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removing carbon in top engine
Posted by: timor19 ()
Date: September 04, 2015 07:04PM

Hi guys,

I have a 110 HP 1964. I have a lot of ping on idle and on acceleration even with 91 octane gas. I do poured a can of seafoam liquid in the gas tank, this is a bit better but not that much. I would like to do the tap water trick, but I don't want to hydro lock the engine and wreck it.

This is what I am planning to do:

1- warm up the engine to normal running temperature
2- remove air filter
3- gently spray tap water directly in a carb and on the other one for about 250 mL of water
4- change oil and filter

Is this the right way to remove the carbon build up in top engine?

Thanks a lot

Mike,
Monza 1964 110 HP, powerglide
Quebec, Canada

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Re: removing carbon in top engine
Posted by: Ratt643 ()
Date: September 04, 2015 07:46PM

As long as you mist the water into the throat of the carbs you wont run the risk of hydraulic locking. Be sure you run the engine up so the water can turn to steam in the cylinders and the engine wont die. Run water thru until the exhaust clears up and you should be good to go!

1964 Monza Coupe
1965 Corsa 140
1967 Monza Coupe

Maryville, TN
U.S. 129 The"Tail Of The Dragon"

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Re: removing carbon in top engine
Posted by: Timothy Shortle ()
Date: September 04, 2015 08:22PM

That is how I would do it. And what is your initial base timing set at?

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Re: removing carbon in top engine
Posted by: steve c goodman ()
Date: September 04, 2015 10:48PM

The final step in 'decarbonizing the valves' is drive the car for 10+ miles preferably at speed. The theory is the water will loosen the carbon and then the driving will knock it off the pistons and combustion chambers and valves. Then you can change oil/filter.

This operation used to be a part of flat rate labor book pricing.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: removing carbon in top engine
Posted by: richard1 ()
Date: September 05, 2015 04:27AM

That is how I did it back in the 50's and 60's. Then I learned about Techron. Double up the dose for better cleaning, as their standard recommendation is for normal cleaning. I fixed a lot of ping with that, and now have my version, where I sell it in the bottle 50% stronger than the original. No real need to change the oil after this. On my Grand Cherokee I use my cleaner every 4000 km and change oil every 12,000. (we have lousy gas)

When you have a lot of carbon in the upper cylinder, you probably also have a lot in the rings, so I'd also use AutoRx in the oil to free them up or clean them up before then start sticking, and clean up the passages in the oil control rings.

Restoration in Bolivia
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Richard's Renault Dauphine

Selection of the Right Motor Oil for the Corvair
Selection of the right transmission oil for the Corvair
How to polish and restore stainless and aluminum trim

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Re: removing carbon in top engine
Posted by: Frank DuVal ()
Date: September 05, 2015 06:01AM

I pour from a "Coke" bottle. Rev up, pour water until I have full throttle wit engine maybe 1500/2000 rpm.

GM top engine cleaner is also very good. That includes a stall engine and soak cycle in the instructions. Follow close so no hydro lock with that one.

Water has no need to soak, keep it running.

Frank DuVal

Fredericksburg, VA

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Re: removing carbon in top engine
Posted by: rowin4 ()
Date: September 05, 2015 06:21AM

I knew a guy that used to go to the car wash, stick the wand in the carb with the engine reaving at about 4,000 RPM's. Seemed to work for him, I just thought EEEK!!!!

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Re: removing carbon in top engine
Posted by: timor19 ()
Date: September 05, 2015 07:06AM

Ok thanks a lot guys,

Timothy my advance is at 16 I think. A little high, I will set it to 12 or 14 after my cleaning of carbon.

Mike

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Re: removing carbon in top engine
Posted by: RobertC ()
Date: September 06, 2015 02:03AM

Ping at idle - never heard of this...

Which jets are in the carbs?

Which spark plug are you using? Personally, I would not use an extended tip plug on a Corvair engine.

Timing is too high - imo, 110/pg can be "sensitive"; you may need to set timing at 10...

