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

block bore chamfer

Old Jun 16, 2017 | 06:09 PM
  #1  
gtred's Avatar
Thread Starter
Junior Member
 
Joined: Apr 2011
Posts: 301
Total Cats: 4
From: Oregon
Default block bore chamfer

I've got an odd potential problem with a block after machine work was done. I'd like to ask if any of you have any issues with a bore campher like this?
I took this to a reputable race shop. I had them bore and hone the block and set up my ring end gaps. They radiused the top of the bore, which made assembly quite easy (the pistons literally fell in). But, after placing my head gasket it looks like the beveled edge could slightly undercut (maybe .010 - .015") a portion of the head gasket (depending on where the gasket can shift upon the alignment dowels). Before I load up the block and have the shop re-inspect, are there any thoughts any potential problems here?... or am I just over thinking this?

Last edited by gtred; Jun 16, 2017 at 06:35 PM.
Old Jun 17, 2017 | 03:47 PM
  #2  
Stealth97's Avatar
Elite Member
iTrader: (5)
 
Joined: Oct 2007
Posts: 2,156
Total Cats: 67
From: Canton, Ga
Default

You definitely DO NOT want the head gasket intruding into the chamber.
Old Jun 23, 2017 | 05:59 PM
  #3  
gtred's Avatar
Thread Starter
Junior Member
 
Joined: Apr 2011
Posts: 301
Total Cats: 4
From: Oregon
Default

I had thought about using a larger bore cometic head gasket. However, these are thicker (0.40") than the oem (0.30") gasket. I already have too much quench area with the JE 9:1 pistons (they are .020 below deck).

I remember an old trick that an engine builder showed me once. It used to be that you had to O-ring your block with a steel wire as the oem gaskets were often not able to hold with high compression or forced induction. What he showed me to do was to paint the gasket with a light coat of shaker can silver spray pain (which is essentially aluminum suspended in the paint) to help glue the gasket exactly where you wanted it; and keep it from slipping when installing the heads. I think that I'll do this.

I wonder if the other low compression pistons (wiesco, supertech, etc) deck out at -.020? Even the OEM msm pistons deck at -.005 (0.035" piston to head clearance) and have attention to the blending of the quench area to the minor dome. You'd think that a purpose built performance piston would be designed at least as thoughtfully as OEM. OEM MSM miata pistons @ TDC
JE 9:1 @ TDC

Last edited by gtred; Jun 23, 2017 at 06:10 PM.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Eunos91
Build Threads
215
Jan 29, 2026 04:44 PM
elior77
Build Threads
302
Jun 17, 2021 04:48 PM
achervig
Engine Performance
16
Jan 30, 2017 02:29 PM
Euphues
Engine Performance
6
Oct 21, 2016 11:55 AM
Virus
DIY Turbo Discussion
9
Nov 22, 2006 10:42 PM


Thread Tools
Search this Thread

All times are GMT -4. The time now is 03:01 AM.