Overbore questions for a d16 engine.
 

Hey guys, I have a few questions to ask.
I personally have assembled a few engines in the past but non required an overbore. I am going to be rebuilding two fairly high KM Honda engines but I'm just having a few problems understanding the over bore process.


ok, factory bore size on a d16 is 75mm...now from what I understand, there are two main overbore sizes that can be done .025 and .050
So if I were to overbore a 75mm engine by going .025, would that make the bore 75.25mm?

if the bore of the cylinder walls is 75.25mm...what size piston would I need to purchase.
Reason I'm asking is because on the first engine, I want to have the cylinder walls bored out by .025" but the pistons I was sent have 75.5 stamped on top of them.
Was I sent the wrong pistons? or am I all confused and lost?

thanks https://honda-tech.com/forums/images/smilies/emthup.gif

Re: Overbore questions for a d16 engine. (Mr.R)
 

ok, I was pretty confused but got my issue resolved....thanks to a local guy on a forum. I'll keep this here just incase somebody else ever needs this for reference or clarification. https://honda-tech.com/forums/images/smilies/emthup.gif

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HELP &raquo;</TD></TR><TR><TD CLASS="quote">You just have your measurements a little confused.

The two common boring sizes you refer to are .020" and .040". Thus if you bore .020" on a stock d16, you dont end up with 75.25mm. You need to convert inches to mm, and then add.

.020" = .5mm
.040" = 1mm

So if you want the cylinder walls bored out by .020", then you require the 75.5mm pistons, which you already have.</TD></TR></TABLE>

Re: Overbore questions for a d16 engine. (Mr.R)
 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.R &raquo;</TD></TR><TR><TD CLASS="quote">Hey guys, I have a few questions to ask.
I personally have assembled a few engines in the past but non required an overbore. I am going to be rebuilding two fairly high KM Honda engines but I'm just having a few problems understanding the over bore process.


ok, factory bore size on a d16 is 75mm...now from what I understand, there are two main overbore sizes that can be done .025 and .050
So if I were to overbore a 75mm engine by going .025, would that make the bore 75.25mm?

if the bore of the cylinder walls is 75.25mm...what size piston would I need to purchase.
Reason I'm asking is because on the first engine, I want to have the cylinder walls bored out by .025" but the pistons I was sent have 75.5 stamped on top of them.
Was I sent the wrong pistons? or am I all confused and lost?

thanks https://honda-tech.com/forums/images/smilies/emthup.gif </TD></TR></TABLE>

it's .010" and .020" aka .25mm and .5mm over

you have your measurement signals crossed.