Turn a small drill press into a Bore/ Hone. Bolt it to the top of your engine block & do your own machining .
Let me know the results on the run out....and explain what that means for the operator.
Run out would mean how true the shaft is turning, in this case the shaft of the drill motor.
If the runout of the drill shaft is too excessive for cylinder boring, the cylinder would never be round. Also side load of the shaft is a big factor, as the shaft comes out to drill a deeper hole or in your case a bore, how much side play will be encountered, will there be chatter from the bit against the cylinder wall
Look at a milling machine, notice how large the shaft is that the tooling attaches to, now look at a boring bar
Look up a Van Norm boring machine, notice how large that shaft is
Its the same principle as cutting a inside hole in a round piece of stock using a lathe
I did a dozen easy couplings for motor and pumps, the coupling comes in a set, if memory serves me right, there was a small hole in the coupling, we would drill first and than bore the coupling to size for the shaft, it was always a shrink fit so it had to be spot on or either it would be to loose or once installed you could never remove it unless you split it with a burning outfit and yes I split a few
So again, using this press you have to get it exactly centred in the bore, remember the invisible centre line we discussed
And the machine absolutely cant move at all
I think if a bonafide machinist explained this all to you, better than I could you would understand that how noble a idea you have and I give you credit for trying, using a drill press to bore a cylinder is just not the way to go
Seek out a expert, ask for opinions and take that advice, you will save money and aggravation in the end
Years ago on another forum there was a very very talented guy, he flew private jets for clients, this guy had a shop to die for and everything he did seemed to be perfect, he also as I found out had a huge ego and nobody was telling him ****
He posted a picture of a weld he did with his 110 MIG welder and was proud of how good it looked, he claimed that he could weld a 1 inch pad eye on to something I forget and it would be perfectly sound and safe
When I pointed out to him that his weld was "cold", what some call cold lap and poor penetration, plus the fact that no 110 volt Mig welder could make a sound weld on steel that thick, well the **** hit the fan
The guy carried on like a lunatic towards me. No matter how I tried to explain myself he wouldn't hear it. Finally I simply told him, I would (have many times) weld a properly fabricated 1 inch pad eye on a suitable beam with stiffeners if required. I told him my co workers lives depend on what I welded. Failure could mean death
I asked him to be honest and would he be confident his weld would be the same.
That was the end of the conversation and he never replied
My point is at some time its wise to listen to advise given by people, not sarcastic put you down posts, but people who know and thats why before you screw up that block id find someone who knows and talk to them. If you dont want to thats up to you and who knows maybe you will be successful. Either way best of luck and enjoy the weekend
Enjoy the weekend