Interesting bore dimensions

[Bored&Stroked]

Any competent machine shops will tell you that you don't use a hone (even a rigid stone hone) to take out that amount of taper in a bore. You're talking about .013 of taper (or incorrectly bored) in those cylinders - this is NOT how boring is done.

A good boring bar will hold a consistent diameter the length of the bore. The hone is used to tune the final clearance and to prepare the bore surface for the type of rings you're planning on running.

If it was mine, I'd have it rebored/honed for .060 pistons/rings.

[big job]

Originally Posted by Bored&Stroked

Any competent machine shops will tell you that you don't use a hone (even a rigid stone hone) to take out that amount of taper in a bore. You're talking about .013 of taper (or incorrectly bored) in those cylinders - this is NOT how boring is done.

A good boring bar will hold a consistent diameter the length of the bore. The hone is used to tune the final clearance and to prepare the bore surface for the type of rings you're planning on running.

If it was mine, I'd have it rebored/honed for .060 pistons/rings.

Well said I could not agree more..........

[GB SISSON]

Thanks all! I now know this block is not suitable for an 'in house' overhaul. I will look into the other ten and maybe find something.

[GB SISSON]

I have some breaking news on this subject... While it's kind of embarrasing to admit here I was not using the telescopic gauge correctly. In my mind I thought that rolling the locked gauge over center in the bore would give me a false reading so I tried to hold it as close to center as possible, then locked it and slowly withdrew it. I decided to remeasure these two blocks with that flawed method and sure enough, got inconsistent results. Duh. So I went to Youtube and searched use of telescopic gauge. Sure enough four videos in a row locking the pin at a cocked position and rolling it over center. The .040 block is still too big to hone, but it is very consistent. The top bit above the rings is 3.225-3.227 and a ring has a gap of .006 +_ and the bores are quite even at 3.220-3.221. The new .040 rings will insert down into the bores 1" before the gap closes completely and they stop. I then went and got the sunnen hone kit that my stepson had given me a few years back.... I suppose I could give it a shot if I was desperate, but I don't want to set this fresh ground 4" crank into a home shop experiment. Besides, it's for the woodie. I turned my attention (and telescopic gauge) to the .030 block that had also showed no ridge. That measures very well as though it had been bored and honed. I bought it mostly apart at Portland with no history. That will go back together as is with it's ford crank and numbered pistons. The third block I went for needs a bore, but dangit, you will like this one. Details at eleven.....

PS, told ya there was an ugly valve seat.

[petehoovie]

Originally Posted by GB SISSON

PS, told ya there was an ugly valve seat.

[GB SISSON]

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Thank you Pete!
This is block 3. Above the ridge it is 3.187. Just got off the phone with the machine shop. I will mag and pressure test first.

[petehoovie]

Originally Posted by GB SISSON

Thank you Pete!
This is block 3. Above the ridge it is 3.187. Just got off the phone with the machine shop. I will mag and pressure test first.