Thread: decoke?
View Single Post
  #2  
Old 09-01-2005, 10:26 AM
hotrod hotrod is offline
Senior Member
 
Join Date: Oct 2003
Posts: 307
Default cleaning effects

The carbon cleaning effects of WI are well documented. I've never pulled the heads on a WI car but have seen first hand the effects of water on carbon build up.

Many years ago 1950-1970's it was a common tune up "trick" used by many hotrodders to remove carbon buildup on the high power V8's in use at the time. Carburators were jetted quite rich to control high load detonation.

Carbon build up became a problem, especially in the 1970's when the oil crisis hit and folks were trying to run cheaper grades of fuel or high octane fuel simply disappeared from the market.

We would take an engine that was well warmed up, set it at a fast idle and trickle a thin stream of plain old water down the throat of the carburator, gradually opening the throttle until you got to about 3000 rpm or so, then increase the water flow until the engine seemed to have trouble with the excess water (sounded like the engine was strangling). It is truely astounding how much water you can pour down the bores of a large V8's carburator at a high throttle setting.

On an engine that had heavy carbon build up on the spark plugs prior to the "treatment" they would be nearly as clean as new if you pulled them afterward. If the engine was pinging due to carbon build up, it would magically go away after just a few minutes of this process.

Red hot carbon and steam react in a process called the "water gas reaction" --- look it up. It converts the carbon to gaseous CO and hydrogen both of which burn off inside the engine. This was used to by industry for many years to produce combustable "water gas" ( substitute for natural gas ) from coal.

You may need to back off your excess fuel a bit if you add water injection, to avoid a slight power loss caused by the combination of too much fuel and WI, but that would be the only down side I can see.

Larry
Reply With Quote