Author Topic: Terry's boring weekend. (Read 5630 times)

Terry in Australia · « **on:** February 15, 2009, 04:22:41 AM »

Well the bushfires are slowly coming under control, but seeing how all my favorite ride roads go through the affected areas, I decided against going for a ride today.

Also, the authorities are asking that "sightseers" stay away from the area to avoid getting in the way of the firemen and other emergency workers, and also, the locals are angry that there has been some looting, so are threatening to shoot anyone acting suspiciously. I'd hate to be the bloke who stopped on the side of the road to have a pee, or to give a Koala a drink of water, and got shot by a jumpy local, ha ha!

So instead, I started to bore out Al Harper's CB550 cylinders to accept his new 61mm big bore kit. Like I've mentioned elsewhere, the kit is marked "605cc", but in fact it's about 592cc. Oh well, I guess every little bit counts. Here are some pics:

1. Cylinder block set up on my old "Repco" boring machine that I "inherited" from my cousin, it's probably 50 years old but still works fine, and has bored just about every type and make of small engine ever built.

2. First cylinder done. I need to remove 2.4mm and I only take 0.125mm (.005 in) cuts, so the difference equates to close enough to 20 passes with the boring bar, or at least one hour per cylinder. If you were wondering why boring is so expensive, now you know.

3. Well I took this pic at 5.30 pm, it was 30 deg C in my garage and I'd just spilled a pint of Kerosene on my pants, so I still need to do one more cylinder.

More to follow in a day or two! Cheers, Terry.

bwaller · « **Reply #1 on:** February 15, 2009, 04:39:48 AM »

Don't light a match Terry!

Good work... and I hope you get your roads back soon.

Friggin thieves, I quess nowhere is exempt huh?

jtb · « **Reply #2 on:** February 15, 2009, 07:41:13 AM »

Nice work, Terry. Glad you're OK.

Jim F · « **Reply #3 on:** February 15, 2009, 07:41:32 AM »

Looks like very good work Terry
Glad you and the family are safe from the fires
I hope they catch the people that did this and put them in the fire for punishment
(alive)
Why only .005 per pass? Because the boring machine is so old?
seems like a long day

Jim

OldSchool_IsCool · « **Reply #4 on:** February 15, 2009, 07:57:46 AM »

Are you saying you look suspicious when you pee??

Maybe it's the aroma of Kerosene! Guess if I came across someone pissing Kerosene in a wild fire zone, I'd be jumpy too!

Glad you're OK. And nice work too!!

754 · « **Reply #5 on:** February 15, 2009, 08:39:29 AM »

It looks suspiscious when you only cut .005 per pass..

Alan F. · « **Reply #6 on:** February 15, 2009, 08:40:45 AM »

The sleeves are made of? Cast iron maybe? Pretty tough to machine, so .005" cuts will leave a nice surface quality without generating too much heat. Have you ever tried to smooth a busted thumbnail with a coarse file? Finer cuts will leave better results than taking a large cut too quickly.

I've got a mini-mill and a mini-lathe, I know a just little about small cuts and slow feedrates.

cb750fbomb · « **Reply #7 on:** February 15, 2009, 08:59:29 AM »

Looking forward to more pics, Terry and good luck with those fires. Glad to see your safe.

754 · « **Reply #8 on:** February 15, 2009, 09:35:46 AM »

Lack of rigidity in smaller tools often leads to chatter.

The boring bar looks to be a stout machine, often, it is the tool sharpening though, that causes the chatter/heating during the cut.

Terry in Australia · « **Reply #9 on:** February 15, 2009, 12:23:47 PM »

Thanks guys, I can take larger cuts but I'm a little "over-cautious" after muffing a couple of cylinders when I was teaching myself how to use the machine.

Also, with .005 cuts, there's little requirement for a lot of finish honing at the end, those pics are of the cylinders before honing, they're almost good enough to use as they are. Cheers, Terry.

Trevor from Warragul · « **Reply #10 on:** February 15, 2009, 03:05:31 PM »

Hi Terry,

Do you have a boring bar small enough to handle a 350/4 block?

Trevor
Glen Waverley

moham · « **Reply #11 on:** February 15, 2009, 04:41:24 PM »

Quote from: Alan F. on February 15, 2009, 08:40:45 AM

Have you ever tried to smooth a busted thumbnail with a coarse file?

I haven't yet but I'm going to right now...my Sunday's planned!

Jerry Rxman Griffin aka MuthaF'er · « **Reply #12 on:** February 15, 2009, 06:18:23 PM »

Pissing kerosene?! You musta run outta Makers, ha

Terry in Australia · « **Reply #13 on:** February 15, 2009, 08:58:55 PM »

Quote from: morini on February 15, 2009, 03:05:31 PM

Hi Terry,

Do you have a boring bar small enough to handle a 350/4 block?

Trevor
Glen Waverley

G'Day Trev, yeah mate, mine came from a Suzuki dealership in Bairnsdale, and will do anything from 50cc mini bikes, to my 76mm Wiseco 1170cc kit for my GS1000 engine, and my cousin even made a jig to mount the boring head directly onto his 1928 Dodge "Fast Four" to take his 4 inch cylinders out to first oversize many years ago. Cheers, Terry.

