Why not just go 427?
Thread Starter
Teching In
Joined: Jul 2005
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Why not just go 427? Im about to begin a build and I see people contiplating all kinds of different cube possibilities. If you are going over 400, why not just go as much as you can?? People talking about 402,408,414 etc....Is there a reason why some of you guys arent going straight to the top and doing as much cube as possible?? Is it rod angle, clearance issues....what?
Most of the people with 408's do not want to use the aluminum block with sleeves.. Cast iron blocks are stronger and cheaper to build. Look at how many people have had problems with cracked sleeves, leaking sleeves, sleeve installations, etc. You dont have to worry about any of that with a cast iron block..
TECH Apprentice
Joined: Jun 2004
Posts: 355
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From: Houston,TX
A 408 is much cheaper than a 427. It will also hold nitrous alot better. Besides, I've seen hydrolic roller 408's with 550+ hp and 520+ tq so, the numbers can be there. Check out VINCE. His 408 is bad ***. Futral seems to have found their specialty.
427 The new Darton LS2 dry sleeve solves the problems of previous dry sleeve installation failures. Bore will go from 4.125" to 4.160" max. Problem is the lack of used LS2 blocks. You must obtain a new core which must be stress relieved for best results. A lot of folks don't want to spend the grand or so for a new block. You do end up with a much better deal with the bigger bore because the larger bore helps unshroud the valves. Much lighter than the iron block as well.
Steve
Steve
Originally Posted by ovaltobowtie2
Im about to begin a build and I see people contiplating all kinds of different cube possibilities. If you are going over 400, why not just go as much as you can?? People talking about 402,408,414 etc....Is there a reason why some of you guys arent going straight to the top and doing as much cube as possible?? Is it rod angle, clearance issues....what?
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Originally Posted by ovaltobowtie2
I was going to use an LQ4 block.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
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The 6.0 blocks generally don't have enough meat in them to allow you to bore them over enough to get to 427. They have to be sonically scanned and the cast shift inside most blocks is enough to limit them to 408. As for the resleeved aluminum blocks, they are sometimes problematic and expensive to build. You get one built right they are great, but if you have a problem with the sleeves alot of times you have to start over with a new block.
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Originally Posted by ovaltobowtie2
Why is a 427 more expensive? Bigger bore for more machining??? I thought the rotating assemblies were the same cost. Help me here. Sleeving??
I was going to use an LQ4 block.
I was going to use an LQ4 block.
you can do a 421ci iron block with a standard ironblock bored 4.030(.030 over) and use a 4.125" crank
4.030x4.030x.7854x4.125x8=421ci
LS-1/6 aluminum blocks can only be bored .010" max. In order to get the large bore, you need to have the old sleeves removed and new larger sleeves installed. This is what they mean by sleeving. This process is fairly expensive. New sleeved blocks run anywhere from 2k to 4k depending on who does the work and what type of sleeve and machine work you get done. Steve@ race enginering, who posted above, is the co-inventor of the best sleeves avalible and really the only one I would trust to install my sleeves. Once you get the block, then the big cubes start to come out....
And I wouldn't recommend a 4.125" stroke, because of oiling problems and oversquare blocks don't like revving. A lot of people go iron block with a 4" stroke. The Eagle strokes are $1k cheaper than the Lunati or Callies, so the cheap blocks are coming in below $4k and they work well.
If you go with a Darton MID and go with an offset ground stock crank (3.71" or so and it's plenty strong) you can do 397 or 403 for about the same price as an iron block with a Callies or Lunati stroke. The difference is that it's undersquare, so it'll rev much better, and the 4.125 or 4.155" bore will allow more airflow at high rpms. Not to mention it's lighter than the iron block and makes similar torque and horsepower numbers with less displacement and generally less radical cams.
If you go with a Darton MID and go with an offset ground stock crank (3.71" or so and it's plenty strong) you can do 397 or 403 for about the same price as an iron block with a Callies or Lunati stroke. The difference is that it's undersquare, so it'll rev much better, and the 4.125 or 4.155" bore will allow more airflow at high rpms. Not to mention it's lighter than the iron block and makes similar torque and horsepower numbers with less displacement and generally less radical cams.
Originally Posted by JakeFusion
And I wouldn't recommend a 4.125" stroke, because of oiling problems and oversquare blocks don't like revving. A lot of people go iron block with a 4" stroke. The Eagle strokes are $1k cheaper than the Lunati or Callies, so the cheap blocks are coming in below $4k and they work well.
If you go with a Darton MID and go with an offset ground stock crank (3.71" or so and it's plenty strong) you can do 397 or 403 for about the same price as an iron block with a Callies or Lunati stroke. The difference is that it's undersquare, so it'll rev much better, and the 4.125 or 4.155" bore will allow more airflow at high rpms. Not to mention it's lighter than the iron block and makes similar torque and horsepower numbers with less displacement and generally less radical cams.
If you go with a Darton MID and go with an offset ground stock crank (3.71" or so and it's plenty strong) you can do 397 or 403 for about the same price as an iron block with a Callies or Lunati stroke. The difference is that it's undersquare, so it'll rev much better, and the 4.125 or 4.155" bore will allow more airflow at high rpms. Not to mention it's lighter than the iron block and makes similar torque and horsepower numbers with less displacement and generally less radical cams.
Originally Posted by Scoobie
Would an LS2 402 be cheaper then an LS1 397 or 403?
Thread Starter
Teching In
Joined: Jul 2005
Posts: 9
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So now your saying to that you dont recommend going over sqaure. Well everyone that has a 427 is oversqaure and they are getting it done. Im confused. So if I were to go with an LQ4 block 4.030 bore with a 4 inch stroke.......what CID would that be?? 408?
Thanks
This is going in a z06 and I have had people tell me not to do an iron block. I cant imagine 75lbs. making a huge difference. I meen these guys that add chargers are putting 50-60lbs on there front end as well. So I figure I might as well do it with cubes.
Your thoughts.
Thanks
This is going in a z06 and I have had people tell me not to do an iron block. I cant imagine 75lbs. making a huge difference. I meen these guys that add chargers are putting 50-60lbs on there front end as well. So I figure I might as well do it with cubes.
Your thoughts.
Originally Posted by ovaltobowtie2
So now your saying to that you dont recommend going over sqaure. Well everyone that has a 427 is oversqaure and they are getting it done. Im confused. So if I were to go with an LQ4 block 4.030 bore with a 4 inch stroke.......what CID would that be?? 408?
Thanks
This is going in a z06 and I have had people tell me not to do an iron block. I cant imagine 75lbs. making a huge difference. I meen these guys that add chargers are putting 50-60lbs on there front end as well. So I figure I might as well do it with cubes.
Your thoughts.
Thanks
This is going in a z06 and I have had people tell me not to do an iron block. I cant imagine 75lbs. making a huge difference. I meen these guys that add chargers are putting 50-60lbs on there front end as well. So I figure I might as well do it with cubes.
Your thoughts.
a 4.030 bore and a 4" stroke would be a 408ci
a 4.060 bore and a 4" stroke would be a 414ci, some of the iron blocks can be bored to a 4.060 bore, just need to sonic check the block to be sure.
