View Full Version : Build My 402


Stol3n
12-01-2008, 12:14 AM
i currently have an 02' z06 cam only (g5x4) with supporting mods making pretty good numbers 451/417. lately i've been kicking around the idea of building a 402. what i would like in the end is 520/500 out of my 402 build. i plan to use my lg pro headers and g5x4 cam in my 402 build so how should the 402 build sheet should look to achieve my goals, as if u were picking out the parts.

1997bird
12-01-2008, 02:27 AM
- LS2 block
- Compstar rotateing assembly w/Clevite H-series bearings & no holes drilled balancing
- Melling 10% HV oil pump
- S.A. Gear timing chain set
- Morel lifters
- Custom Cam 254/246 @ 0.050 duration, .622"/.622" lift w/1.7's, 113*+2*
- ETP 245cc cylinder heads
- T&D shaft mount rockers
- Smith Brother's pushrods
- ATI harmonic balancer
- Ported FAST 92/92 combo
- A very talented tuner like Ed@ www.thehpfactory.com (this is a site sonsor)

This should make your HP goals & then some (I know for a fact that this will make at the very least 532/491 in a M6 Vette).

JL ws-6
12-01-2008, 09:24 AM
If you want to get away with more of the parts that you already have, you might want to look at using an ls3 block and go with a 416 ci motor ( 4.060 bore, 4 inch stroke) as the block cost is so close that it's a mute point, pistons aren't gonna be any more or less and everythign else is the same, and that little bit more CI is only gonna make your goals easier.

You probably can reuse the camshaft, if the car will never see any kind of power adder, I'd go as light with the rotating assy as you can as it will be that much easier to get the power out of the setup.

Et 240 head, or a set of the 235 trickflow would work fine, you can use your stock rockers with the ET head which would save you some $.

A 92mm fast should be more then adequate as well.



I have a big compression 402 with the 240 et heads, hydraulic roller with stock rockers, and a cam that's mot much different then yout g5x4 and it made 470 thru a 5000 n/a converter, TH400 and 12 bolt unlocked. Even if I dropped the compression back down to 11.5 to 1, I am 100% sure that it would blow right past the 500 rw mark with a M6 tranny.

Oh4GTO
12-01-2008, 01:11 PM
No need for ETP 245cc heads. AFR 205c heads and you are set. Dozens of 402 with those heads over 500/500.

JL ws-6
12-01-2008, 02:45 PM
AFR will work fine too, but there's a reason that the newer builds are getting away from them. Yes they make good power there's no doubt about that, but there's other heads out there now that just make more, and have more available options.

knappbunch
12-01-2008, 02:52 PM
my 402 should be on the dyno this week
trick flow 235 cnc
harland sharpe rockers billett double roll timing chain set, fast 92/92 ls6 ported oil pump with stiffer spring, ls7 lifters and 11.5 compresion. flowing through 1 7/8 hooker long tubes and 3" off raod y with catback and cutouts.hoping to see 530 or so we will see.

Gregory
12-01-2008, 04:30 PM
You can check out the components in the signature of my lower cost (heads & rocker arms) build. It made 554/492, and there are probably 10-15 more in this combination as it gets fine tuned a little further. Oh, and I run E85 or Premium 93 in it as-is without issue.

99blancoSS
12-01-2008, 04:42 PM
AFR will work fine too, but there's a reason that the newer builds are getting away from them. Yes they make good power there's no doubt about that, but there's other heads out there now that just make more, and have more available options.


It's more tha fact the cubic inches are getting bigger now as a standard and AFR doesnt have a head in place yet for the larger 427 plus cubic inch engines. Also the AFR is more of a street head unless your looking for a competiton port job. Where AFR's were the more expensive heads in the past they are now priced lower than the ET and TFS. AFR 225's on a 383 made 540 from Mamo so a properly set up AFR topend will still hold its own. I forget what his time slips/trap speed was but it was no slouch.

So a set of AFR 225's on 403 with the right valvetrain should do the job and save some money over the more expensive heads.

JL ws-6
12-01-2008, 05:02 PM
I won't take anything away from afr like I said, the results have spoken for themselves over and over, I'm not that up to date on head cost, but a couple hundred bucks to me isn't a deal breaker either way.

JDP
12-01-2008, 06:03 PM
http://www.ls1tech.com/forums/lsx-parts-sale/1021632-sale-402ci-ls2-l92-heads-basically-turn-key-setup.html

theres my setup, and its for sale too ;)

but its not to hard to make 500+whp with a 402 just make sure you have a good set of heads and a properly specced out cam, mine made 505whp with 1 3/4" headers, stock L76 intake, through a stock maf and a stock crank pulley. and my motor is built for the bottle, so the cam isnt an all effort N/A cam. im sure now the motor is closer to 530-540whp