LZ4 + 4T65-E Swap Into an 85 Using rusEFI
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- CaptainHindsight
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LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Starting a swap of a 2007 G6 LZ4 + 4T65-E into an 85 currently with an iron Duke and automatic. I will be using rusEFI for the engine and trans control.
LZ4 https://en.wikipedia.org/wiki/GM_High_Value_engine#LZ4
2007 GM 3.5L V6 VVT ( LZ4 ) https://www.g6performance.com/forum/arc ... -1334.html
Hydra-Matic 4T65-E Transmission Repair Manual https://procarmanuals.com/wp-content/up ... Manual.pdf
rusEFI is an open source software and hardware ECU
https://rusefi.com/
https://github.com/rusefi/rusefi/wiki
I'll post all the tuning configs and mods for anyone else that wants to follow in my footsteps.
The engine and trans were only $300 for the pair on CL from Central WI. All it took was for the previous owner to put a 10 cent garbage bag over the engine when he stored it. Oh well, but it will run better than new when completed.
The cylinders all had pretty good compression test results ~215 psi except for the middle two ~190 psi. So I figured a valve job after squirting some oil in each cylinder and retesting. The compression all went up evenly about 15-20 psi. I pulled the valve covers off and found the rockers and pushrods covered in rust!
The engine turned over freely with a wrench and the cylinders all looked good looking into the park plug holes. The oil had already been drained from the engine but what did drip out looked good.
After pulling the entire engine apart it looks like water had sat in the oil pan for a few months. There is a rusty water line on the crank and some rust on the roller lifters. So what was supposed to be just a tear down, cleaning and all new gaskets is now a complete rebuild with boring, honing, pistons, rings, bearings, oil pump, push rods, etc . etc. All the gaskets were original and the head gaskets looked good.
LZ4 https://en.wikipedia.org/wiki/GM_High_Value_engine#LZ4
2007 GM 3.5L V6 VVT ( LZ4 ) https://www.g6performance.com/forum/arc ... -1334.html
Hydra-Matic 4T65-E Transmission Repair Manual https://procarmanuals.com/wp-content/up ... Manual.pdf
rusEFI is an open source software and hardware ECU
https://rusefi.com/
https://github.com/rusefi/rusefi/wiki
I'll post all the tuning configs and mods for anyone else that wants to follow in my footsteps.
The engine and trans were only $300 for the pair on CL from Central WI. All it took was for the previous owner to put a 10 cent garbage bag over the engine when he stored it. Oh well, but it will run better than new when completed.
The cylinders all had pretty good compression test results ~215 psi except for the middle two ~190 psi. So I figured a valve job after squirting some oil in each cylinder and retesting. The compression all went up evenly about 15-20 psi. I pulled the valve covers off and found the rockers and pushrods covered in rust!
The engine turned over freely with a wrench and the cylinders all looked good looking into the park plug holes. The oil had already been drained from the engine but what did drip out looked good.
After pulling the entire engine apart it looks like water had sat in the oil pan for a few months. There is a rusty water line on the crank and some rust on the roller lifters. So what was supposed to be just a tear down, cleaning and all new gaskets is now a complete rebuild with boring, honing, pistons, rings, bearings, oil pump, push rods, etc . etc. All the gaskets were original and the head gaskets looked good.
- Shaun41178(2)
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Always good to see another lz swap.
Curious as to the pistons you are choosing. You gonna keep vvt?
Curious as to the pistons you are choosing. You gonna keep vvt?
FieroPhrek working on that ls4 swap for 18 years and counting now. 18 years!!!!! LOL
BEWARE OF BEN PHELPS. YOU HAVE BEEN WARNED. WORSE THAN MILZY IMO
BEWARE OF BEN PHELPS. YOU HAVE BEEN WARNED. WORSE THAN MILZY IMO
- CaptainHindsight
- Posts: 117
- Joined: Tue May 11, 2021 3:29 pm
- Location: Comaville/Chicago Area
Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
A stock set of pistons. The owner works for a GM dealer. We are keeping the VVT and DBW. ~240 hp should make for a nice daily driver here 9 months out of the year. It is being built more for reliability and modern updates than anything performance. The dash will become all digital in the stock bezel. The 90-ish hp 4cyl was just too boring to keep in the car. Down the road it might get a suspension and brake update as well.
i used to restore older Pontiac's (1957 - 1973, GTO, FB/TA) decades ago. Some became race cars with silly amounts of money for >>1,000 hp for the drag strip.
