Jump to content


186 piston sizes

186 pistons sizes 202

  • Please log in to reply
5 replies to this topic

#1 _bilby64_

_bilby64_
  • Guests

Posted 29 September 2016 - 12:03 AM

Hi all, 

I have been given a 186 engine and have pulled it down. 

5 pistons have a part number 7429479, this number is on the inside of the piston. 

1 piston has RAZ202Z 040 10P 01 QE, these numbers are on top of the piston. 

Are the 5 pistons equivalent to a 202 piston 4 thou over. 

Is anyone able to help?

Thanx, 

Bill. 

 

Attached File  Piston 1.jpg   33.98K   2 downloads

 

Attached File  Piston 2.JPG   39.31K   1 downloads



#2 dattoman

dattoman

    Do I feel lucky? Well, do ya, punk?

  • Administrators
  • PipPipPipPipPipPipPip
  • 16,471 posts
  • Name:Neil
  • Location:Perth Western Australia
  • Car:LX SS , 76 Cadillac , 3 x dattos
  • Joined: 04-February 07

Posted 29 September 2016 - 12:12 AM

40 thou over



#3 S pack

S pack

    Scrivet Counter

  • Members
  • PipPipPipPipPipPipPip
  • 15,540 posts
  • Name:Dave
  • Location:Luggage Point
  • Car:73 LJ
  • Joined: 25-January 10

Posted 29 September 2016 - 12:58 AM

RA2027 040 T0P 001 CE



#4 _bilby64_

_bilby64_
  • Guests

Posted 29 September 2016 - 01:23 AM

Thank you and would that the same for the 5 Pistons.
Bill.

#5 warrenm

warrenm

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 2,107 posts
  • Location:Central West NSW
  • Car:1972 LJ Torana
  • Joined: 08-November 05
Garage View Garage

Posted 29 September 2016 - 06:48 AM

Should be .040" over for all pistons, unless someone has done a dodgy job. Clean the tops of the other pistons to see.



#6 yel327

yel327

    Oh My, Don't you post alot

  • Members
  • PipPipPipPipPipPipPip
  • 13,086 posts
  • Joined: 10-February 08

Posted 29 September 2016 - 08:30 AM

Bill

 

It looks to me like someone has replaced a busted 186 piston with a 40 thou over 186 piston as a cheap job.

 

202 and 186 use an identical bore but 202 has a longer stroke with the same rod length hence the pistons are not interchangeable. Every other Holden red-blue-black 6 from 130ci to 186ci shared the same stroke and used a bigger bore but 202 is the only one where the stroke was increased. So for example a 179 is a 173 +0.0625" (or 1/16") bore, a 186 is a 179 +0.0625" bore.  







Also tagged with one or more of these keywords: 186, pistons, sizes, 202

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users