Removing material with a flex hone?

[Gabriel]

I picked up a 200X cylinder from a local guy. It was a fresh over bore 65.5mm

Measured 2.5762-2.5765

Ordered a new Wiseco and the piston skirt measures 2.576-2.5761 at it largest point.

Well FACK!!!!!


I just ordered a new a flex hone of appropriate size. I'm hoping to be able to get .002 or so worth of material out of there for proper clearance. Is this possible without screwing it up?

THIS is what you get when you DON'T have a shop fit the piston to the bore at the same time. *sigh*
It's always SOMETHING!!!!!

[fabiodriven]

To the best of my knowledge the hone should work fine. Obviously don't loiter in any particular spots with it.

[Gabriel]

I tried it with the 3 stone spring loaded one I have but it's a 220 grit stone and the stones are pretty old. It didn't do much. The flex hone I ordered is 180 grit.

Fingers crossed.


I'm really getting sick of these retroactive solutions to engine building. One of these days I hope to assemble one without any words that would embarrass a sailor.

[barnett468]

I'm hoping to be able to get .002 or so worth of material out of there for proper clearance.

And I'm hoping to find a winning lotto ticket.



I just ordered a new a flex hone of appropriate size.

I sure hope it is a us made one with 2 arms attached.



Is this possible without screwing it up?

Highly unlikely....well actually, let's just make that a no, but on the positive side, you can just get the next size over piston if (once) you screw it up and send it out with the cylinder this time and get it bored.



THIS is what you get when you DON'T have a shop fit the piston to the bore at the same time. *sigh*
It's always SOMETHING!!!!!

This is sometimes correct.

[fabiodriven]

It's not a "no" in my book barns, and not even unlikely. It's been done before and will be done again. Is it optimum? That's a definite no. Will it work? Most likely yes, and it would likely be fine for the long run.

[Gabriel]

Well, the flex hone i ordered will be here tomorrow.

If you see a brand new 65.5mm 10.25:1 Wiseco piston for sale in the classifieds ya'll will know it didn't work. LOL!!!!!!!!!!

[barnett468]

Yes, fabio, of course it certainly "can" be done, however, it is not possible to remove .002" with a budget hand hone and have it be perfectly true. That will simply never, ever, happen, especially if it is the single arm type of hone. Obviously it does not need to be perfectly true to simply run, but I don't see the logic of running a "substandard", untrue cylinder after going thru all the time and expense etc to r and r the cyl and piston then buy a new piston and gaskets and get the cylinder bored etc.

Also, it will take a fair amount of time to remove that much material with a hand hone because it does not apply a lot of pressure to the cylinder walls. I removed just around .0002" from my both of my YZ465 cylinders 3 days ago with a hand hone and it took a while.

[barnett468]

Well, the flex hone i ordered will be here tomorrow.

If you see a brand new 65.5mm 10.25:1 Wiseco piston for sale in the classifieds ya'll will know it didn't work. LOL!!!!!!!!!!

If there is no place near you that can hone it to the proper size using the proper machine, why don't you simply box it up and mail it to a place that can. I can give you the contact info for a few of them.

Below is a video of one of the 3 main types of professional hones that can hone it out .002" and still keep the bore true. Some of these machines can also true and untrue bore, which is something a hand held hone can not do.

https://www.youtube.com/watch?v=IuzBQlYFgXo

.

[barnett468]

.

If you repair something properly the first time, you won't have to repair it again any time soon.

.

[fabiodriven]

I don't think he's planning on running the Indy 500 with it or anything.

[barnett468]

.

Perhaps the Baja 500 then?

.

[Gabriel]

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Perhaps the Baja 500 then?

.


Only thing my azz is running is the Bierdose 12.

[El Camexican]

I picked up a 200X cylinder from a local guy. It was a fresh over bore 65.5mm

Measured 2.5762-2.5765

Ordered a new Wiseco and the piston skirt measures 2.576-2.5761 at it largest point.

Well FACK!!!!!


I just ordered a new a flex hone of appropriate size. I'm hoping to be able to get .002 or so worth of material out of there for proper clearance. Is this possible without screwing it up?

THIS is what you get when you DON'T have a shop fit the piston to the bore at the same time. *sigh*
It's always SOMETHING!!!!!

So what tools at you using to measure your piston and bore to 4th decimal place?

[barnett468]

Only thing my azz is running is the Bierdose 12.

It looks like that is either German for Beer Can or a seriously painful rectal malfunction. https://www.mustang.org.au/forum/Smileys/smilies/leaving.gif

[El Camexican]

What kind of tool do you think he is ?............he`s got skills !!

Maybe a David Lee Roth signature series tape measure? :wondering

[Gabriel]

So what tools at you using to measure your piston and bore to 4th decimal place?

Mitutoyo dial bore gauge.

[El Camexican]

Are you sure that opening that bore .002” would be enough for a forged piston? I’m about the farthest thing from a piston fitting expert you’ll find on here, but I do know that a forged piston required a slightly larger bore and the numbers you posted look pretty tight.

I’d contact Wiesco and ask them what size the bore should be for that piston.

[barnett468]

60 to 73 mm .0025"

[barnett468]

Oops thats for a 2 stroke, back in a few minutes but they somerimes include that info with the piston.

[barnett468]

Ok wiseco no longer gives piston clearances. They told me lsst week thst the piston will have the correct clearance when the cylinder bore is the correct size, meaning if the piston is for a 65 mm bore, then it will have the correct clearance when the bore is exactly 65 mm. My 465 bores were slightly under size plus they had some light scratches so i honed them out to the correct size and ended up with around .00025 clearance on an 85 mm bore but this is on an air cooled 2 stroke.

