil and a good flush out and fresh oil would be a nice process. I think I'll just do a short interval on standard classic oil and then replace it really early with more classic targeted oil.

Engine knock is caused by carbon on the piston tops and valve faces or any space in the cylinder that doesn't have something sliding against it. Oil doesn't lubricate any of those areas and a flush won't do anything to address that. You need a cylinder cleaner that you either pour down the throat of the carb or add to the gas tank.

https://www.amazon.com/ACDelco-10-3...lpcontext&ref_=fplfs&psc=1&smid=ATVPDKIKX0DER

As long as the engine is not too filthy that Comma flushing oil should be ok, but i'm not sure how that would fix the pinging, to remove carbon build up what i've done is water decarbonisation, using distilled water in a spray bottle and spraying it down the carb while revving it between 2000-3000rpm, it works.
As far as what oild to run in it, i would go for a 15w40 HDEO such as Shell Rimula R4X or Mobil Delvac MX

Yeah I understand that. That's why I was going to use the Redline Si-1 first, then after that tank full do a oil flush and change. I think I'll just go for regular oil at a much shorter interval and treat that as the flush. I've always been scared of the water trick! I'd be worried it would hydrolock if I got carried away!

You may find that the sludge being cleared away could expose some new leaks.

Yeah that could well happen I suppose!

 

[Cujet]

Back in the 1980's, I'd drive a beater 1967 200 cubic inch six cylinder Ford Mustang about an hour+ into NYC for contract work. Parking was stupidly expensive, and difficult. So instead of paying $45 for parking, I would have the oil changed with Castrol GTX 10W-40, at a local garage for their $9.99 special. After a week of this, the Italian mechanic said "Mr. Cujet, your oil, it's a-clean now!".

The engine was just as sludged up as ever though. I'm not at all sure the multiple oil changes cleaned anything. I ended up burning an exhaust valve when leaded fuel was phased out, and pulling the cylinder head, hot tanking it to remove the sludge.

Sure, today's conventional oils are supposedly better. But I would not expect them to clean anything.

 

[FCD]

Back in the 1980's, I'd drive a beater 1967 200 cubic inch six cylinder Ford Mustang about an hour+ into NYC for contract work. Parking was stupidly expensive, and difficult. So instead of paying $45 for parking, I would have the oil changed with Castrol GTX 10W-40, at a local garage for their $9.99 special. After a week of this, the Italian mechanic said "Mr. Cujet, your oil, it's a-clean now!".

The engine was just as sludged up as ever though. I'm not at all sure the multiple oil changes cleaned anything. I ended up burning an exhaust valve when leaded fuel was phased out, and pulling the cylinder head, hot tanking it to remove the sludge.

Sure, today's conventional oils are supposedly better. But I would not expect them to clean anything.

It's counter intuitive but Group 1 Conventional oils, which are the least refined or pure kind of conventional do actually dissolve deposits relatively well compared to Group II or III oils, thanks to the Aromatics in Group I , the detergents and dispersants in an oil do little to clean already existing deposits, on the other side of the spectrum, certain types of Group 5 Ester base oils also have good solvency, whereas Group IIIs and PAOs are the worst, precisely because they are quite "pure" and very neutral so to speak.

Now it's probably difficult to find many Group 1 oils anymore especially in the US, here in Europe you can still find some Group 1 15w40 / 20w50 PCMOs and HDEOs , so running short intervals with an oil like that could be a good idea to gently and slowly clean an engine.

 

[Astro14]

There are various flush products, like Liquimoly, that clean in the way that you’re hoping. I guess the question is - does it need to be done? Is there actually another problem you’re trying to solve? I often see folks trying to fix things that aren’t broken, and wonder if that’s the case here. This is a relatively low compression engine, with relatively modest lift on the flat tappet cam - so you could run just about any oil and it would be fine. Why not run an oil that’s high in Esters and/or Alkylated Naphthalenes and clean it slowly (if it needs cleaning at all).

And stop puttering about with the choke out. Warm it up and run it - that will help with keeping the carbon down.

 

[GR_CoB]

Oh the flushing oil...
I remember my dad always using flushing oil in between oil changes. It was in the VAZ (LADA) 2101. Identical to the one pictured, just without the white walls.

I also remember how every year he would completely overhaul the whole suspension. Being a missionary meant you gotta get waaay out of town and civilization often, and little LADA took us there. But roads were so bad (and still are outside of like ~10 main cities in Russia) that all of its suspension had to be replaced annually. I think that is what started my love of cars.

P.S. Once we left to US - my dad gave the car to another pastor in need. Well, that man wasn't that great about vehicle maintenance... The engine seized up due to oil starvation, which was caused by lack of oil changes and all the old oil turning into sludge. R.I.P. Копейка.
"Kopeyka" is what people call this car since USSR, it's also the name of the smallest currency, like a Penny here in US.

 

[Revving2Redline]

For a flush, if it were me..

https://www.liqui-moly.com/en/oelschlammspuelung-p000020.html#5200

Drive it and get it nice and warm. A high humidex would help or getting it up to a mid rpm and carefully atomize pure filtered water through a squirter bottle. I think the Redline Si-1 is a good idea too.

Got any pictures of the vehicle?