Decking Block While Keeping Numbers
#1
Instructor
Thread Starter
Decking Block While Keeping Numbers
Hi Everyone!
I'm in the process of rebuilding my 1969 L36 motor which blew a head gasket. There has been very minor damage to the block from the blown gasket and the rebuilder has told me there is a chance it may require decking. This motor is the original numbers matching motor so I need to keep the numbers at all cost. My machinist has told me its basically impossible to deck a block and keep the numbers using a non-CNC machine - Does any of you happen to know of shops around the Orange County/Los Angeles area that can accomplish this? I'm really hoping I dodged a bullet and that the damage is so minimal that is does not require decking. However, I think it's better to be prepared for the worst. Picture attached of the damage the head gasket did to the block. Pitting is very minor and is smooth to the touch. All I did after I removed the heads is took brake cleaner and rubbed the area very lightly with a rag.
Appreciate any help/insights you all can give! Thanks!
I'm in the process of rebuilding my 1969 L36 motor which blew a head gasket. There has been very minor damage to the block from the blown gasket and the rebuilder has told me there is a chance it may require decking. This motor is the original numbers matching motor so I need to keep the numbers at all cost. My machinist has told me its basically impossible to deck a block and keep the numbers using a non-CNC machine - Does any of you happen to know of shops around the Orange County/Los Angeles area that can accomplish this? I'm really hoping I dodged a bullet and that the damage is so minimal that is does not require decking. However, I think it's better to be prepared for the worst. Picture attached of the damage the head gasket did to the block. Pitting is very minor and is smooth to the touch. All I did after I removed the heads is took brake cleaner and rubbed the area very lightly with a rag.
Appreciate any help/insights you all can give! Thanks!
#2
yes it can be done with the proper machining equiptment. I have a picture of it done but this new way of posting pictures here is a pain in the ***
Last edited by PAmotorman; 07-10-2018 at 01:37 PM.
#3
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes
on
2,602 Posts
St. Jude Donor '05
QMP racing engines in Chatsworth has a CNC program to do just this. Used them many times.
818) 576-0816
818) 576-0816
Last edited by cv67; 07-10-2018 at 03:29 PM.
#5
Race Director
Member Since: Jan 2000
Location: Corsicana, Tx
Posts: 12,616
Received 1,877 Likes
on
915 Posts
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Clean it up and lay a straightedge across it and see if it's hurt. May be OK.
Ck head same way.
JIM
Ck head same way.
JIM
Last edited by 427Hotrod; 07-10-2018 at 03:41 PM.
#6
Instructor
Thread Starter
Regarding the heads - They've already been decked and are done. They are 1969 oval ports and came out to be 106cc after machining. I think he put 2.19s in to get those extra CCs.
Last edited by Dammakins; 07-10-2018 at 04:13 PM.
#7
Instructor
Thread Starter
Hi Fellas,
In case you were curious, I spoke with the machinist last night who informed me that the head gasket did not wound/damage the block enough to where it requires decking. Looks like I dodged a bullet.
Thanks!
Alex
In case you were curious, I spoke with the machinist last night who informed me that the head gasket did not wound/damage the block enough to where it requires decking. Looks like I dodged a bullet.
Thanks!
Alex
#9
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes
on
2,602 Posts
St. Jude Donor '05
If you mag the heads and they arent cracked, Id surface them anyways just to make sure they are flat as possible. Not a have to but probably should thing.
#10
Instructor
Thread Starter
#11
Le Mans Master
Member Since: May 2008
Posts: 8,966
Received 2,686 Likes
on
1,414 Posts
2022 C3 of the Year Finalist - Modified
I know nothing at all about deck machining, but I find it very hard to believe in the modern world of CNC machining that you could not deck an engine, and retain the VIN number pad.....in fact, I don't believe it. If someone tells you that...go somewhere else.
#13
Administrator
Member Since: Jul 2000
Location: About 1100 miles from where I call home. Blue lives matter.
Posts: 51,414
Received 5,331 Likes
on
2,775 Posts
And absolute worst case scenario don’t agree to let anyone near the engine who doesn’t clearly agree the numbers will not be touched. Wrap the block up in plastic and replace it first.