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Engine Honing


Twitch de la Brat
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Going to do a hone on my EA81 and was curious about any tips on proper honing technique.

Such as if the oil is a requirement and if it's recommended to do it in a certain temperature range.

Figured this would be good info for anyone doing bottom end engine work.

Thanks in advance guys.

 

Twitch

 

PS: This is the hone I'm planning on using: http://www.amazon.com/gp/aw/d/B002PIBBSK/ref=ox_sc_act_image_1?ie=UTF8&m=A221LQEWFFVQAG

Edited by Twitch de la Brat
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I use a ball hone on slow speed lubed with 10-30 oil is very important to go up and down consistantly and smoothly and try not to stay at top of cly to mutch as they wear tapered so more honing at bottom of cly than top. I also putt a old gasket on top of block to protect it from scraches

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I use a ball hone on slow speed lubed with 10-30 oil is very important to go up and down consistantly and smoothly and try not to stay at top of cly to mutch as they wear tapered so more honing at bottom of cly than top. I also putt a old gasket on top of block to protect it from scraches

Thanks for the tip Ivan. I know about the taper, and shockingly this little EA81 has almost immeasurable taper on the cylinder :grin:

Even after 200k. But I will be focusing on the bottom of the bore more-so than the top.

Do you run the bore in spinning or slide it in and then start spinning it?

 

Twitch

 

PS: Part Number for the pistons is RY2666, an old Beck-Arnley number. Not sure who the pistons are officially made by yet.

Edited by Twitch de la Brat
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The rate of up and down is relative to the rotational rate... you are looking for a 45degree crosshatch, which means same speed up and down as the speed of the abrasive going around the cylinder.

 

If, at tear-down, you can still see hone marks top-to-bottom on the cylinders then their is little-to-no wear or taper.

 

The ring facing-type matters as to which hone grit you use.  A molybdenum facing requires only a mild hone, whereas a chromed facing requires a coarser hone in order to "wear in" the chrome facing.

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I have no idea what a "chrome-moly" is in this context.  (I am a little out of date on these things, so it could just be me :)  )  In my view of the world, typically you will have ductile iron compression rings, with either a chrome-plated facing or a molybdenum filled groove on the facing.   It's been over 30 years since I have done a complete rebuild on an engine, so I may be way out of date.

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"Chrome-moly" is an alloy featuring primarily chromium and molybdenum. The material tends to be extremely wear resistant as well as non-corrosive/corrosion resistant.

It is used heavily in high grade tools and long wear items (such as rings).

From my research, it appears to be the "premium" ring material. Your typical rings with be basic iron with maybe a moly face. The chrome face rings are probably chrome-moly.

 

Twitch

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Well, after a quick peruse around the web, including Federal Mogul, it would appear that chrome-moly alloy steel rings do not exist, at least not for automotive purposes.  Iron is the rule, with some industrial applications specifying "steel" rings.

 

(BTW, I have known about CrMo steel for many decades, just not in the context of piston rings where its properties are mismatched for the application.  My fault for being vague on my previous post.  Cheers!)

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Looks like I was looking at the wrong info, than you for the clarification. The pistons and rings I'm getting are ITM, so I'm not sure how they fall in the ranks of manufacturers. So far they seem to use the Beck Arnley part numbering system, and if their quality is similar, I should be good to go.

 

Twitch

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  • 7 months later...

This is one of the definite guides for Honing Cylinders, I always start out with a normal Sunnen type stone hone with three stones to make sure there are no hollows or high points, Flex Hones or ball Hones will follow the worn cylinder points so while it looks good it may not measure up so nice.

 

I do however use the Flex Hone for finishing as it gives you the ability to Plateau Hone for longer bore life, If you do not know what Plateau Honing is just look at this link for more detail on the whys and wherefores of Honing Engines correctly.

 

http://www.enginebuildermag.com/2000/09/cylinder-bore-surface-finishes/

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  • 3 months later...

A ball hone is the best for braking the glaze in a cylinder if you are reringing an engine .   A rigid hone is best for setting piston clearance after reboring a cylinder but will work if used sparingly .  DONT try to get out all the marks or scores in a used bore , its not neccesary and will create too much piston to wall clearance by the time you are done hacking away .  Remember , you are just breaking the glaze so the new rings will seat .  A nice even crosshatch is what you are looking for .  Subie cylinders are good material and rarely taper or wear very much .  

 

Another thing thats critical is to wash the honed bores out with hot soapy water  , NOT just solvent or brake clean .  Solvent takes out the oil but leaves the abrasive in the crosshatch to wear the new rings . You can use solvent first , but finish off with the soapy water .  Douche out the block completely with soapy water , rinse , and blow it out with compressed air and coat cylinders with oil so they dont flash rust and you are good to go .  Make sure the valve guides are tight and seals if used are new and you wont have any oil consumption problems .  

 

For break in I used to let the engine pull full throttle from about 15 -20 MPH up to speed in top gear back down again .  Do this maybe 10 times or so in a row and the new rings are seated .  

 

Bob

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  • 7 months later...

The very first car I ever had was a used 1971 Plymouth Duster with a 318 my dad bought for me for $200 saying how we would rebuild the engine. I was not interested in auto mechanics at that time as electronics and software were my geeky pursuits. I just wanted a car to drive.

 

So after the engine was apart, my dad decided he would hone the cylinders using those three stone setups on the end of a drill. All seemed fine until we took it to a machine shop to get the rest of the work done. The guy measured the cylinder walls and said it was done wrong and would have to be done oversize. It was the largest you could go before hitting the water jacket and the last time it could be rebuilt.

 

Sine then, I have never had the need to do honing but if I ever did it would be strictly done by a shop. Now there are those that know what they are doing when it comes to honing at home and more power to them. It is just not a job I would trust myself to be able to do right.

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