I started a thread about this on 60degeev6, but I'm going to start posting here also starting now. What I plan on doing is swapping a LZ9 (Technically a LGD) from a 2007 chevy uplander into my 1987 Fiero GT. I'm going to use a MegaSquirt3 Pro Mini as the ECU. I chose this ECU over the MicroSquirt even though its more expensive because it can run sequential injection, where the Micro can only do batch injection. I tore the LZ9 down to the shortblock, and removed the old VVT cam. I replaced it with a 3.4 LNJ cam from a 2007 Equinox. The LNJ cam is still a stock cam so shouldn't be any more power over the VVT cam but this is the only cam that I know of with the same bearing journal size that is not a VVT cam. The other option would be to run bearing spacers and use a cam from any other 60 degree v6. Either way this keeps things simpler for now. I got it timed Using a 3.4 timing set, and a LZ9 tensioner. I covered it using the 2.8 timing cover and water pump I already had. I used the LZ9 timing cover gasket for this which caused a slight problem I found out about later. Originally, there was a coolant crossover connecting the heads on the front side of the engine. I plan on mounting the dog bone there, so that had to go. The solution to this is to flip the heads and head gaskets around so the coolant flows out the back. I made some blocks that cover the outlets, and adapt it to -12 AN fittings. I'm going to use the stock LZ9 manifolds, and route them in a similar way to the way the Fiero was routed from factory. Of course the manifolds aren't meant to fit in this car, so some modification was needed for the rear manifold. It originally has a crossover that connects the front manifold to the rear, and a flange on the rear manifold is the exit for all 6 cylinders. because of this the rear manifold has all the ports pointing toward this flange, so I cut out a section and welded in a straighter section so it might flow better. For the intake manifold, I'm going to use a LZ4 manifold. It will bolt up to the LIM on the LZ9, but it deletes the variable intake runner. I did not want to use the LZ9's electronic throttle body, so I found a LS4 to 3 bolt throttle body adapter, which mostly fits to the LZ4 manifold. The 4 holes that mount to the manifold didn't line up perfect so they were ground down a bit to fit. the intake hole also wasn't concentric with the manifold hole. so I ground down a bit to make a better transition for it. The throttle cable cam was pointing at a weird angle for the throttle cable to go, so I took it off and welded it back in 90 degrees from where it was. When I got the crank and water pump pully in, I realized the problem that the LZ9 timing cover gasket caused. The gasket spaced the cover and water pump off just enough that the pulleys didn't line up anymore. The solution I ran with was cut a spacer the same thickness for the crank pully. I got the engine bolted to the transmission, and tested the 2.8 engine mount. it will bolt to the engine, but with only one bolt. The oil pan on the LZ9 also runs in to the forward stud on the mount. I cut away the part of the oil pan that was interfering, and modified the engine mount to tie in to the oil pan. That's where I'm at so far! I'm going to put the modified mount on when the paint dries.
LNJ camshaft Heads are flipped Coolant block I made with -12 AN fittings Rear exhaust manifold modification LS4 TB adapter Modification inside intake hole Throttle cam modification Pulleys are offset The crank pully spacer Pulleys are fixed! Engine in cradle thanks to Mr. Hoist Oil pan shaved where it interfered with engine mount stud Modified Fiero engine mount for the LZ9
That's some nice work! I'd like to do an LZ9 at some point, but I'm thinking about the cam bearing spacers, and a fat cam. Being that you're using the Megasquirt, I'd be tempted to keep the VVT, and make the accessories work in the Fiero. (The Megasquirt will run the VVT... right?)
That's some nice work! I'd like to do an LZ9 at some point, but I'm thinking about the cam bearing spacers, and a fat cam. Being that you're using the Megasquirt, I'd be tempted to keep the VVT, and make the accessories work in the Fiero. (The Megasquirt will run the VVT... right?)
Thanks! Yes from what I've seen the megasquirt can run VVT. I'm planning on putting in a bigger cam at some point. Either bearing spacers or try to regrind this Equinox cam.
Originally posted by TheMoist1: ... I'm planning on putting in a bigger cam at some point. Either bearing spacers or try to regrind this Equinox cam.
I'm not sure about the Equinox cam, but I've heard that many of the V6-60 roller cams are hollow, and pressed together. (Sounds kinda sketchy to me, but...) Point being, I'm not sure it can be reground.
There is a 60 degree V6 group on Farcebook. Lots of knowledge, there.
Please keep us updated on your build/swap.
[This message has been edited by Raydar (edited 12-31-2024).]
[QUOTE]Originally posted by TheMoist1: ... I'm planning on putting in a bigger cam at some point. Either bearing spacers or try to regrind this Equinox cam.
