85.5mm bore with boost??? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-28-2011, 11:40 PM   #1
Senior Member
Thread Starter
iTrader: (6)
 
Join Date: Jun 2010
Location: San Rafael, CA
Posts: 1,125
Total Cats: 41
Default 85.5mm bore with boost???

Has anyone run the 85.5mm Supertec pistons with boost? I was wondering if the walls become to thin at that point.
k24madness is offline   Reply With Quote
Old 11-29-2011, 12:44 AM   #2
Elite Member
 
Join Date: Jul 2007
Location: Little Rock, AR
Posts: 3,110
Total Cats: 127
Default

Why couldn't you bore then sleeve the block?
jacob300zx is offline   Reply With Quote
Old 11-29-2011, 01:00 AM   #3
Senior Member
Thread Starter
iTrader: (6)
 
Join Date: Jun 2010
Location: San Rafael, CA
Posts: 1,125
Total Cats: 41
Default

Good idea.
k24madness is offline   Reply With Quote
Old 11-29-2011, 01:16 AM   #4
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,312
Total Cats: 1,335
Default

Sonic test block. Close attention to top of bore on thrust side. .090 absolute minimum, .120 preferred.
emilio700 is online now   Reply With Quote
Old 11-29-2011, 07:38 AM   #5
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,363
Total Cats: 1,324
Default

Quote:
Originally Posted by emilio700 View Post
Sonic test block. Close attention to top of bore on thrust side. .090 absolute minimum, .120 preferred.
This. We threw a perfectly good 01 block away this year because an incompetent engine shop decided to jam 85.5s in it without checking first. #3 came out at .060" and the customer was forced to supply us with a new block to continue the build.
Savington is online now   Reply With Quote
Old 11-29-2011, 11:00 AM   #6
Senior Member
Thread Starter
iTrader: (6)
 
Join Date: Jun 2010
Location: San Rafael, CA
Posts: 1,125
Total Cats: 41
Default

It sounds like the 84mm are the safe bet then. Are there some years that have more material than others or is it just luck?
k24madness is offline   Reply With Quote
Old 11-29-2011, 10:43 PM   #7
Senior Member
iTrader: (3)
 
Join Date: Jun 2008
Location: Port Orchard, WA
Posts: 620
Total Cats: 4
Default

Quote:
Originally Posted by Savington View Post
This. We threw a perfectly good 01 block away this year because an incompetent engine shop decided to jam 85.5s in it without checking first. #3 came out at .060" and the customer was forced to supply us with a new block to continue the build.
That block averaged .060" thick on the front side of the bores... the thinnest spot was .049"! The thin area was also about .400" tall just under the deck, which is the worst possible place for it to be thin. Having only sonic checked that one block, I don't know if the block castings are subject to core shift, or whether the machine shop machined it incorrectly as the rear of the cylinder walls averaged ~.200".

If you really want to throw a big oversize in, I'll second Emilio and say definitely sonic check it. I'd also tend to stay towards the thicker side of Emilio's recommendation for any FI engine.
Rennkafer is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
LucaCarMods's Boosted Dutch Miata Build! LucaCarMods Build Threads 11 02-14-2016 07:13 AM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 01:15 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:16 PM.