Technical van norman boring bar bit came loose - wrecked?

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?

 

Pics ?

 

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.

 

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 -



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-

 

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..

 

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.......

 

Never had one that didn't get a top cut.

 

Are you a machine shop? Lippy

 

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!