Cylinder boring without a cylinder borer.

[tonyfoale]

Thanks tonyfoale! We've added your Carbide Insert Holder to our Machining category,
as well as to your builder page: tonyfoale's Homemade Tools. Your receipt:

I note that you have added my post into 3 categories. I didn't know that happened.
At the time of making that post I couldn't find the pix. that went into more detail on the boring bar and tip holder. Since then I have found the pix and I intend to make a separate post with more detail on those items.

[crazypj]

I've been thinking of boring in the lathe for a while but using a bar between centers as I have much smaller lathe. I used to have access to boring bars and did a lot of 'conversions (800cc Yamaha XS650, 378cc Honda CB360, plus 'stock' kits) I hadn't thought of welding up an 'angle plate' although I had expected to face it with a flycutter. (I'll probably make something from an old automotive brake rotor, they run true and are decent quality cast iron)
HD has something of a history acquiring companies, particularly if they want a specific piece of patented technology.
When I was teaching at MMI I did a little research on the HD/Aermacchi, HD bought Aermacchi in 1961 when the 250/350 were still competitive race motors.
BTW Tony,I've read a lot of your motorcycle stuff over the years, were you involved with the Suzuki 'NUDA' concept bike? It has similar steering set up to the GSX you built (pictures at Cadwell Park)

[tonyfoale]

I've been thinking of boring in the lathe for a while but using a bar between centers

Between centres is fine, the only problem is making an easily and accurately adjustable tool. It the lathe is solid enough then the way I did it allows the use of a store bought boring head with fine adjustment. Both ways work OK.

BTW Tony,I've read a lot of your motorcycle stuff over the years, were you involved with the Suzuki 'NUDA' concept bike? It has similar steering set up to the GSX you built (pictures at Cadwell Park)

Maybe you are thinking of the Rusty Falcon which predated the Nuda. The Nuda had conventionally orientated handlebars whereas the Falcon had roughly vertical bars as did the QL and Q2 series of bikes that I built, the first versions predated both of Suzuki's concept bikes. I had nothing to do with of those. Both the Suzukis had FFEs (Funny Front Ends) as did those of mine which you mentioned. However, the mechanisms were quite different to mine.
For those unfamiliar with these concept bikes here are a picture of each



Here are more. showing a test bike converted to my FFE and upright handlebars from around 1980.

[Frank S]

When talking about funny front ends the idea of hub steering on a motorcycle dates a long ways back
I had one called a ner-a-car
Ok this is a boringly crazy old bike I had one given to me that was little more than a rusted frame. Through the years I restored it to almost new but let it get away from me.
Here is a video of one nearly like mine except mine was a 1923 American made with the smaller 2 cycle engine

[Frank S]

This video shows the steering better and is a lot closer to how mine looked when it got away.

[crazypj]

Yep, it was the Falcon I was thinking of. I know I downloaded a picture of a GSX (maybe GSX-R?) engined special a few years ago (probably 12+?) If it isn't one of yours I'm wondering who built it? It had 'vertical' bars similar to the BM

[tonyfoale]

Yep, it was the Falcon I was thinking of. I know I downloaded a picture of a GSX (maybe GSX-R?) engined special a few years ago (probably 12+?) If it isn't one of yours I'm wondering who built it? It had 'vertical' bars similar to the BM

That sounds like one of the Q2s that I built. I did post a photo of one here in another recent post but here are some different pix. of both a QL and a Q2.



I am familiar with the Ner-a-car and I had pictures in my chassis design book.

[marksbug]

THE ISSUE WITH THIS TYPE OF BORING IS CENTERING UP RIGHT/ACCURATELY..and square. from end to end.yes it can be done, but be sure to get it square from end , to end. also it should be bored .004~.0055 smaller than the finish size for cast materials like cylinders on engines. the cast is not realy cut well but rather cht&broken out leaving fishers about .002~.003 deep, ( depending on the amount of material being taken out per pass, rigidity set up and type and sharpness and shape of the cutter. the cutting edge is usualy about .020~.025 wide, angled of corase.If i was using a carbide incert i would go for a incert with a raidi, dont use a sharp point that will tear the material deeper and effup the cylinder and possiably pull the cutter into the bore. on a std boring bor used for engine block boring the chtter is sharpened after every block done...well it should be, doing it that way the cutter will cutt better, less heat, less chatter, better hole, less stress and the cutter will last longer....yes last longer if you sharpen them more often,other wize when your burning up the cutter and then go to sharpen it you end up taking a lot more material off the cutter shortining it's life and the sharpening diamonds. I see no issue using a bridge port boring unless yours is all wore out, there not a lot different than a boring bar, boring bar has a small er quill but bearings are spread appart farther but the quill does go a lot farther than a bridge port type mill. and if you know how to use a mill correctly you know that you can use the knee for the Z not the quill and that keeps the quill supported way better., but many people dont seem to know what the movable knee is for. be sure to adjust the ways/gibs if you havent.you can also check it with dial indacator from locked to non locked possition, it should be less than a thou....if not ADJUST IT!!!!! Ive seen lathes with way more movement in the carrage,cross slide/compound than a mill has., and yes Ive seen wore out mills too.. as for the spring return hone & hand hone...... if you bore the correct amount then try to hand hone...your wore out . and cheep hones are ****. use a good hone with the propper stones( usualy 3-4 grades of stones for every hone job to get it right).torqueplates are also mandatory for most engines if you want them right. I have boring heads I use in my mill,never thought about sticking one in my lathe...I do like the idea especialy for wonkey shaped thin stuff that is hard to put in the lather and spin it along with boring bar chatter that can creep up and bite you that a boring head with right incert in it. Ive seen that addaptor for the boring head to use a incert,I was gonna make one, or just but the boring head that takes the insert..$64 on flebay, addaptor....about the same.go figure. I only have 2 3" bridgeport boring heads so i was thinking on getting some smaller ones...

[tonyfoale]

THE ISSUE WITH THIS TYPE OF BORING IS CENTERING UP RIGHT/ACCURATELY..and square. from end to end.yes it can be done, but be sure to get it square from end , to end.

Square end to end is not the way. That relies on the bore being true to start with. I set it square to the mounting flange and align it as shown.

[marksbug]

if your sure your jig is straight&true.but I would check it. if it's out a few tenths one one end....and it's 7" long...it's out quite a bit at the other end.yes set it up from the machined end and go from there. but check to be sure your jig is true every time. std practice is use a file to make sure there are no puled up threads or any thing else , burr, bump,gasket material/sealer what ever that will throw it off on the jig. no not all bores are where they are supposed to be, we use a BHJ bore true for many engines so you could put the bore where it was supposed to be. some engines the deck surface is AFU from the factory and needs to be trued.if you were top use that you would be boring the cylinders at the rong angles and much bigger. some oe engines were around .020" out from end to end and up to .010 side to side. boring of something that far off is disaster. all of the mopar 340 blocks were out .016~.020, Ive done a lot of those and every one is about the same, witch dosent make good sence since it's about the same engine as the 273,318&360 witch are usualy withen about .008 witch is about the same as other american v8 engines. the 340 must of had a spcific machining center diferent than the other small block mopars for the roughly 5 years it was in production., chevy blocks have waves on the decks of most, ford can go either way. inline engines are usualy withen about.006.end to end and side to side.very few if any are dead on.