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Re: removing carbon in top engine
Posted by: timor19 ()
Date: September 06, 2015 05:53AM

Ok thank you RobertC,

I will take a look at it.

Mike

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Re: removing carbon in top engine
Posted by: Templar8 ()
Date: September 06, 2015 08:27AM

As a mechanic for more than 40 years, i can't understand how so mutch carbon can build up on a cylinder with all no lead gas. The ONLY reason is oil consumption.
No accumulation of carbon will build up on a cylinder with a normal operating engine. Even if ,like me,you are pempering your engine by not over revving and never floring the trotle. The carbon accumulation ,if it is realy that who made pinking your engine, must be a worn engine . I dont recomment At all to pour water in the carbs. I would never do this to my car. Water and oil are not compatible. I remooved the head on my v8 chevelle 1968 last years after more than 25 years of operation and there was not a single trace of carbon on pistons. And i can tell you that i never pour any water on the engine.
That is my opignon.

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Re: removing carbon in top engine
Posted by: steve c goodman ()
Date: September 06, 2015 11:32AM

Water isn't being mixed with oil here. Water is well known to be a carbon 'cleanser'. Reason I say this is because everyone who has used water injection as a way to control detonation has always noticed the tops of the pistons and the combustion chambers and valves are clean from carbon. There used to be a water 'vapor' injection system too, water was pulled into engines from the manifold vac of carbs and for the same result, clean combustion chambers and cooler mixture temps.

As I said in my first post, there used to be an actual flat rate charge in shop manuals for 'decarbonizing the valves'. What we have been talking here is exactly that, dribbling water into the carbs to 'set the mood' and then driving the engine and the water will help break up the carbon.

Only the reply from someone talking about putting a hose into the carb is of no help here, pouring that much water into the carb would stall the engine in moments with the only effect being a hydraulic lock afterward.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: removing carbon in top engine
Posted by: rowin4 ()
Date: September 06, 2015 12:50PM

I bought a corvair engine that was supposed to be good. It had been in dry storage for decades It was stored on the bell housing end and turned over by hand. Once I got it home put it on the engine stand to check it out the engine would only turn over about 359 degree's. When I originally picked the engine up I was only concerned that it wasn't stuck so I didn't rotate it over a full turn. I did the usual rocker arm check figuring a dropped seat. Every thing looked OK so I pulled the first head, Lot of carbon on the pistons but it still wouldn't turn over 360 degree's , pulled the second head found carbon had fallen off one piston and compacted enough to stop the rotation.

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Re: removing carbon in top engine
Posted by: steve c goodman ()
Date: September 06, 2015 01:07PM

The 140hp engine in my CORSA that was rear ended heavily several years ago also would not roll over after I pulled it from the car. Carbon had broken from the pistons/heads and collected in the bottom of the cylinders.

Just to put the wreck into perspective for those who didn't see the picture from the highway, the hit was hard enough (from the rear) to break the windshield. It broke the joints on the A pillars to the top and cowl as the entire top was pushed forward. It deformed the shift tubes into a J position and even bent the shift coupler pin which is hardened. In other words, a pretty hard hit; not surprising some carbon was vibrated loose.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: removing carbon in top engine
Posted by: Templar8 ()
Date: September 06, 2015 01:43PM

I am pretty Sure that carbon chunk getting loose in the cylinder will close up the spark plug gap in a moment. And this chunk have to pass the exaust valve......oufff! Quite difficult.
I saw some years ago a kind of water injection device for a corvair engine....nothing to compare to a coke bottle poured in the carb. Even slowy taken,the water came in contact with the cylinders wich is supposed to be coated with a thin film of oil.
There is not supposed to have carbon accumulation on a normal engine.
Maby if you are running mutch to rich of you have oil cunsumption some accumulation will appeer.
You can see that on a old snowmobile engine. To mutch oil mixed on the gas and some sort of carbon will happened.
That is my 2 cents like some say.
Alain

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Re: removing carbon in top engine
Posted by: steve c goodman ()
Date: September 06, 2015 02:18PM

The chunks get broken up into small pieces at higher rpm while driving down the road. You aren't doing the high rpm at the curb, you are hopefully 70+mph. I have done it many times and it was common on flathead Fords etc back in the day, nothing gets stuck in valves and nothing gets stuck in plug gaps but the view out the rear mirror will show a mess coming out of the exhaust tips.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: removing carbon in top engine
Posted by: OttawaCorvairGuy ()
Date: September 06, 2015 08:10PM

Why do a half or quick fix... when you can do a lot more while driving and enjoying your car.

