Carbon removal via water ingestion..?

[HammerDown]

Thinking about trying this on my 81 Vette.
Reason...getting some pinging at hwy speeds under load (especially in summer months). High octane (93)really doesn't help much, either does moving the timing back.
I recall hearing of people using water back in the 70's and 80's but never tied this myself.
Unless there's something on the shelves that I'm not aware of and (will) remove valve and combustion deposits.
Any feedback?

[mondorally]

Thinking about trying this on my 81 Vette.
Reason...getting some pinging at hwy speeds under load (especially in summer months). High octane (93)really doesn't help much, either does moving the timing back.
I recall hearing of people using water back in the 70's and 80's but never tied this myself.
Unless there's something on the shelves that I'm not aware of and (will) remove valve and combustion deposits.
Any feedback?
I did this in an 81 Yugo. Heard about it. Tried it. Never laughed so hard in my life. Rev to full throttle, all 800cc or whatever it had, dump a bunch of water down the carb throat, watch it sputter and shoot steam out the back. I have a stupid grin on my face just thinking about it. Did it work? Who knows. Was it fun. Hell yes.
Justin

[Oldsquirt]

GM sells(or used to sell) a "top end cleaner". We used to use it a lot on older cars. If it is no longer available you can actually give the engine a "water blast" by slowly trickling water into the carb at a high idle speed. When I say "slowly" i mean slowly!!
I would be inclined to say you may have a defective EGR system. If the problem has been coming on slowly over several years, either the passageway from valve to intake plenum is becoming increasingly restricted, or the valve itself is getting plugged up. A quick test for an egr valve usually involves applying vacuum to it with the engine idling, at which time it should stumble badly or die. Unfortunately, this wont work with all GM egr valves as they have an internal back pressure sensing design. In this case you would have to use something along the lines of a pocket screwdriver to lift open the valve instead.

[Some Kind Of Monster]

Use "Seafoam". I put it in my truck and it worked great! It says to use a vacuum line, but be careful and restrict the line so the motor doesn't ingest too fast. I tried it and later did a rebuild and everything was spotless. They also say to use it in the oil for a couple hundred miles before you change. I did that as well and I couldnt believe the crap that came out.

[Snowboat]

Please do not POUR anything down her throat. Use a spray bottle. Years ago I bent a rod on a 350 Merc while easing a little ATF into her for winterizing. I found the slightly bent rod during a rebuild after the kids ignored the overtemp alarm.

[Taylorman]

I'd try ATF. My dad used to do that alot to remove carbon. How about a picture of that Vette?

[Oldsquirt]

Please do not POUR anything down her throat. Use a spray bottle. Years ago I bent a rod on a 350 Merc while easing a little ATF into her for winterizing. I found the slightly bent rod during a rebuild after the kids ignored the overtemp alarm.
Note I did not say POUR, I said trickle and slowly, at that. :) Used to have to do this a lot back in the late 70's and early 80's. It works just fine but one must use COMMON SENSE. Saved more than a few customers from paying for rebuilds(what's that knocking sound?) that were not even remotely necessary. Seems cars of that era were more prone to carbon buildup than the modern stuff.
Taylorman, don't use atf. It can hurt the catalytic converter and O2 sensors on cars that have them and it makes a ton of unnecessary smoke, regardless.

[Mighty Thor]

The water down the carb trick is a sugestion for eliminating carbon deposits that may be present and are usually indicated by the engine continuing to try to run after the ignition is shut off. Your post talks about pinging under load and that is not usually a carbon build up issue. I note that you have already looked at timing and octane as factors, but in my experience load detonation is not a carbon problem. That being said, there used to be water injection systems that would spray water into the engine to prevent detonation by cooling and inhibiting the combustion process. It was not done on a one time basis. The water was injected anytime the load on the engine started to cause detonation. You don't see it anymore because it was mostly just a crutch for systems that were not tuned or easily tunable to the fuels available. Anti knock sensors and electronic ignition controls have mostly solved these problems.

[HammerDown]

Anti knock sensors and electronic ignition controls have mostly solved these problems.
This could be very true of newer vehicles...however my 81 has at best a pretty basic computer.
Quick history...about 5 years ago I pulled the heads and had new valves/springs and guides installed. There was a ton of deposits on some intake valves... :yuk: The guides and seals were toast! Also some carbon build up on piston tops...I cleaned it off.
The pinging started a few years ago...and pretty much on any brand gas except Amoco Premium. Plugs are clean, but I suspect carbon on the piston/combustion chamber.
Now 120,000 on the engine minus the fresh top end that has maybe +14,000 on it. I only put a few thousand miles per year on the car since new in 81.
So back to the water deal...spray ot trickle it in?
Also could the original Catalyic Converter maybe be somewhat clogged and causing back pressure/heat and pinging?

