How it's Done

[AK47KID]

Good thing I'm in Oregon. Your about an hour or 2 away from me

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[bkm]

Thank you for the kind words; “How it’s Done” keeps me so busy that I can’t keep up. This is why I’ve decided to throttle things back some. It’s time for somebody else to step up & lend a hand. There will be cylinder repairs to support a family for years to come. A machine shop background or a couple years in community college are an absolute must. I can’t train a person who can’t read a micrometer. We have time to do this together but need to get started. Give me a call after dinner.

I wish I was closer, I'd work for free just for the knowledge.

[Billy Golightly]

I wish I was closer, I'd work for free just for the knowledge.

You're not the only one!

[bkm]

John, do you remove all the studs prior to boring the cylinder? Is it also good practice to set up a cylinder in a lathe to true the deck and the base surface in order to assure that the cylinder is true in the boring machine and the new bore will be perfectly straight?

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[John Tice]

Most times when at all possible the cylinder is bored upside down, this way the studs aren’t an issue. When we bore the cylinder upside down the studs make good spacers for the clamping mechanism.
In the manufacturing process cylinders are characteristically machined parallel on both gasket surfaces.
On many larger & multi cylinders the upper & lower gasket platforms are large enough that boring from top or bottom of the cylinder doesn’t matter.


I avoid skinning the upper & lower gasket surfaces since it can foul up the cylinder deck height. Only the side opposite the bore chucking surface.

[bkm]

Do you have a pic of the clamping mechanism? I'm trying to picture how it's held in place.

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[John Tice]

This is how I do the clamp; it swivels in the center.





You can see how it pivots on the bottom



There should be enough to get the pivot ideas.

I’ve got a new boring plate to be ready next week. 1-3/4” thick with a wider slot for the larger OB motors. 1 of the smaller tables goes to shop #2, the other is available to purchase.

[bkm]

So if it can be bored upside-down, the base is the surface that is resting against the bottom of the table to square it to the boring bar? As long as the bar is perfectly 90 degrees to the bottom of the plate, and the base of the cylinder is square, the new bore should be straight?

[John Tice]

That is correct; upside down, square mount. After the cylinder is clamped, I carefully look around the base & look for any daylight which would show an improper mounting. If any day light shows; I loosen up the clamp & wiggle the cylinder around until it’s square.
Are you thinking about buying your own machine?
Use my email address please. www.john@smallenginemachineworks.com

I’ve got a new boring plate to be ready next week. 1-3/4” thick with a wider slot for the larger OB motors. 1 of the smaller tables goes to shop #2, the other is available to purchase.

[John Tice]

WTB Need a new standard bore piston for a 1972 125cc, 54mm Zundap engine.
Engines were in a Rickman cycle.

[Dirtcrasher]

I am expanding my shop. I would take this on if I felt there was enough work to warrant it.

I have a strong toolmaker and machinist background with a SB Heavy 10 and a Bridgeport. Band saw too.....

[bkm]

That is correct; upside down, square mount. After the cylinder is clamped, I carefully look around the base & look for any daylight which would show an improper mounting. If any day light shows; I loosen up the clamp & wiggle the cylinder around until it’s square.
Are you thinking about buying your own machine?
Use my email address please. www.john@smallenginemachineworks.com

I’ve got a new boring plate to be ready next week. 1-3/4” thick with a wider slot for the larger OB motors. 1 of the smaller tables goes to shop #2, the other is available to purchase.

I've been kicking it around if I could find one local and for the right price. I've got a few irons in the fire I need to finish before I take on a project like this, but I'd really to explore it at a later date.

[John Tice]

The big quad thumpers are starting to wear out; I’ve been busy with some interesting projects. It takes only a moment to cut a fire ring groove if you’ve got a lathe to work with.

[Dirtcrasher]

Whats a fire ring groove John??

[onformula1]

The big quad thumpers are starting to wear out; I’ve been busy with some interesting projects. It takes only a moment to cut a fire ring groove if you’ve got a lathe to work with.

Do you use- mild steel wire, copper wire or are you going to use o-rings?