I'm not sure about the Equinox cam, but I've heard that many of the V6-60 roller cams are hollow, and pressed together. (Sounds kinda sketchy to me, but...) Point being, I'm not sure it can be reground.
There is a 60 degree V6 group on Farcebook. Lots of knowledge, there.
Please keep us updated on your build/swap.
[/QUOTE]
Yeah the Equinox cam is hollow. I don't exactly know the requirements for regrinding cams but if being hollow excludes it then I'll probably just go with spacers or something similar.
[This message has been edited by TheMoist1 (edited 12-31-2024).]
Yeah the Equinox cam is hollow. I don't exactly know the requierments for regrinding cams but if being hollow excludes it then I'll probably just go with spacers or something similar.
Delta is probably the leader in regrinding cams. At least they're the ones I most frequently hear about. But, from the looks of things, you probably already are familiar with them. I would give them a shout and ask.
Anyway, it looks like you've got this well in hand. I'll just kick back and applaud your progress.
[This message has been edited by Raydar (edited 12-31-2024).]
Nice swap and excellent work. IMO that 3900 engine should make 300+ HP
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Got the crossover tacked in place. It's using the majority of the original LZ9 crossover on the back side, and merging about where the Fiero originally did. The crossover is 2" and merges to 2.5". It has a V band clamp on the end.
I feel like ditching the stock accessory drive is kinda odd, I definitely prefer all the stock 60V6 serpentine drives to the stock fiero mess.
Nice job on the mount, simple, and effective.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I have done a few 3500/3900 vvt swaps with MicroSquirt and will hopefully be helping a local with the ms3 mini like you are planning on using. Currently my personal fiero is a turbo VR6 running on MicroSquirt and I just got the ms3 mini in the mail for it to get proper vvt control along with the sequential
I have yet to keep the fiero timing cover on a build I usually keep the 3900 set up, but I respect the direction
If you need any files for tuner studio I would be more than happy to send you some of the different builds I have done base files
I am very excited to see how your exhaust sounds. I have done the modified rear manifold with stock crossover on routing on two cars, the other car is now turbo using a similar design and then was redone to have equal length using a g6 rear manifold to join to the factory crossover that was then modified to be the turbo inlet manifold. I am hoping to convert one of the cars to a dual non collected manifolds routed to equal length manifold similar to your crossover. I love hearing how each different set up sounds
You look more than capable of crossing all the bridges but if you need any help I would love to lend any assistance I can
I have done a few 3500/3900 vvt swaps with MicroSquirt and will hopefully be helping a local with the ms3 mini like you are planning on using. Currently my personal fiero is a turbo VR6 running on MicroSquirt and I just got the ms3 mini in the mail for it to get proper vvt control along with the sequential
I have yet to keep the fiero timing cover on a build I usually keep the 3900 set up, but I respect the direction
If you need any files for tuner studio I would be more than happy to send you some of the different builds I have done base files
I am very excited to see how your exhaust sounds. I have done the modified rear manifold with stock crossover on routing on two cars, the other car is now turbo using a similar design and then was redone to have equal length using a g6 rear manifold to join to the factory crossover that was then modified to be the turbo inlet manifold. I am hoping to convert one of the cars to a dual non collected manifolds routed to equal length manifold similar to your crossover. I love hearing how each different set up sounds
You look more than capable of crossing all the bridges but if you need any help I would love to lend any assistance I can
Chris
Awesome! Thanks. I might just have to take you up on those offers!
Got the alternator bracket made! I'm using the Fiero alternator and putting it in a similar location to factory. It is a little closer to the block than before though. the belt uses an automatic tensioner now. The tensioner is from an s10 and the pully is an old one off the LZ9 turned down so the V's are now smooth. the belt is actually the stock Fiero belt. Didn't mean for it to fit but it just happened to work haha. I also got the crossover all welded and wrapped! Once those things were done, it was about time to put the cradle back in the car. I put it in and realized I cut it pretty close with the crossover clearance to the driver side decklid hinge. It did clear though. I'm going to try to use as much of the stock dogbone mount as I can, so bolting it to the head where it lines up showed that the valve cover had to be shaved down a little bit. It's in though! Ill figure out coolant routing and wiring while its in the car, and after I delete this cruise control and some other things.
New bracket and routing with automatic tensioner Its wrapped! Closer than I would like but it works Valve cover with extra clearance Its in!!!
What transmission is in your car? I want to do this same swap in my build, almost exactly how you are doing yours. My car currently has the TH125 automatic trans, I will probably have to switch to something different though. Are you happy with the Microsquirt, does it come ready to run or do you need to have it programmed?
What transmission is in your car? I want to do this same swap in my build, almost exactly how you are doing yours. My car currently has the TH125 automatic trans, I will probably have to switch to something different though. Are you happy with the Microsquirt, does it come ready to run or do you need to have it programmed?
