Well, I've been wanting to get some pistons, and today I decided to look through the Wiseco catalog. So, I search through it, and find two different pistons for the Beta 1. Now, I know NOTHING about pistons. All I know about is compression ratios. All those other numbers, I've got no idea what they mean.

So, could anyone just give me a brief explanation of what they mean? I'd really appreciate it.

 

I think there are 2 pistons with different bore diameter - 82.5 mm and 83 mm.

Stock bore is 82.0 mm so you will need to machine the block to fit them.

 

If those aren't the numbers your talking about(82.5mm and 83mm) which they probably are... then your going to have to give us a bit more info on the numbers your seeing. For all we know it could be page numbers... one piston on page 33 and the other on page 34.

 

http://www.wiseco.com/PDFs/Catalogs/SC06_H...azdaMCooper.pdf

Bore--------Oversize--Stroke--RodLength--CompHt.-HeadCC-DomeDish-GasketThickness
82.50/3.248__.020____3.681__5.753_____1.220____46-49__-11.5______.028
83.00/3.268__.040____93.5___146.1______31______46-49__-11.5______ 0.71

So, which would be better for a daily driver/require the least amount of modifications to the engine? Both are 8.8-1.

 

the ones that dont require the engine to be bored as much? i dont knw either, but that'd be my guess.

 

Wiseco is F-ed up. The top piston is listed in English measurements. The bottom piston is listed in Metric AND English measurements. No wonder you're confused.

inches multiply by 25.4 to get to mm
MM Divide by 25.4 to get Inches.
_______Bore_Oversize--Stroke--RodLength--CompHt.-HeadCC-DomeDish-GasketThickness
Inches_3.248__.020____3.681__5.753_____1.220____46-49cc__-11.5cc______.028 Inches
MM____82.50__.50______93.5___146.1_____30.1_____46-49cc__-11.5cc______0.71 mm

_______Bore_Oversize--Stroke--RodLength--CompHt.-HeadCC-DomeDish-GasketThickness
Inches_3.268__.040____3.681__5.753______1.220___46-49__-11.5______ .028 Inches
MM____83.00__1.0_____93.5___146.1______31______46-49__-11.5______ 0.71 mm


Basically, one is made for 82.5mm bores (.5 mm overbore) and one is made for 83mm bores (1mm overbore)

Hope that helps

 

OEM pistons comes in 5 sizes:
STD (82 mm)
82.25 mm
82.5 mm
82.75 mm
83 mm



To fit anything that is bigger than 82 mm you need to machine block (make bigger bore).
It doesn't matter if you go 82.5 or 83 mm labor will be the same and work will be the same.

I would choose 82.5, cause later, in future I will be able to overhaul my engine again and go with 83 mm.