NastyZ28 Forum



Go Back   NastyZ28.com > Drivetrain & Performance > High Performance Modifications
User Name
Password

Reply
 
Thread Tools Display Modes
Old 04-10-2009, 12:44:19 AM   #1
ss monte
New Member
 
Join Date: Mar 2009
Location: pontiac michigan
Posts: 11
Red face L2307af 4.270 ?

Big Problem Im Putting Together A 454 Bbc High Comp Motor Im Using Or Was Going To Use A Trw L2307af 30+ Piston. Block Is Bored 30+ 4.280 I Bought These Through Ebay Nos Pistons They Looked Great. Untill I Went To Check Bore Clearence And Found Out That After I Miced The Pistons They Are 4.270 0,005 Under My Minimum Recomended Specs. Trw Says They Cant Be More Than 0.0055 Clearence Wich Means The Pistons Have Got To Be 4.750 Could They Have The Wrong Pt# Stamped On Them. They Are Probley At Least 10 Yrs Old But They Were Nos If Any One Could Give A Clue Of Just What This Piston Is Thanks Looks Like I Will Be In The Market For New Slugs Ss Monte
ss monte is offline   Reply With Quote
Old 04-10-2009, 01:33:04 AM   #2
ss monte
New Member
 
Join Date: Mar 2009
Location: pontiac michigan
Posts: 11
[quote=ss monte]Big Problem Im Putting Together A 454 Bbc High Comp Motor Im Using Or Was Going To Use A Trw L2307af 30+ Piston. Block Is Bored 30+ 4.280 I Bought These Through Ebay Nos Pistons They Looked Great. Untill I Went To Check Bore Clearence And Found Out That After I Miced The Pistons They Are 4.270 0,005 Under My Minimum Recomended Specs. Trw Says They Cant Be More Than 0.0055 Clearence Wich Means The Pistons Have Got To Be 4.750 Could They Have The Wrong Pt# Stamped On Them. They Are Probley At Least 10 Yrs Old But They Were Nos If Any One Could Give A Clue Of Just What This Piston Is Thanks Looks Like I Will Be In The Market For New Slugs Ss Monte
ss monte is offline   Reply With Quote
Old 04-10-2009, 03:28:32 AM   #3
74RAT
Veteran Member
 
Join Date: Dec 2003
Location: ft. stockton,tx,usa
Posts: 3,400
i am using that piston currently in .060 over. L2307AF60 speed pro version of TRW. has .580 dome. has graphite coating on the skirts. mine are in at .006 clearance.

sounds like a box of seconds you may have there,, or ones that couldn't be sold in the past,, for just your reasons. either new pistons,, or bore/hone a block to fit those pistons.

if you use them,,, make sure those skirts haven't been collapsed,, or been dropped or something like that.

do they all mic that small from the top of skirt to bottom of skirt? should be about .002-.003 skirt taper from the skirt tips to the top,, just under the oil ring land. forged pistons have more skirt taper for the increased heat expansion of the piston head/crown area compared to a cast or hyper.

mine measured .0055 under the nominal oversize at 90* to the base of the lower pin bore support area...... and recommended that for clearance. i used .006 clearance.
andy
__________________
you know you really blew it when,,, all your parts will again,, fit loosely in a 5 gallon bucket!!!!
74RAT is offline   Reply With Quote
Old 04-10-2009, 03:31:40 AM   #4
74RAT
Veteran Member
 
Join Date: Dec 2003
Location: ft. stockton,tx,usa
Posts: 3,400
trw says they can't be LESS than .0055 clearance. they'll seize up in the bore. just to clearify. that's a minimum clearance listed.
andy
__________________
you know you really blew it when,,, all your parts will again,, fit loosely in a 5 gallon bucket!!!!
74RAT is offline   Reply With Quote
Messages from Our Sponsors !
Awesome NastyZ28.com Merchandise !!

T-shirts, wearing apparel

Drinkware, Mouse Pads, Decals

Old 04-10-2009, 02:33:05 PM   #5
ss monte
New Member
 
Join Date: Mar 2009
Location: pontiac michigan
Posts: 11
Yes They All Are The Same These Look Brand New They Still Have The Maching Grooves On The Skirt The Skirt Is Not Coated So There Over9 Years Old I Think Im Screwed My Block Has Allready Been Bored Big Mistake Not Having Pistons In Hand Befor Boring Ss Monte
ss monte is offline   Reply With Quote
Old 04-10-2009, 07:51:47 PM   #6
74RAT
Veteran Member
 
Join Date: Dec 2003
Location: ft. stockton,tx,usa
Posts: 3,400
pistons are someting i'll only purchase from the mfgr or a reputable reseller. not a one time shot type company.

if it were me,, i'd go after that dude and get your money back,, then go through a reputable dealer so you get a piston set that mic's out correctly....... jmo.
andy
__________________
you know you really blew it when,,, all your parts will again,, fit loosely in a 5 gallon bucket!!!!
74RAT is offline   Reply With Quote
Reply




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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



Copyright © 1997 - 2014 NastyZ28.com Inc.
Powered by vBulletin Version 3.5.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.