Topic: Cylinder Rust Removal

[754]

It's 2.5 mm.. on a 750 boring out 4mm over is OK. Maybe 500 has thinner sleeves ?
 I don't know bore size if the 650 ....but good 750 pistons are easy to source..
 Ok so 650 is 59.8mm  or 2.354... sort of like having a 5th oversize. . Not sure how pistons compare.

[PeWe]

If going bigger at next future option, these will fit?
https://www.cruzinimage.net/2017/08/25/honda-cb550k-cb550f-600cc-bigbore-pistons-kit-61-50mm/

About total clearance:
(bore diam - piston diam at skirt)
Max 0.025mm as I have read about the cruzinimage pistons.

[dave500]

dont go big bore,just go oversize.

[Darren Jakal]

Thanks again everyone!

Plan is to only go as big as necessary. Hoping for one over (is that 59mm)?

Going to try to bore at 58.881 and see what that looks like (finish with honing to final dimension).

That’s the plan anyway. Put the jug on the mill to check for flatness and I still need to tram “nod” better. I’ve only got dial indicators with magnetic base. I would rather buy a spindle square and figure out my own boring than pay over $500 for someone else to do it.

Cheers, dj

https://www.cruzinimage.net/2017/08/17/74-78-honda-cb550k-0-5mm-oversize-pistons-set/

Hoping something like this will work.

[754]

Best is indicator turning with spindle, dial test indicator.. I used to mount one in a piece of bar stock , that went I boring head.
 Tram is a bit tricky till used to it, you can also indicate top of sleeve and shim..

[bryanj]

59 is 0.5mm os or 2nd os

[Darren Jakal]

That's good stuff Frank. I'm thinking of getting some new tools and a spindle square seems like a good investment.

So, 59 is 2nd over. Thanks Bryan ! Hopefully that would be enough to clean up the walls and pistons are available (I've not seen 58.75, what I assume would be 1st over?)

I've been looking for info on 1) boring cylinders on a bridgeport clone with the boring head I have and 2) the best way to attach the jug to the bridgeport table.

Of course this led to a search into boring bars and all kinds of things. One of which was boring cylinders on the engine lathe. I found some talk on dropping the cylinder sleeves out of the jug using heat and then boring them in the lathe (much easier and with tooling I already have, see picture).

The discussion then led to talk of cylinder distortion during heating and such.

Anyone ever try this with a sohc/4 here? Or is this just not a good idea.

Cheers, dj

[bryanj]

Dave Silver has 0.25 piston kits, at least here in UK he has.

I have never known anybody remove liners to bore and the length of bar you need on a lathe tends to promote chatter at the cut.

[Darren Jakal]

Hi Bryan, thanks for the heads up on the one over pistons !

So, no one removes cylinders sleeves to bore?

In my case I could get a much bigger boring bar into the sleeve if it was on the lathe and could choke it much shorter than the one I can get into the boring head on the mill.

The bore head only takes 0.625 bars, but I can go bigger on the lathe, and because the boring head is too big to use a horizontal cutter I need to extend down with a vertical bar and then add the cutter. This is much longer and thinner than what I could do on the lathe. So, actually my concern was chatter and deflection with the bore head and why I thought the lathe could be an option.

Anyway, I’m doing more research to figure out the plan and have talked with some more engine machine shops about doing it (so far not good).

Cheers, Darren

[754]

Yo can always use a bigger stiffer bar in the lathe, we bored Sportster cylinders in the lathe , pretty well have to .. you take out 1/2 of material and they are much longer than a Honda barrel... that is on an 883 to 1200 bore.
 Put the barrel on blocks  then clamp down click the top of sleeve, then bore.
 I only did a few Whizzed barrels to see how deep pits are, but yes chatter I'd finish .ca  be a problem. . My boring head uses 3/4 bars ,,,a bit stiffer. . Btw them sets of boring tools, cheap ones are often terrible quality.
 You will have to go slow,  and cut like 10 or 15 thou at a time.
Mis the mill yours , or a buddies ? The cost you could save by boring yourself , should cover any nice tools you need , and will use a lot down the road.

[754]

This is what I use , it's a treat. . Easy . Make sure it fits spindle nose. 

[Darren Jakal]

Hey 754, thanks for the discussion.

The mill is at my work, but it’s kind of been left behind in the move to digital (no precision digital tools, but CNC routers, 3D printers, laser cutters, water jet and the like).

We don’t do precise repair work so the need for certain tools has not been as issue. I have full use of the stuff and want to up my skills so I’m using these sohc/4 bikes to try things out.

What you pictured is one of the tools I want to get, along with the spindle square and bore gauge.

Any thoughts on dropping the sleeves to bore in the lathe?

Cheers, dj

[754]

 You are lucky to have use if such a tool,,
 I am not sure what you mean by cylinder square ?
  Is that lathe at home, or work ?. Just thinking  in terms of access.
 Boring I  lathe is not  always a bad idea, just not preffered by many..  nobody complains about buying a sleeve made on a lathe , do they ?   HONDA sleeves  come out easy so that US not an issue.
 So it's a matter of holding..safely and reducing set up time. , and longer jaws  on the chuck can help here , less vibration.
 Simplest thing I can think of is to make a bushing   to hold the  sleeve, around the length of the sleeve, and at least  3/8 wall... bore so sleeve just slides in , then slit lengthwise and remove burrs.  Then sleeve is supported while being cut.
 If you  use a 4 jaw chuck.. easy to dial in..
 
 You have a set of cylinders that at this point are unusable , and may or may not clean up to a regular size.. so can't hurt anything..

 Just be glad you are not taking out .495 on a 6.5 inch or longer bore... it's a huge pike of shavings..

[Darren Jakal]

 I am not sure what you mean by cylinder square ?
  Is that lathe at home, or work ?. Just thinking  in terms of access.

Are you thinking “spindle square” and not cylinder square? Spindle square is two dial indicators on a beam with a centred shaft to collet in the mill. For tramming.

The lathe is also at work. I have access anytime.

Thanks for all your thoughts. I’ll keep you posted on how I plan to proceed.

Later, dj

[754]

I see ..... I only use a single indicator  to tram . A lot of what you do can be done 3 sides, then final check on 4th..
 The indicator holder allows indicator dial to lay flat in most cases.
 Tramming front to rear  is tricky at first sometimes if you are close to tram, shimming work can be faster.

[Darren Jakal]

Yea, I’ve only trammed with the single indicator and can get it dam tight on the x axis, but the nod is taking a lot more time. It’s a magnetic base that I stick on the spindle, but it’s not super secure. I’ve been looking at new measurement tools and the spindle square seems so much faster and accurate that I now want one. They are not ridiculously priced either. I figure if I am going to try to bore my own cylinders then I need to do it as right as I can.

Later, dj