70 gsconvt

Hi, I've been getting converted to possibly building a 6.0L engine for my 1978 Z28 with a turbo rather than more cubes and stay naturally aspirated.

So if I take my used engine, what should I do to it to make it live a long time. My original goal was 600 flyweel horsepower. I've been told I can do that easy with a S475 turbo.

I'm thinking new pistons, rebuilt bottom end to get compression at 9.5 or so. I'd use the stock 317/L92 heads, with bowl blending and port cleanup and appropriate springs for new cam. I'd use ARP head studs with good Felpro head gaskets. I'd probably try and get a FAST intake/TBI. I would like to use the stock truck manifolds flipped for the turbo.

Car is a manual trans from the factory and I'm liking the idea of a TKO600 or T56.

I was told I would need a 2.5" crossover tube (I have no idea what this is), a specific turbo cam. What else shoud I be looking at? Is there a specific company that has a turbo kit that I should be looking at? Thanks in advance.

70 gsconvt

No one?

Screamin'04

I'm certainly not an LS expert (yet), more of a noob to the whole LSx movement to be exact. But from what I'm seeing, if you wanted to "go through" the shortblock, your OE parts cleaned up and put back together correctly can easily sustain 600 at the flywheel. Many people are taking these LQ4 motors straight from junkers and making that much power easily with much success and some decent longevity.

My plan for my good motor is your basic ARP fasteners, OE crank (or forged if I find a deal), good rods, good pistons, good balancer and a good balance. But I'm seeing that unless you're shooting for well over 1,000 at the tires, these motors are quite durable with little effort.

If I'm wrong, someone please correct me as I too am trying to learn. I'm just trying to convey some of the info that I'm seeing as I walk the (temporary) noob path myself.

a4ls2goat

You can hit 600hp with it with out even trying stock with the s475 with the right fuel.

grim_ls1

A lot of problems arise on the piston ring lands when boosted. I keep seeing the lands breaking so I'd go with a nice set of pistons. Unfortunately, when you buy pistons you've gotta get rods to match Tue compression height. The rods need to be longer. They do make direct replacement pistons for stock rods but idk how they handle up. I'd just go with some scat, eagle or callies forged h beams. The stock cranks are mules so 600 hp isn't nothing. Is you do go the direct replacement piston route at the minimum change out the rod bolts to some Arp bolts. The rods are pretty strong but the oe bolts are not. The crossover pipe is what conects the driver and passenger manifold to the turbo. It equalizes backpressure so you down have on side of the engine running different than the other. Other than what you have listed you'll also need fueling upgrades. New injectors and a high flow pump to feed those injectors. Also you'll need a blow off valve and wastegate. Depending on if the turbo is internal oil fed or hooks to the engine oil you might want a turbo timer. When ran on engine oil wity no timer hold oil sits on the turbo bearing and cooks them to say the least. Just as screamin04 said these engines handle it. Look up an article called the big bang theory. Nice read. Also go with a set of nice iron ductile rings (hellfire rings are good ones). They'll seal under the harshes conditions.

PewterZCar

iTrader: (2)

Don't touch the motor. Spend your money on a very nice fuel system and the stock 6.0 can handle a ton of power. Get some LS9 head gaskets and head studs and boost away. If you are only wanting 600 flywheel horsepower, you might look at a different turbo. The s475 is very capable, but a smaller turbo might provide the power you are looking for with a little less lag especially on a manual transmission car.

Feel free to PM me with any questions you might have. I have a very similar set up in my car

1CAMWNDR

iTrader: (21)

Rebuild the motor with cleaned up stock pistons and rods. Get new piston rings gapped for the boost. Factory rings are too tight and tend to expand and bind breaking the ring land on the piston in high hp motors. ARP fasteners for the rod bolts, studs for the heads and mains. Simple valve job and good valves for the heads. For 600hp there are several turbos that will work nice and offer plenty of room to grow. Use a 2 1/4" crossover to keep the heat and velocity up.

