The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Engine & Drivetrain > LSx Swaps

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 04-20-2018, 08:08 PM   #1
Gunnin4ya
Registered User
 
Join Date: Mar 2015
Location: Moore, Ok
Posts: 93
5.3 pistons

I searched and couldn't find an answer for some reason. My question is will 3.809 piston work when my machinist says the block is 3.810 without problems? My first is build and don't want to screw up. I can find a ton of 3.809 piston but trouble finding 3.810. Thanks in advance.
Gunnin4ya is offline   Reply With Quote
Old 04-22-2018, 07:22 PM   #2
88Stanger
Registered User
 
88Stanger's Avatar
 
Join Date: Mar 2015
Location: Washington State
Posts: 1,644
Re: 5.3 pistons

have it bored out .020 over stock and get .020 over pistons
88Stanger is offline   Reply With Quote
Old 04-23-2018, 12:45 PM   #3
71cadc10
Registered User
 
71cadc10's Avatar
 
Join Date: Apr 2004
Location: Boiling Springs, PA
Posts: 435
Re: 5.3 pistons

some pistons (most) are listed in a size for the finished bore. so a piston labelled 3.809 is the bore size the block should be machined to.
the actual piston measured might be ~.003" under that.

http://https://www.summitracing.com/parts/slp-h1132cpa75mm/overview/make/chevrolet

if you look at the p/n's for something like this...basically the stock replacement GM piston...the end of p/n has 75MM. Since we are talking 5.3L and everything is metric now...that is 0.75mm over size (=.030").
if you see a 50MM at end...it is 0.5mm oversize (=.020").
These oversize numbers is what the bore should finish at in the block, the pistons are smaller when you measure them to give proper clearance.

I guess you need to clarify with your machinist what exactly you need...sounds like he is talking .030 (0.75mm) over stuff.
or better yet maybe ask him to source the pistons if the price is fair...and then he's on the line to get it all married together
__________________
71 C10 long bed, 2003 6.0L, 06GTO E40, T56, 12bolt 4.10 rear
71cadc10 is offline   Reply With Quote
Old 04-23-2018, 05:03 PM   #4
Root2812
Registered User
 
Root2812's Avatar
 
Join Date: Aug 2011
Location: Barnum, Mn
Posts: 795
Re: 5.3 pistons

I agree with that 71cadc10 said. When I did my first engine build (a 5.3 also) I had my machinist order the pistons for me and when I picked up my engine I got the new pistons already attached to the rods so all I had to do was assemble the engine. It takes the guess work out of things to get a little help.
__________________
My 1950 Chevy build
Root2812 is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:18 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com