Author Topic: greasy's re-rebuild 'the utilitarian transcendentalist' 71 cb750 (Read 42893 times)

traveler · « **Reply #50 on:** June 11, 2010, 09:59:47 AM »

Put the case in a drill press, and use a carbide bit and keep the bit oiled and ease it in.

Re tap the holes and install a slightly larger bolt.

call it good.

~Joe

RAFster122s · « **Reply #51 on:** June 11, 2010, 11:25:12 AM »

I've drilled out broken bolts until I could jam a screwdriver into them to get them to screw out. Once you drill out most of a bolt you can sometimes take a fine punch or other tool to drive the sides (threaded part) to collapse and have enough to grab onto and unscrew.

I would center punch the bottom side if it is a through hole in the case and see if I could drill it out from the other side. Once you have a hole started a diamond ball bit with lube can cut into it until it reaches the hardened extractor. Then step up in size or cut a slot in it.
Don't be gentle when you center punch it either. Sometimes the shock of the blow can help get it to loosen the threads.
I've cut into the threads on a bolt but as long as I didn't make the hole larger than the bolt's threads I was able to retap the hole (run a tap through the same hole) to clean up the threads and not go with an oversized bolt.
Use a slow drill speed and drill it true and left hand bits can help as they sometimes are able to grab the bolt and spin it out instead of drilling it out.

Broken bolts are a PITA and one of the things you have to deal with as a mechanic.
Antisieze paste is a wonderful thing for those bolts that can use it...some bolts really need the opposite, a thread locker.

Find out what the EDM machine job would run. Might be worth it, rather than having a munged up case.
It's not a machine you can normally afford to buy as it is very specialized and $$. Essentially a plasma type cutting device.

You can anneal a bolt to make it easier to drill or you can harden it to sometimes make it easier to remove.
Depends on if you go cherry red and let it cool naturally back to room temp (anneal) or heat it up and then cool it quickly to harden it. You are past the point of anneal or hardening, as it is buried in the case now and you run the risk of melting the case around the broken bolt with too much heat now.

greasy j · « **Reply #52 on:** June 11, 2010, 02:27:14 PM »

thanks for all the info guys. wish I had a drill press. my buddy does, though. maybe tomorrow I can get it taken care of.

and I can't get at the back side.

greasy j · « **Reply #53 on:** June 20, 2010, 02:28:51 PM »

another member on the site, George, who sold Ty his bike, 'project lolita' offered to let me use the drill press at his shop. he is retired but is a british luxury car mechanic/restorer by trade. his shop was full of Rolls Royce's, Bentley's, Jaguars and just tons of cool stuff. he has a 33 rolls royce at home that is amazing. It is the 'D back' style, a phantom, I think. it is giant! the engine runs incredibly smooth and quiet. the distributor cap advances the timing as the rpm's go up by rotating slightly as you gas it. you can adjust the ride with controls on the steering wheel, which adjust the oil in the shocks! and you can adjust the timing and throttle from the steering wheel as well. hard to believe it's 80 yrs old when you hear it run.

we couldn't get the damn bolt out, though. I am going to have to go the EDM route.

this case is in good shape and everything is nicely mated at this point with just enough miles for all the parts to be in harmony, but not so many that things have started to wear. so I don't want to replace the case and mess with the flow.

if you know of a place local to me...

RAFster122s · « **Reply #54 on:** June 20, 2010, 08:13:39 PM »

J, sorry to read the drill press didn't work.
RR and other makes of that day are marvelous engineering pieces. The tolerances on the WWII BMW motors was phenomenal for its day with accuracies that rival today's machines and those in Germany in the WWII era were human operated with tolerances and accuracy that rival today's machines being ran with computer assist.
Automotive engineering back then was a different beast than what is called auto engineering today. Today it is off the shelf supplier management for most of the vehicle...
Those fenders on the Rolls, they were made by hand, not stamped steel but formed by hand. The Rolls Royce was largely handcrafted. Beautiful machines.
David

greasy j · « **Reply #55 on:** June 22, 2010, 10:13:33 AM »

hey RAFster, does that mean Royal Air Force?

so I found a place in San Leandro that will do the EDMing. gonna bring the case in tomorrow. he said they don't normally do small jobs like that, so the cost is to be payed in beer not dollars. awesome!!!

I was thinkin I might have to pay up to $100.

in other news, I am super late for work. gotta hop on the bike and battle the bridge hoggin SUV bastids.

RAFster122s · « **Reply #56 on:** June 22, 2010, 10:48:37 PM »

J, Sounds like a great deal... 12 pack or 6 pack of beer for the EDM work... Very cool.

RAF122S is a nickname for a '66 Volvo 122S 2-door that I have that needed new floor pans back in the early 90s. The replacement pans needed more metal to reach good metal in many spots (car was in Illinois for several years and driven in the salt.)
We used a roof panel to provide the bridging pieces and my friends thought that hilarious for I now had a
Roof - As - Floor 122S.
So I became known as RAFster

http://www.google.com/images?hl=en&q=volvo%20122S&um=1&ie=UTF-8&source=og&sa=N&tab=wi

That's what a 122S looks like... sweet cars. Not a boxy Volvo but a svelte one...Back when Volvos had curves.

David

greasy j · « **Reply #57 on:** June 23, 2010, 12:04:44 AM »

very cool. I dig those old volvos.

I thought maybe you jumped out of planes.

traveler · « **Reply #58 on:** June 23, 2010, 07:00:10 PM »

(awaiting good news from the EDM work)...chirp,chirp,chirp......

greasy j · « **Reply #59 on:** June 24, 2010, 02:26:47 AM »

I dropped off the case with offending bolt today, find out the damage tomorrow...

so, I have a ?

