Notices
Forced Induction Turbochargers and Superchargers..Got Boost?

Thicker headgasket for lower compression ratio

Thread Tools
 
Search this Thread
 
Old 10-14-2008, 05:07 PM
  #1  
hydroflip
Registered User
Thread Starter
iTrader: (2)
 
hydroflip's Avatar
 
Join Date: Sep 2007
Location: Brooklyn, NY
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default Thicker headgasket for lower compression ratio

i know it has been done by other N/A vehicles to "band-aid" a lower compression. however, companies like inlinepro.com and cosmetic.com have shown that this can also be a long term compression lowering method.

one installs a thicker than average(by the mm) under each of our heads.
this spaces the head out more, thus decreasing the compression ratio.
for boost, 9:1 or even lower.

i know of many cars that have used this method and were able to get 500whp out of motors that were normally limited to 300whp due to stock internals.

the catch is, your tuner must be top notch and he must meticulously do the tune. the second catch is that it is a band-aid for the real compression lowering job one by getting low comp pistons.

my question is, has anyone done this with the 350z?




my flame suit is on, so speak your mind and i know i'll get at least a couple good posts of peoples input.
Old 10-14-2008, 05:09 PM
  #2  
rr_z33
Registered User
iTrader: (2)
 
rr_z33's Avatar
 
Join Date: Mar 2007
Location: Hawaii
Posts: 1,268
Likes: 0
Received 0 Likes on 0 Posts
Default

not sure but my understanding was thicker headgasket higher compression not by that much. the thing is that it doesnt really matter because the rods are the weak link. the amount of torque they are subjected to doesnt change with compression.
Old 10-14-2008, 05:17 PM
  #3  
QuadCam
Registered User
iTrader: (8)
 
QuadCam's Avatar
 
Join Date: Apr 2003
Location: Vero Beach, Florida
Posts: 3,869
Likes: 0
Received 4 Likes on 4 Posts
Default

cometic will made any thickness gasket you want.

go too thick and you'll have issues with the timing covers lining up.
Old 10-14-2008, 05:33 PM
  #4  
wannabuy350z
Registered User
iTrader: (27)
 
wannabuy350z's Avatar
 
Join Date: Dec 2007
Location: SD SoCal | Jed, KSA
Posts: 1,301
Likes: 0
Received 2 Likes on 2 Posts
Default

the VQ35DE has gay rods
Old 10-14-2008, 07:12 PM
  #5  
SnyperZ
New Member
iTrader: (10)
 
SnyperZ's Avatar
 
Join Date: May 2008
Location: Connecticut
Posts: 1,175
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by rr_z33
not sure but my understanding was thicker headgasket higher compression not by that much. the thing is that it doesnt really matter because the rods are the weak link. the amount of torque they are subjected to doesnt change with compression.

you have it backwords. The thicker the gasket the more room inside the cylinder...so the lower the compression.
Old 10-14-2008, 08:12 PM
  #6  
go-fast
Banned
 
go-fast's Avatar
 
Join Date: Jun 2007
Location: under the hood
Posts: 1,342
Likes: 0
Received 0 Likes on 0 Posts
Default

you would have to add somewhere around .070 on top of stock compressed height to gain one compression point.hg should be used to fine tune compression ratio,not create it.with a flat top piston and that much volume you will destroy your squish and the motor would probably be a dud.
Old 10-15-2008, 04:05 AM
  #7  
Audible Mayhem
My350z
iTrader: (48)
 
Audible Mayhem's Avatar
 
Join Date: Oct 2005
Location: United States
Posts: 5,165
Likes: 0
Received 3 Likes on 3 Posts
Default

this is a V6 engine with timing covers that bolt to the block and the heads.


you cant raise or lower the heads much at all or the bolts that go into the block and heads in the permanent fitting timing cover wont line up at all....
Old 10-15-2008, 04:49 AM
  #8  
Car vs. Driver
Registered User
iTrader: (14)
 
Car vs. Driver's Avatar
 
Join Date: Dec 2007
Location: Middletown, DE
Posts: 603
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Audible Mayhem
this is a V6 engine with timing covers that bolt to the block and the heads.


you cant raise or lower the heads much at all or the bolts that go into the block and heads in the permanent fitting timing cover wont line up at all....
+1 ... don't bother, if you need lower compression replace the pistons. Also, put better rods in while you're at it.
Old 10-15-2008, 09:33 AM
  #9  
hydroflip
Registered User
Thread Starter
iTrader: (2)
 
hydroflip's Avatar
 
Join Date: Sep 2007
Location: Brooklyn, NY
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default

thank you go-fast and audible mayhem for the input. i guess this will lead me into my next post.

if anyone else has any input, please feel free to post.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Lt_Ballzacki
Brakes & Suspension
39
08-06-2021 06:19 AM
MicVelo
2003-2009 Nissan 350Z
34
05-30-2017 03:28 PM
ars88
Zs & Gs For Sale
18
04-04-2016 07:52 AM



Quick Reply: Thicker headgasket for lower compression ratio



All times are GMT -8. The time now is 05:23 AM.