Register now to get rid of these ads!

Technical van norman boring bar bit came loose - wrecked?

Discussion in 'The Hokey Ass Message Board' started by Fstarocka, Oct 23, 2020.

  1. Fstarocka
    Joined: Mar 29, 2013
    Posts: 175

    Fstarocka
    Member

    Hi all - so as i was about to snap a pic of the bar at work on the 3rd cylinder of a 454, as predicted, something went horribly wrong on a customers block :( ..

    The bit came loose (i didnt check it - so 100% my fault)! Anyway - so now I have a lovely gouge in the cylinder.

    This is a thick 4 bolt main 70s block - plenty of meat but im considering sleeving it - 50/50 whether i should get another block or deal with this.

    I already ordered a 3/32 sleeve- about 2 thou clearance shd be ok for cast iron-

    I am now from at 4.330, about 4 more cuts to reach approx 4.430 (ill leave 5 on the table for when sleeve arrives).. does it matter how much of a step i leave at the bottom?

    Also - any tips (pun intended) on how to grind a tool to cut down protruding sleeve, as well as a 45 degree to chamfer for rings?
     
  2. Mr48chev
    Joined: Dec 28, 2007
    Posts: 30,019

    Mr48chev
    ALLIANCE MEMBER

    I don't have any issue with a sleeved 350 as I had one hole sleeved in the one in my 48 and drove it a lot of miles, sold it to a friend who put rings and bearings in it with my help and put it in his pickup and drove it for a while and then sold it to someone else who I think may still be driving it 30 years later.

    I'd have to go with what the sleeve manufacture suggests as far as that lip/edge.
     
  3. Fstarocka
    Joined: Mar 29, 2013
    Posts: 175

    Fstarocka
    Member

    dang didnt get any of the damage - but the tool ripped a hole in the side, and then of course as an idiot i presumed it was still aligned! so i cut a nice 30 slice out of the side and stopped.. it was bad -

    basically ended up with a 30 over slice half cut- ive run it up now and ordered a sleeve.. i can send a pic 2moro but the damage is mostly gone- its down to about 20 thou i guess.. with about 110 to go itll disappear-

    correct me if im wrong - but a 4.250 sleeve with a 3/32 wall = 4.4375 total OD, with a 2.5 thou interference i should aim for 4.4350. Now at 4.340 -

    [​IMG]

    id say in the next cuts i should be down to a clean cut- after that ill be left with about 50-80 thou of a step at the bottom, is that enough? im gonna try get this thing all the way in so i dont have to top cut it-

    [​IMG]
     
    Last edited: Oct 23, 2020

  4. Fstarocka
    Joined: Mar 29, 2013
    Posts: 175

    Fstarocka
    Member

    I have written in bold sharpie and attached to manual cover:

    "Check bit is tight!"
    "Keep paws out while tightening down clamp!"
    "30 MAX cut - with sharp bit. 20 preferred"
    "If tool bites - RE-CENTER"

    Literally - would have been done honing today already - paid for fast shipping from rockauto and everything arrived in 32 hours! Now i screwed it up :(

    Theres a 2 bolt for 200 in good shape- much difference 2 vs 4 bolt? i have read many articles stating the 4 bolts weaken the mains..
     
  5. When I was rebuilding Kwik Way boring bars transmissions destruction from too aggressive cuts - we always tested my rebuild at 10 - 20 - 30 cuts....just saying - it does save the cutting bit as well.......
     
  6. john walker
    Joined: Sep 11, 2008
    Posts: 1,121

    john walker
    Member

    Never had one that didn't get a top cut.
     
    ironrodder likes this.
  7. lippy
    Joined: Sep 27, 2006
    Posts: 5,665

    lippy
    Member
    from Ks

    Are you a machine shop? Lippy
     
  8. Fstarocka
    Joined: Mar 29, 2013
    Posts: 175

    Fstarocka
    Member

    I own a boat shop.. now and then I'll rebore a customers block if required vs crate longblock.

    Never had the bit come loose till yesterday:/ one small detail and boom- wont be forgetting the bit screw from now on!
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.