What kind of cleaning solution works best for getting the cylinder walls clean before final engine assembly? I’ve heard lots of stories of different homemade solutions and I was interested in what you recommend.

D.B.

Each engine builder has their own personal way of cleaning cylinder walls but I thought I would start by going to the people who make piston rings who would probably have a good answer. I contacted Keith Jones at Total Seal to see what he recommends.

Jones says that he first cleans the cylinder walls with a high detergent oil like automatic transmission fluid since the detergents will pull up fine junk out of the crosshatch. He follows this up by cleaning the entire engine with hot water and Dawn dish soap that uses a high level of surfactants. A surfactant is a chemical that reduces the surface tension of a liquid like water which tends to improve its wetting abilities. This will remove all waxes, grease, and oil from the cylinder wall and then he dries the entire engine with 130 psi compressed air.

Once the engine is clean and dry, Jones told us he prefers to use a clear solvent like lacquer thinner on a lint-free towel. He says the lacquer thinner flashes off fast and he can see if there is any grime on the towel. He continues to clean the cylinder wall until there is no more dirt on the towel.

My process is similar but different. Many years ago I asked a friend of mine who is also an accomplished engine builder what he used and he surprised me by saying he uses Marvel Mystery Oil. My procedure is to clean the engine with laundry soap and hot water and also completely dry the engine with compressed air. I’ve tried lacquer thinner but found that cleaning afterwards with Marvel Mystery Oil will pull even more junk out of the cylinder wall than lacquer thinner.

If you compare Jones’ procedure with mine, you will see that they are far more similar than different and probably achieve the same results. The ATF that Jones uses is likely very similar in cleaning to Marvel Mystery Oil in terms of using high detergent levels to achieve the same result.

I use regular household, heavy-duty white paper towels with a mild soaking of Marvel Mystery Oil to clean and use a clean towel with the reddish oil on it until the towel no longer shows that grayish grime. That’s when we know the cylinder wall is clean.

As for a lubricant on the cylinder wall for break-in, Total Seal recommends a dry film lubricant called Quickseat.

Jones says he lightly sprays WD-40 on the cylinder wall and wipes out the excess. This is used as a lubricant to spread a thin coating of Quickseat on the cylinder wall. If you don’t have the Quickseat, Jones says a light coating of engine oil is sufficient on the cylinder wall. The rings need a lubricant on the walls to ensure proper break-in in the first few moments of engine operation.

While we’ve had success with this procedure, we’ve never really inspected the cylinder walls for their condition nor have we ever done a different procedure to evaluate the change. However, we’ve had success making good power with the engines we’ve assembled in this fashion. I think that the quality of the honing process has much more to do with ultimate ring seal than cleaning the cylinder walls, but again we’ve never done any back-to-back testing to evaluate that statement.

If you follow one of these procedures or possibly combine these to create your own, I think that this will produce the results you are trying to achieve.

The final clean on cylinder walls uses clean white paper towels lightly soaked with Marvel Mystery Oil. Once the towel no longer shows dirt, it’s clean and ready to assemble. We leave the Marvel Mystery Oil on the cylinder walls to help lubrication. (Image/Jeff Smith)

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Ask Away, Cleaning, engine assembly, Featured, Jeff Smith
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Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.