I picked up my 406 assembled short block awhile back, and didn't notice this tiny flaw in the deck until I got home. I dont' think it should hurt anything due to where its located. It's pretty shallow, I can just barely catch my fingernail on it. What's your opinions? I really dont want to tear this thing apart to deck it.

 

wow it would be nice to know how that happened. Not good. you could possibly get some cracks around there so i would watch out for that.

 

i would be concerned about the head gasket not sealing and possible cracks forming from that.

 

Its not nice, but ive had to put together worse, only coz people often dont want to know, when you tell them how much to get it dead right.
But touch wood none have ever gone wrong, depends a lot on if you are going to hammer this motor?
Its easier to repair now tho, before it goes in.

 

The short block is brand new, was a virgin gm block, so this happened when the block was still "stock". I am going to give this motor a little heck, but its not going to see any street use, trailer it to the track, race, tailer home.

 

If it really bothers you, fill it with Turcite, scrape it flat, and forget it.

 

Where can I get turcite? I did a quick google of it, all I could find were bar stocks of solid turcite.

Thanks for the help!

 

I used to be able to get that in pourable resin/hardener. I'll have to check sources at work. Your other options would be bronze putty/scraping, brazing the void full and machining it flat, or welding the void with a nickel filler material, then machining.

Frankly, the void looks small enough and in a relatively low stress area, and may not cause any problems.

 

Yea... me too.

 

You could just mill the block and call it good.

 

Looks like a casting void or some other defect. Maybe corrosion? If its a defect that occured during casting, its sort of ominous as there could be more hidden in the block. Anyway, if it was the only thing bad about the block, I wouldnt loose any sleep over it. Its not near anything really critical sealing wise and appears to be pretty shallow.

 

that spot in the deck is not going to cause you any problems.
It is not near the combustion chamber edge or near a water hole.. Probabily been there since day 1.

I would not try to fill it or anything. just assemble the motor and forget about it.

 

I agree with F-bird. It's a casting flaw and where it is it won't cause a problem. Decking it would turn a non-problem into a non-fixable problem. Sure hope those are forged pistons, there is some major clearance between it and the bore going by the pic.
~giving him something new to worry about~

 

If you are building a highh end motor you'll probably want to zero deck it anyway, and that should take care of it. I'd magnaflux it as well just to be safe.

 

Block has been magnafluxed and checked out ok. So f**k the flaw and just assemble the rest of it, sounds good to me!

I trust the people that did the machine work, and assembled the short block, they're a pretty big race shop here in Iowa. No, they aren't forged, I think the small radius at the top of the piston and the lighting makes it look like a bigger gap in there.

 

Like Dimented said that flaw isn't near any area that is critical for sealing, just put it together and forget it, it won't hurt a thing.