I have an 8V-71 that consumes a lot of oil due to in air induction failure and lots of playa dust. A reputable source told me an old time cure, or mitigation, for high oil consumption due to cylinder liner glazing (an effect of dust ingestion?) was to drop a tablespoon of bon ami into the induction air stream. He said it breaks the glaze. The guy is service manager at a Smith - Detroit dealership.
But, before I inject Bon Ami dust into my engine to fix what playa dust caused I would like to hear from some body else who thinks this is a good idea.
-RickBrown in Reno, NV
I've seen it done once.
I've heard from the person who did it, it works.
I was not around it long enough to verify the result.
The person who did it was Elmer Elzig ... a Master mechanic at a DD dealership that I worked at in 1973 -75.
I am not sure that Bon-Ami is the same "stuff" it was 40 years ago.
I doubt like "heck" you could make it worse if it was truly dusted...
He used more like a half a can over a long period of time.... maybe a half hour and just dust.. not glumps.
I just tried this trick with my generator engine, a Mitsubishi 3 cylinder diesel. I bought it used and it smoked a fair amount, too much to not be noticed when using it. The engine burned 1 quart of oil every 20 hours. I accidentally shorted out the generator head when I dropped a small washer which inexplicably found it's way inside the rotor stator housing. Since I planned to remove the head to replace it, I decided to try the Bon Ami trick fully planning on a complete engine rebuild if it didn't work.
I heard about using Bon Ami from two employees of mine when I owned a John Deere dealership. The previous owner and the parts manager of 25 years both claimed that dusting the engines would sometimes break the glaze and seat the oil rings. It was really considered a "last ditch effort" before rebuilding the engine. If it didn't work, you REALLY needed to rebuild it after trying it! According to them, sometimes it would work. The engines would be put on the dyno and run at max rated HP for 7 or 8 hours afterwards.
In my engine it didn't work. I used a tablespoon per cylinder (I removed the intake manifold). No change at all. I ended up tearing the engine down to the block to have it honed and then I re-ringed the pistons. The cylinders walls were heavily glazed, the cause I assume was from 2800 hours of very light load on the generator.
Mark
I learned from the east coast Diamond T factory trouble shooter the simple method was to simply change oil to a NON detergent 30wt, drive until it stopped burning oil. Then change back to my Rotella 30wt.
In my case I had a new 1971 Ford F250 with the 360 engine, burned 1 qt every 500 miles, no smoke, no drips. It took about 1,000 miles of towing a heavy trailer, it stopped using oil, turned out to be a great engine other than the weak valves.
Have used that trix a few times on our generators since. Catch is, non detergent oil is Break in oil, will get rid of the glaze, sure will not rebuild a worn out engine.
Have had good luck on DDC 92 & 60 series, Ford 300 six, Mitsubish 4 cylinder 3600 rpm engine.
Dave M
Rick, what oil are you using?
Multi weight oil is known to go right thru a DD 2 stroke in greater volume than the recommended straight weight oil.
Happy coaching!
buswarrior
The Bon Ami trick was use on the old 1000 rpm Cat engines when one would start to slobber and have excessive blow-by we would spray water into the intake to break the carbon loose and dump a little Bon Ami into the intake and you were good for a couple of months.
I still use water on a 2 stroke sometimes for carbon build up but no Bon Ami I never heard of anyone using Bon Ami on a 2 stroke fwiw with Rick's oil combustion he has problems even with 15/40 they won't pass that amount of oil
Quote from: luvrbus on February 04, 2015, 05:23:36 AM
The Bon Ami trick was use on the old 1000 rpm Cat engines when one would start to slobber and have excessive blow-by we would spray water into the intake to break the carbon loose and dump a little Bon Ami into the intake and you were good for a couple of months.
