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240z Build - LQ4 bottom - L99 (LS3) Heads - T56


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After getting my car stolen 4 years ago I'm finally getting back into the swing of things.  I just purchased a 1972 240z with a SBC 350 / TH400 from an IROCz.  It's a great motor and will serve me well while I piece together my new motor.  In the meanwhile it had an oil leak so I decided to change the gaskets and paint the existing engine/firewall to clean things up a bit.  I was originally going to buy an LS1/T56 but decided to go with an LQ4 so I could install a nice set of rectangular port LS3 heads.  I decided to go with the LQ4 because I wanted to keep costs down.  The car has good bones and no frame damage.  I know the exterior needs work, but that can all be fixed via parts cars on Craigslist.  I'm still doing my research and planning it out, but I've listed some photos/parts list of what I have so far.  I've been a member of this forum for 9 years and finally have a 240 to work on.  I'm excited to share my progress--hopefully this post will be helpful to someone in the future who wishes to do something similar.  

 

HLS30: That's the previous owner in the second photo smoking a cigarette  

Car%20-%20Front.jpgCar%20-%20Rear%20Left.jpgCar%20-%20Rear%20Right.jpg

 

Existing Engine:

     350 SBC (Casting 14010207)

          Weiland Intake Manifold

          Edelbrock 4 Barrel Carburator

Before & After Paint: I painted the firewall and engine with duplicolor high temp paint.  

Engine%20-%20Before%20Paint.jpgEngine%20After%20Paint.jpg

When I install the new motor, I plan to have everything sandblasted and repainted.

 

Future Engine:

 

     LQ4 Shortblock

          Purchased from Craigslist for $300 local (from 2003 2500HD, mileage unknown)

          Planning to have this honed, hot tanked, and re-assembled

          Will do an .030 overbore, pistons, and balance the rotating assembly if the shop recommends

          Oil Pan - TBD

 

     L99 Heads (Casting: 823 with 11,000 miles)

          Purchased from Ebay for $715 shipped

          My understanding is this is equivalent to LS3 heads but with VVT

               (Fitted to automatic Camero SS's)

          Rocker Arms - TBD

               Note: The 8 Intake rocker arms need to be offsett

                    i.e. from a rectangular port head: LS3,L99,L76,L77,L92)

                    while the exhaust rocker arms do not need to be offset and  are interchangable with (LSx...etc)

          LS1 valve covers purchased from eBay for $75 shipped


     LS7 Cam: I chose this cam after reading these articles: (5.3L LM7 & 6.0L LQ4)

          Purchased from eBay for $105 shipped

               I wanted to increase lift as much as possible while keeping the stock valve-train

                    Lift: 0.558/0.558 with 1.7 rockers (LS7 Cam)

                    Duration: 211/230 (LS7 Cam)

                    LSA: 121 degrees (LS7 Cam)

               The LM7 article lists the specs on a stock LM7 w/ beehive valvetrain upgrade: 

                    Crank HP: 422 at 6,300 rpm

                         Crude estimate on my setup: 422HP * 6.0L/5.3L = 478 Crank HP

                    Crank TQ: 395 at 5,000 rpm

                         Crude estimate on my setup: 395TQ * 6.0L/5.3L = 447 Crank TQ  

                         Note: An LQ4 equipped with L92 heads will flow much more air than an LM7

               The LQ4 article lists the specs on an LQ4 with L92 heads fitted with a 4-barrel carb and GMPP

                    GM Performance Parts - Hot Cam: part# 12480033

                         LIft: 0.525 compared to the LS7's 0.558

                         Duration: 219/228 compared to the LS7's 211/230

                    Crank HP: 471HP @ 6,600 rpm

                         Crude estimate on my setup: 471HP * (211/219)*(230/228)*(.558/.525) = 487 crank HP

                    Crank TQ: 417TQ @ 5,000 rpm 

                         Crude estimate on my setup: 417TQ * (211/219)*(230/228)*(.558/.525) = 431 crank TQ

               My understanding is that a 58 tooth gear will be needed as well as the front cover/timing sensor

               Cam Gear, cover, and timing sensor - TBD

 

     L77 Intake Manifold, Fuel Rail, Injectors

          Purchased from ebay for $305 shipped from Austrailia 

          Coil Packs - TBD

          Throttle Body - TBD

          Intake - TBD

 

     Exhaust: I plan to use the existing system: 

          2.5" Dual Magnaflow (no crossover)

 

     Standalone Harness

          I haven't done much research hear but I'm hoping to learn how to modify an existing Ly6 or L92 harness

               I listed an LY6 or L92 above because my gut tells me these will be inexpensive compared to

               LS3 harnesses but again, I haven't done much research here yet.

 

Existing Drivetrain:

     Differential: The previous owner installed an R200 with turboZX axles.

          I'm planning to install billet stub axles

          I will need to research if the existing R200 will need to be upgraded

               I'm planning on having anywhere between 400-500 ft-lb of torque 

 

Existing Transmission

     TH400 with a B&M shifter (came with care from CL)

 

Future Transmission

     T-56 - (I'm currently looking around for deals)

 

Suspension: I plan to keep the existing setup 

     Tokiko Shocks and springs (came with car)

     15" Panasports (came with car)

 

Brakes: I plan to upgrade the brakes before I install the new motor setup

     Toyota Brake upgrade: TBD

 

Body:

     I plan to sandblast the whole body and replace the rusted panels in the future.

 

Running Total of Expenses

     $4,200 Car

        $300 LQ4 Short Block

          $75 LS1 Valve Covers

        $715 L99 Heads

        $305 L76 Intake Manifold, Rails, Injectors

     $5,595 Total

 

Please let me know if any of my information above is incorrect.  I anticipate this will be a 2-3 year project.  My goal is 400hp/ft-lbs @ wheels using mostly stock parts so I can maintain the vehicle using GM's recommended service intervals.  I'd like to have the flexibility to take the car on road trips and weekend road course events.

 

Here's a photo of me on the day I bought the car (notice the smile from ear to ear).  That's my friend in the back in my Mercedes which I will be selling to pay for this project.

240%20with%20me_1.jpg

 

Wish me luck!

Edited by wongboh
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Sounds like a nice build, just use gm parts for all the stuff you are missing. I would have recommended buying a complete motor assembly, the little parts add up in price quickly (bolts, gaskets, wires, sensors, etc). I have a LY6 which is a 6.0 that came factory with those L99 heads, I swapped in a cam with .590 .580 lift and added an LS3 intake assembly. Just got back from the dyno today and made 392hp and tq at the wheels through a TR6060. Also good luck on finding the 6 speed, those things are like gold to everyone these days.

 

Also I am using the stock R180 with stock axles and some stock tires size and compound. With that combination it is surviving so far, I imagine if I got some sticky tires and did hard launches it would not last very long, but me just driving around on the street and only flooring it once it builds up some speed is keeping it alive. The R200 and turbo axles that you have on the other hand should survive even with some hard launches.

Edited by crapforum
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