Question about 81.5mm overbore pistons
08-20-2007, 12:50 PM
#1
1.5 BAR
Thread Starter
Join Date: Jul 2005
Posts: 1,069
Question about 81.5mm overbore pistons
Hi,
When I had my B18b block machined, I had the machinist bore my block to accept 81.5mm pistons (Topline brand Oem replacement .020 over pistons). If I want to upgrade to 81.5mm forged pistons (I was thinking SRP), is the bore needed the same as what is in there now, or will it differ slightly from manufacturer to manufacturer?
When I had my B18b block machined, I had the machinist bore my block to accept 81.5mm pistons (Topline brand Oem replacement .020 over pistons). If I want to upgrade to 81.5mm forged pistons (I was thinking SRP), is the bore needed the same as what is in there now, or will it differ slightly from manufacturer to manufacturer?
08-20-2007, 01:29 PM
#3
1.5 BAR
Thread Starter
Join Date: Jul 2005
Posts: 1,069
Re: Question about 81.5mm overbore pistons
Yeah, thats what I'll probably do. I hope that the Topline pistons I have in there now didn't call for a bore larger than that of an SRP 81.5mm piston. I would have to get a new block and spend the extra cash to get it re-machined. 
08-20-2007, 07:21 PM
#4
0.0 BAR
Join Date: Feb 2003
Posts: 0
Re: Question about 81.5mm overbore pistons
It's called the piston to wall clearance. Depending on the material of the pistons and the heat expansion and all that, the manufacturer of the piston will have a recommended piston to wall clearance. I wouldn't bore/hone a block until I had the pistons to match each hole.
08-20-2007, 08:02 PM
#5
Guest
Posts: n/a
Re: Question about 81.5mm overbore pistons
Originally Posted by Stealthmode
It's called the piston to wall clearance. Depending on the material of the pistons and the heat expansion and all that, the manufacturer of the piston will have a recommended piston to wall clearance. I wouldn't bore/hone a block until I had the pistons to match each hole.
08-20-2007, 09:23 PM
#6
1.5 BAR
Thread Starter
Join Date: Jul 2005
Posts: 1,069
Re: Question about 81.5mm overbore pistons
Originally Posted by Stealthmode
It's called the piston to wall clearance. Depending on the material of the pistons and the heat expansion and all that, the manufacturer of the piston will have a recommended piston to wall clearance. I wouldn't bore/hone a block until I had the pistons to match each hole.
Thread
Thread Starter
Forum
Replies
Last Post
claytonsmith
Wanted
0
11-29-2006 12:15 AM
2stockrocketz
Hybrid/Tech
10
11-01-2005 08:08 PM
