Atlas Cylinder Honing

Hi all
Got my cylinder back re-bored .020 over " rough" which means within .005 of finish. Here's the question what would people here do to achieve the final finish? Do it myself with a flex hone? Straight blade hone? Grit? Send it out for final? Thanks

jms said:

Hi all
Got my cylinder back re-bored .020 over " rough" which means within .005 of finish. Here's the question what would people here do to achieve the final finish? Do it myself with a flex hone? Straight blade hone? Grit? Send it out for final? Thanks

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Do you mean to say/write .0005"?

Honing five thousands is not practical.

Recommended procedure:

sorry actually there's .003 to go

If it was bored to .003 of finished size it requires a sizing hone to finish it to size. Not a normal DIY job or tool .

Barrels need to go to a machinist that knows what is required -> for me it would be a plateau finish. A hone at home will make the bores out of round more than anything else. The plateau finish bore diameter should be specified and requested when the bore is done.

Is that too harsh a comment? I can't tell.

bill said:

If it was bored to .003 of finished size it requires a sizing hone to finish it to size. Not a normal DIY job or tool .

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Thanks

Schwany said:

Barrels need to go to a machinist that knows what is required -> for me it would be a plateau finish. A hone at home will make the bores out of round more than anything else. The plateau finish bore diameter should be specified and requested when the bore is done.

Is that too harsh a comment? I can't tell.

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Nope not too harsh. Jim Schmidt told me to get the bores finished at 2.893 and that would be .005 clearance on the forged pistons he supplied. Like I said I’m now .003 under that

jms said:

Nope not too harsh. Jim Schmidt told me to get the bores finished at 2.893 and that would be .005 clearance on the forged pistons he supplied. Like I said I’m now .003 under that

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You know I’ve spent some time on the BRM Flex Hone site and it seems like they promote hand tool flex hone operation as a perfectly acceptable practice. Seems like most people are uncomfortable with this approach

jms said:

You know I’ve spent some time on the BRM Flex Hone site and it seems like they promote hand tool flex hone operation as a perfectly acceptable practice. Seems like most people are uncomfortable with this approach

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Go for it. Make sure you get all the grit those produce out of every possible place it can go. And it will go everyplace.

I doubt I could be precise enough to meet Jim's tight spec. I'd have the machinist get the bores plateau finished to spec while he/she/they had them. That is what I did when I had my iron 750 barrels bored +.040 for Jim's Wiseco high CR pistons for long rods. Tight like a Tiger.

I have used a BRM flex hone on a SBC V8 to break the glaze but I wasn't trying to meet any spec. Rings seated quickly and the engine never smoked. They work, but are messy.

It's not so much about being uncomfortable with a flex hone, it's about experiences I've had in the past.

jms said:

You know I’ve spent some time on the BRM Flex Hone site and it seems like they promote hand tool flex hone operation as a perfectly acceptable practice. Seems like most people are uncomfortable with this approach

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A flex hone is NOT ment to remove .003 from a cylinder. Is more of a tool for platuo honing or as a glaze breaking and is perfectly acceptable for that. Again you MUST use a sizing hone first. Take it back to who ever did the boreing with the pistons in hand and have them finish the job.

bill said:

A flex hone is NOT ment to remove .003 from a cylinder. Is more of a tool for platuo honing or as a glaze breaking and is perfectly acceptable for that. Again you MUST use a sizing hone first. Take it back to who ever did the boreing with the pistons in hand and have them finish the job.

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I got the feeling jms was hell bent on getting the finished diameter himself somehow and it was an opportunity for a lesson to be learned. An expensive lesson is hard to forget. That is harsh

I'd wager against anyone being able to get an in-tolerance, concentric, round, parallel bore by removing .003" with a flex hone in a hand drill. You'd spend 10 times more time and money on the tools to measure the bore accurately than you'd pay a professional to knock it out before lunch.

Match the quality of the bore to your lovely brand new pistons.

t ingermanson said:

I'd wager against anyone being able to get an in-tolerance, concentric, round, parallel bore by removing .003" with a flex hone in a hand drill. You'd spend 10 times more time and money on the tools to measure the bore accurately than you'd pay a professional to knock it out before lunch.

Match the quality of the bore to your lovely brand new pistons.

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Agreed.
When I start arguing with myself about whether to take the project on alone or send it out I consider this...is the guy that can perform the required work, and does it for a living, going to be able to do it better than I can? Most of the time the answer is yes.

The notation on tool expenses is a big deal.
Think you can pull it off without having the right tools? I did. When I was 16 and broke all the time from spending my money on chasing girls.

I hate tearing projects down and returning to step one because I didn't apply the quality required due to, inexperience, not having the right tools, drank too much beer before starting, thinking this shouldn't be that hard and so on. It almost always ended up costing me more too.

One other aspect. If you do hire the pro from Dover to apply their skills to your project, you can learn one hell of a lot about the right and wrong way to go about it come next time. Seems next time is always hanging around too.

Came to my senses and found a guy that did it correctly and learned quite a bit along the way. Time to assemble the reminder of the engine!