I have the factory getrag 282 in my car. so far I haven't done anything with the megasquirt so I have no input on that at this time. I will need to tune it and I will need to make the wiring harness for it.
You mentioned in your original post that you swapped out the throttle body, which is what I want to do as well. What model throttle body did you use?
I'm using a 75mm 3 bolt TB from a 1999 5.7 truck. I used a ls4 to 3 bolt throttle body adapter and it bolted right up. from what I've heard almost all v8s from that era have the same throttle body.
I'm using a 75mm 3 bolt TB from a 1999 5.7 truck. I used a ls4 to 3 bolt throttle body adapter and it bolted right up. from what I've heard almost all v8s from that era have the same throttle body.
Thank you for that! Do you know the height difference between the stock Fiero V6 and the LZ9 with the LZ4 manifold on top? I have heard they are very close to the same height, just wondering if the finished height of the LZ9 sits higher in the engine compartment when complete.
Originally posted by Murcie-Me: Thank you for that! Do you know the height difference between the stock Fiero V6 and the LZ9 with the LZ4 manifold on top? I have heard they are very close to the same height, just wondering if the finished height of the LZ9 sits higher in the engine compartment when complete.
I didn't do a super exact measurement for that, but from the top of the bellhousing to the top of the intake manifold it was ~10 in on both engines. there is plenty of room from the top of the manifold to the decklid.
Thank you for that info! I went to the junkyard today and got the throttle body and LZ4 upper manifold, and was wondering if you knew what this mount is for on the intake? I kept the part that was mounted there in case it was something necessary but it looks likes it might be and IAC that was mounted there. The LS throttle body I got has and IAC in it, so I imagine using this port on the manifold isnt necessary? What are your plans for the IAC, do you think the megasquirt can control the IAC that is in the LS throttle body, or are you going to use something else. I'm thinking maybe this port on the manifold can be cut off and welded shut.
[This message has been edited by Murcie-Me (edited 01-31-2025).]
Thank you for that info! I went to the junkyard today and got the throttle body and LZ4 upper manifold, and was wondering if you knew what this mount is for on the intake? I kept the part that was mounted there in case it was something necessary but it looks likes it might be and IAC that was mounted there. The LS throttle body I got has and IAC in it, so I imagine using this port on the manifold isnt necessary? What are your plans for the IAC, do you think the megasquirt can control the IAC that is in the LS throttle body, or are you going to use something else. I'm thinking maybe this port on the manifold can be cut off and welded shut.
I actually think that port is for the evap purge solenoid. the IAC is built in to the throttle body im using also. I'm planning on using that port for a general vaccum source. I'm probably going to tap it for npt and have a vaccum nipple. I am fairly certain that the megasquirt I'm using can control the IAC.
I'm genuinely curious, Why get rid of the 3.9 timing cover and install fiero parts? Shaun does this with his swaps, and I don't understand why? to me it seems like it would be far easier and faster to keep the stock 3.9 setup, and also know you have something that will for sure work without issues compared to a homebrew setup. it's very counterintuitive to me.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
I'm no expert on these builds, but am in the process of doing one myself with the forum members help. From what I have learned, there are a couple reasons for fitting the Fiero timing cover on the LZ9 engine. The LZ9 is a VVT engine and has a VVT cam set-up. Most people opt out of using the VVT and trade the camshaft out for the stock Equinox cam and 3.4L timing sprocket set (w/LZ9 tensioner). Its simpler to now use the "87 and later timing cover, since the LZ9 timing cover sits out further to allow for the addition length on the LZ9 VVT camshaft. I am doing mine for the same reason. I don't need the VVT and would rather have the Equinox cam setup, plus my 2.8 as it is only has the crank pully, water pump pully and alternator pulley. Having just these three pulleys is not possible with the LX9 timing cover without a lot of extra work. I converted my car to the Prius electric power steering assist, so i'll never need a power steering pump, and my car doesn't have AC so I don't need that either (my Fiero is converted to a Lamborghini replica). It might not seem like it but by removing the LZ9 timing cover and all the accessory pulleys, you are making the engine build a far less complicated change-out while retaining all the benefits of the LZ9 engine. .The stock 2.8 water pump attached to the Fiero timing cover allows for easy reconnection in the original formation.
[This message has been edited by Murcie-Me (edited 02-02-2025).]
I'm genuinely curious, Why get rid of the 3.9 timing cover and install fiero parts? Shaun does this with his swaps, and I don't understand why? to me it seems like it would be far easier and faster to keep the stock 3.9 setup, and also know you have something that will for sure work without issues compared to a homebrew setup. it's very counterintuitive to me.
