Anyone got tips for effective Decarbonizing please?

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dom14
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Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 10th, 2016, 11:08 am

Hey Guys,

Can you please give me few tips on how to get rid of the cylinder wall & piston crown, etc etc carbon/soot buildup?
I know I can pour little bit of water in the intake of fully warmed up engine.
I'm wondering whether there's more effective method/chemical I can either pour
into the intake or add to petrol to brake down all the carbon soot crud from the engine bore.
Of course, I can pull the cylinder head out and do a manual scrubbing, but that bit too much work and too drastic at this stage.
Compression readings are bit too high(180-190 range) on all cylinders & I can clearly see soot on the cylinder wall when I point a light at it through the spark plug hole.

Any tips, advice are very much appreciated.

P.S. Vehicle is RB30 Patrol, carby.

thanks
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typhoeus
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by typhoeus » December 10th, 2016, 8:37 pm

An old trick we used to use on old paddock bashers was to use old brake fluid and dribble it in while the motor is running at about 2500 rpm. it would clean the carbon off old grey holden oil burners real well.

mydmax
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by mydmax » December 10th, 2016, 8:53 pm

Except for the piston land area ( the ring above the top ring, there won't be any carbon on the cylinder wall cos the rings scrape it off very frequently.
Because of the very small gap between piston and cylinder wall there cannot be much carbon there either. A small film perhaps. You can squirt some Subaru combustion/intake cleaner into each hole and wait a while, then run. Follow instructions of course.

dom14
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 11th, 2016, 1:31 am

thanks mate.
Would you use brake oil?!
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dom14
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 11th, 2016, 1:33 am

typhoeus wrote:use old brake fluid and dribble it in while the motor is running at about 2500 rpm.
Come to think of it, it would be a pretty effective carbon remover, but I suspect it might kill my tired old engine? :)
Mine is a well maintained old girl tourer. :D
One quarter of the food you eat keeps you alive
The other three quarters keep your doctor alive

mydmax
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by mydmax » December 11th, 2016, 7:11 pm

I believe, any fluid which quenches the heat of glowing carbon will cause it to fracture the grain structure and make it depart the scene when loosened.

Water having a high thermal quality, ie, soaks up lots of heat before steaming, ("Latent Heat of Vaporization") will do it better than many things other than chemical carbon remover.
Don't know the effects of brake fluid. Why old brake fluid anyway? Old brake fluid possibly has a fair degree of absorbed water in it, it is HYGROSCOPIC after all.

typhoeus
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by typhoeus » December 11th, 2016, 9:45 pm

Why old brake fluid? because we were poor, and saved it for that purpose rather than using new brake fluid. . which, we needed on a regular basis as we used to drive really old holdens, and Morrises, Anyone who knows old BMC vehicles knows the brakes weren't the best. . . !!!

dom14
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 11th, 2016, 10:59 pm

Yeah, if brake oil works like a treat on this particular job, then old brake oil is definitely better 'cos it has some water absorbed into it over the years. :D

But, I'm bit too concerned with brake oil, as the RB30 engine on my my GQ Patrol hasn't come to the end of it's life yet. :lol:

I used water and it looks like it removed a fair bit of soot, 'cos I can see the blowby that I haven't been noticing for few days has come back.
Oil(mist) comes out of the rocker cover breathers, when I rev the engine to around 4000k or so.

thanks guys.

Cheers
Dom
One quarter of the food you eat keeps you alive
The other three quarters keep your doctor alive

typhoeus
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by typhoeus » December 12th, 2016, 8:53 pm

sound like the old girl needs rings. . .!

dom14
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 13th, 2016, 10:33 pm

She does, but it's a big job you know.
Unless I do everything myself, it's not worth it.
It's a messy, heavy and time consuming job.
Pulling the gearbox out, then pulling the engine out, 'cos I don't think it's possible to do a "comfortable" and good bottom end rebuild without having the engine block on the ground or on a bench/engine stand.
Leaving the block on the engine bay is possible, but I reckon it's not worth doing it that way, 'cos it would be back breaking to hone the cylinders while bending over to
the engine bay.
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mydmax
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by mydmax » December 14th, 2016, 6:24 am

Have you tried a good quality engine oil. Try a full synthetic for once and see if the blowby decreases. It usually does because of the better sealing of rings.
A lot cheaper than removing the donk and mechanical work which always runs into more $$$$$$ than you wish for.

Mobil 1 perhaps?

dom14
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 14th, 2016, 10:03 pm

thanks Mydmax.
I've never used synthetic or semisynthetic on mine, 'cos I was told by the guys
it's probably wouldn't make difference in old engines.
Now, hearing from you that it can do good, I'll get synthetic oil for the next oil change.

I remember putting in some "engine oil enhancer" or something like that years ago(Wynns brand) and I think it improved the blowby for a short period of time.
I didn't keep doing it 'cos I felt it's bad to keep adding chemicals to oil.

Cheers
Dom
One quarter of the food you eat keeps you alive
The other three quarters keep your doctor alive

mydmax
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by mydmax » December 15th, 2016, 7:56 am

Except some money for the cost of the full synthetic you have nothing to lose.
With a motor wrecker friend we used Mobil 1 in a Holden fitted with an RB30 injected engine. It was the only oil which would stand up to the work it did. Fuchs full synthetic stopped working the valve lifters when very hot. M1 didn't.

Besides cleaning, cooling and lubrication, oil also has a sealing function. Some oil molecules are different to others and some are far better than others at sealing rings,cylinder, piston which is a dynamic sealing situation.

I currently use M1 Diesel Full Syn. in my Isuzu and the sealing is noticeably better as there is less carbon from combustion getting into the lube oil. = cleaner oil for longer.

dom14
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by dom14 » December 15th, 2016, 11:56 am

thanks mate. It's really valuable information. Synthetic oils are on special atm & I think I get them heaps cheaper from the promos.
Cheers
Dom
One quarter of the food you eat keeps you alive
The other three quarters keep your doctor alive

Shann Low
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Re: Anyone got tips for effective Decarbonizing please?

Unread post by Shann Low » December 15th, 2016, 2:52 pm

Seafoam.

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