Brush Research GB312240AO FLEX-HONE®, 3-1/2" (89mm) Diameter, 240 Grit, Aluminum Oxide, For Aluminum, Brass, Bronze and Softer Non-Ferrous Materials

I decided to rebuild my snowmobile motors as preventative maintenance, and was replacing pistons and rings. The piston suppliers all recommend cylinder prep with these type of ball hones. I bought two hones, one for my 500 cc sleds and one for my 800 cc sled. There are many grits and compounds available, but for Nickasil cylinders these 320 grit Aluminum Oxide versions are recommended. They worked perfectly for de-glazing and refreshing the crosshatch to help in proper cylinder oiling and piston and ring break-in. Choose the ball hone size you need based on the actual cylinder bore diameter. If you buy the hone that matches your diameter it is actually slightly oversized to create just the right amount of pressure to the cylinder wall for effective honing. Using these ball hones takes a bit of technique, but in a home shop environment I found doing the honing in a 5 gallon bucket worked to contain the lube oil from flinging all over the shop, I also made a short spacer to place under the bottom of the cylinder edge inside the bucket to lift the cylinder just enough off the bottom to allow the hone to effectively reach through the cylinder with a full stroke, but not protrude too far through and allow the balls to wrap the lip and bind. Holding the cylinder solid in the bucket also helped to keep the hone centered within the cylinder as cocking it at any angle while holding the cylinder by hand tended to end up with the hone hooking a port or the lip and stopping the process (my first attempts were a bit of a learning curve). Once I figured out how to hold the cylinder and limit the travel properly the remaining cylinders were easy to complete. If you do bind the hone and twist some of the ball fingers, they are very forgiving, and easy to re-set the fingers, straighten them out, and continue on, being more careful about your process. These hones should last forever if you're only using them periodically in a home shop. Using them per the included instructions left a beautiful surface with correctly angled cross-hatch, and made for a perfect top-end rebuild. These are far better than the old spring loaded stone-hones of old, especially for nickasil. These also have a far less likelihood of catching a port if you keep it centered. And if it does catch one due to your (My) own mistakes, it will simply bend around itself but not cause any damage, unlike the potential damage that could be caused if a stone catches a port with the old style hones. Highly recommend this product and the seller.

Used to deglaze the cylinder of a 2006 CRF450R. Worked great!! Wish I had something else to use it on.

Used it on a 1976 Oldsmobile 350 out of a cutlass. Worked great, very simple and easy to use.

I am a motorsport engineer and i never reassemble an engine before giving it a couple runs with the flex hone especially if it is under done by the honing

Item works good but I can't seem to get the hatched effect yet. I'll keep trying.

Excellent for deglazing cylinders

we used this to hone our forklift cylinders, it worked very well. You could probably do it several times, than the little stones will be used up

My engine inly had 11,000 miles on it so i basically just hade to break the glaze. For my new forged piston and rings in my gen5 LT1. I went with 320 grit but accidently bought aluminum oxide this company was very helpful in refunding my order since u had notice the mistake and already ordered a silicon carbide 320 grit due to time restraints. Great product does what it suppose to.

Used this to remove the rust from a motorcycle engine barrel. After I was done it looked like it was freshly honed. Took about an hour to do two barrels. I highly recommend this brush. You won't be disappointed

Easy to use with great results

Ok

Bought two at once so they cut me some slack on the shipping. Need these to cross hatch Harley big twin cylinders.