Pontiac Street Performance
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password

 All Forums
 Pontiac Performance
 Firebirds / Formulas/ TAs
 428 head gasket question
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

Merrik66
Cochise

USA
380 Posts

Posted - 17 Dec 2017 :  5:39:11 PM  Show Profile  Reply with Quote
Machine shop found I had a weld done at the top of the cylinder right at the ridge where the head gasket sealing ring expectedly would sit. It?s been zero decked and after a small tig weld and resurface he thinks we?ll be safe but that last step will put the pistons around .003 to .005 out of the hole. I?ve read this is ok. He assured me it would be. I?m scared. Nonetheless, the gaskets I had set aside for this are a bit bigger than the bore itself. Felpro. Is there any gasket makers out there which make a head gasket closer in diameter to the 428 with a .030 overbore? Thoughts about the whole scenario? Already had a bunch much of machine work done to this block. Main line, deck, etc. nervous.

Merrik66
Cochise

USA
380 Posts

Posted - 18 Dec 2017 :  12:22:40 AM  Show Profile  Reply with Quote
Sorry guys posted in wrong section
Go to Top of Page

Lee
Sitting Bull

171 Posts

Posted - 18 Dec 2017 :  2:26:22 PM  Show Profile  Visit Lee's Homepage  Reply with Quote
You can get Cometic gaskets, and I believe they'll make them to whatever specs you desire. Not cheap, but an option.

So, is the block cracked, is that the reason for the weld? If so, the shop should have found that before they did any of the other work. 5-thousandths out of the hole is not going to hurt anything, just give you a tad better quench.

CURRENT: '73 T/A clone, starting to get less boring!...
67 Firebird (sold) 11.27 @ 119.6 Feb. '05 issue HPP
69 Falcon wagon, 10.51 @ 130mph Feb. '10 issue PHR (sold)
72 Cutlass Convertible, first car, owned since '82, now with a 6.0 LS, mild, putting just under 400 hp/tq to the wheels.
www.LNLPD.com
Go to Top of Page

Merrik66
Cochise

USA
380 Posts

Posted - 18 Dec 2017 :  5:10:52 PM  Show Profile  Reply with Quote
Thanks for the reassurance Lee, wasn?t cracked. But it had to have been a factory casting issue. It was an obvious that it was a weld fill of some type about the size of a pencil eraser. It was about 1/8 from the top of the bore. What appears to have happened is that it was filled but had some small pits or bubbles in the weld itself. Was definitely not visible until we started to take material off to zero the deck. It magged good befor we started.
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
Pontiac Street Performance © 2006-2017 Go To Top Of Page
This page was generated in 0.12 seconds. This Site Sponsored By:
Powered By: Snitz Forums 2000 Version 3.4.05