Get out the straight jacket
- Thread starter Schwany
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You should get a high pipe P11 beater to throw big rooster tails of dirt on that piece of property you have your new and improved man cave on. Maybe build a steeple chase track while you're at it.
grandpaul
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I have already laid out multiple possible tracks...You should get a high pipe P11 beater to throw big rooster tails of dirt on that piece of property you have your new and improved man cave on. Maybe build a steeple chase track while you're at it.
Get or borrow an engine stand (stand may need to be stiffened laterally). Clamp stand with crancases to the table of a drill press featuring a coordinate table. Ensure top deck is level in two perpendicular directions. Adjust coordinate table so that spindle is perpendicular to C/L of each of the 4 holes using a standard drill bit which just touches the threads. I think JSM has shown the procedure in one of his videos. Then carefully drill each of the 4 holes using the drill bit supplied with the Helicoil kit.Yes the through bolts are going to require the inserts. Knew that, but have been blocking thinking about it.Alternatively, I can buy Molnar cases that are stronger and have the inserts in them already. Might be less painful buying new cases that having to deal the frustration involved with putting my cases in machinist jail for a month to get 4 inserts installed. I could do the inserts myself, but if they are out of alignment at all, I'll be fighting getting the through bolts started and properly torqued.
The Molnar through bolts are 3/8-16, which I have helicoils for. I think I'll do the deed and if I mess it up, buy the Molnar cases. Good excuse for doing so.
Tap holes using the spindle position as a guide. Now fit Helicoils in the tapped holes.
You won't screw up if you follow this methodology.
- Knut
A drill press with a coordinate table is hardly part of a home garage tool collection, unless your neighbour is someone like Jim Comstock.
One idea might be to make friends with a teacher at a nearby advanced metal working trade school. Some of these schools are quite well equipped.
Just an idea.
- Knut
One idea might be to make friends with a teacher at a nearby advanced metal working trade school. Some of these schools are quite well equipped.
Just an idea.
- Knut
grandpaul
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Not only is that a great idea, but it MIGHT just be the "spark" that one or more of the students there need, to get interested in classic motorcycles, and motorcycle machineworking!
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Better phone ahead and let them know you're coming.... just in case
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I can fake it like I do everything else. Plumb level the drill press chuck with a long 1/2 shaft in it first, then tilt the "uncoordinated table" to get the case barrel flange horizontally level once the motor is mounted. Do a couple other things to be sure the bits slide in and out of the existing holes straight without interference and I should be able to do it. I may have to make the table I have larger. Like I said I can always buy new cases. 50 years ago I would have done it with a hand drill and probably got it perfect. Then again, 50 years ago I could walk into a local British motorcycle dealer and have it done in a couple of days. Times have changed.
I will look into your idea first though. Thanks
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Way ahead. I'll have to square cut my scraggly beard and roll up my blue jean cuffs too. I'll be lucky if anyone is interested. I also imagine I'll have to sign a "we take no responsibility for the work" waver.Better phone ahead and let them know you're coming.... just in case
concours
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I had A LOT of friends like that over the years.
Now, I kindly mention the name of a quality shop where they can get their work performed.
Leaves more time for my kids, wife, motorcycle riding, etc.
concours
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Use a piloted drill, it can be done, with a hand drill, accurately, in 15 minutes.
Millwright skills.
Just
My
Worthless
Opinion
Reach out if you are interested in real world problem solving, I can help you.
The only set I have looked at for this are the eBay MK3 cases I used for the 920.
Those cases did have inserts in those holes. I was led to believe that engine was never taken apart until the Breaker got his hands on it.
Glen
Those cases did have inserts in those holes. I was led to believe that engine was never taken apart until the Breaker got his hands on it.
Glen
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concours
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My '74 850 has inserts, that, as I understand it, came from the factory that way.
The barrell can be used as a drill jig, with an aircraft drill.
drillsandcutters.com
The barrell can be used as a drill jig, with an aircraft drill.
3/8" x 12" HSS Aircraft Extension Drill Bit, Qualtech
3/8" x 12" HSS Aircraft Extension Drill Bit, Qualtech. Find this item and other cutting tools on DrillsandCutters.com.
drillsandcutters.com
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Thanks for letting me know more about the case thread inserts all youz guys. I was fantasizing that I might get away with not doing it. Not really a big deal, but overthinking is a curse that comes with age apparently.
Concours thanks for that link to the long bit.
Concours thanks for that link to the long bit.
concours
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Helicoils are used as a thread repair, SOMETIMES.
MANY times they are engineered into the parts original design.
It's GOOD ENGINEERING.
Called "Aircraft drills", most good machine shop supply, or REAL hardware stores have them.
These people ship FAST, without an overnight charge.
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Hmm, maybe I should have had the journals ground -.010 and polished them.
Weighed the cranks and barrels today. The Molnar crank is 3lbs lighter at 20lbs than the 23lbs crank that was in my P11. The Molnar barrels weigh 9.5lbs less than the iron barrels. Chasing threads and getting mentally prepared to do the inserts. Fun times ahead.
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