WCCH Small Bore LS7 heads
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From: Battlecreek, MI / Mansfield, OH
WTF! Something is not right with that article.......
You definately arent going to stick a super badass 102 LSXr blah blah blah or even a small single plane for that matter on a 400CFM head . You gotta move up to a sheetmetal or Carys single plane intake. Even then, at sub 7k RPM you will not utilize all of it unless you have close to 500 CI.
FWIW my L92's flowed around 380cfm at the max lift of my cam and went over 400 at close to 1" of lift. They never stalled out or backed up.
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From: Battlecreek, MI / Mansfield, OH
I'm still trying to figure out this popular mechanics 4.030" bore with LS7 heads....
Idk about killing the airflow, but you would still have a 11 degree valve angle, 255 cc intake runner, 2.20 intake valve and a thicker deck cylinder head. Seems like a winner to me? Or sonic test a Ls3 block and go bigger on the bore?
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From: Battlecreek, MI / Mansfield, OH
i found this from richard at WCCH..... i would say he knows better than just about anyone about LSX heads
so.... i dont know what the hell popular mechanics did...maybe they didn't know what the hell they where doing and have a engine that is about to have some catastrophic failure
The intake valve is not the problem. The exhatust valve runs into the top edge of the cylinder bore. A 4.080" bore will see the exhaust valve scrape the bore when started and run. The intake side is roomy. The nominal bore for the LS7's is 4.100".
We're working on a Stage 3 L92 port program. It'll use a 2.20" intake valve and have comprable flow to the LS7 heads. Still a month or two out on those. You'll see near LS7 performance for a lot less $.
Richard
We're working on a Stage 3 L92 port program. It'll use a 2.20" intake valve and have comprable flow to the LS7 heads. Still a month or two out on those. You'll see near LS7 performance for a lot less $.
Richard
so.... i dont know what the hell popular mechanics did...maybe they didn't know what the hell they where doing and have a engine that is about to have some catastrophic failure
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Verdad Gallardo I have....check
I did....check
Few cubes short but close....
Not disputing the "need", just raising the issue in what seems to be a "want" with these reoccuring discussions. As you pointed out, combo and application should specify the "need".
I did....check
Not disputing the "need", just raising the issue in what seems to be a "want" with these reoccuring discussions. As you pointed out, combo and application should specify the "need".
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From: Battlecreek, MI / Mansfield, OH
doesn't mean what they did is right.... if that thing really is 4.030" bore and they really used oem LS7 heads... that thing is a ticking time bomb.
Staging Lane
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The end of February 2010 is when I purchased them directly from Cary along with his Ls7 2 piece intake. Mine were actually blemished heads that he gave me a deal on. It seemed like a few months later is when he started the merger with Mast Motorsports. Mine came with REV 2.125 and 1.60 solid stem stainless valves, but there are other options. Call Shawn Miller at Virginia Speed he might have a set. If that don't work call Mast Motorsports I'm sure Cary could make a set upon a special request. The place I'm doing my motor at flowed the heads and cc'd an intake runner for the hell of it. Average around mid 360s CFM on the intake and high 240s on the exhaust around .700 lift. Mid range numbers and port velocity were also impressive. Flow bench was a Jamison 600 with a 4.00 bore plate at 28 H20. The intake runner was around 247cc. The Intake valves weighed around 125 grams and the exhaust around 95 grams. Hope this helps.
Staging Lane
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From: Battlecreek, MI / Mansfield, OH
ok i figured it out.... it was driving me nuts... they used a smaller exhaust valve and seat
Stock sodium filled exhaust valves 1.61-inch
Exhaust valve diameter of the valves they used: 1.54-inch
You would think they would mention that in the article so someone doesnt go try to bolt some stock LS7 heads up to a 4.030" bore and think its going to work.
Stock sodium filled exhaust valves 1.61-inch
Exhaust valve diameter of the valves they used: 1.54-inch
You would think they would mention that in the article so someone doesnt go try to bolt some stock LS7 heads up to a 4.030" bore and think its going to work.
Staging Lane
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I couldn't agree more. I've seen so many people put better flowing heads on their motors with a bigger intake runner and bigger intake valve and actually slow down in ET or not pick up at all. It's all about port design and port velocity. Sure they are coming out with heads that flow more then mine, but really are they going to run faster at the tract, I seriously doubt it. I'll give up 20 to 30 CFM in a head for port velocity any day of the week. I read somewhere lately that the old 960Hp prostock truck motors would outrun the 1040Hp motors. Just like flow numbers people put to much faith in motor dynos and chassis dynos also.
I'm not looking for a 400cfm head . I'd just like a head that flows an honest 340-350 through a moderately sized port & valve . This head would also have an intake that wouldn't negate most of the gains in the head . Here's a link to the head I mentioned http://shop.virginiaspeed.com/produc...&categoryId=64 . This head is designed to fit on a 4.00" bore and Cary has been making this style of head for years . These were offered when he was @ ETP and for some reason they're not as popular as I think they should be . I think this is the ideal head for an aggressive but very streetable combo . I want to move from a CNC ported 243 to a rectangle port head on my 402 but the cost goes up quickly Since the advent of LS3 heads 243's aren't worth anywhere near what some have paid for them years ago . I think this is going to be my happy medium http://shop.virginiaspeed.com/produc...&categoryId=63 , they just need to have a sale on them .
I'm not looking for a 400cfm head . I'd just like a head that flows an honest 340-350 through a moderately sized port & valve . This head would also have an intake that wouldn't negate most of the gains in the head . Here's a link to the head I mentioned http://shop.virginiaspeed.com/produc...&categoryId=64 . This head is designed to fit on a 4.00" bore and Cary has been making this style of head for years . These were offered when he was @ ETP and for some reason they're not as popular as I think they should be . I think this is the ideal head for an aggressive but very streetable combo . I want to move from a CNC ported 243 to a rectangle port head on my 402 but the cost goes up quickly Since the advent of LS3 heads 243's aren't worth anywhere near what some have paid for them years ago . I think this is going to be my happy medium http://shop.virginiaspeed.com/produc...&categoryId=63 , they just need to have a sale on them .
Last edited by Fifedogg; Feb 24, 2011 at 10:56 AM.
Take a closer look @ these heads and you'll see the difference . The port and valve sizes are smaller while still providing excellent flow . This translates into a high velocity intake that will be very responsive and generate great torque throughout the rpm range . The driver will have a smile that wraps his head twice when the car is taken to the dyno AND the track . TSP is just working with the factory casting as is most everyone else so they're stuck going in the direction the factory started . It would be cost prohibitive to make the port smaller while reshaping or removing & replacing the intake valve seat . The CNC ported factory casting have a good value but I do not think they're the ideal choice for my 402 . I wish I could get the other heads for less but I do understand the investment & complexity in doing that level of machining . Cary's work is awesome, I just need to save up . We'll see what else comes out soon that will be ideal on a 4.00" bore .
Staging Lane
Joined: May 2010
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