I only use 44k by BG products.. It NOT only cleans carbon - it will clean anywhere gas flows and even the top ring.....

I use it once a year on cars that have carbon build up issues.. Or when I do a tune-up as preventative maintenance...



Edited 1 time(s). Last edit at 09/06/2015 08:12PM by OttawaCorvairGuy.

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Re: removing carbon in top engine
Posted by: Frank DuVal ()
Date: September 06, 2015 08:27PM

Well, maybe I'm just too old, but decarbonizing engines was a normal operation back through the early 80s. GM still sells top engine cleaner for the purpose. Motor Vac even created an entire line of expensive tools to help with the problem. They are much better at sucking money out of your wallet than cheap water!

Of course it is from oil burning. Know of any 50s, 60s engine that would go 1000 miles without needing a quart of oil after it got 50 K on the clock? They did exist, but we're very rare. Until recently (10 or so years) I never owned a car that would not need oil between oil changes, no that was 3 Mile changes.

I have used several water injection systems, both on Corvairs and my 10:1 455 Buick. Water works fine until temperature gets below 32 F! I also ran the water vapor injection styles on many Corvairs back in the early 80s. And pouring water through the carbs was done on many of the cars I worked on the cure knocking (pinging). Good results. But, I have not needed to do it in years now, since most of my friends no longer drive 60s era cars 20K miles a year, including lots of stop and go driving to and from work.

Passing carbon chunks through an exhaust valve opening is easy. Like Steve, I have floored many a car/truck from the 50s and 60s and seen chunky black smoke flowing out at speed. Back then even laymen referred to it as "blowing out the carbon". You might not ever see this on a car of modern design with a catalytic converter. Times have changed, but Corvair engines have not unless updated by someone recently.

Frank DuVal

Fredericksburg, VA

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Re: removing carbon in top engine
Posted by: OttawaCorvairGuy ()
Date: September 06, 2015 08:45PM

Frank,

Carbon build up can also happen on engines who's owner's run high test when not needed.

Cars that require hight test - are timed and operate best on such fuel...
However, most vehicles on the road are designed to operate on regular...

I met Pat Goss from Pat's garage, many years ago, and he had several demonstrations to prove to people what running a vehicle on high test can do - when the car is NOT design to run on it..

Another demonstration that blew me away was with Anti-Freeze..
He had three jars:
1st jar with water and some nuts and bolts
2nd jar with the same kind of nuts and bolts mixed in 50/50
3rd jar all anti-freeze with the same kind of nuts and bolts inside.

Each jar was dated with the same date. The condition of the hardware in just water and more so in all anti-freeze was unbelievible..

Seeing is believing



Edited 1 time(s). Last edit at 09/06/2015 08:46PM by OttawaCorvairGuy.

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Re: removing carbon in top engine
Posted by: richard1 ()
Date: September 11, 2015 08:53AM

For those that want to see what a steamed head looks like, this is the head of my 2002 Toyota Pickup with 280,000 miles. A small, thin, crack developed behind one of the exhaust valves of the cylinder on the right, so for a few miles, maybe not more than 5, vapor was coming into the cylinder when that exhaust valve opened.

The cylinder on the left is just normal carbon for the 280,000 miles, although it gets somewhat irregular treatments of my Techron based cleaner in the gas (last time was 6000 miles ago.

Second picture shows the crack.

Restoration in Bolivia
Richard's Mini Pickup
Richard's Corvair
Richard's Renault Dauphine

Selection of the Right Motor Oil for the Corvair
Selection of the right transmission oil for the Corvair
How to polish and restore stainless and aluminum trim

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