WHen putting new pistons into a block, is it necessary or 'highly recommended' to bore? Also, while anyone is reading this...I've done a search on removing 1 layer of a 3 layer headgasket to increase compression and never really seen a straight answer. Anyone have any insight???

 

It's always recommended to re-hone the block when putting new pistons in, unless your pistons are oversized or your cylinder walls are scared then go ahead and bore. But no more than .5 mm unless you want to resleave the block. For the two-layer gasket creation, just pull apart the layers like an oreo and remove the center; this would be a Y8 headgasket by the way.

 

it depends on whut rings u use, and the condition of the cylinder walls.

if the block has no abnormalities , and cross hatch pattern looks good. usually fine on low mileage honda blocks. ive gotten away with using factory honda rings without honing at all , no smoke either.

if you are using any type of aftermarket rings that are chromoly or some other material , hone and pray

i love factory rings

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fobtions &raquo;</TD></TR><TR><TD CLASS="quote">it depends on whut rings u use, and the condition of the cylinder walls.

if the block has no abnormalities , and cross hatch pattern looks good. usually fine on low mileage honda blocks. ive gotten away with using factory honda rings without honing at all , no smoke either.

if you are using any type of aftermarket rings that are chromoly or some other material , hone and pray

i love factory rings</TD></TR></TABLE>

Does it take some luck to get everything working well with aftermarket rings??? Is it better just to go with factory? I assume honda makes oversized rings for larger pistons? Thanks for the help.

 

you don't need to hone unless the cylinder is damaged. you do want to put the cross hatching on the walls though. if there is a cross hatching then it doesn't matter what rings cause they will break in. chromemoly rings break in a little slower but are better for wear. about the head gasket i don't think it is worth it. you'll be removing lessthan .001 after it is torqued. your compression will not make a notisble change. its better to change pistons for the compression and not have to worry about the integrity of your head gasket with higher compression

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by litshoot &raquo;</TD></TR><TR><TD CLASS="quote">you don't need to hone unless the cylinder is damaged. you do want to put the cross hatching on the walls though. if there is a cross hatching then it doesn't matter what rings cause they will break in. chromemoly rings break in a little slower but are better for wear. about the head gasket i don't think it is worth it. you'll be removing lessthan .001 after it is torqued. your compression will not make a notisble change. its better to change pistons for the compression and not have to worry about the integrity of your head gasket with higher compression</TD></TR></TABLE>

Cool, thanks for the information. How exactly is a cross hatch applied my a machinist???

 

Ok, here's the big question. I'm probably goign to be able to get an awesome awesome awesome deal on some 81mm pistons and rings. Naturally, I'd like to stay stock bore so that I could use these pistons. Is it possible to remove the tiniest amount of material so that I can stay within clearences and keep stock bore????

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spankjelly &raquo;</TD></TR><TR><TD CLASS="quote">Ok, here's the big question. I'm probably goign to be able to get an awesome awesome awesome deal on some 81mm pistons and rings. Naturally, I'd like to stay stock bore so that I could use these pistons. Is it possible to remove the tiniest amount of material so that I can stay within clearences and keep stock bore????</TD></TR></TABLE>

Bump because I need an answer to this asap!

Err....sorry. But another question while I'm bothering you guys. Will rings meant to fit a 81mm piston fit on a 81.25 piston? I know the rings need to be gapped anyway. Same with a headgasket, I'm under the impression that a headgasket with 81mm bore can fit on a motor with 81.25 bore.

 

just a small tip of advice. spend the extra cash to have your block looked at to make sure the cylinders are not out of round. it's a very simple process. the measurements will determine whether or not you will need to bore.

also, if you ever get the chance to see a 81.25 mm block, place a 81 mm piston in the cylinder. it's not much play, but it does have space to move.

 

here's the thing if your gunna be workin a few engines a dial bore guage will quickly and easily tell you if there is any out of round and taper in the cylinder. the tool to make cross hatching is fairly inexpensive and hooks up to a drill. if you feel confident do a few practice runs on like a lawn mower engine cause there cheap. for the piston your talkin a quarter of a millimeter. just make sure the gap in inside of the specs and it should not be a problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by litshoot &raquo;</TD></TR><TR><TD CLASS="quote">for the piston your talkin a quarter of a millimeter. just make sure the gap in inside of the specs and it should not be a problem</TD></TR></TABLE>

Now I don't mean to be an ***, but on any engine I know of, a quater of a millimeter is a long way. To just bore it out to 81.25mm and throw in 81mm will not only make it sound like a deisel for 20 seconds, but cost you a motor. The service limit on piston to cylinder wall clearence is 0.05mm. There is a reason Honda sells oversize pistons and rings.