reboring cylinders using a boring stand

[barry100]

Hi all
I have a cylinder boring machine and single cylinder boring stand and wish to  bore  HR Lister  cylinders ( 4 1/4" bore) , the hole in the  top of stand is about 70 mm (3 1/2")  so I think I need to bore  the hole to just over 4 1/4 so the boring head can go through to the clamped cylinder below. The clamped cylinder sits on the under side  of the soon to be bored top plate , but my concern when I have bored the hole  most of the machined area where the cylinder will sit will be gone leaving a ring of about 6 mm which should be ok, I think, but will seek advice here before I go ahead.
Regards Barry

[dieselgman]

If your boring stand (head and shaft) is capable (adequately sized) for handling the 4 1/4" jug then I would not worry about the 6mm remaining bearing surface. I have seen a torque plate with similar fit used for these jugs before but I think it had a recess to exactly fit the jug. I know that use of the torque plate is important for this operation... but I am an engine builder - not much of a machinist.

dieselgman

[harryzx-12]

 You should no problem as long as you set it up correctly. I have a quik-way fn boring bar with the 054 boring fixture. i also have a van norman 999 boring bar. I've been a machinist since 1975.

[barry100]

Hi All
Thanks for the replys, I havn't got around to boring the stand yet,  what would be the minium ring of metal  i would need left for the cylinder to sit on?
Barry

[mike90045]

Ar you rebooring for a new sleeve, or a new piston ?   Just wondering where you get oversize pistons ?

[dieselgman]

Barry is boring an HR... oversize pistons are readily available and in stock here.

dieselgman