Jax326

Ok let me see if I can help out a fellow 2nd gen'er! First think budget. What do you want to spend? Then what motor do you have. Lq4 w/317s are cathedral port heads so you can use an ls1 or ls6 intake if the truck intake wont clear hood(plus its ugly as ****!). The ly6 has rectangular port heads and would require an ls3 intake. As far as a 600hp goal run the motor as is. The gen 3 rods and pistons have proven to hold at this level, the beefier gen 4 ('05+) stuff can do more.
As for the hotside I've been told over and over flipped truck manifolds facing forward and down wont fit. To the contrary there's a guy an here and NastyZ28 (2nd gen forum )I forget his name that did it no problem just had to weld bend on the passenger side because the manifold points down at the crossmember.
There aren't any kits for our cars just gonna have to weld one up yourself. 2.5" crossover seems to be the norm but there's a thread on here suggesting 2.25 or even 2" may be better.
An s475 will be fine but if you ever want to step it up you might wanna go s480. That's the one i'll be using 96mm 1.32 a/r t6.
Oh and cam, ls6 ls9 custom take your pick. I bought an ls9 but decided to step up to custom after seeing denmah( look up his threads lots of info) go from an ls9 cam to custom and make more power on less boost.
Phew! That's alot of typing. Hope it helps and if you have anymore questions ill try to help.

Edit: Im running a th400. Some of the manual guys may want to suggest different turbo specs

Jax326

Heres my build if it helps.

'05 6.0
317 heads
Pac 1218 springs
Ls1 intake stock fuel rails
Truck throttle body
siemens deka 80# injectors
KMJ (ebay) head studs
LS9 head gaskets
custom cam
Ms1/msd

T76s10

iTrader: (6)

Don't touch the bottom end and save your money on the fast intake. Do ls9 gaskets like stated earlier and Ebay kmj had studs for $69. Talk to martin at tick and have him spec you a cam for the s475 and you'll have no problem spooling it. Plus, s475's are only $650 from forcedinductions. If you port the 317's you'll hit your goal on pretty low boost and that will make it more reliable. Get Tooley springs from Martin to.

denmah

iTrader: (2)

if that is all you want, i would recommend looking at a 5.3 if they are alot cheaper in your area and picking up a gt45 turbo, that combination can easily do 600whp

Twin turbo c5

I have 6.0 out of a totaled truck I bought the wiring harness and tranny for 700 dollars that's in my fairmont. I personally would just put new head gaskets on maybe arp studs and boost it. Denmah's right 5.3 's are cheaper I have a few laying around they work great but there no replacement for displacement. 600 rwhp is no problem for any of those truck motors.

HRHohio

I'm doing a similar setup in a 72 Camaro. I picked up a 4.8 out of a 2005 Silverado. Had the heads ported, put in larger valves, and new springs. Also put in a 228/234 .588/.598 on 114LSA cam. Going with LS9 Head Gaskets and Chinese head studs. Oh, I took the stock pistons out and gapped the top rings to .28 and 2nd ring to .30, then put them right back in. All that's left is to torque down the heads.

For the turbo, I'm looking at CX Racing's version of the Magnum XT80, or their slightly smaller 76mm. Check out this thread for info:
https://ls1tech.com/forums/forced-in...flow-more.html

Certainly the S475 will get you there as well if you're preferential to BW, but they're pretty big. I think bigger than the Magnum XT80, but I could be wrong.

Mine will be a single front mount, probably sitting where my battery box is, depending on space. I'm keeping power steering and AC, so that will limit my space some.

As for the crossover pipe, I believe they're talking about the pipe that goes from your driver's side exhaust manifold to the passenger side, to the merge at the turbo flange. At under 1000 rwhp, you can even go with a 2" pipe... according to this thread:
https://ls1tech.com/forums/forced-in...over-pipe.html

Good Luck!

70 gsconvt

Well, thanks for all the great reading. As for the 600 hp, I have no problem making more. I haven't picked up an engine yet, but I can get one on the cheap. I'd be inclined to do this simply to get all the covers/sensors/etc that are needed. And for as cheap as I'd be spending, I'd want to just rebuild the bottom end.