Quote from: Jerry Griffin aka Rxman on February 15, 2009, 06:18:23 PM

Pissing kerosene?! You musta run outta Makers, ha

Yeah mate, I'm drinking el-cheapo "rot gut" at the moment, all the MM and Chivas I got for Christmas seems to have "evaporated" under the hot Aussie sun? Funny thing is the cheap stuff is "evaporating" at a remarkably similar rate!

aussie · « **Reply #14 on:** February 16, 2009, 02:35:22 AM »

Gidday Terry
Do those sleeves have a lip on top? as they seem really thick. If they dont, looks like you could go even bigger with the slugs

Terry in Australia · « **Reply #15 on:** February 16, 2009, 02:39:29 AM »

G'Day Wayne, yeah mate, they do have a big lip on top, there's not much metal left in the sleeves now, ha ha! Cheers, Terry.

Trevor from Warragul · « **Reply #16 on:** February 16, 2009, 03:14:37 AM »

Thanks Terry,

I'll keep you in mind for when I get hold of another standard block. I have two sets of NOS 3rd oversize pistons/rings, but the mob who did the boring job stuffed it right up. I like the idea of the block being bored to size without a final hone as there's no chance of it being oversize (1 pass of the hone is fine, 2 passes is too much, 3 passes & the cylinder is stuffed). I ended up fitting a 2nd hand standard block with matching pistons. Better than the screwed up block but still not perfect..

Terry in Australia · « **Reply #17 on:** February 16, 2009, 06:07:47 PM »

Quote from: morini on February 16, 2009, 03:14:37 AM

Thanks Terry,

I'll keep you in mind for when I get hold of another standard block. I have two sets of NOS 3rd oversize pistons/rings, but the mob who did the boring job stuffed it right up. I like the idea of the block being bored to size without a final hone as there's no chance of it being oversize (1 pass of the hone is fine, 2 passes is too much, 3 passes & the cylinder is stuffed). I ended up fitting a 2nd hand standard block with matching pistons. Better than the screwed up block but still not perfect..

No worries mate, who stuffed up your rebore? Cheers, Terry.

Markcb750 · « **Reply #18 on:** February 16, 2009, 06:25:21 PM »

How much is a "stuffed up"?

An answer in mm is fine.

Is that 0.005 on the bore diameter, depth of cut, or feed per revolution.

What kind of boring tools do you use? On the machines I designed we would use carbide insert boring bars, one for rough, one for finish. Each had an insert designed specifically for the task and Material. Much more then O.005 inches.

Old Machinist taught me bore for straightness, ream for size, hone for finish.

With modern tooling the second and third steps are generally not needed. Although we set up the boneheads in Milwaukee with a hone to finish their connecting rods.

valvolux · « **Reply #19 on:** February 16, 2009, 09:00:49 PM »

apt subject line terry. At an hour a cylinder, boring sound boring.
glad everyone's vouching your good work, chat to ya later in the week.
Emailed this to ya, but maybe ya learned mates might want to see my new ally tank and seat.
all the best, al

Trevor from Warragul · « **Reply #20 on:** February 17, 2009, 02:31:01 AM »

It was a few years back. I took it to "Parts & Pieces". They no longer exist. "Stuffed up" means a plug that oils up & is kaput within 100 kilometres. When you see the size of a 350/4 piston you realize that the boring is critical - there's just not that much room for error.

david 750f · « **Reply #21 on:** February 17, 2009, 02:55:37 AM »

markcb750, boring is much more accurate than reaming. Reamers can wear...just an old toolmaker rambling.......

Markcb750 · « **Reply #22 on:** February 17, 2009, 04:32:37 AM »

Quote from: david 750F on February 17, 2009, 02:55:37 AM

markcb750, boring is much more accurate than reaming. Reamers can wear...just an old toolmaker rambling.......

From one old Machinist to another;
On production work for precise holes, reams will beat bores for sizing. Particularly with long bores as single tool tip can wear significantly, resulting in a tapered hole. The ream will cut the whole length at once to the accuracy of the tool. I have used many reams that are adjustable. To account for wear. We also only used the ream to remove about 0.0015" on the diameter.

Reams are much better minimizing hole size differences due to to variances in the material of the hole to be bored.

Many production techniques use some or all my old Machinists advice. But as I said, good modern boring bars can both rough and finish the bore. Once a good spindle is attached to a good slide, and the part is secure, and the tool holder is pit well, its all up to the boring bar and the cutting edge. Well it is really up to money; each boring bar can cost $400, a good inset $10

FYI I am not recommending a reaming process for boring cylinders in a repair shop. I am curious as to what kind of tooling is applied, as proper tooling can make a huge difference in rate of material removal and final size consistency.

Mostly I just want to bullsh*t a little.

754 · « **Reply #23 on:** February 17, 2009, 07:55:36 AM »

Terry would hate boring 883s to 1200, we take out 500 thou.

Markcb750 · « **Reply #24 on:** February 17, 2009, 09:16:13 AM »

Quote from: 754 on February 17, 2009, 07:55:36 AM

Terry would hate boring 883s to 1200, we take out 500 thou.

With the right equipment & tooling that is about 4 passes...

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Author Topic: Terry's boring weekend. (Read 5630 times)

Markcb750

Markcb750

Markcb750