86_irocz-28

iTrader: (5)

Times come to build up the ol girl goals 900+fwhp could use some opinions/critique on it build list so far is as follows

-6.0 bored .030 over
-408 stroker rotating assembly with k1 crank and rods weisco -2cc pistons
-Clevite calico coated main and rod bearings
-Tea TFS 235cc heads with nitrous exhaust port
-Durabond can bearings
-Fast 102 intake
-Holley fuel rails
-Ls7 lifters ls2 trays
-Melling high press pump
-ARP everything
-Cometic head gaskets
-Tsp 100mm maf
-4k circle d stall
-Flt lvl7 trans
-8.8 with 3:73's
-Nx plate spraying 2-400

Biggest thing I need help with is cam selection these are the two I'm thinking:
Btr EPS stroker cam-244/256 114+3
Or
Btr 400+ci nitrous cam-251/266 112+4


Also what springs should I go with?

tug686spd

iTrader: (11)

https://ls1tech.com/forums/dynamomet...t-numbers.html

We'll both be chasing after this guy. Him and I are running the 251/266. I havent sprayed mine yet, still getting things figured out. He has quite a bit of info in that thread its a good read.mine on motor alone has gone 10.7 @ 3800 race weight. Hes been 9.0 i believe on 300 shot

86_irocz-28

iTrader: (5)

Bump.

pantera_efi

iTrader: (1)

OK, my calls :

1. Hone block only, no bore. (+.003"+.007") with Ti-Ni "steel" top ring.
2. Rod Bolt ? (L-19)
3. Steel Main Caps with Studs.
4. Non-ARP Head Studs that will yield. (match Aluminum head growth)
5. GM Oil Pump (2010 Camaro)
6. LS-7 (IWIS) single timing chain with block.
7. GM OEM Head Gaskets.
8. Lobe Centers 116*-118*.
9. Spring ? What valves and weight ?

Lance

speedtigger

iTrader: (16)

Those big difference between those two camshafts is in the overlap:



If you look at the valve events circled in red, you will see the the intake valve open is much earlier and the exhaust valve close is much later on the 251/266. These two valve events are also represented in the overlap number. The 244/256 on 114 has 22 degrees of overlap. The 251/266 on 112 has 34.5 degrees of overlap. This earlier IVO and later EVC is a recipe for high RPM horsepower. It is also the recipe for a radical race car idle and pretty much no street manners.

So, it just depends on what you want. If you want to squeeze every last horsepower out of the engine with no regards for drivability, then the 251/266 on 112 will be the one. If you want something that is a bit easier to drive around and might power a vacuum brake booster, then you might want the 244/256 on 114.

The camshaft I have in my 403 falls in between these two camshaft in overlap. I have 27 degrees of overlap. My car idles at about 1100 rpm in neutral and about 900 RPM in gear. For an old school hotrod guy like me, I think it drives pretty good even with my tight Circle D 2C nitrous converter.