30 replies to this topic

[sixtyeight]

spray water carefully into the carby inlet (filter removed). it's steam cleaning for your head/combustion chambers. there are procedures as to how to do it - google it. I don't know if I'd try this method though... maybe if the engine was near knackered and a last resort to fix excess smoke or something. 

 

There are a number of other things you can do... to decoke around the rings put some ATF/Mystery oil in the crankcase and in the fuel. run it up to temp, let it sit, then flush... again not sure if I'd do this... mystery oil/atf have a lot of detergents which are not good in mini gearboxes.

 

I've just taken the head off and decoked it by hand and relapped the valves, and soaked the bores in ATF/Acetone - its amazing how much carbon comes up. it's a good check of the condition of rings/bores too. if your fluid drains through noticeably, then rings are stuck, or cracked, or worn, or the cylinder wall is worn.

 

It took 40 minutes to get the cylinder head off. and 15 quid for a head gasket, it's much easier to just whip the head off and do it properly.

 

If you car has been overfuelled, if it has done any damage it will be a bit smokey (blue smoke from burning oil)  due to glazing of the bores. if it aint burning oil, I wouldn't be too concerned.

Edited by sixtyeight, 14 February 2017 - 09:41 AM.

[panky]

I've heard of taking the vac advance line off the dizzy and placing it in a container of water. The water is drawn up through into the manifold slowly and in a controlled way and supposedly has a steam cleaning affect, not tried it myself but it's supposed to work.

[tiger99]

You can clean the engine successfully by spraying WATER into the air intake with the engine running. A light mist is sufficient. Do not drown it. This was discovered by people using water injection to be able to run high compression and get more power and efficiency.

No need for snake oil. But crushed walnut shells are ok too, just not too much at once and keep the revs up. They are widely used by airlines to clean turbofan engines, and approved by the appropriate authorities, but a piston engine is different and you must avoid clogging the cylinders. A hand-pumped spray bottle should be ok for water, pausing frequently to rev the engine and expel crud. You would use some kind of funnel to slowly feed in walnut shells. Steam can also be used, but it will need more than a boiling kettle to feed in sufficient.

A spray of WD40 down the intake is also useful. It produces interesting looking yellow exhaust smoke, probably not good to inhale.

Whatever you do, take the head off immediately afterwards to ensure that all is well. I tried water and was amazed at how little carbon was left. I ran it for about 10 minutes.

And don't fall for the old wives tale of having to leave a ring of carbon round the edge of the piston to help form a seal. It does no such thing, as lateral piston movement erodes it back flush with the edge of the piston. You do leave a ring if hand scraping to avoid the risk of cylinder damage. It is appropriate to lower the piston slightly in the bore and insert an old piston ring to keep your scraper away from the edge, but that is to avoid forcing scrapings down the gap between piston and cylinder. There are good reasons for this sort of thing, but if the water spray has removed the carbon completely, those reasons become irrelevant.

[1984mini25]

From 25 minuets in...

 

Edited by 1984mini25, 14 February 2017 - 04:03 PM.

[mini-geek]

DO NOT PUT CRUSHED WALNUT SHELLS INTO AN ENGINE!

What has how a jet engine might be cleaned got todo with this?

[tiger99]

If they are very well crushed and fed in very SLOWLY so that they do not accumulated in the cylinders I strongly suspect that they will do no harm at all. But did you not notice that I was mainly recommending something much cheaper and of proven efficacy, namely water?

Sadly, I fear that many people will be afraid to try water, out of some irrational fear that it will corrode the bores or cause hydraulic locking and bend the crankshaft. It doesn't do either if some basic care and competence is applied.

Actually, I wonder why water injection is currently out of fashion as it brings so many performance benefits in addition to keeping the combustion chambers free of carbon deposits. Maybe people are too lazy to top up the water tank? Just like the imbecile SUV drivers with modern turbodiesel who ignore the warning light when it comes on to tell them that the Adblue is running out, and the the emissions control system shuts down the engine. Most seem to believe that the Adblue can only be topped up by a dealer during a service, which is utter nonsense, and the stuff is neither expensive nor hard to get, yet you see them sat by the roadside awaiting a breakdown truck.

