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Discussion Starter · #1 ·
Whats up guys.. I have few questions. which is better? How much hp does a 392 na motor put out? Will da new heads n cam work wit either of the motors or i need a whole new combo? Later i will put a turbo or supercharger. Also how long is the install for a new short block? Im on da border of buying a new motor or waiting till spring. So guys can i get some of ur input on this?
ohh n whats da install cOst?
Thanks in advance
 

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A 392 would be better for boost later, especially higher boost numbers.
 

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Discussion Starter · #3 ·

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nvm didnt see u wanted to add boost...i personally go with a 426 if i wanted boost + a new engine.
 

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Absolutely no question about it. 392 is better for boost, 426 is better for na. The heads and intake are perfect for a 392 or 426 but you will need to change the cam out.

Heads/cam install: 13 hours + 3 hours for tq converter (plus 20 hours later for shortblock)
392/426 install: 20 hours including converter
 

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It really depends on what your end goals are. Take time to think about what you really want, if you are really going to the track, or if you want a bad azz street set up. If you really want turbo either stay 6.1 and do heads and cam or if you want a NA set up go 426. I would price each step out towards what yo really want this way you make the best choice and you won't throw money away.
 

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Why is a lower displacement motor better for boost? Always have wondered why.
Thicker walls i believe.


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The cylinder wall thickness is the same, the change in displacement is due to a change in stroke.

We always push the 392 over the 426 for high boost/nitrous applications for 2 major reasons.

Compression Height and Crankshaft Overlap

Compression Height: When Compression Height gets as small as 1 inch, it often requires narrow piston rings. It may also require the rings to be closer to the top of the piston than you may want for nitrous or endurance use. Short piston height means lighter weight, which is good, but it may also give up reliability you need. Sometimes a compromise for less stroke or shorter rods is prudent.

426 Compression Height: 1.085"
413 Compression Height: 1.115"
393 Compression Height: 1.218"

The increased compression height allows us to utilize a thicker crown for extreme boost/n2o applications. You will slowly see us transitioning from 393 builds towards 413's for our higher hp applications. As soon as I get my car back, we will be building a 413 for it. The 393 is still going to be a stronger option, but the 413 will allow us to make the same amount of hp as a 393 with less boost due to the additional 20 cubes.


Crankshaft Overlap: Crankshaft overlap is simply how much of a crank's main and rod journal diameters overlap each other. As stroke is increased, moving the rod journals farther away from the main journals reduces overlap and compromises strength and durability.

426 Overlap: .255"
413 Overlap: .330"
393 Overlap: .430"
 

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Thank u for the correction andy. Very informative. PWR for the wiiiiiin


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Discussion Starter · #14 ·
Andy's a vendor here


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Discussion Starter · #16 ·
:) i was just trying be funny


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lol, that is funny.

And Harrison, your absolutely right in your thought process on the 6.1. It has even more overlap then the 392 although it has less compression height and possibly a weaker crank but thats very subjective. I dont think anyone has broken a 6.1 crank yet but no one has broken the 392 crank yet either and we are using that crank in Mr Norms car which has seen as much as 1500rwhp and 8200rpm. Mondo has a 6.1 crank that was precision ground and ion nitrided, it should be pretty damn strong.
 

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Well..... you know me. I like to push shit to the limit so we'll see how strong that 6.1L crank really is.:D
 

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lol, that is funny.

And Harrison, your absolutely right in your thought process on the 6.1. It has even more overlap then the 392 although it has less compression height and possibly a weaker crank but thats very subjective. I dont think anyone has broken a 6.1 crank yet but no one has broken the 392 crank yet either and we are using that crank in Mr Norms car which has seen as much as 1500rwhp and 8200rpm. Mondo has a 6.1 crank that was precision ground and ion nitrided, it should be pretty damn strong.
A couple blue pills will make anyone's crank harder. :eek::D:silly:
 
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