Help SuperK Hone, Please!

[SuperK]

Hey guys, I'm going to start dismantling my ZE for a rebuild. This isn't my first engine rebuild, but it is my first KL rebuild.
I really really want to do this rebuild right. My last two were amatuer builds that I did a half-arsed job on because I had no guidance, I know no one locally that knows how to work on cars, so I'm the smartest there is around this area. Scary!

So anyways, I didn't hone my first B6 rebuild, and I honed my roommate's b6 build wrong.

I would love to hear from you who have honed engines before, and you who've rebuilt KL's before, your advice on this, any specific tools I need, should i rent it, or buy my own (the one i rented looked horribly tacky) so on so forth...

your advice is golden... If you've never done either before, then your advice is... uh, georgia clay or something. Thanks!

[Ryan]

The cheap backyard "do it right" with bold quotations...

Get a spring powered honing stone drill attachment, like this:




And use it until you can no longer see stroke-wise marks on the cyl walls. Make sure not to go to deep to hit the bottom of the bore (or fall out of the top, rounding off the deck edge) Also, never slide it out without rotating it, any in-out movement should be done only if you've compressed it with your hand so it doesn't drag.


The REAL way to do it is send it out to a shop who have the proper tools to make sure the bore is round, ie, an overbore. New piston time! whoo!

[RS_OBD'oh_2]

shouldn't you have a torque plate to simulate the head attached during the honing process?

[Inodoro Pereyra]

I'd say, first, make sure you actually NEED to hone. I've heard of 100000 mile KL's with their original honing marks still intact.

Then, if you do need to hone, I personally prefer the brush style honing tool (the one that looks like a brush, with little steel balls on the ends of the "bristles"), as I find it more forgiving, for those of us who don't do this every day.

IMO, the most important part of honing is to know when to stop. Honing is just meant to produce light scratches on the cylinder walls, so it's important to stop as soon as those scratches are achieved. This is a prime example where less is more.

Finally, make sure you use plenty of motor oil while honing. Honing without oil will cause the tool to vibrate, which will produce a series of consecutive pits, instead of the smooth, continuous lines you're after.

And, as RS said, you SHOULD use a torque plate, if you use the stone style honing tool Ryan suggested (which, as a trade off, if you know what you're doing, will probably give you a better hone than the one I suggested).

[SuperK]

but... butbutbutbutbut... torque plates are 600 dollars...

[Inodoro Pereyra]

If you use the kind of tool I suggested (I just found it's called a "flex honing tool")...



You don't need the torque plate.

[SuperK]

hmmm, you got a lot of "balls" posting that picture! Get it? Hur hur... I give up.
Thanks I'll look into that. anything else I should know? I'm supposed to do something to the lip of the cylinder port? I'm not too sure I know what they mean by camfer the edge...

[Inodoro Pereyra]

Slightly chamfering the cylinder edge will make inserting the piston easier. You don't need to do it, if you have a good quality piston ring compressor.
Personally, I don't like to chamfer my cylinders. I just oil the piston rings (and ring compressor) thoroughly, and take my time inserting each piston.

[Daninski]

Kris is no stranger to handling balls so he should feel right at hone

[Ryan]

I suggest NOT chamfering the edge. Just a place for carbon deposits to form. Keep it as square as possible.

[Josh]

I prefer the ball style as well, but make sure you check the upper edge of the cylinders too. If there is a lip from wear you should use an edge reamer to eliminate it.

[davmac]

The REAL way to do it is send it out to a shop who have the proper tools to make sure the bore is round, ie, an overbore. New piston time! whoo!

^My vote for doing it right.
Sorry no advice to offer on honing, but if you really need a rebuild then use a machine shop to get the block (and heads) prepped. You'll get your block back clean with cylinder walls properly honed and ready for your new pistons. There will still be plenty of work to do to get the engine back together, installed, etc.

[SuperK]

No... SuperK prefers doing it himself, thanks!

[wytbishop]

I've never done a KL, but I have done a handfull of other automotive engines aaaand I'd say roughly 30, 1 and 2 cylinder bikes.

The problem with a ball hone (the flex hone IP posted) is that they are not rigid at all, so if there is an out of round condition in the cylinder already it will just follow that existing countour. A ball hone is not really intended to be used for "honing". In industry it's referred to as a "Glaze Breaker". It is used when an engine's cylinders are within spec but need to be roughed up to seat a new set of rings.

There is no way to fix an out of round cylinder with a ball hone. You need a rigid hone. Like this. I would recommend against the spring loaded one Ryan posted for the same reason. A decent hone should be available to rent from your local parts store (you will have to buy a set of stones) and will have a collar which allows you to set the tension. It should be tight but you should still be able to turn it by hand.

Guys with experience are able to hone dry. I myself prefer to hone dry because it's much much neater, but I've done it many times and I can tell when it's getting jiggy. You can use motor oil, but use the thinnest oil you can find. Cooking oil, even mineral oil is fine. The purpose of the oil is to reduce the heat generated by the stones on the cyliner wall. Going dry will heat up quickly so you have to be very aware of that and stop periodically to allow it to cool or you will warp the cylinder wall.

A torque plate is used when your are actually cutting material from the cylinder walls during a boring process. You do not need a torque plate.

When you get your engine apart, get your hands on the most accurate bore measuring tool you can. A dial bore gauge is best, but a good set of micrometers and bore gauges are fine to. This is what I use. Follow the online manual for instructions on how and where to measure. I've read through it and it's very thorough. If you find that a cylinder is more than 2.9536" you will have to go to 2.9628" to accomodate the next size piston. If you have to do one you have to do them all.

Don't use an engine stand. It will flex as you stroke the hone in and out. Put the engine block on a very sturdy table or workbench and secure it somehow. Squirt a liberal amount of oil on the stones and cylinder wall. Put the hone in the cylinder so that the entire stone is in the cylinder. Tighten it so it's tight but you can still turn it. Start your drill slowly. It's ok if the drill spins for a second in one spot, but not too long. do three or four strokes and stop to inspect your cross-hatch. If it's really steep, like "X"s your going too fast. If they're really shallow, you're going too slow. You want 30-40º. Once you feel like you have the feel for it you can start honing. I usually do 10 strokes and remeasure letting it cool for a minute each time. I do this beacuse with this type of hone after about ten strokes the hone will be a bit loose in the bore and that's when you start getting wierdness. You want it tight all the time so do ten, let it cool, remeasure and reset the hone in the cylinder to the correct tension for the next round.

You can get course, medium and fine stones. Go with medium. Course remove material too fast and fine stones give too fine a finish.

If you don't need to oversize the cylinder AND the cylinder is round and straight and you just need to rough it up for new rings, a ball hone/flex hone/glaze breaker is just fine.

If you find that the top and bottom measurements are different (taper) you can fix this, but it's tricky. If the bottom is bigger than the top for example you would put your hone in at the top and snug it up. then you're going to start honing but bias your strokes at the top of the cylinder. so first stroke you go half way in then back to the top. next stroke you go all the way in, then back up. do this for about 10 strokes...half, full, half, full...then remeasure. If you have less than 0.001" taper leave it. If you have more than .001" try that, let it cool and then measure again. Take off as little material as possible to get it straight, then start honing for the size you need.

I would recommend going to a bike wrecker and buying an old single cylinder block for $50 and practicing on it. It's pretty easy, but there is a knack to it. In school they made us hone a cylinder to within 0.0005" bore, 0.0005" round and 0.0009" taper.

Good luck. You can totally do it. PM me if you have questions.

[mikeinaus]

want me to scan/upload the pages on honing in my textbook for you superk?