moekluse

iTrader: (2)

Hi guys. Im assembling my bottom end sometime this month when forged internals are done being balanced.

I was planning going turbo so I purchased 317 heads, had them all cleaned and gone through as machine shop but I think I'm wanting to go N/A.

I already have all the 5.3 parts so I'm not really wanting to sell and grab a 6.0.

Is it possible to make over 400WHP through a t56 magnum, 3:73 rear-end? Haven't gotten to tires/wheel combos, car is HEAVY, around 4300 lbs

I just can't seem to find many N/A 5.3 all out builds. People just like turbos I guess.

any suggestions would be great, I know I need heads cam headers etc

was thinking of grabbing a set of PRC 2.5s from Texas speed. Not sure about cam etc.

thanks

07NBSChevy

iTrader: (1)

317 heads are perfect for boost on a 5.3, for N/A, I do not know. With a larger cam and high compression you may come close to 400 rwhp.

If you can sell your 317s and get a set of TSP-PRC Stage 2.5 ported 243s, run around 12:1 Compression with a TSP 224R cam or around there. You can also run a TSP 228R for a max effort cam, but I have heard it is pretty large for a 5.3. My guess is you can get between 380-400 rwhp with that combo.

The 317's might be better, I am no expert on that. I know the 243's are great on 5.3s. I also prefer the stock 2.00"/1.55" valves since they can support over 500hp. I am also using LS6 valves for lightweight purposes. The Stage 2.5 would be more for Max Effort High HP builds or Boost, in my opinion.

My current setup in my sig made 437-Hp at 58xx RPM/422-Tq at 46xx RPM at the crank with a small cam, Stage 1 ported 243s and running 10.5:1 Compression. Now this is at the crank and my guess on a Dyno I should hit 355-Hp/340-Tq. With a Manual trans you should see around a 6% increase or more. So in my case, somewhere around 380-Hp and 365-Tq. With a larger TSP 224R, you should see another 15 crank Hp. So it will be close and doable.

I am pretty sure I seen someone on this forum or PerformanceTrucks using a Gen4 Aluminum 5.3 with ported 243's milled to 61cc for around 12:1 Compression, TSP 224R cam, Ported NNBS Truck intake, LS3 90mm Throttle body and a few other goodies and made 455-Hp at the crank.

Others should chime in with more experience running larger cams on 5.3s for better answers for you.

moekluse

iTrader: (2)

Well, my biggest issue is that I was going for dirt low compression to prevent detonation, as it was supposed to see 20+lbs of boost. As a result, the wiseco pistons with 317s give me 8.3:1. That's just ridiculous for a N/A build. With tsp's 58cc heads, I should be around 11.3ish:1 which is ok.

also, I need to retain driveability, I love huge cams to be honest but I need as much low-mid as I can get, this will be a daily driver. I want this thing to lope super hard, I need to do some more research on cams

KCS

iTrader: (20)

How did you come up with that?

moekluse

iTrader: (2)

website I got pistons from gave cr with different head cc. I personally thought it would be around 9.5-10:1. Not sure If it was accurate

uraloser2me2

I have not had mine on a dyno but through a TH400 and a 8.8 rear end my mph and trap puts it around 400 whp.

carb 5.3 with ported 706's milled .042, weisco junkyard dog pistons -6cc, compression is just over 12 to 1, ljms ls3 stage 4 cam on e85.

moekluse

iTrader: (2)

CR calc said 10:1 with 317s not sure if that's correct, pistons are -10.7 dish.

KCS

iTrader: (20)

Be sure you're putting in the right value for the dish. Some calculators use a negative volume for a dome.

moekluse

iTrader: (2)

That was a big help, I did put - first, looks like 8.35:1 with 317s and 9.56:1 with 58cc prc heads

HeavyMetl

iTrader: (2)

I'm slapping together a junkyard 5.3 for my old 68 Nova. Its gonna be a cheap-ish type thing.

2010 LC9 aluminum 5.3
Tick 229/235 cam
DOD Delete
Stock 243s (stock in LC9)
NNBS intake (stock for 2010 lc9 too)
Btr springs
TH350/3800 stall
10 bolt 3.73
EBAY 1.75 headers $160!
UDP
Holley efi.