The reason I chose to go with the fiero timing cover, was because of the coolant routing and alternator location. the water inlet on the stock timing cover is about in the same spot so it should be fairly easy to make that work, but the alternator in the factory spot was right in the way of the dogbone. the alternator would have had to be moved down where I put it with the fiero timing cover. the accessories would have been in a row and would have been made belt routing more complicated with the vvt sensor in the way.
[This message has been edited by TheMoist1 (edited 02-02-2025).]
The reason I chose to go with the fiero timing cover, was because of the coolant routing and alternator location. the water inlet on the stock timing cover is about in the same spot so it should be fairly easy to make that work, but the alternator in the factory spot was right in the way of the dogbone. the alternator would have had to be moved down where I put it with the fiero timing cover. the accessories would have been in a row and would have been made belt routing more complicated with the vvt sensor in the way.
I guess that's one way to do it then, be careful to make sure you don't dead head the cooling system when you figure out where you want your thermostat to be.
also, just FYI, the thing for VVT on the timing cover is a solenoid, not a sensor.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.
Unfortunately no. I'm at training for my work right now for another month before I can work on it again. best I've got for an update is that I have been looking at a Bosch PWM IAC to use for the swap, after learning that the MS3Pro Mini doesn't support the built in IAC...
Oh ok. Question, do you know if the LZ9 with the flex fuel version is the same engine as the one you are doing? It seems some vehicles with the LZ9 engine also came with a "LGD" option which meant it was flex fuel capable. Its still rated at the same horsepower, but I wonder what would be different about it other than ECU settings (maybe injectors?).
Oh ok. Question, do you know if the LZ9 with the flex fuel version is the same engine as the one you are doing? It seems some vehicles with the LZ9 engine also came with a "LGD" option which meant it was flex fuel capable. Its still rated at the same horsepower, but I wonder what would be different about it other than ECU settings (maybe injectors?).
Yes. This one I am using is an LGD. as far as I know it's the exact same engine to the lz9 other than injectors. shouldn't change how it's tuned.
I am assuming you bought new lifters for the LNJ camshaft install? If so which lifters did you go with? I ordered my camshaft tonight, had to go with GM everything else was out of stock.
[This message has been edited by Murcie-Me (edited 02-08-2025).]
I am assuming you bought new lifters for the LNJ camshaft install? If so which lifters did you go with? I ordered my camshaft tonight, had to go with GM everything else was out of stock.
I'm actually reusing the old ones. The only new parts on the engine are the camshaft, timing set, gaskets, and seals.
Ok thats good to know. Does the LZ9 come with roller lifters? I figure that since i'll have to pull them all to put the cam in, might as well put new lifters in as well. I looked up the LGD engine (code) to see what the differences were, and all I can find is that the LGD doesnt have the variable intake manifold, and the cam might be slightly different than the LZ9. Since you are swapping out the cam, intake manifold and ECU, it should be back to being an LZ9. Everything says they have the same injectors as the standard LZ9, any other differences have to do with the ECU programming. Does the Equinox cam have the same lift and durations as the LZ9, is that why you went with that one? Thank you for having this thread and posting all your info and progress, it'll be the go-to thread for anybody wanting to do this swap in the future!
[This message has been edited by Murcie-Me (edited 02-08-2025).]
Ok thats good to know. Does the LZ9 come with roller lifters? I figure that since i'll have to pull them all to put the cam in, might as well put new lifters in as well. I looked up the LGD engine (code) to see what the differences were, and all I can find is that the LGD doesnt have the variable intake manifold. Everything says they have the same injectors as the standard LZ9, I think any other differences have to do with the ECU programming.
yes it has roller lifters. replacing them while you are there is probably a good thing. my LGD from a uplander had a variable length manifold.
Yes the one that I just bought has the variable intake as well. I dont think GOOGLE is a very good source of information anymore, to many people polluting it with misinformation to the point you cant trust any of it.
this is probably a dumb question, but is it possible to test run the engine while it is still attached to a stand? Meaning, does it need to be in the vehicle and hooked up to the gauges and other things to function properly, or can the ECU be hooked up to the vital engine controls (cam sensor, crank sensor, injectors, IAC and so on) while it is still out of the vehicle to test before installing? Is this something you will be doing to yours prior to install? Also, in your experience, do you know if the starter from the 2.8L will fit the LZ9?
[This message has been edited by Murcie-Me (edited 02-11-2025).]
But, from the looks of things, you probably already are familiar with them. I would give them a shout and ask. 
I'm at training for my work right now for another month before I can work on it again. best I've got for an update is that I have been looking at a Bosch PWM IAC to use for the swap, after learning that the MS3Pro Mini doesn't support the built in IAC...
