InchUp

iTrader: (2)

Alright. Here's what I've got so far. I've been at it all day disassembling the motor and thinking up ways to make power and while not going overboard. I have a 2001 5.3L that is being swapped into a lifted 1996 Sonoma.

What I'm looking for:
-Comfortable daily transportation and reliability
-1hp/cubic inch
-Broad torque curve for 35" tires and 4.56's/4L60E (70mph @ 2146rpms)
-Really aiming for 20mpg highway

The build:
-Decks trued to 45 degrees of crank centerline (IF NEEDED)
-Bored over to 99mm (5.7L iron block aluminum heads, 346cubic inches)
-Main caps align honed
-Rods checked for straightness, crank polished
-Stock OE Replacement LS1 pistons (not sure on final compression ratio) Link to pistons
-241 heads (66.66cc chambers) cleaned up with LS6 valve springs, port match and polish per what machine shop thinks needed
-XR265HR camshaft 212/218 .522/.529 114 LSA Link to cam
-1-5/8" equal length long tube headers
-Magnaflow high-flow cats welded to collectors
-2.5" ID true dual exhaust down the passenger side, X-pipe and two Magnaflow 2.5"/2.5" mufflers, 22" long (trying for quiet mufflers without too much sacrifice in CFM)
-LS6 springs
-Kick *** tune by hirdlej

I spoke to hirdlej about my build already, now just looking for more opinions. You know what they say, 3 heads are better than 2, 4 better than 3, ect ect.

trever1t

iTrader: (14)

Heads....look around for some 243/799 castings. 64cc and flow much better.

silver-mod-o

iTrader: (15)

sounds like a pretty sound build... with a little work those 241's can be nice heads... and if you already have them... even better.

jetmann

Sounds like A good combo!Be careful about decking the block as those pistons will have A +.006 to .010 deck. If you deck the block they will exceed the desired maximum amount of .010-.012.The deck surfaces on LS type engines are usually very square to the mains from the factory.Before decking always mock-up(pre-assemble)the engine and see where things are.

BlownChevy

iTrader: (20)

That made me erect.

InchUp

iTrader: (2)

The machine shop said they'll take a little bit off to clean up the head gasket surface and if need be, square up the deck to the crank. Hopefully it's fine as is.

Already have the 241 heads and really don't want 243 heads. I'm looking for low end and throttle response, which the large runners of the 243's wouldn't help with. Plus they're expensive, and I got the 241 heads for $10 bucks. The only difference I found the 241's make over the stock 5.3L 863's, is a larger intake valve and slightly better top end flow. After a P&P, I think they'll flow just fine for a DD truck.

I drive 5.3L vehicles all day long for work, and those 1500's and Suburban's are all heavier than I am so I think with 4.56's, the amount of power this motor will produce will be amazing compared to the V6. The Suburban is 100% stock and gets 18mpg highway, so in my 4000lb truck I'm setting my hopes high for 20mpg after a good tune.

Any ideas on power output? Flywheel. 1hp/cubic inch is a strong must have of mine, for reasons unsaid please.

EDIT: Also forgot to add, 1.7:1 needle bearing roller tip Harland Sharps, ARP rod bolts and new push rods because one of mine is slightly bent..oh and an E-fan.

hirdlej

iTrader: (31)

Where do I start? First of all, you're going the right route but a few key things come to mind. First of all, listen to Jetmann, I just measured my pistons this weekend on my LQ4 and they were .012 out of the hole at TDC. With that in mind, I would be afraid to mill .010 off the deck surface and run any gasket thinner than stock. Reason being I wouldn't want any tighter or less than a .030 quench area on a daily driven engine. Guys can run them tighter but this would only be recommended on a race only engine. My guess would be with all the "ribbings" cast into the LSx blocks, this would make for a very ridgid block that is very stable. I would bet money that it won't need to be decked for straightness. Don't touch the deck surface unless is has to be (which I doubt)
Secondly, you said you had 2 5.3L's if I recall. I would take the better of the two crankshafts and don't polish if you don't have to. Remember, the hardest metal on a crankshaft is always the outermost layer If you truly mean polishing, that's fine, just don't cut!
For heads, keep your 241's. It wouldn't be worth getting the 243's for your build. For what you'll have stuck into the 241's for porting and head work, it'll still be cheaper than the $450 for new 243's and outflow a set of stock 243's. By keeping the 241's and porting them, you will get better throttle response than stock 243's and higher port velocity. This will mean better VE and more power throughout the powerband. You're on the right track!
I guess my final comment would be keep up the good work, your build will put a grin on your face. Don't fall into the trap of a big cam that lopes and gives you a power curve like mt. everest. Stick to that cam and go no larger. I know your intentions from what we talked about and the fact you want to run a nice tight converter for rock crawling, low RPM chugging and Duluth Off-Roading. Just avoid machining where its not neccessary My guesstimate will be 360 RWHP and 370 RWTQ if done right

Red04Silverado

iTrader: (2)

Cant wait to see this done

InchUp

iTrader: (2)

hirdlej, you are the definition of Minnesota Nice...as we're referred to. Thanks for keeping an eye out. I cannot wait to actually meet you in person where I'll give you my truck to flex your tuning skills any day of the week once it's finished.

Now I have three 5.3L's...but only two I have access to tear apart. I just sold my 5.3L pistons, all of them so that's where the extra bit of idea came for the Harland Sharps. Otherwise the stock rockers looked fine upon disassembly. I just want as many potential heat makers gone from this motor ("unsquare" block, possible main cap issues, rockers without roller tips, ect) as possible to ensure long life. After this motor is dropped in I doubt it will ever come back out.

I almost finished rebuilding the transmission today. It's a K1500 tranny that I wanted for strength rather than compatibility with LSx motors, and I have to get the flywheel spacer from ARP. No problem. Now I'm just waiting on a torque converter (TCI built) and a new 13-vane pump from eBay (new). In the tranny now I have a complete overhaul kit from Napa, "Beast" sunshell, B&M Transpak kit, Corvette non-billet servo (for longevity), 29 element forward sprag, new lo/reverse spring, Z-pack clutches, new wiring harness and shift solenoids, Mag-Hytec +3quart tranny pan, 15x7" transmission cooler and rebuilt manual NP241 t-case. Should last just as long as the motor does.

One thing I'm still unsure of and honestly quite uneasy about, is the wiring of the 5.7L. I have the complete harness from multiple motors but the one off this particular 5.3L is still in-tact, and I need to find some way to merge that with my 4.3L harness to keep 100% of my gauges working. I want to do the harness myself, because the "S10 LS1" swap harness is over $800 bucks. Granted it's plug and play, but I don't have the luxury of time to wait 7-12 weeks for Current Performance wiring to get the harness built, nor do I agree with the cost.

TarheelZ

Hey, man, this sounds like a great and fun project...good luck! Is your truck a High Rider (ZR2)? Can't quite tell from the pictures but looks like it might be. My last truck was a ZR2 and I loved it!

Also, GO VIKES!!! I'm probably the most long-term fan of the Vikings in NC...maybe the South! Believe it or not, I've been a fan since Fran Tarkenton began playing for 'em. WAAAYYYY back when we played sandlot ball, my brother always pretended to be Johnny U and I was always Tarkenton. Since he's my older brother (by 3 years), I'm sad to say the 'Colts' regularly beat the crap out of my Vikes. LOL!