Motorsports-X
OBS Enthusiast
Hey guys. I finally have some time to get on the internet and figure out what I'm going to do with this truck I bought. This is a LONG read, but i wanted to put everything in one place, so that over the next year or so, I have a complete history I can point at.
The truck is a 96 Z71.
I picked it up a couple of years ago from a family member. I needed a truck to haul my trailer to Texas from NC, and it had a built engine so I said wth and bought it (mistake 1) that was 2016. Since then, my family increased from 1 to 4, along with having a baby girl so the truck has been pretty much a gas drinking once in a while drive to work, and for the most part has sat. Time to fix That.
SO here's what I know...
#1) the engine install was very shoddy. Loose wires, things not hooked up, wires laying on the headers, etc. I got most of it sorted, but I did have to completely cut out the o2 sensor harnesses because they were burnt to a crisp (more on this later)
#2) engine is from an L31 98 pick up that was total'd at about 20k miles on the clock. Step dad's brother threw a whole bunch of money at it and put the engine in a short bed square body (like a early 80s model I beleive.) Truck was very strong when it was built. Tree fell on that truck in a hurricane, so the motor came out with about 5k miles since the rebuild, and sat for years until it got stuck in this truck.
3) engine is either 10 or 10.5:1 compression with Hyper-u Pistons. Vortech heads were fully ported by an older guy, and from what I remember of that old square body, they must of been done right. The guides have been relieved for lift. I dont know about the valves. and the cam....bleh. I'm gonna have to get the timing cover off to know for sure, but the comment I got was "its the biggest cam they had in the jegs catalog that didnt need a stall" ... so.. 282 maybe? It doesn't run good enough yet for me to really hear it. Its def a high rpm cam, and that may need to change. it does have good vacuum based on my foot vs brake pedal feel. I was told the engine was built with the assumption it would reach 400.
4) tranny (4l60e) was fully rebuilt right before I bought it and I was told it had a couple of upgrades. Probably solenoids or something .doesnt feel like it has a shift kit. The trans IS NOT locking up. it runs 2800 rpm at 70mph. I also dont trust the RPM's on this thing. They seem to read higher than whats actual, but I havent check them yet.
5) I have no clue what gears are in the axles, the sticker says 3.08, the push and count method came up with 3.42, and the speedometer is only remotely accurate with 3.73 flashed into the ecm. so who the hell knows. Im going to pull the cover to find out. need to change fluid anyways. it is 10 bolt.
Ok so that brings me to the BIGGEST problem with this thing. The engine runs like absolute crap. The best I have been able to get it run (and yes, its getting a 411 and a full tune) has been to flash a hypertune into it. Completely remove the o2 sensors, and run it with a 165 thermostat. That has made it mostly drivable. power is flat as hell, it misses, and part throttle sucks, but it least it doesnt buck and ping like it did when i picked it up. exhaust is rich, and oil has a slight gas tinge, so I think its safe on the rich side, safe enough anyway for now.
The plan....
1)Get rid of everything behind the headers. Place new O2 sensors as close to the header flanges as possible. will go to a 2in 2out 30 series flow master or something similar. figure that's about as good as an H pipe anyways, right? may need to change the header to, i havent measure the tubes yet.
2)find a new intake. This spider is for the birds. I'm thinking of getting an RPM air gap and welding in pads for the injector seats to be cut. Ive seen it done, but I would much rather find something I dont have to fab. i would like to keep the egr, but its not looking possible at this point. Regardless, that spider is going in the trash.
3) once the intake is on, Ill swap in a 411. Im leaning towards HP Tuners now. I could pay Black bear to do it, but Id rather do it myself and then I can tune it all 4 seasons, and really get it drivable without paying them. My tuning skill is about a 5 on a 10 scale, but primarily in motorcycle ecu's, WOT, and nitrous. driveability tuning will be new to me. lots of tables I never used before I am sure.
4) After its all running good, the engine is coming out. Ill fix all the leaks, freshen up the bearings, find out exactly what the internals are, make adjustments if needed, and put it back together.
5)after all thats done, Ill get the interior in order, and have fun toy me and the boy can take down to the 4wheel trails and play with.
I expect doing the exhaust, intake swap, and tune to cost me right around $1500 total. at which point, if you don't count normal maintenance, I will have right at 6k in truck. probably cant sell it for that, but hopefully Ill get out the difference in fun factor until I do.
