SStrokerAce

iTrader: (2)

I didn't mean to get on your case but there were way too many assumptions there for me. The shape of these ports is better than the shape of the cathedral ports, just so happens they are larger.

I guess now that info is posted now for everyone to know.

Bret

Dragaholic

iTrader: (180)

I'm no head expert and all this head talk has gotten me lost. Again, I'll be using a stock LS2 block, which will have a 4" bore, and I'll be using a 4" stroke with it. It will have all the nice forged internals in it (crank, rods, pistons, etc.) I have yet to decide on what brand of rotating assembly to use, but that's whole other thing. What my purpose of this thread was to get some suggestions as to what head will net me the best results for a naturally aspirated 402 LS2 as far as power and 1/4 mile times. Again, you can explain in great detail, but more than likely I won't understand because I'm no head doctor. If that were the case, I probably wouldn't be posting here. Thanks.

JL ws-6

iTrader: (50)

look into the ET 240's or the 255's, you can use yoru intake to start, and can upgrade to a single plane later if you want more power.. both those heads, with a BIG radical cam and 13+ to 1 compression would make more then enough power to get your light car well into the 9's I am sure of it. I have the et 240's on my 12.6 to 1 compression 402 now, I built mine so I could still street it a little, and it's awesome, I'll have some track results this weekend, and keep in mind my car's a full weight 3600+ with driver weight, I'm on a 27 inch qtp tire, 4.10 gears, th400 and my converter flashes to about 6200 on the dyno, stalls at probably about what yours does on the transbrake. Had O gone solid roller and put a massive cam, and a single plane on it I bet I could have made another 40+ rwhp.... but I wanted a lower maintenance streetable setup taht would run 10's on motor, and be able to take some nitrous later.

I hope this helps.. you have a damn good car that's only needs a decent motor to get into the 9's.. I am sure if you stuck my motor in your car, it would run in the 9's right now.. and you could drive it to car shows and whatnot.. not to work every day, btu around a little.

Beast96Z

iTrader: (21)

True, there are, but I was just throwing out what I had to offer. I don't take it personal. No one can be right 100% of the time, and if I learn from it, then it is a lesson learned. If the shape of the ports is better, then I look foward to seeing some blistering times coming from these L92 headed motors. Hypothetically speaking, how much room is there to play with these heads, and how much material do you see having to be removed to make these 360+ cfm heads?

Dragaholic

iTrader: (180)

JL ws-6, I'm not necessarily stating that I have to use my FAST 90mm intake. It would be nice to, so that I didn't have to worry about selling it, then buying another one. However, if I'm better off with another intake or one that would be custom built as in a sheet metal intake, then I'm all for it. If I went with a different intake, then that's gona bring me to what throttle body, MAF, bellow, and lid to use?

What do you mean by single plane? Is there a big difference between the 240s and 255s?

I'm kind of torn right now on heads. Both ETPs and L92s seem to be pretty popular right now. However, there really isn't much claims on the L92s, nor a lot of readily parts to make them compatible with the LS2 engine in a LS1 F-body.

Beast96Z

iTrader: (21)

If you buy a cathedral port head and you want it to perform to there potential, then the FAST has to go. However a ported FAST will accomodate you till you can get a intake picked out. Most sheet metal intake makers will accomodate you on which TB you want to use. Most just use the 90mm TB's we have avalible. There aren't many, if any that are truly "compatiable" with all the GM electronics that are bigger than the 90mm's we have. Most people going this all out go to a speed density tune, so the MAF is gone, but LPE does offer a 100mm if you had to have one. Although, you'd have to be moving some serious air to max out the 85mm lid/MAF. Before upgrading, you need to make sure you are maxing out what you have.

The single plane intake is a carb style intake. They make single planes and dual planes. Single planes are for higher rpm's and usaully associated with higher reving track set-ups. They make them in fuel injected versions, but most of them require modifacation to fit under the hood because of the big elbow you have to run.

The diffrence in the 240's and 255's is just that. One is a 240cc version, one is a 255 cc version. If you go to ET's website that I posted earlier in the thread, then you can look at the diffrences in valve sizing and flow.

