I am replacing my pistons with new ones of the same size .020. The cylinder bore walls are smooth. Is it absolutely necessary to hone the cylinder bore walls first? I read somewhere that you should for the new rings to properly set. If I do a light hone, do I need the next oversize piston .030?Thanks.

 

you need a cleanup hone to break the glaze and pattern the old rings left. if the bores are very smooth then the new rings may not seat and you will get lowered compression and blowby.

 

I saw a honing tool at autozone, had 3 stones on some fingers you attach to a drill. Is there a better tool to do a "clean-up" hone? Where can I get one?

 

you could take jugs to local auto machine shop and have them run a bead hone thru them a couple time and your good all you need to do is break the glase on them.

 

definitely my choice!!

 

How much should I expect to pay for that service? This really sounds like a simple thing to do. I am all about doing it myself to save, but if it does not cost more to de-glaze vs $25 for the tool then I am for paying a machine shop.

 

you should be able to find a berry hone for about 35-40 bones. i just did a quick spin w/some laquer thinner as lube and to clean it out real quick, wallllah. nice new cross hatch.

 

Well from a engine builders stand point you need to measure the cylinder and the piston to ensure you have the correct fitment. I can pull several pistons from JE here off the shelf all the same bore size and have sizes ranging from .0002-.0009. Better safe than sorry. Are they the same brand?? both forged, cast hyper?? Better safe than sorry. Take them to a machine shop have the checked. I have a set of Cast HD 80 inch pistons here that are just a tad over a thou from one to the other. This happens and they want you to check these specs before installing the pistons.

 

If the bores are smooth they may have a taper worn in them as well as out of round. A carefull check with a bore gauge is in order to determine if the clearances after cleanup are too much, in which case bigger pistons are in the works. If it mikes out ok then I'd just run a deglazer through the bore. It looks like a big pile of rabbit turds on the end of a wire stick, but have someone do it that knows how to put a good cross hatch hone pattern in there.
Ron

 

I found a reputable (almost famous) local machine shop here that will bore and hone for $100. They said they would bore to fit the pistons. I have decided to play it safe and have it done, since there is probably some variances in the bore. I am going to buy some KB 9.5:1 pistons and have it bored to the next oversize which will be .030. I think these pistons are cast but are high quality. From what I read here on this forum these pistons can be fit with closer tolerances. Thank you for your advice.