[Scootertrash]

This:


I just ordered a new a flex hone of appropriate size. I'm hoping to be able to get .002 or so worth of material out of there for proper clearance. Is this possible without screwing it up?

Contradicts this:


THIS is what you get when you DON'T have a shop fit the piston to the bore at the same time. *sigh*


Why cut corners? To save money? Individuals spent lots of money and time restoring/rebuilding trikes, and they want to cut corners to save $25-$30? The local engine machine shop here charges 25.00 to hone .001-.003.

Do it once and do it right the first time. That saves time AND money!

[Scootertrash]

Ok wiseco no longer gives piston clearances. They told me lsst week thst the piston will have the correct clearance when the cylinder bore is the correct size, meaning if the piston is for a 65 mm bore, then it will have the correct clearance when the bore is exactly 65 mm. My 465 bores were slightly under size plus they had some light scratches so i honed them out to the correct size and ended up with around .00025 clearance on an 85 mm bore but this is on an air cooled 2 stroke.

I was told this by my machinist quite some time ago, he's been in business since '75, but he still requires the piston goes with the cylinder for boring and honing. I also verify clearances when I get the piston and cylinder back before I reassemble.

[DAM shop]

I was told this by my machinist quite some time ago, he's been in business since '75, but he still requires the piston goes with the cylinder for boring and honing. I also verify clearances when I get the piston and cylinder back before I reassemble.

Same here Scooter. Our guy wintt bore anything without piston and rings.

[fabiodriven]

Yup same with my guy. He won't bore sans slug.

[barnett468]

I was told this by my machinist quite some time ago, he's been in business since '75, but he still requires the piston goes with the cylinder for boring and honing. I also verify clearances when I get the piston and cylinder back before I reassemble.

Yup, I have done the same thing since 1975 but, I tell the machinist what clearance I want based on the bike or car engine and the app etc. I used to race 2 strokes (like my 74 Bultaco's) that had studs going thru the cylinder to the head, and these would be prone to seize in the 4 corners where the studs were in the blazing California heat if the factory clearances were used, so I had them bored with additional clearance and they stopped seizing. I also have some cylinders "plateau honed", depending on various factors.

[barnett468]

bore 65.5mm

Measured 2.5762-2.5765

new Wiseco 2.576-2.5761 at it largest point.

I just ordered a new a flex hone of appropriate size. I'm hoping to be able to get .002 or so worth of material out of there for proper clearance.



Well, if it was mine, I would make the clearance at least .002". This obviously means that you need to remove .0018" which is around how much you planned to remove.

I would then use a dedicated break in oil or non synthetic high ZDDP content oil (preferably with low detergents) for break in, then a good Group IV oil after that.

.

[Gabriel]

Well ladies.....It WORKED. It took the better part of 45 minutes with a 180 grit flex hone. 900 RPM, 20 strokes at a time. Clean it, measure, liberal amounts of 30 weight oil and go again. What a frackin' mess I made!!!!!!!!! There's oil all over the place.
Ohh well. I ended up with a total clearance of .0019 That's taking the largest part of the piston and the smallest reading I could get in the bore. The bore has a VERY slight taper. It's about .0006 larger at the bottom. Nope, don't care. She'll run.

Conclusion:
Is it the right way to do things? Emphatically NO!
Can it be done. Yes.
Why did I do it as opposed to getting it done professionally? I wanted a new hone anyway. These Flex-hones are the shizzz!!! I took my three stone traditional spring loaded contraption and tossed it under the lathe for down and dirty work. I'll never do another engine with one.

*sigh*

What's the next thing that'll bite me in the arse? Time will tell. Till next time, this is your friendly neighborhood halfassin' redneck, signing off.


†††Gabriel†††

[fabiodriven]

I just like doing whatever I can on my own when I can, which is probably what you're doing. When you're ready to run Indy, then you can have it double-flare-square-bored-with taper swirl-plateu-hone-nika-poish or whatever the frig Barnett was talking about.

[Dirtcrasher]

Hones are just for making a crosshatch. If you use a drill on low speed and a quick in and out movement, you can get the desired degree of hatching.

Just don't plan on taking off a bunch of material. If your hone does take off a bunch of material, it is too coarse and you'll need another hone to deglaze the surface.

I like the ball hones myself with plenty of oil and a real good eye as well as repeatable motions.

I watched a buddy have his "engine guy" hone his 1986 RM250 cylinder in a drill press!! He turned it on and went up and down slowly, All it did was it made circles in there parallel to each other, no degrees of separation between them (if that makes sense, I'm trying here).

Definitely the wrong speeds, it's really easy when you get the speeds and motions down, maybe check YouTube??

But, none of it is done "fast"...

[barnett468]

It took the better part of 45 minutes with a 180 grit flex hone. 900 RPM, 20 strokes at a time.

Does this mean you will now have to use your opposite hand to do the stroking until the other one can recover? https://www.mustang.org.au/forum/Smileys/smilies/bolt.gif

.

[El Camexican]

My 465 bores were slightly under size plus they had some light scratches so i honed them out to the correct size and ended up with around .00025 clearance on an 85 mm bore but this is on an air cooled 2 stroke.


Dang Barns, you’d best be using KY to put that one together!

[barnett468]

Dang Barns, you’d best be using KY to put that one together!

I like mine tight. :lol:

.

[Scootertrash]

Where is loganhowmanypistonsdoIhavetogothru logjam when ya need him?