Lifter-truing reamer lube question

CNC BLOCKS · Post by **CNC BLOCKS** » Wed Feb 09, 2005 10:15 pm

learner wrote:Well, i bought the newest mandrel from sunnen that i was told would do that size. Its 8.25" long if i remember correctly. I don't have a catalog or part number in front of me. It better work because it wasn't cheap to say the least.

The part number for the .904 has a 900 in the prefix for the diameter if you need it I can get it for you tomorrow. And your right they are not cheap.

learner · Post by **learner** » Thu Feb 10, 2005 11:06 am

Ok Carl, the extended mandrel number is AAY20-869BH-LK7X
Its for an .875" lifter. The range is .869"-.900". They told me it would work for the .904". You say it won't work, that's great...I've had this stuff for 7-8 months now waiting for me to get around to the job. It better work or i will be a little upset. What did they charge you to make your madrel?

CNC BLOCKS · Post by **CNC BLOCKS** » Thu Feb 10, 2005 12:41 pm

learner wrote:Ok Carl, the extended mandrel number is AAY20-869BH-LK7X
Its for an .875" lifter. The range is .869"-.900". They told me it would work for the .904". You say it won't work, that's great...I've had this stuff for 7-8 months now waiting for me to get around to the job. It better work or i will be a little upset. What did they charge you to make your madrel?

The OAL of my mandrell is 7.500 and the P/N is AAY20-900BH-JT4X and I don't remember what it cost I have had this for about 7 years.

learner · Post by **learner** » Sat Feb 12, 2005 4:14 pm

Carl, i have have .0015"-.002" to hone out. I assembled the mandrel and expanded it in the lifter bore. The stone only sticks out of the top of the mandrel about .060". So assuming i will be able to use more stone than that i shouldn't have any problems. Maybe they made a revision to the mandrel to cover that size since you bought yours. I'll let you know how it goes.

Guest · Post by **Guest** » Sat Feb 12, 2005 8:45 pm

learner wrote:Carl, i have have .0015"-.002" to hone out. I assembled the mandrel and expanded it in the lifter bore. The stone only sticks out of the top of the mandrel about .060". So assuming i will be able to use more stone than that i shouldn't have any problems. Maybe they made a revision to the mandrel to cover that size since you bought yours. I'll let you know how it goes.

You should consider "truing" the stone and shoe to the ~.900 size if you plan to stretch the .869 to .904. Sunnen sells truing sleeves which are just mild steel bored to a size and a knurl applied to the OD so you can hold on. P/N ST-900 should work.

You true the mandrel by wetting the mandrel with honing oil, then turn off the oil and stroke the sleeve (or the hone in the sleeve) as if you were honing it. Without oil, the stone and shoe wear rapidly to the sleeve size. Of course the sleeve gets bigger also. Be sure to reverse the sleeve frequently. Oh, and start with a new stone or at least one that is nearly full size.

Once you true in the 869 to 900+ it will cut a round hole (very important) and it will actually allow more honing oil to flow than the 900 will. We often "stretch" mandrels past their design sizes this way, but be sure to true it.