I am trying to not have to take the oil pump apart. I cleaned off the gunk and put it in an oil bath. I figured I'd turn the gear and it would pump oil through it to clear out the nasty crap.

oil comes out of one of the exit holes, but not the others, at least not as much. does this mean it's clogged? I tried covering the hole that it is coming out of to force it out the others, but it doesn't seem to do anything.

what's up? should I be concerned?

laser145 · « **Reply #60 on:** June 24, 2010, 11:24:05 AM »

I want to turn my K6 into the bike you began with! Not that I doubt you'll end up with a great bike after your rebuild...but I love where you started...

Where did that seat come from? How did you modify the tank for the pads? Is it bare metal and clearcoated?

Maybe I shouldn't hijack your build by asking questions about it's origins...but I love it.

Cheers

greasy j · « **Reply #61 on:** June 24, 2010, 11:41:36 AM »

no prob.

the seat is a modified stock seat pan, it has a short metal box welded in for a back stop. the cover is from a king and queen seat. I modified it and used a seat strap from a 78 hawk. cut down foam from the k&q seat. the strap hides the crease.

the tank is stock, stripped to bare metal and polished. with stripes painted on, and the top bare metal stripe is brushed. there is no clear coat, I use Gibbs oil to keep the rust at bay. if I reuse it, though I will probably clear coat it. the knee pads are just glued on, they were for another bike, but worked out ok. there are lots of knee pads on ebay if you search for 'knee pads' and 'tank'. the new ones will have adhesive. old ones can be hot glued on, then removed w/out damaging anything.

if you need help when you do yours let me know. I can also do a similar tank for you if you want to spend $. I'm pretty inexpensive compared to a body shop. there are more polished/painted tanks on my site for reference, some are clear coated.

http://sites.google.com/site/dimalepainting/home/photos

laser145 · « **Reply #62 on:** June 24, 2010, 12:20:46 PM »

Thanks for the info.

The tank I've got is void of dents and rust...which would make it an easier process. The hardest part for me would be the seat, as I can't weld, and have never modified a seat before!

The bike has a similar seat on it now, but not quite as cool as yours...mine is like a baby king/queen.

I'll get a thread up with some pictures of it, then pm you the thread so you can chime in there... that way I don't take over this one.

Thanks

greasy j · « **Reply #63 on:** June 25, 2010, 01:02:35 AM »

I got that pin out, here's how:

http://forums.sohc4.net/index.php?topic=72774.msg810879#msg810879

sangyo soichiro · « **Reply #64 on:** June 25, 2010, 08:58:42 AM »

Clever trick.

greasy j · « **Reply #65 on:** June 25, 2010, 06:12:10 PM »

another problem. I have a crack in my lower case. it's on the bump from one one of the oil galley passages. there is a hole in the crack that goes through. it was clogged up with gunk and the busted bits before, but now that it's clean it's open, I'm wondering if it'll be a problem.

can I fill the oil galley with something temporarilly, then epoxy the crack? jbweld? it's a pretty small hole so I might not even need to fill the passage.

it's hard to see in the pic, I drew on it to help illustrate what's going on. maybe it's not even a problem? I wouldn't know.

here's a pic of the bottom side, so you can kind of see where the passages lead.

scottly · « **Reply #66 on:** June 25, 2010, 07:04:19 PM »

Was a too long bolt screwed in? Blow air or carb cleaner thru the oil passage and see if the crack is through to the oil galley.

HondaMan · « **Reply #67 on:** June 25, 2010, 07:11:05 PM »

If it is a hole thru, take it to a welder and have him tack the hole shut. JB Weld or epoxies will let go in time.

greasy j · « **Reply #68 on:** June 25, 2010, 07:21:49 PM »

it's hard to say if it's through or not. I think if it isn't it's really close. it's about 1-2 mm deep. I tried squirting oil in there and it doesn't seem to leak, but it might eventually.

I also just noticed a small chip in one of the lower crankshaft bearings. it is smaller than the unnecessary holes that are there for the oil passages if they were on top. I have plastigaged these and they are all like new. should I replace the set w/ the chip or is it not a prob?

now that it's clean all the problems are visible. I should've left it a mess.

Industrial Cafe · « **Reply #69 on:** June 25, 2010, 07:28:02 PM »

I have a spare K1 case...

greasy j · « **Reply #70 on:** June 25, 2010, 07:34:52 PM »

thanks IC, but I'm kind of attached to this one. I'd like to mostly keep it together. if I have any more problems, though...

I think I'll have the spot welded. better safe than sorry...

might as well buy new bearing shells, too. what the hell.

seriously, though. one has a chip and I noticed some semi-deep scratches in another. I'll have to see how spendy they are, then decide. it's just a shame since they plastigaged so nicely.

Industrial Cafe · « **Reply #71 on:** June 25, 2010, 07:36:16 PM »

ok,
it's here on the bench if you need it.

greasy j · « **Reply #72 on:** June 25, 2010, 08:01:12 PM »

thanks again!

I know it's silly, but it's sentimental. me and this engine have bonded.

Industrial Cafe · « **Reply #73 on:** June 25, 2010, 08:04:15 PM »

perfectly understandable.

scottly · « **Reply #74 on:** June 25, 2010, 09:36:50 PM »

Is the crack directly opposite one of the bolt holes that hold the oil line fitting? If so, from what I can tell from the photos, a bolt that was too long was threaded in to a blind hole, and pushed the floor of the hole up. The oil passage is probably fine. Worst case is a minor oil leak around that bolt since it is no longer a blind hole. JB weld will probably work just fine here.

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Author Topic: greasy's re-rebuild 'the utilitarian transcendentalist' 71 cb750 (Read 42893 times)

traveler

traveler