We will not be having Adblue or anything like it on many Minis yet. But we could have water, now, with compression or turbo boost cranked up a bit and much cleaner combustion.

[midridge2]

So you can tell why a SUV has broken down by just driving past.  What world do you live in.

[Midas Mk1]

So you can tell why a SUV has broken down by just driving past.  What world do you live in.

 

A world which entertains us all on here, deffo not ours.. 

Edited by Midas Mk1, 15 February 2017 - 03:59 PM.

[tiger99]

I got that info from a member of one of the breakdown services. Their biggest reason for being called out on certain models is running out of Adblue. If you do not believe me, you could Google for other sources.

And it is also proven fact that very many ignorant drivers continue to drive when a RED light is on, indicating a safety-critical failure. We probably all know some. We even see it on this forum, where the level of mechanical expertise is likely to be well above average, notwithstanding certain obvious exceptions. Looking through the forums you will find plenty of depressing tales of incompetence amid lots of much better stuff. The worst I noticed was the guy who was obsessively and by brute force removing all the plywood from his Marcos shell. I never did check to see whether it collapsed before or after putting it on the road.

[Carlos W]

My van has done nearly 9000 miles and hasn't yet indicated it needs topped up with adblue, although when it does I've identified a petrol station which has it on pump.

 

As for water or water/meth injection, I've had friends who've used it to lower inlet temperatures on turbo engines, one of which was a diesel and it smoked like anything.

 

 

Given that carbon particles are the latest target I'm not sure we want our little minis smoking like this when getting rid of carbon

[sonikk4]

Just as ahead up with regards to Modern Jet engine cleaning, we now use just good old fashioned water. It is applied correctly and directly into the core with specially placed nozzles at a certain temperature for a period of two minutes, with the engine being turned over by the starter only. Rested for five minutes, then turned over again for 2 minutes, rested for 10 minutes then a final wash of two minutes. The engine is then started to dry it out properly by being run for Approx 10 minutes or so. (starter motor running here is the limitation as they will overheat and can physically go bang)

 

The video below shows this method although the company we use actually recycle the water by collecting it using special equipment placed behind and underneath the engine.

 

 

Yes the crushed walnut method has been used along with other products, chemical based or natural but now water is the preferred method by a huge amount of Airlines / Operators. Its cheaper and cleaner and does make a considerable difference especially on older engines.

 

As for our little cars and engines then a basic head off and decoke would be far more beneficial.

[Steve220]

Do not put any solids, no matter how fine, into a piston combustion engine!!!

Water or water/methanol mix ONLY in a VERY fine spray if you're going to try it.

[Dusky]

What I have done before on engines to decoké them, is putting the distributor advance pipe in a bowl of water. It sucks the bowl empty quite slowly. Black spark plugs looked quite clean again afterwards so it has to work to some degree.

[tiger99]

Using water in a jet engine makes me think that the engine on the A380 that could not be shut down, and was stopped by the fire service from nearly full power, must have been spotlessly clean afterwards. Not so sure about the thermal shock! But flying through clouds must have a small but useful effect.

 

I don't think that water injection usually belongs in diesel engines. The injection experts at work don't think so either, but who knows, someone may have found a use for it. No wonder it smoked! You want GAS (LPG or maybe CNG) injection on a diesel, for a different reason, POWER! (And low emissions.) The forthcoming truck engines from certain major manufacturers in certain markets are going to run mostly on gas with the diesel just for pilot ignition. Direct gas injection, apparently, which some said could not be done. Commercial secrecy prevents me from saying more, but around 2021 it should become apparent.

 

I would rather "atomise" the water into tiny droplets with a spray device than trickle it in through the vacuum advance line, in case it just forms a trickle. It needs to be well mixed with the incoming mixture.

[Dusky]

You're not trickling it in, you let the engine suck it out. Much like howpetrol is sucked out the jet tube on our carbs.