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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!
Clean it up and lay a straightedge across it and see if it's hurt. May be OK.
Ck head same way.
JIM
Thanks Jim - Prior to handing it off the machinist, I did lay a straight edge across it and it seemed good. Pitting was extra extra minor. After I took brake cleaner and wiped it across the area with a rag, it smoothed it out. At this point, the only thing that's bad with it is the discoloration. However, I don't have the tools to measure the thousands of an inch it may or may not have wounded it.
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; Jul 10, 2018 at 04:13 PM.
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.
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.
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.
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.
I got them magged and they were good. I had machinist surface them as well so all good on the heads too.
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.
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.
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.
Decking Block While Keeping Numbers
