I'm told it's called a "rabbit turds" hone . . .

......................Now I feel better. I've heard of the Katzenjammers but can't remember actually seeing them.

:-)

Check out the Brush Research web site for more info.

I bought mine from the MAC tool man who is always happy to sell me stuff. The price may have been just about the same, however. It was too long ago for me to remember.

I chuck the hone in a drill press, med/slow speed, and hold the jugs in my hand. I spread a couple of tablespoons of engine oil inside before I start.

Get a second person to turn the hone on and off, so that the hone doesn't whip free and bend itself. You also don't want to insert or remove the hone while it isn't moving. I start with the hone just stuck in a bit and push it on right as the switch is flicked on, then run up and down for about 20 seconds, about 1 second in each direction, making sure not to come off in either direction and not to pause at either extreme. I shout "OFF" as I'm going down and slip the jug off the hone as it comes to a stop.

This is a messy business. Don't ask your wife to help when she has on her new white pants. Don't ask me how I know this. ;-)

-

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

-----------------------------------------------

30 seconds per cylinder is all you need.

john Aircooled.Net >

at 100,000 rpm!

Er, what would be the rpm you'd suggest?

I'm gonna wear a yellow rain slicker. Ask me what I'm wearing under it.

A coat of lithium grease?

Michael -- is it your feeling that more honing than John suggested is needed? In my case, I have pistons and cylinders with 5,000 miles on them, the original honing marks are still visible. The engine suffered an overheat, but no damage was done to the P&C's so I'm reusing them, as well as the rings, after cleaning them up. Pistons and rings are all going back to their original cylinders.

Oooh -- slippery.

No, I was just trying to make a joke. I doubt you really need to hone the cylinders but if you've got things out you might as well scour them for a moment as suggested just to be on the safe side.

Oh -- right.

On Mon, 07 Jun 2004 18:13:29 GMT, Michael Cecil ran around screaming and yelling:

LOL...Michael, how did it work out for ya? JT

What -- the cylinder honing project o' the week? I'm tooled up and gettin' ready to do the onerous duty tomorrow afternoon.

I've been hesitating because of the huge variation in the suggested time for how long I need to hone each cylinder. Ranging from "a few passes," through "a minute or two," (from members of RAMVA)to "20 minutes, an hour, depending on condition of honing tool and cylinders and coolant type and drill rpm, etc." (from someone who specializes in honing), then wrapping back to "don't do it at all," as posted here:

This being an important step I have been doing my research and reading as much as I can get my hands on.

===

Two things I have learned about cylinder honing:

1. It's not really cost-effective to hone your own cylinders if you only have four to do.

1. You can forget doing as good a job as a machine.

More about those, below.

But first . . .

====== Background, or the "What I Have Learned About Honing (and probably misunderstood), Dept. "

As I understand it, freshly-honed cylinders have rough peak-and-valley surface. The peaks are sharp with little surface area. As the rings seat the peaks get flattopped, like mesas. At the same time, the coarse surface of the cylinder wall causes wear on the rings so that they both end up fitting together well.

During normal engine operation, the tiny valleys formed by honing act as oil reservoirs and hold oil up to the top level of the grooves where it then spreads over the flat mesa surfaces. The piston ring travels up and down over this valley/mesa surface, and hydroplanes (oleoplanes?) on the oil film provided by the valleys. Without this film, the ring would make metal-to-metal contact with the cylinder wall and the cylinder would quickly wear out.

However the ring will only ride on this film of oil if there is sufficient surface area to support the ring on the oil -- there needs to be enough mesa area to support the cushion of oil for the rings, but not too much, because there needs to be enough valleys to hold the needed oil.

The ratio of mesa area to valley area and depth, the size of the mesas, and the angles everything is cut at, these all matter.

Honing is also commonly done simply to remove oil that has baked on to the cylinders. This "glaze" is the result of too much heat and it is believed that unless it is removed the piston rings will glide over this surface without ever breaking in.

End Background, as I understand it. =====

The First Thing I Have Learned:

Home cylinder honing is a remarkably silly thing to do if all a fellow needs to do is four cylinders. The cost of the tools plus the hassle of setting up to do the job makes buying a new piston and cylinder set quite attractive. They are not expensive. I could have done that, but I wanted to do this myself.

There seem to be many ways to go about this operation. Not possessing a shop with a floor-standing drill press, I got a 1/2'' variable speed drill. For the honing tool, I got a Brush Research brand "Flex-Hone" ball hone.

I have built up a fixture to hold the cylinder. In my case, the cylinder is clamped between a couple of 2-foot lengths of 1 x 6 (metric equivalents unknown) board with holes for the cylinder spigots and head bolts using 3/8'' threaded stock and suitable hardware. I have a kitty litter box to catch the runoff coolant in, and have taken a plastic bucket and drilled a hole on the side near the bottom and attached a length of 3/8'' vinyl tubing to it. This will sit on a stand above the work and coolant can run out of the tubing onto the work. My assistant will need to anchor the cylinder holding fixture and control the flow of coolant. When the bucket empties, we'll stop and pour the coolant from the kitty litter box back into the bucket.

This is a clumsy and awkward arrangement, but it should work.

The discussion of coolants can be saved for another thread -- MM oil, lard, ATF fluid, kerosene, etc., etc. I've chosen to use a 50-50 mixture of Pine-Sol (pine oil cleaning solution) and water. Will not clog the pores in the abrasive balls, is easy to clean up, and smells outdoorsy fresh. In addition, being water-based, is certain to offer plenty of opportunity to shock the c**p out of me while I stand in a pool of coolant holding an electric drill. This last is a bonus.

The Second Thing I Have Learned:

The preferred and effective machine-honed 30 to 45 degree (or so) cross-hatch pattern is not humanly-achievable by hand. The machines that do it shove that hone in and out at a fixed linear speed with effectively no slowing when reversing stroke direction. Try doing that: try swinging a door shut at a constant speed and reversing its direction (nearly) instantly so that it is opening at the exact same speed with no slowing down or speeding up. Then reverse it again, over and over. I can't do it with a door or a drill motor. So anything I do by hand is going to be only a sloppy representation of what a cylinder-honing machine does.