De-glazing cylinder walls

Pulled the cylinder head, and its in the shop for valve seat refacing. Interesting, all the exhaust valves were becoming more or less "tuliped", while the intake valves and seats looked good. I ended up pulling the cylinders and pistons. I glass beaded the pistons to decarbonize and am ready to deglaze the cylinder walls. I was wondering what deglazing tool you'all would recommend as I have zero experience in this area. I was looking at the "flex hone" and thought someone would have an opinion about it. And yes, I am putting in new rings. Thanks


1981 KZ750E2, 28000 miles

Post edited by: Jim65, at: 2006/06/27 18:40

Have you measured the bores to ensure they are still within specs?

Seems like lots of peole use the ball hones for deglazing.

Post edited by: steell, at: 2006/06/27 20:13

well its a little too late now,but dont glassbead skirts of pistons.you can glassbead the crowns with no problem but when you glassbead the skirts the glassbeads actually get driven into the aluminum and will do terrible things to your cylinder walls.:S the reason your exhuast valves look more beat up is because they are constantly being heated in combustion chamber and by hot exhuast gases flowing over them.intake valves are cooled by incoming air/fuel.

Thanks for the info, the only thing I blasted was the tops and the ring groves ( I guess this includes a small portions of the skirt). I also plan to use a scotch bright pad to remove any of the left over residue, maybe it will also help to get rid of any embedded glass.

Jim, next time, don't glass bead the piston ring grooves either. These have pretty tight specs. Best way to clean the grooves is to break one of the old rings and use it to scrape the groove (also called a piston lan). I use carb cleaner to cut the carbon in there a bit (I also have lots of carb cleaner) and scrape with the broken ring... this cleans the groove nicely. Once done, you should also measure the depth and groove top to bottom measure as well. Many folks will measure piston diameter but not measure the ring grooves when rebuilding.

I've used steel wool on nikasil plated bores in the past with good results.

However, since you are already going through the head and putting in new rings I would possibly think about having the jugs professionally honed. Call around if you have choices as you will most likely get many different prices. I would say anything over $40 for a quick deglaze hone is a rip.

I also agree that you should measure your piston to bore clearance while you are at it too. Have fun!

Post edited by: savedrider, at: 2006/06/29 01:25

barrel shape or taper in the cylinder needs to be measured for spec piston to cylinder clearances and ring end gap. A long time ago I once spent 40-60 hours re doing a 900 cleaning, cross hatching ya know just really getting into doing a top end, I re used piston rings from another engine Ifigured it had to be better than what I had....
nope I put a worse smoker together ha!! my buddies really let me have the ribbing and still do at times. oh yeah I have good measuring tools now because of that incident. jeepers!!

TP - I have micrometers, digital calipers and tee bore gauges. Most of the stuff is low end and I would like to be able to measure cylinder bores and piston diameters with precision. Also would like to be able to measure inside diameter of guides better... I also intend to get some sort of dial guage as I seem to only work on bikes where someone has SLIGHTLY bent valves... Please make some recommendations for some good bore gauges and a dial guage. I think my calipers and micrometers are OK but wonder how good my tee gauges can work or if you have suggestions on better types of measuring tools, I am very interested. I am thinking that when I get some money, that stuff might be on my buy list. Although I generally work on carburetors, I am now rebuilding about 10-15 engines a year for some reason and the cylinder bore to piston clearance, ring groove depths and guide roundness/diameter and valve straightness is kind of critical to get real close. I am also thinking about some machine stuff... like a good cylinder hone and valve grinder set up as I now have to drive to another shop to get this stuff done and it is a time waster.

You can't go wrong with Mitutoyo brand measuring tools.
Check out the Bore Gauge at www.goodson.com/ , you can spend all day drooling over the engine rebuilding tools they have available



$128.99 at Goodson tools

Watch out WG, before you know it you will be shopping for a vertical mill, then you will want a lathe, then a tool cutter grinder, then something else that would just be so nice to have, it turns into a never ending quest and eats up every bit of floor space

Being a tool freak just gets to be so expensive

Post edited by: steell, at: 2006/06/29 12:03

I'm diving into mine next week and doing all the same stuff. Keep us posted. AlsoWG you should build some motors for us. I'm sure you could give us all a sweet deal! KZ crate motors-KA CHING$$$$

donthekawguy wrote:

I'm diving into mine next week and doing all the same stuff. Keep us posted. AlsoWG you should build some motors for us. I'm sure you could give us all a sweet deal! KZ crate motors-KA CHING$$$$

ive seen one of his motors in action brand new made 3/4 of a turn and started! he should be building motors for great biker buildoff,their motors never start!

OK....I've been sitting on this, but I second the notion George does great engine work. With or without new tools. It may blow up tomorrow - but I was pretty impressed that my engine restarted on the first crank after 18 years. View the actual video of it's re-birth here:



That's my voice but the video compression made it sound worse than it is! :blink: