Flex-Hone Tools.

dicky · Post by **dicky** » Sat Oct 27, 2007 12:24 pm

Was just researching plateu honing and came accros Flex-Hones.

They recomend using them for bearing shells and valve guides as well as cylinder bores.

Was wondering what you think of this and has anyone tried it?

I am looking at getting a Silicone Carbide 320gritt Flex-Hone for my bores.

Look here at the PDF page 20.

ian.stewart · Post by **ian.stewart** » Sat Oct 27, 2007 12:49 pm

I am in two minds about Flexi Hones, In theory they are Ideal for glaze busting, If I put my engineering head on, you can not guarantee the bore or anything will be concentric or parralell it would be very easy to ruin a bore in a performance engine or go oversize so you will need a Rebore, and certainly will not remove high or low spots without removing more from the surrounding area,
Personally, even being an Engineer by trade, I am having a good engine machine shop hone my bores, so I know they will be Spot on size,

kiwicar · Post by **kiwicar** » Sat Oct 27, 2007 1:33 pm

good idea if you just have glazed bores, but by the time they are glazed the bores usually have a step at the top and are worn a bit so arn't round. much better to get it bored and honed properly. They would get you through a rebuild on an engine that is being rebuilt because of another problem or a real budget job but in the long run. . . . . . .
Mike

HairbearTE · Post by **HairbearTE** » Sat Oct 27, 2007 5:16 pm

If you do with a plateu hone be very careful running in. It is apparently very easy to land yourself back at square one.

dicky · Post by **dicky** » Sat Oct 27, 2007 7:13 pm

So best to get the bores oversized and honed then.
280 grit hone, 400 grit hone and nylon brush platue honed.

I was quoted abou £200 for that.

So what about honing bearing surfaces?

Paul B · Post by **Paul B** » Sun Oct 28, 2007 1:41 am

ian.stewart wrote:I am in two minds about Flexi Hones, In theory they are Ideal for glaze busting, If I put my engineering head on, you can not guarantee the bore or anything will be concentric or parralell it would be very easy to ruin a bore in a performance engine or go oversize so you will need a Rebore, and certainly will not remove high or low spots without removing more from the surrounding area,
Personally, even being an Engineer by trade, I am having a good engine machine shop hone my bores, so I know they will be Spot on size,

It will take fair bit of honing to take more than a thou or two off with a standard flex-hone, if they are the ones I use at work. We have the ones with carbide balls on nylon wire, mounted on a central rod. I find it hard to believe you could ruin a bore unless you went overboard with the speed or length of time you ran the hone.

stevieturbo · Post by **stevieturbo** » Sun Oct 28, 2007 10:53 am

Ive also used them in the past. If you are sure your bores are otherwise fine, then they can work well for getting a new surface to bed the rings in.

Of course its always better to have a competent machine shop do the job, but if you are going that far, are they also using a deck plate when honing/boring too ?

You can go from one extreme to the other, always saying one way, is the wrong way.

Perhaps buy a bore mic, and measure it all to see if the bores are round....again, maybe a little OTT too unless you can get one cheap.

You should see anyway with these DIY one tools, if the bore is round or not by the finish it produces, unless the entire bore was perfectly oval.
When I did my LS1 block at the end of July for a temp engine to get me to TOTB, the finish was bloody terrible !! My bores were so untrue.
So in August when rebuilding properly, I did have it honed properly with deck plate etc. Unfortunately I had to send it to England to get this done.

Paul B · Post by **Paul B** » Sun Oct 28, 2007 7:35 pm

stevieturbo wrote:Ive also used them in the past. If you are sure your bores are otherwise fine, then they can work well for getting a new surface to bed the rings in.

Of course its always better to have a competent machine shop do the job, but if you are going that far, are they also using a deck plate when honing/boring too ?

You can go from one extreme to the other, always saying one way, is the wrong way.

Perhaps buy a bore mic, and measure it all to see if the bores are round....again, maybe a little OTT too unless you can get one cheap.

You should see anyway with these DIY one tools, if the bore is round or not by the finish it produces, unless the entire bore was perfectly oval.
When I did my LS1 block at the end of July for a temp engine to get me to TOTB, the finish was bloody terrible !! My bores were so untrue.
So in August when rebuilding properly, I did have it honed properly with deck plate etc. Unfortunately I had to send it to England to get this done.

The whole deal with the flex-hone is that it follows whatever shape your bore is, so if it is oval, you'll neatly hone the hole oval. If it has worn recesses, the balls will neatly follow them and you won't see any sort of a mismatched finish like you do with one of them spring loades tone hones.

We use them on air compressor cylinders, that have ports in them like two strokes, and they neatly hone over the holes yet take the sharp edges off too.

stevieturbo · Post by **stevieturbo** » Sun Oct 28, 2007 11:28 pm

I guess mine wasnt quite a flex hone then. It was one with the 3 legs, and stones mounted on them, and you stick it in a drill.

No idea which would be better

dicky · Post by **dicky** » Mon Oct 29, 2007 6:23 am

It is one of theses...