As for th eL92 stuff, you'll just have to wait and see, or go with something that's already proven.

Dragaholic

iTrader: (180)

So if I have the extra money, go with the ETP 265 40 heads, get a custom fabbed sheet metal intake, have Beck build it since he's local and popular for these intakes, and go solid roller. I would however need to upgrade to the Jesel rockers which is an additional $1400. Then I would also need the spring upgrade for a drag application.

If I don't have that much money to spend, use the ETP 255 heads. Can I still get a custom sheet metal intake built for the 255s? I know you stated that I would be able to use my FAST 90mm intake with the 255s, but would I have better results with the a sheet metal intake?

Either way I go, I should consider getting rid of the SLP 85mm MAF and do a speed density tune?

What about the throttle body? On either setup I should reuse my Nick Williams 90mm or use one of the few bigger throttle bodies out there? I've seen a LPE 100mm and a Accufab 105mm mentioned here on the board.

Lastly, what's the deal on the L76 intake? What about this Victor Jr.? I have not a clue what either one of those are.

SSilverSSurfer

iTrader: (8)

the victor jr. is the carb style made for our cars, i see them mostly used on FI set ups and some nitrous cars. speed density for the win, and im glad to hear your going solid roller, i would go 105mm TB unless you plan goin bigger than a 427ci, but your staying 403 so use the 90, hell DJ's car uses the 90 and he has the 408LS2 and the victor jr, sheetmetal elbow, but damn that sheetmetal is worth it if you can afford it

Dragaholic

iTrader: (180)

Should I consider a bigger stroke than the 4"? Maybe 4.100"? What's the maximum stroke that can be used on a stock 4.00" bore?

Beast96Z

iTrader: (21)

Go with the best intake you can afford for any head. 255's, 265's, whatever, they all have the same bolt pattern. The fabbed intake will net you the best results because it will flow the most. If you go solid roller, you will need the spring upgrade. I would do speed density on any set-up. It's just better. TB should be fine at 90mm, but if LPE makes a bolt on 100, that would be nice, but probablly not needed. Keep the lid you have. L76 intake? That's the intake for the L92 heads. Not to many head people have been able to get ahold of one for testing. We'll just have to wait on that one, just like the L92's. As for the Victor Jr., think old school. Looks/and is a intake for a carborator. However they make fuel injected versions that use a large center mount TB. Don't care for them myself, but i'm not into hacking up my cowl and possibally cutting up my hood to get it to fit underneath. That's why I spent $3400 on my intake.

2002C5COUPE

iTrader: (3)

Instead of trying to piece it together w/ info off the intraweb, why don't you just call LME, tell them what you want out of the car, and let them build it?

I would leave it to the experts before i go spend $$$$$$ on stuff piecing it together

JL ws-6

iTrader: (50)

Something to be said for that approach as well......

WKMCD

iTrader: (2)

We're building a 402 right now using the L92 heads and L76 intake with a crazy cam designed by Bret Bauer specifically for this combo and my intentions. I wanted to try something different that on paper should produce very good numbers. This will not be a track car nor a dyno queen but more what I call a "Gentleman's Cruiser" M6 C5. I hope to be 515-530 RWHP but with close to 500 in RWT.

The motor is being assembled and SD tuned by phil99vette.. I hope to have some initial driving impressions up in about 3 weeks.

Stay tuned.

beardWS6

iTrader: (1)

I will tell you my ET25`s flow there *** off on my set-up 408. I love them and the power is awsome.

SSilverSSurfer

iTrader: (8)

beard what kind of flow numbers did yuo get outta those heads?

beardWS6

iTrader: (1)

This is how my ET245`s flowed at LME when I got them in!
Int exh
300 213 165
400 268 206
500 313 226
550 329 231
600 339 234
650 348 236
700 ??? 238
intake 2.100 exhaust 1.600 Bore 4.0

I had over 450trq at 3000rpms-500trq at 4600rpms with car in sig. Love it!

GrannySShifting

iTrader: (10)

If it makes 515 Id be looking for something wrong with it! That has the parts to make 550 for sure