[Boater Bill]

OLDSQUIRT - you have been around for a while. :wink: That GM stuff was real good and saved the day for many back in the day.
HammerDown, may I suggest some Berrymans B12 liquid, not spray. Use the same technique as water, just like OLDSQUIRT said. I would recommend a little more than "high idle speed" however. Try a couple o' cans, cant hurt.

[HammerDown]

Thanks for all the feedback...will look into it. :cool:
PS oldsquirt...I'll remove and check the EGR for carbon build up and operation, I did replace it a few years ago when I had the heads rebuilt.

[quiet riot]

If you just want to remove the carbon buildup, then go to a local marine supply and buy some outboard tuner in a can. You spray it down the throat of the butterflies while slightly rev'ing the engine just enough to keep it running. For a 350 u should use about 3/4 of a can. Then let it idle down and die. Let it sit for about and hour and start it up, warm up, and then run it hard for a few to burn the residue out. Ask at any marine place and they'll know what I'm talking about. Very similar to fogging process for winterizing but used to clean out carbon.
We used this all the time for 2-strokes before the tcw-3 oils that have the carbon dispersers built in the oil nowadays. Also used to clean up 4-strokes and parts after dissassembly.
U'll still have the issue of why the carbon built up to deal with but at least you'll know that its clean for awhile.
jd

[H2OT TIMES]

Back in the early 70's they used to say that the water injection units would give you better power and fuel mileage. I trid it and still use it today. It didn't give me better power or fuel mileage but, You could pull a head off at anytime and the combustion chamber looked like a brand new head. You could eat out of it. And that can't be a bad thing. It takes in very little water. You run a small rubber tube to a vacuum port on the carb or intake and it causes bubbles in a plastic reservoir about the size of a coffee can and the mist that rises off of the water is sucked into the engine.
As far as reving the engine and putting water down the carb. It used to work for me before the water inj. I reved it and sprayed the water with a windex bottle. All it is doing is steam cleaning the combustion chamber.

[FASTRAT]

the water inj thing has been around since the 50's & maybe before that...my Dad was always trying new things back then (water inj, no electrode spark plugs etc) some worked...some didnt...the water inj did work as advertized & is still around today...J.C. Whitney sells the complete kit...i have also seen a system made from a washer fluid bottle & windshield wiper motor & line to the carb...worked great
fastrat

[HammerDown]

Thanks for the feedback guy's...I would like to try the injection method on my 81 Vette, and maybe try to clean up some carbon hot spots.
No way should this engine require 93 octane fuel...but that's all it seems to like.

[rrrr]

the water inj thing has been around since the 50's & maybe before that...
fastrat
Been around a lot longer than that. Water injection got its start in aviation engines. The big radials in 50's airliners like the DC-6 and Constellation used it on takeoff. Here's also a bit about the P-51 Mustang with the Packard Merlin engine....
The final major production version of the Mustang was the P-51H. This re-designed model incorporated major improvements, as extensive in scope as those incorporated into the FW 190D or Spitfire Mk. 22. It was based on the experimental lightweight F and G versions. These were attempts to build extremely long range Mustangs for escort work in the Pacific War.
n the H model, the structure was increased in strength by 10%, to allow higher "g" loads in combat maneuvers. No structural part was left in common with earlier models. The Mustang, already more maneuverable than most of the enemy fighters it faced, could now pull even tighter turns. Also, the canopy was raised for better visibility, the ailerons were altered to improve the roll rate, the wing was re-designed for greater lift and less drag, radiator fairing contours were improved, and the tail was re-designed for greater strength and more surface area. This last change is easily visible, as the size of the vertical stabilizers fin fillet was greatly reduced. Streamlining was improved to increase speed, and stability was increased. A new version of the Packard/Merlin, incorporating water injection, delivered over 2000 hp. All of these changes resulted in the finest American fighter of the war. Speed was 486 m.p.h. at 30,000 ft. best climb rate was 5,350 ft./min. at 5,000 ft. Service ceiling was 41,600 ft.
The Merlin in the earlier P-51B was rated for 1,565 HP at war emergency power so the water injection obviously helped control detonation on the hopped-up H Model.