I'm actually just buying the Holley EFI wiring harness and gonna swap out the ecu and tune between my Camaro and this old Nova. I'm cheap on this project. The car already had the th350 and converter, I'm basically removing the weak old 355 and going ls.

NAVYBLUE210

400 RWHP is roughly 490 HP @ Crank with ~ 18% loss through
the driveline. 490 HP/327" ~1.5 HP/CI. Very doable, however,
streetable/daily driver friendly with 4300 lbs is the challenge.
Always start with the very best Heads that you can afford/justify
lol. For a 5.3 the best heads IMO are MMS 205 CC heads designed
for 5.3 liter bores with small valves these flow between
295-300 CFM @ .600" lift with phenomenal velocity which
will help low end torque and throttle-response in a small
engine moving 4300 lbs. A ported LSXRT Truck intake will
also provide the best low and top end power. Now you can
use a smaller cam to reach your goals and have a much more
enjoyable toy, to really go for it use a LLSR from Cam Motion
maybe reach 425+ RWHP with the same driving experience
(spinning to 7500 RPM LOL) all it takes is money.
Also need to get to 11:1 comp if at all possible.
Good Luck

moekluse

iTrader: (2)

Wow thanks, I'm going to start looking for heads, this is by no means a budget build, its a 78 transam protouring car, and I want nothing but the best lol. If I didn't have a 5.3 though, I would of gone 376 lol. Maybe next time.

NAVYBLUE210

Don't think the LSXRT will fit, and you would be WAY DOLLARS AHEAD
with a turbo set up on a 5.3! or sell/trade up to a 376".

S2KIWI

I too would look at going 376, trade/sell/part as necessary. It's pretty much going to do what you want with a stock cam and zero changes and have all that low end at the same time.
I respect that you want to build it because you already have it, but if you can sell it for a good price and are looking at expensive heads.... I'd just start with a better NA platform in the first place. I bet you'll be happier in the long run. Also takes things from 400 to 500whp if you go all out.

edit: I nearly went for the easy option on my build too. Sure I would've had a working car, but LS3 price for a 250hp 2L spoon engine is an absolute waste of $ IMO.... Just start with the better platform and don't look back.

moekluse

iTrader: (2)

I just posted my motor for sale in classifieds. I'll try to sell it and pick up a 408 short block. If I can't sell it, I'm throwing it in the car and saying f*** it!

chrisfrost

iTrader: (8)

HeavyMetl , how's it going ? Just wanted to clarify . Are the gears You talk about from an f body ? If so They're 3.42's I see that alot poeple think They have 3.73's in Their older camaros ......etc when They are 3.42's Anyway good luck

HeavyMetl

iTrader: (2)

I travel for work so I have not had a chance to assemble the engine yet. I hope to get the DOD delete and so forth finished this week.

Definitely 3.73 gears, previous owner actually put the posi and Moser axles in a 10 bolt. I'll run it and not have a worry.

I'll be posting up track results ASAP. I'm super curious how this low buck thing will run.

Tuskyz28

Cam: COMP XR281HR .571/.573 lift, 228/230 duration split, 112 LSA
Heads: TFS GenX 205
Intake: FAST LSXR
TB: FAST 102 mm
Headers: QTP 1¾-inch long-yube
Peak Power: 501 hp at 6,500 rpm
Peak Torque: 452 lb-ft at 5,400 rpm
Torque Curve: Exceeded 425 lb-ft of torque from 4,200-6,100 rpm

This is your answer here. No guess Work involve. Stock bottom end LM7. If you have hood clearance and want to save a couple some serious coin but still meet your goal I would use a trailblazer SS intake instead of a Fast intake.

DavidBoren

Considering the OP already posted the 5.3 for sale with plans of going larger, does that mean this thread is dead already? I was hoping to find some info on Tony's MMS205's in here, but I guess we all just have to wait for 1FastBrick to finish his build and post his results.

moekluse

iTrader: (2)

actually, my machine shop purchased it but I bought it back, I'm going to continue with it, then while that's in the car I'm going to buy a 408 shortblock and do top end, then that 5.3 might go in another project