Line honing

[GregKiser]

Hello all,

Looking for first hand experience with line honing bush side main bearings.

Has anyone had their bottom end rebuilt ? Who did you use and how did they do it ?

Thanks for your input, Greg

[Nornet]

Greg

I've posted requests for this information on several sites under the subject of line boring. I believe this is the process used.

The factory replacement bearings used to be reamed for final fitting.

The current replacement bearings (Draganfly?) are considerably undersized and can not be bored or reamed to final size due to the amount of material being removed.

Regards Paul

[CycloneDan]

Greg...A whole bunch of us are on the hunt for someone to do line boring...Might be a guy in the LA area. Waiting to hear back on to how a Sq he is doing turns out...Sounds like it would be straight forward, but that's not the case. Just building a jig to hold the cases perfectly steady seems to be the holdup when doing this procedure...Will keep all posted..Cheers, Dan

[Old & slow]

Greg, I know you all are looking for a place in SoCal to line bore the timing side bushes but I found a place in (believe it or not) Maine that does a first-rate job of it. Daniels Machine Shop in Augusta, Maine. Steve, the owner is an avid restorer and machinist and really knows his way around a square engine. I live in Texas but I simply boxed the cases up, sent them to Maine and they magically returned to me all line bored. My '55 MkII runs great!
His phone is 207-622'7826. Good luck . . . . . Joe

[CycloneDan]

Great info Joe...Maybe we can get someone West Coast (I'm working on that)...Dan

[GregKiser]

Greg, I know you all are looking for a place in SoCal to line bore the timing side bushes but I found a place in (believe it or not) Maine that does a first-rate job of it. Daniels Machine Shop in Augusta, Maine. Steve, the owner is an avid restorer and machinist and really knows his way around a square engine. I live in Texas but I simply boxed the cases up, sent them to Maine and they magically returned to me all line bored. My '55 MkII runs great!
His phone is 207-622'7826. Good luck . . . . . Joe

Hey thanks Joe, that's good info. I got that same number from another member. I'll give it a try. You did send the cranks as well?

Greg

[phil.auldridge]

I am currently using Steve as well, but my cases have been at his shop for just a bit over a year. I do have confidence in his work, but just be aware that he can't be hurried, and he is very old school with communication (or lack of it.. no email address, and rarely responds to phone messages.. you just have to keep calling until you actually get him on the phone.. generally after his work day ends at 4Pm ET)

[Old & slow]

Greg, I did not send the cranks with the cases for several reasons. First, there was no damage of any kind to the engine except for some etching of the bearing surface due to sitting in old oil for over 40 years and second, it was a complete running engine when I parked it 49 years ago and third, I was a machinist in a previous life and knew what to look for inside the engine. And yes, Phil is right, Steve is old school - very good at what he does but very old school. I think that some of the folks we encounter in this type of work are more like artists that mechanics due to the passion they seem to have for these old machines. But, we all know just how temperamental artists can be. In our eagerness to get our projects done we all want things done right and done fast. Sometimes we have to choose one. Darn it!

Again, Good luck . . . . . Joe

[GregKiser]

Joe,

So he trusted your measurement and you trusted his. hmmm. What did you end up with for clearance ? I'm in Arizona and just couldn't
stand sending my cases to Maine , especially with his rep, I think I would die waiting. I'm a machinist too , I know just enough to get in trouble.
I don't have a line boring machine tho. I have been encouraged to mount the bush side case on a mill, level it up and machine the hole to size.
Makes sense but I just don't know. If the original hole is perpendicular with the case half , which it should be and the bush is pressed into the hole
and I machine it to size. Bam ! it should be as good as good as new. Or would it ?

[Old & slow]

Greg,
Yes, we both trusted the measurements and it worked out just fine, The cranks were not worn (1.250") and the bushings were bored to 1.251 - 1.252. I would NOT bore the bushings using on one half of the crankcase, that misses the whole idea of "line boring". There is no guarantee that the holes that the bushes press into are where they should be or even if they are perpendicular to the split face. It only would take a couple of thousants to cause problems and we all know how well the British built things back in the 50's. Of course, that is just my humble opinion.
By the way, the proper term is "line boring". Honing only affects the surface finish and to a much lesser degree, the size of the hole. If the hole is crooked of egg-shaped, the honing will be crooked or egg-shaped also. Boring corrects both of those conditions.