Motor for MP122

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02-07-2009, 02:30 AM

#21

SuperchargedSS

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Quote:

Originally Posted by zippy

My guess would be around 2k for the short block. One of my friends did one like that with only around 9:1 compression and ran a Procharger on it. We had it to as high as 16psi, but that wasn't very belt friendly. At somewhere around 6psi or so it made 495RWHP through a 4L65E, 14 bolt rear, and 20" wheels on 91 octane.

$2K isn't bad at all. Maybe that'll be on my wish list after I get the 122 installed and get my rear and tranny built up! Thanks for the info sir!

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02-07-2009, 06:06 AM

#22

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Quote:

Originally Posted by stock48

I would run either a Iron block 346 with Mahle pistons ~10:1 CR and Scat I beam or LQ9/LS2 style rods, or a 6.0L set up the same way.

346....is that a stock bore LS1 or something done with a 6.0L bore and a 4.8L crank? It's too early and I'm too lazy to do the math.

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02-14-2009, 06:17 PM

#23

GoatChs

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346ci in an iron block is (usually) a 4.8/5.3 block bored to 3.898 (LS1 std bore), using std bore dia. LS1 pistons and LS1 3.622" stroke crank--rod length is your option based on the pistons you select (normally std LS1 6.098" rod length or a 6.125" aftermarket).

HONESTLY, at this point I wish I would have stayed with a 347ci instead of the 383ci...I would be in tall cotton instead of "searching" for the optimal components to make the 383/122hh perform the way I anticipated.

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02-15-2009, 07:00 AM

#24

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I guess I'm going to stay with 6.0L size and use the stock crank. I'll upgrade the rods and find some forged pistons that would get my static C/R in at around 10.5:1 with the stock heads. Where's a good place to find the pistons and rods? I don't think I'll do anything to the heads other than a good valve job. I just don't believe there's much extra power to be had by doing headwork on my setup. Think I'll leave the LS6 cam in the mix too. Might try an O/D crank pulley to speed the 122 up a bit. Thanks for all the tips!

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