Alright guys, sorry for the long read, but that's that back story and the plan at this point. Let me know if you have any suggestions, thoughts, comments, things i should do different, etc.
The truck is a 96 Z71.
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I picked it up a couple of years ago from a family member. I needed a truck to haul my trailer to Texas from NC, and it had a built engine so I said wth and bought it (mistake 1) that was 2016. Since then, my family increased from 1 to 4, along with having a baby girl so the truck has been pretty much a gas drinking once in a while drive to work, and for the most part has sat. Time to fix That.
SO here's what I know...
#1) the engine install was very shoddy. Loose wires, things not hooked up, wires laying on the headers, etc. I got most of it sorted, but I did have to completely cut out the o2 sensor harnesses because they were burnt to a crisp (more on this later)
#2) engine is from an L31 98 pick up that was total'd at about 20k miles on the clock. Step dad's brother threw a whole bunch of money at it and put the engine in a short bed square body (like a early 80s model I beleive.) Truck was very strong when it was built. Tree fell on that truck in a hurricane, so the motor came out with about 5k miles since the rebuild, and sat for years until it got stuck in this truck.
3) engine is either 10 or 10.5:1 compression with Hyper-u Pistons. Vortech heads were fully ported by an older guy, and from what I remember of that old square body, they must of been done right. The guides have been relieved for lift. I dont know about the valves. and the cam....bleh. I'm gonna have to get the timing cover off to know for sure, but the comment I got was "its the biggest cam they had in the jegs catalog that didnt need a stall" ... so.. 282 maybe? It doesn't run good enough yet for me to really hear it. Its def a high rpm cam, and that may need to change. it does have good vacuum based on my foot vs brake pedal feel. I was told the engine was built with the assumption it would reach 400.
4) tranny (4l60e) was fully rebuilt right before I bought it and I was told it had a couple of upgrades. Probably solenoids or something .doesnt feel like it has a shift kit. The trans IS NOT locking up. it runs 2800 rpm at 70mph. I also dont trust the RPM's on this thing. They seem to read higher than whats actual, but I havent check them yet.
5) I have no clue what gears are in the axles, the sticker says 3.08, the push and count method came up with 3.42, and the speedometer is only remotely accurate with 3.73 flashed into the ecm. so who the hell knows. Im going to pull the cover to find out. need to change fluid anyways. it is 10 bolt.
Ok so that brings me to the BIGGEST problem with this thing. The engine runs like absolute crap. The best I have been able to get it run (and yes, its getting a 411 and a full tune) has been to flash a hypertune into it. Completely remove the o2 sensors, and run it with a 165 thermostat. That has made it mostly drivable. power is flat as hell, it misses, and part throttle sucks, but it least it doesnt buck and ping like it did when i picked it up. exhaust is rich, and oil has a slight gas tinge, so I think its safe on the rich side, safe enough anyway for now.
The plan....
1)Get rid of everything behind the headers. Place new O2 sensors as close to the header flanges as possible. will go to a 2in 2out 30 series flow master or something similar. figure that's about as good as an H pipe anyways, right? may need to change the header to, i havent measure the tubes yet.
2)find a new intake. This spider is for the birds. I'm thinking of getting an RPM air gap and welding in pads for the injector seats to be cut. Ive seen it done, but I would much rather find something I dont have to fab. i would like to keep the egr, but its not looking possible at this point. Regardless, that spider is going in the trash.
3) once the intake is on, Ill swap in a 411. Im leaning towards HP Tuners now. I could pay Black bear to do it, but Id rather do it myself and then I can tune it all 4 seasons, and really get it drivable without paying them. My tuning skill is about a 5 on a 10 scale, but primarily in motorcycle ecu's, WOT, and nitrous. driveability tuning will be new to me. lots of tables I never used before I am sure.
4) After its all running good, the engine is coming out. Ill fix all the leaks, freshen up the bearings, find out exactly what the internals are, make adjustments if needed, and put it back together.
5)after all thats done, Ill get the interior in order, and have fun toy me and the boy can take down to the 4wheel trails and play with.
I expect doing the exhaust, intake swap, and tune to cost me right around $1500 total. at which point, if you don't count normal maintenance, I will have right at 6k in truck. probably cant sell it for that, but hopefully Ill get out the difference in fun factor until I do.
Alright guys, sorry for the long read, but that's that back story and the plan at this point. Let me know if you have any suggestions, thoughts, comments, things i should do different, etc.
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