Cometic head gasket question - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 08-20-2011, 04:04 PM   #1
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jan 2008
Posts: 161
Total Cats: 0
Default Cometic head gasket question

I got a quick question about 84mm vs. 83mm head gasket.

Recently purchased a Cometic HG from Good-Win, by mistake the one I received is 84mm, instead of 83mm, which the BP engine block is not bored.

Just to check how different they are I had a spare old 83mm factory metal head gasket and placed it in top of the new Cometic 84mm. Spent like 5 minutes comparing the two and could not see a difference.

I want to prevent to go through the hassle of returning it, wait for the other one, the car has been in the garage for a while and want to put everything back together.

Is it possible to use the 84mm Cometic on the 83mm BP block?

It "seems" to the naked eye that both gaskets are the same bore size, besides that the quality and craftmanship of Cometic is evident.
psiturbo is offline   Reply With Quote
Old 08-20-2011, 08:09 PM   #2
Junior Member
 
Join Date: Sep 2010
Location: Wahiawa, HI
Posts: 237
Total Cats: -3
Default

I'd play it safe and get the one that's right.
x808drifter is offline   Reply With Quote
Old 08-20-2011, 10:46 PM   #3
Elite Member
iTrader: (8)
 
Join Date: Dec 2008
Location: Kingston, Ontario
Posts: 2,791
Total Cats: 71
Default

get a micrometer, open 1mm, try to see through it, notice that it is virtually nothing and then proceed to install the HG into your car.


now, if you were bored to 84mm and had an 83... that would be more of a problem.
shlammed is offline   Reply With Quote
Old 08-21-2011, 11:21 PM   #4
I'm Miserable!
 
Join Date: Aug 2011
Posts: 17
Total Cats: 0
Default

Don't thicker headgaskets raise cylinder compression?
dubtastic is offline   Reply With Quote
Old 08-21-2011, 11:38 PM   #5
Junior Member
iTrader: (3)
 
Join Date: Jun 2011
Location: Charlotte, NC
Posts: 277
Total Cats: 24
Default

No, a thicker gasket will lower compression
RussellT94 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 57 07-19-2017 05:11 PM
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
Another Alternator thread ihiryu General Miata Chat 9 09-28-2015 11:22 AM


Thread Tools

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 06:39 AM.