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-   -   400 block question? (https://www.racingjunk.com/forums/showthread.php?t=30018)

Prater22 03-08-2011 06:00 PM

400 block question?
 
I baught a 400 engine casting number 3951509 that is punched .060 over is this safe for a dirt modified? Let me know what you think.

fla1976 03-08-2011 06:05 PM

One way to know is to have it sonic tested.

hillzmod 03-08-2011 06:14 PM

what is sonic tested and where can it be done at

JEFF69Z28 03-09-2011 01:58 AM

509 BLOCK I THINK IS THE WEAKEST OF THE FACTORY 400 BLOCKS.
BECAUSE OF THE 4 BOLT BEARING CAPS.

mbaker3 03-09-2011 02:35 AM

Sonic Testing
 
Here is a brief article explaining what Sonic Testing is.

http://racingarticles.com/article_racing-73.html

hink 03-09-2011 03:32 AM


Originally Posted by fla1976
One way to know is to have it sonic tested.

X2!!!!!!!!!!!! and at the bore on a 400 block there is a good chance of cracking from the head bolt hole to the cylinder.

Look it over close

wrightway 03-09-2011 04:24 AM


Originally Posted by JEFF69Z28
509 BLOCK I THINK IS THE WEAKEST OF THE FACTORY 400 BLOCKS.
BECAUSE OF THE 4 BOLT BEARING CAPS.

not all 509s are 4 bolt

pistonpopper 03-09-2011 01:02 PM

i heard that that some shops drill the steam holes, thread them and plug them,to prevent cracking in this area, for drag race use. any experiences with this? i believe that a 509 block is one of the stronger 400 blocks. i have one in my garage now that is a two bolt block that has been studded,line bored, and filled to the bottom of the frost plugs.

markdunlap 03-09-2011 06:32 PM

400
 
To see what is required to add life to the head deck of a 400, you may want to check out the old Bill Jenkins smallblock chevy engine building book.

It details how to drill, tap, and plug the steam holes. It also shows to add plugs with holes in them to the big water holes in the deck and mods to other water holes.

I followed this once and the 400 block lived 7 full seasons of drag racing. It eventually cracked from a head bolt hole to the bore. Rest in Peace.

pistonpopper 03-09-2011 06:37 PM

mark, were you using studs,or bolts in the decks of that block?


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