400 sbc deck hight?

crazycuda · Post by **crazycuda** » Wed Dec 21, 2005 3:28 am

Anyone know what the blueprint spec deck height for a 400 sbc is supposed to be. All I have is a measurement between 9.020-9.025 in my books.
Thanks

CNC BLOCKS · Post by **CNC BLOCKS** » Wed Dec 21, 2005 7:10 am

9.025 is blue print on a 400 block.

machine shop tom · Post by **machine shop tom** » Wed Dec 21, 2005 5:05 pm

Many of the blocks 400 SBCs I check before decking are at 9.033" to9.035" Makes a BIG difference to zero-deck them!

tom

Wolfplace · Post by **Wolfplace** » Wed Dec 21, 2005 8:43 pm

machine shop tom wrote:Many of the blocks 400 SBCs I check before decking are at 9.033" to9.035" Makes a BIG difference to zero-deck them!

tom

=
Inquiring minds need to know,,, how is there a difference?
If you are decking to zero what changes

As Carl stated, the "blueprint deck" is 9.025

machine shop tom · Post by **machine shop tom** » Wed Dec 21, 2005 10:53 pm

Wolfplace wrote:
machine shop tom wrote:Many of the blocks 400 SBCs I check before decking are at 9.033" to9.035" Makes a BIG difference to zero-deck them!

tom
=
Inquiring minds need to know,,, how is there a difference?
If you are decking to zero what changes

As Carl stated, the "blueprint deck" is 9.025

I am speaking of the difference between an undecked block that measures at 9.035" and then decking it to 9.00" to achieve a zero-deck height. Doing so increases compression (obviously) and promotes more efficient quench. An engine with .035"-.040" quench will run more efficiently (all else being equal) and will be less prone to detonation than one with .065" to .070" (undecked).

There are a lot of guys slapping together street (and some track) engines without decking the block. When you do an engine properly for these guys they pretty much have to wear a diaper the first time they try it out.

tom