LQ-4 Questions
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TECH Apprentice
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From: New Hampshire
LQ-4 Questions I have a 2006 LQ-4 thats up and running but may consider doing a rebuid. Couple of questions, How big an over bore can be done? How much can the stock cast crank take if it were nitrided, chamfered, and polished. Would plan to go with forged pistons and new forged aftermarket rods. Would like to do a complete Scat rotating assembly, but those are big bucks. Just looking for an alternative. Car would be drag raced just for fun, not competitive. I want it to hold up though when I pound on it. Currently running L92's and a carb. (yep I am one of those old school carb guys) Current set-up runs low 11.00's
Or should I look for a new short block that has all the right parts already there?? Thanks
Or should I look for a new short block that has all the right parts already there?? Thanks
TECH Senior Member
Joined: Mar 2004
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From: BFE
In general poeple bore to 4.030 for 408ci with 4.00 crank.
You could bore more to 4.060 but that requires sonic testing of block. The thing is best to do minimal bore and keep the door open for further rebuilts down the line. 2>3 added cis do not make a noticeable difference.
No need to nitride the crank unless you plan over 700hp or in FI application. 4.030 bore and stock crank will yield 370ci. Get a nice set of rods and pistons and you're good to go.
Spend your $$ on porting your heads.
You could bore more to 4.060 but that requires sonic testing of block. The thing is best to do minimal bore and keep the door open for further rebuilts down the line. 2>3 added cis do not make a noticeable difference.
No need to nitride the crank unless you plan over 700hp or in FI application. 4.030 bore and stock crank will yield 370ci. Get a nice set of rods and pistons and you're good to go.
Spend your $$ on porting your heads.
10 Second Club
Joined: Jul 2008
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From: Columbus Ohio
.030 over is the norm for these, but people have gone bigger.
If you're trying to make a bunch of power I'd get a different crank rather then put effort into the stocker. The stock crank holds up to so much that by the time you exced that you're just better off with a forged aftermarket crank. just my 2 cents.
If you're trying to make a bunch of power I'd get a different crank rather then put effort into the stocker. The stock crank holds up to so much that by the time you exced that you're just better off with a forged aftermarket crank. just my 2 cents.
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TECH Apprentice
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From: New Hampshire
Thanks for the info. I thought some of head porting but have read that L92's are pretty good already. Would there be much of a gain for the cost involved? I do like the idea of a forged crank. How about the Scat (not the expensive lightned version ) Would it be cheap insurance to nitride the stocker anyway. No plan to use nitrous.
TECH Senior Member
Joined: Mar 2004
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From: BFE
The heads make or break a combo and that is where the $$ should be spent IMO.
I use 200 shot dual stage nitrous in a 370 ci, 680 rwhp, still on stock crank, but Wiseco nitrous pistons and Hellfire rings. treating the crank is not needed untill you exceed those limits and even I am still shy of doing that.
I use 200 shot dual stage nitrous in a 370 ci, 680 rwhp, still on stock crank, but Wiseco nitrous pistons and Hellfire rings. treating the crank is not needed untill you exceed those limits and even I am still shy of doing that.
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TECH Apprentice
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From: New Hampshire
So the stock cast crank is that good? Wow. I have no plans for nitrous so I should be good. I will plan to use ARP main cap studs. So maybe just a .030 overbore and a good set of pistons and rods will do me fine. Any preference for rods? I guess I should look into head work a little more as you suggested. Thanks
