Push Rod Tubes

Cleaning the inside of push rod tubes

Method one:

Use a brass shotgun cleaning kit brush, which works well to clean push rod tubes. Twelve gauge is too big. 20ga is about .612", just about right. There are specialty brushes, but firearms brushes are cheap and can be obtained at Walmart. Another suggestion - chuck the brush rod in a cordless drill and run WashTank mineral spirits at the same time. Polish the o-ring grooves with 600 grit sand paper until they shine. This can be done by cutting the paper into long strips 1/4" wide and using them like a shoe shine rag in the groove.

Method two:

3/8" wooden dowl rod with a slot cut in one end, a small piece of 3-M scuff pad, WD-40 and an electric drill. Lubricate the pad and spin the rod with the electric drill until the inside of the tubes look like a gun barrel. Make sure you flush the inside of the tube when you are done, to remove all of the grit.

Cleaning the outside of pushrod tubes

Dave Gardea has a picture posted on his website of the method he used to clean the outside of his pushrod tubes. He used a scotchbrite wheel to clean up the outside and ended up with a good result.

Painting push rod tubes

When painting or powder coating the outside of push rod tubes, mask off the ends where the O ring grooves are so that the paint doesn't interfere with the seating of the rings. There should be no paint in the area of the o-ring groves. This area can be polished until it looks very shiny with thin strips of 600 grit paper while spinning the tube on either a lathe or a drill press. To grip it for driving in a lathe, hold the tube between two rubber suspension snubbers. Snubbers can be obtained from Summit Racing.

Avoid getting any paint on the inside. It should be bathed in oil, so paint sticking shouldn't be a problem, but still, try to avoid getting paint inside. WilliamWynne advises that the best color is white, as it reflects the most heat from the exhaust stacks.

The tubes themselves run at a hotter temperature than the oil in a flying Corvair engine because the down wash of the cooling air flows from the exhausts over the push rod tubes. The tubes actually slightly heat the oil rather than cool it. WilliamWynne has done elaborate tests with ceramic coating the tubes on the inside and outside, and says it didn't make a big difference. A good paint job in white is all that is needed.

Really polish the area in the heads and the case where the O rings ride. This is easily done with a 2" square of Scotch Brite driven by a dulled out 3/4" ForstnerBit, soaked in WD-40. WilliamWynne says that engines that are properly prepped run bone dry, it just takes some care. He says it should take several hours working on a set of pushrod tubes to get a dry engine and that the time is well spent.