I still use water on a 2 stroke sometimes for carbon build up but no Bon Ami I never heard of anyone using Bon Ami on a 2 stroke fwiw with Rick's oil combustion he has problems
Now the water trick I have done myself and, as Clifford says, it will break up the carbon deposits. We would use this trick on the flat head Kohlers (K301, K321, etc) that are used on the John Deere 100 and 200 series lawn tractors, as well as Wheel Horse, Gravely, etc. One Dixie cup of water, wide open throttle, muffler removed, then slowly trickle the water into the carb. Wear eye protection!
lol I use the red solo cup many of Rver's have paid dealers big bucks to remove carbon from the Onan as Onan said to remove the heads a cup of water and out the door they went for big bucks
I know of two 8v71's (Prime Power) at an AT+T remote Comm Center that ran on Delo 400 15/40 for years (more than 20) .
It was not my call, At+T approved it. How do I know, because I ranted about it and tried to convince them only 100 would do....I lost.
One would be amazed at the owners using 15/40 in the old engines but you can be assured they will not admit it here ;D
Thanks for all those comments.
I use CF2 (non detergent) 40WT Rotella oil. The swap oil type to detergent for a while sounds like a harmless test. May free stuck oil rings if they contribute to the problem.
The water in the induction trick also sounds harmless.
Nobody says Bon Ami is a bad bet (I was worried about seals).
So my work plan is to first establish an accurate use number. Now my data is a very noisy 100 - 400 mpg. The drill will be to drive a constant 50 mi route. Park in the same spot, wait 24 hours and measure the stick.
I'll keep you posted
-RickBrown in Reno, NV
Bon Ami is an abrasive and if it works it will remove metal from your cylinder walls and from the rings and probably some from the pistons as well It can also effect other combustion related parts. The problem you are addressing was presumably caused by introducing an abrasive dust into the engine. Seems counter intuitive to solve that issue by adding additional abrasive. Glazing of the cylinders is the natural consequence of the rings and cylinders wearing together to form a tight fit. I have heard all kinds of "OLD BOY" remedies for stopping an engine from this that or the other thing, but you will never hear an engineer suggest solving an engine problem by increasing wear. Can you break up some of the smooth surface of your cylinder walls by putting the abrasive in the engine? Sure, probably. Can you reduce engine oil consumption by doing so? depends on why the engine is using oil. Examples, A broken or stuck oil ring will not be fixed this way. I have a really HIPO chevy 350 that uses oil because the rings never did seal properly. My fault for using synthetic without a proper break in. Could an abrasive fix this? Maybe, but I will live with the oil burning rather than shorten the life of the engine. So your choice to use Bon Ami is yours alone, but you should know what is happening inside the engine in order to make that choice.
i neglected to mention that the bonami trick i mentioned in my reply was in a boat...much easier to sift into the intake under full power...
I agree, the Bon Ami trick is an absolute "last" ditch effort before rebuilding...... meaning you aren't concerned with ruining anything else in the engine with the Bon Ami because if it doesn't work you'll be replacing all those parts anyways.
Glazed cylinders and rings are very common in diesels that see light loads or idle for long periods of time, like generators and large Ag tractors that don't get worked. A dusted engine will have worn out rings. I replaced the engine in my 4106 because it smoked and had excessive blow by. When I removed the supercharger horn I noticed that the gasket had slipped down on the upper part of the blower, leaving a huge gap for air to get sucked in. The blower lobes were worn, rings were worn, it was a mess. I don't know how long it was sucking air in past the gasket, but it certainly ruined the engine. Bon Ami wouldn't have made any difference in that engine.
Someone mentioned changing to non detergent oil for a while. Would 40 wt straight mineral oil work? This is what they use in a lot of airplane engines to seat the rings.
His rings are seated or it would not start as easy has he said the 2 oil rings are like glass they break easy or get install upside down I saw that from a DD dealer back east and of course the engine was out of warranty
I bet his piston pin seals are not sealing ,he has never said how much smoke the engine is producing it makes it hard trying to help him ::)