I'm a big believer in an ounce of prevention is worth a pound of cure. As for $$$, my wife thinks that I should spend nothing on a perfectly good running car. However, I'd initially budgeted about $7,500 for the engine, $4K for the trans, $1,500 for wheels/tires, and $5K for suspension stuff, possibly a Hotchkis total package and frame connectors.

I'm not stuck on this S475 turbo, that's just what was recommended to me by a guy who's done turbo engines. I'm not interested in a lot of turbo lag. I'd prefer something that fairly responsive. That's why I've always been an all-engine kind of guy. This car is going to be 98% street driven, only going to the track once or twice a year for fun. I came up with the 600hp number because I don't want some kid to buy a new cobra off the showroom floor and think he's king of the road....at least not around where I'm living. My Buick runs in the high 11's and that's been pretty good for me. Now being a good 500 lighter, I'm hoping for LOWWW 11's (possibly squeak into the 10's) with this car as a performance benchmark. But I don't need 750hp. I know I'll never put that to the ground on the street.

Rebuilding sounds like a stock crank will work with new rods/pistons. Clean up the heads and some bowl work. LS9 head gaskets and head studs. If you guys say an LS6 intake is fine, I can live with that. That should leave me plenty for a turbo and whatever else it takes to mount it properly and get it running properly. I had always planned on a better fuel system including pump/injectors/rails/lines. I'm assuming I can re-use the factory coils.

My only other concern I guess would be the manifolds. I'd heard about the flipping of them facing up, but not down. I'd like to put a vintage air on the car as it had none from the factory. So I guess I'll have to look into that and see if I'll have issues.

TheLS1Lover

Personally I wouldn't do anything internal. ARP 12 Point Head Studs, Chevrolet Performance LS9 Head Gaskets, good valve springs, an appropriate Turbo camshaft, and pushrods, maybe and oil pump if need be. Leave the 317 head stock, they will work fine un-ported. At this point a FAST is a waste of money, run the Truck Intake if there is hood clearance, or run and LS6 intake if not. Again, personally I would do an Auto, a 4L80e with a Shift Kit and good cooler will last longer than a Stick. A crossover is the pipe that connects the headers or manifolds and merges the exhaust gases into the Turbocharger, sometimes called a "Y" Pipe. For you application I would do a 2 1/4" crossover. I don't think anyone makes a bolt on system for the LSx Motor in your car, it will be a self done ordeal.

70 gsconvt

Well, the car's a stick from the factory, and I like rowing the gears, so the manual stays. I'll definitely do the ARP around the engine. And I just couldn't leave the truck manifold on the engine. YUK!!

As for no kit, I may contact CK and see if they can help me out with putting something together. I've built 6 engines over the years, so I have some skills. And I can get something welded up easy enough.

HRHohio

If you get an 05 or newer engine, they have the newer connecting rods and floating wrist pins. The rods and pistons have proven themselves out to 1200 hp, with only attending to the rings. BUT if you've got the money to burn, a set of forged pistons and rods would be a nice "peace of mind" upgrade, I guess. I'd focus on heads/cam with regards to the engine. As was recommended by LS1Lover, get an appropriate Turbo cam spec'd for your setup (Martin@Tick is one of the trusted cam speckers, but there are certainly others). Also, if you haven't already, you should read up on denmah's build's. He's been through a lot and has shared it with all of us... the do's and the don'ts. Good source of info, with a lot of pics and entertaining videos!

He's certainly proven that you don't have to spend a ton of money to make big power. Important thing is having all the supporting systems in place so you're not left stranded.

70 gsconvt

Been reading my brains out online here about systems. And man, LS6 ntakes don't go cheap. It seems like it might be worth the extra couple hundred and get a FAST 92mm one with TBI.

PewterZCar

iTrader: (2)

I believe the fast 92 and 90's don't do well with boost. The 102's seem to hold up ok though. I still think it's dumping too much money in the wrong area for the limited gain you will receive.

70 gsconvt

In a NA engine, the FAST 102's seem to pick up about 30hp. Not too bad for the extra $400 or so. Much better than these dumb ricers who spend $300 on a cold air intake system to gain 6 hp!