Cricket99SS

Well I ordered up one of the new MTI Darton Wet-sleeved blocks, and have started work on my new engine. I am going with the new Eagle 4" crank and will pair it up with Diamonds off the shelf 4.125" -7 cc pistons.

On the car right now is a set of Absolute Speed Stage II's with Manley 2.02/1.575 valves. Here are the flow numbers from back in Febuary when I purchased them. They were only flowed to .563 because that was the cam I told Jay I was going with, the Thunder Racing 224 with a .561 lift. Because of this, I'm not sure how they would flow up towards .600-.615, around the lift I would like the cam for the 427 to be.



I follow the classified sections here and at other LS1 related sites as well, and the used Stage II head market is a bit like used cars, no one is buying anything. I searched and found many for sale posts left open, no one ever biting on them. Even when $1,700 heads are posted for $1000-1200, people still don't seem to bite. So I am trying to see if these heads will produce the numbers I want to get from it, rather than trying to sell them, only to turn around and purchase a set of $2000+ Stage IIIs.

The car is a autocross, open track, drag race, weekend, everything car, and I want the engine to be a max effort project. I don't care about driveability at all, the interior only has seats, steering wheel, and a shifter now anyway. Also, I know I can't put "max effort" and not seriously consider going to expensive Stage III heads, but it is very hard for me to sell of these heads and loose $1000 on something I just recieved less than year ago.

According to the Ross Pistons compression ratio calculator at http://www.rosspistons.com/calculator.php I would be at 12:1 compression if I keep my heads as is. This is assuming a 4.125" bore, 4" stroke, 64 cc heads (which I am not sure about, this may be wrong), 0.041 compressed gasket thickness, .0001 deck height, and a -7 cc piston dish. I believe that is all correct.

So have any of you big cube boys run Stage II heads, or is it just not worth the effort? If these heads can flow say 305 @ .6, how much power am I leaving on the table with the extra 20 cfm obtainable by going with a good set of Stage III 6.0 heads with bigger valves?

Thanks for all the advice folks!

-Kyle

C4VetteLS1

Despite what everyone will say about how a stage 3 head will work better...I believe they will work very well. You can still expect a nice 450-500 rwhp setup with heads like that.

KGSloan

jay is getting some amazing flow numbers out of his new stage II's. his latest design flowed 314cfm at .600" of lift, and his stage III's are even better. his new designs flow very well with the intake on as well. you should call jay and see what upgrades he can make on the heads and how much it runs. jay is awesome to work with and i'm sure he could help you out. this way you wouldn't be out all of the money on your heads.

LG Motorsports

Just send them back to Jay and get them fluffed and buffed and opened up for the bigger bore and you will be very happy. We just got 510rwhp 517rwtq with a set of Absolute heads on a C5R block 427 cu in that we did. There is plenty of flow left in your heads if you have them built for the application that you want to use them for.

Thanks

LG

Cricket99SS

Good info so far. If the LS1 heads aren't "that bad" for the big cube engines, I suppose I will see what Jay can do to them.

I also didn't expect The MAN to reply in here. Lou, you taunted me with that two day track day at Texas World Speedway and then just stopped. What kind of drug dealer are you? Don't you know you have a group of addicts to satisfy? When is the next LG event?!?!? I need my fix, all this off season drag racing is becoming just that... drag racing!

-Kyle

2001 Pewter WS6

iTrader: (43)

I sent my first set of heads back to Jay when I first redid my 383. Decide on which cam you are going with and he can get your heads reset back up for the new combo.

absolute

Kyle, give me a call we can go over some options. We can turn your stg2 heads into stg3's then I will come up with cam specs to match or work out a trade in. Dont forget The deals I give for larger tb's and ported intakes

Scoobie

iTrader: (8)

Jays the Man! Hes in the process of doing some heads for a 382 All Bore im working on. Im sure it will be the baddest LS1 around with his heads on it.

Cricket99SS

Sounds good. I just hope that a Stage III LS1 head isn't an oxymoron, since I never hear of anyone reworking LS1 heads that much.

Also Lou, I read in another thread you are working on the World Challenge Vette. I see you have REAL racing to worry about at the moment, rather than us wannabes!

mike m

iTrader: (6)

cricket when he says reworking the heads . that means bigger valves and opening up the ports.

Cricket99SS

Oh yes I know, what I was trying to imply was that I can't remember ever reading about ANYONE with LS1 heads on a big motor like this. Everyone has either the 6.0s or LS6s on top of them, so I'm just trying to make sure I'm not going to bork this up too bad.

With LG and Cartek hitting around 500 rwhp out of the 346, I can't wait to put this engine together and watch it squirt out 470-480.

07BlueDevilZ06

iTrader: (8)

actualy matt was there yesterday and he has a 5.3 up to 317 cfm jay your heads rock

o btw jay did you get a good laught out of those heads i sent you from the vette i just tuned what a joke 270 out of a stage 2 head he will get good power with your new heads

george

DOC OTIS

iTrader: (9)

Well I am going to try the same thing. I have a 427 and am using a set of 5.3 GTP stg 2 heads that have been reworked. Heads flowed 312 @ .600. I already had these heads on a old set-up and am waiting for the 225 AFR's later this year. I should have some dyno #'s and track times in March. Hoping for around 480rwhp (th400, 12 bolt, slicks, etc) and mid to low tens N/A at the track.