I have a GT that I am building a 2002 LQ4 370 CI forged rods and pistons. I already have an L76 and will be using all I can off this motor. Just wondering what issues I might run into and what parts I will have to get in addition to what I can use off the L76. I had the machine shop change the 24x to a 58x reluctor wheel. I believe I will have to relocate the knock sensor. I have the new valley cover already. I ordered the pre 04 head studs.
OTHER PARTS I already have
New cam with ARP
trinion upgraded rockers
BTR dual 660 with Titanium retainers
hollow stem LS3 valves back cut with new guides
Cloyes Timing 3 bolt set and ls2 tensioner
underdrive pulley with ARP
P.S. New to the forums and have had the car for around 6 months
I will be putting some boost to it but not the whole reason I picked the Iron block. To make a long story short my L76 took on a lot of metal shavings due to me not installing a thrust bearing when installing a cloyes timing set and I had the LQ4 short block with 90K on it sitting in the shop. So I figured if it was going to cost me 900 to have the motor freshened up anyway. Why not spend the extra money and get some forged rods and pistons.
Also, the block is 04 and newer not 02 as stated in the first post. Found out when I was installing the head studs. Good thing I still had my studs from the 76.
I will be using the oil pan off the 76 so no worries on the filter or cooler.
For heads I am using the L92s off the 76 for now with the ls3 intake. Trying to save a little money on the build.
Just incase there is anyone that has looked into doing this here is some info on what I did and some issues that I ran into.
I used an LQ4 2004 short block had it bored .030, put in wiesco -3cc pistions, scat rods, and polished factory crank. Then I took everthing off the L76 and put it on the LQ. With new gaskets and the parts listed on the first post. Everything went pretty well. If I dont mention something in this post then it most likely just bolted right up with no issue. Ill post pics next week when I get back.
1) The reluctor wheel will need to be changed to a 58
2) The L76 oil pan bolted right up but there is no hole in the block for one of the bolts. You can drill and tap it. I just put the oil pan on and if I see a leak pop up ill tap it then.
3) The LQ block has a oil dipstick hole in it that will have to be blocked off. The L76 oil pan already has one. So I just taped it and put in a bolt.
4) The valley cover on the LQ is different than the L76. On the LQ the oil pressure sensor screws into the block in the same spot that it is on the L76 valley cover. So you need an LQ/LS1 vally cover.
5) The knock sensors on the LQ were located in the valley and were 1 wire sensors. The L76 had one mounted on each side of the block and are 2 wire sensors. You have a few options here.
A) Delete the knocks (must be deleted in the tune too)
B) Find a way to mount the knocks to the side of the block. On the LQ the spots are there for the knocks but were never drilled and tapped by GM. You can Drill and tap them. Some people weld bolts to the block in those spots and cut the knock bolts short. I found a free bolt hole on both sides of the block and extended the knock sensor harness to reach the holes. The holes I found were too big for the knocks bolts so I picked up a thread kit thing from Advanced Auto (cant remember what its called) that you use a tool to put a reducer in the existing threads to make them smaller. It worked perfect.
6) This relates to both number two and number three. Since the knocks are on the side of the block now and there are no knocks in the valley. The factory LQ/LS1 valley cover has 2 holes in it where the old knocks were. You jave 2 options.
A) Put in knocks to plug the holes and just dont plug them into anything.
B) Get an aftermarkek Ls1/LQ valley cover made for carbureted builds. They are flat plates with no holes.
7) The Cam position sensor on the L76 is on the front timing cover plate and monitors the cam timing gear. The LQ had variable valve timing built into the main cam gear on the front of the motor. So the cam position sensor was mounted on the rear of the block right next to the oil pressure sensor. I used the L76 sensor and just left the sensor on the back of the motor to pug the hole.
8) The alternator and bracket on the L76 have 4 holes to mount to. 3 on the front of the block and one on the side by the motor mount. The side hole is there on the LQ but there is only one hole in the front of the motor. There is a spot for a second hole that will need to be drilled and tapped for it to work. I am running now without the 3rd bolt in the front and seems to be working fine.
I am no expert and am just providing info to help out. Dont rely on this information only please do your own research and make your own decisions.