john.tempest

Hey Guys,

Again I am new to forums here and done a little searching, but haven't really found the answer I am looking for.

Originally, I planned on building a mild 5.3 LS with high compression and keeping it N/A just for fun at the track and strip, but given some recent events that made me believe I could not get the HP out of the 5.3 with the 243 heads I have while keeping the stock bottom end, I am now considering adding a turbo to the 5.3.

This is going into a Datsun 240z. Drivetrain will be a T56 6 speed and a R200 LSD

Here is my thoughts for the motor:

5.3 LS Stock bottom end from a truck

243 Aluminum Cylinder heads from a truck motor. They are being rebuilt as we speak, not sure about valves or springs, but probably going to go beehive with the springs and stock Mill, no shaving for the heads.

I am open to cam options, but please keep in mind I am in Canada for elevation and timing and all that fun stuff as I am hoping to keep this a street car, mostly lol.

I am hoping to keep the truck intake and just add ls1 fuel rails, injectors and an in tank pump with sump.

My questions are these:

1. The turbo I am considering is a T70/76 from Magnum. Have read good things about these turbos and seem to be able to acquire one for a decent price. Will this spool decently quick and provide the flow needed for my 450/500 RWP goal?

2. I have a set of LSA manifold off a ZL1 Camaro lying around, with these be ok for flow to the turbo?

3. Suggestions for Cam / other supporting mods and will this combination of the 243s and the turbo give me enough low end power?

I will be running a Holly EFI in the car.

Thanks GUYS!

RonSSNova

iTrader: (3)

Post this in the Forced Induction section.

Project GatTagO

iTrader: (7)

243 heads never came on a truck.

Andrew

SilverSS

iTrader: (30)

L33 5.3 truck motor has 243 or 799 heads depending on where it was built.

Op. I suggest to keep the cam small. Thats all from me.

Project GatTagO

iTrader: (7)

That's internet lore. Show me GM documentation of that.

243 heads only came on LS6s and LS2s.

Andrew

Photochop

iTrader: (74)

Do some research. 799 and 243 are the same cylinder head. The 243 head came with sodium filled valves and better springs. The castings are identical.

mightyquickz28

iTrader: (8)

Cam: Staying with GM(inexpensive) The LS6 cam.
_____Aftermarket: Stock48's tried and proven Isky Triple 12 cam.($4xx)

Valve Springs: Brian Tooley. Again tried and proven, highly praised.

If using the stock truck oil pan, check your ground clearance. The truck pan is rather deep and might be too close to the ground. I have a 5.3 turbo in development (96 Z28) and had to opt for the 4th gen Fbody pan/pickup. I found an Ebay vendor selling the pan, windage tray and dipstick/tube included (all new).

From what I read, you're off to a great start using the Holley EFI setup!

NoorJ

I would go for a s366 if you're only shootin for 4-500whp

Beanslsxnova

iTrader: (1)

My 07 Silverado has a 5.3 with 243 heads on it. I thought it was crazy to, but sure enough it does.

john.tempest

Ok so the 243s are good which is what I wanted to hear and the valve springs are the ones I ordered so that is also good to here. As far as the cam is concerned what type of lift and duration am I looking at if I keep the stock rockers? Should I go after market for rockers?

As far as the pan is concerned I will be going to an Fbody pan and windage tray and pickup for my build. Stock ground clearance is nil with the truck pan.

I guess my next question is in regards to fuel injectors. I am thinking the 42 lbs injectors will be good, but should I be looking at an LS1 intake or is the truck intake good enough? Do I have to modify the intake to accept these injectors other then a bigger fuel pump, regulator, and rails?

Finally, again, with the LSA exhaust manifold flow good enough for that turbo? I see tons of guys using the truck manifolds, so I cant see why not, but I was just curious if they were used with a supercharge application if they created more back pressure then the truck ones or flow less etc.

Thanks for the great info guys!

mightyquickz28

iTrader: (8)

As far as the rockers, most folks seem to be going with the 'Trunion upgrade'. CompCams part# 13702-KIT
As for injectors, there are calculators out there that will, given the input of desired HP, Number of cylinders, BSFC(brake specific fuel consumption) and perhaps another data point or two, will provide a close match to what you'd need for those parameters. The 60# mototrons are everywhere as well as the 80# iterations. I have a spare set with low miles too.

If that truck manifold will fit under your hood, I've read it is actually better than the LS1. But with boost applied and your stated HP level, I don't think you'd even need to consider a different intake. Low RPM torque is probably better with that (truck) manifold too.

I would think the stock rails and pump would be fine for Gas. If you're going to run E85, plan on around 30% larger fuel consumption.

john.tempest

Thanks for all the great info. Yes the stock manifold will not fit under the hood, luckily, that's what cowl hoods are for lol.

As far as the injectors go, what is a set of those 80# injectors worth? I thought the spacing was different from a truck manifold injector to an ls intake injector?

mightyquickz28

iTrader: (8)

As to the height differences, if any, I'm not aware. I didn't even try my truck manifold. I should fetch it from the shop sometime and mock it up to see.

A quick look thru Ebay for 80# Siemens(sp?) Mototron I found instances where all 8 were variously $425 and $45x. This one is new and appears to have the data sheet too.
http://www.ebay.com/itm/80lb-Siemens-Deka-fuel-injectors-86-95-Mustang-5-0L-5-8L-/231246538451?pt=Motors_Car_Truck_Parts_Accessories&hash=item35d75e26d3

dean85gt

iTrader: (7)

I have two 5.3s both of which have 799 heads..

redss82

for your goals you dont need much you can find those 80lb injectors for 330ish just need to space the rails because they are longer. You can keep the stock cam toss in some pac1218 if you want to push it a little harder. And unless its a piece of mind thing with magun you could get the on3 t70 or t76 or vsracing ones they are all chinese knock offs of the turbonetics turbos giving you the same results. The lsa manifolds will be fine any of the cast factory manifolds will work just need to find ones that will fit in the car well

JoeNova

Here are the Siemens Deka injectors I bought. They are a good bit cheaper.
http://www.ebay.com/itm/Siemens-Deka-80-LB-High-Impedance-Fuel-Injectors-EV1-Set-8-110324-FI114992-/231243948314?pt=Motors_Car_Truck_Parts_Accessories&hash=item35d736a11a&vxp=mtr
Project GatTagO, I had an LC9 with 243 heads, and I've seen an LS2 with one 243 head and one 799 head (yes, straight from the factory).


To answer your questions:

1. Skip the Magnum turbo. They were great when the price was lower. Now you can get a turbo like the On3 7665 for $340 or so and it'll make good power and spool great.

2. Use whatever manifolds you have. Stock truck manifolds work great as well and they're cheap. You can sell the LSA manifolds and pick up truck manifolds for $40/pair.

3. For 450-500 HP, stock cam is great. I have an L33 cam thats slightly larger than the other 4.8/5.3 truck cams you can have for $45 shipped to your door if you want it. Otherwise, that triple 12 is an awesome improvement over the stock cams on a mild build like this.