Forgot to add that this my first Fiero rebuild. I never even looked at them when they were new since we thought of them as a "girls" car. I'm looking very forward to this rebuild.
i used to restore older Pontiac's (1957 - 1973, GTO, FB/TA) decades ago. Some became race cars with silly amounts of money for >>1,000 hp for the drag strip.
Forgot to add that this my first Fiero rebuild. I never even looked at them when they were new since we thought of them as a "girls" car. I'm looking very forward to this rebuild.
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- Peer Mediator
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
There's a (rare) version of the 6 speed auto with the V6/60 bolt pattern used in the Saturn... Aura?
Sounds like you already have the drivetrain picked out and it's a customer's car.
Good luck with it! Yeah, that engine is a mess, but disassembly and tanking will fix that. The LZ4's were ~205 HP, right?
Sounds like you already have the drivetrain picked out and it's a customer's car.
Good luck with it! Yeah, that engine is a mess, but disassembly and tanking will fix that. The LZ4's were ~205 HP, right?
- CaptainHindsight
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
The 4T65E came with the engine. It's a future family members car. She wants to keep it automatic and daily driver.
For 2007 the LZ4 :
Pontiac G6 ( coupe ) 224hp ( 167kW ) @ 5800 rpm SAE CERTIFIED
Pontiac G6 ( sedan ) 224hp ( 167kW ) @ 5800 rpm SAE CERTIFIED
Pontiac G6 ( convertible ) 217hp ( 162kW ) @ 5800 rpm SAE CERTIFIED
Pontiac G6 ( coupe ) 220lb-ft. ( 298Nm ) @ 4000 rpm SAE CERTIFIED
Pontiac G6 ( sedan ) 220lb-ft. ( 298Nm ) @ 4000 rpm SAE CERTIFIED
Pontiac G6 ( convertible ) 217lb-ft. ( 294Nm ) @ 4000 rpm SAE CERTIFIED
What is a strong FWD 6 speed automatic for 400-500lb-ft in front of it? I have lost track of most car things after 1974. It doesn't have to bolt up. I have a complete CNC machine shop. I can fabricate adapters for just about anything.
Answering my own question, GM 6-Speed 6T80 MHM: https://gmauthority.com/blog/gm/gm-transmissions/mhm/
For 2007 the LZ4 :
Pontiac G6 ( coupe ) 224hp ( 167kW ) @ 5800 rpm SAE CERTIFIED
Pontiac G6 ( sedan ) 224hp ( 167kW ) @ 5800 rpm SAE CERTIFIED
Pontiac G6 ( convertible ) 217hp ( 162kW ) @ 5800 rpm SAE CERTIFIED
Pontiac G6 ( coupe ) 220lb-ft. ( 298Nm ) @ 4000 rpm SAE CERTIFIED
Pontiac G6 ( sedan ) 220lb-ft. ( 298Nm ) @ 4000 rpm SAE CERTIFIED
Pontiac G6 ( convertible ) 217lb-ft. ( 294Nm ) @ 4000 rpm SAE CERTIFIED
What is a strong FWD 6 speed automatic for 400-500lb-ft in front of it? I have lost track of most car things after 1974. It doesn't have to bolt up. I have a complete CNC machine shop. I can fabricate adapters for just about anything.
Answering my own question, GM 6-Speed 6T80 MHM: https://gmauthority.com/blog/gm/gm-transmissions/mhm/
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- Peer Mediator
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
The 6 speed I mentioned above is the 6T70. The 6T80 is/was used in the XTS-V with a 400+ HP twin turbo V6. Those vehicles are AWD, but GM has come up with a modular system such that the transfer case bolts onto the transmission and takes its drive straight off the front diff... so it's likely that with minor exterior parts swapping, you can convert the AWD 6T80 into a FWD transmission. However, that transmission only bolts up to the high feature V6's.CaptainHindsight wrote: ↑Thu May 13, 2021 12:47 am
What is a strong FWD 6 speed automatic for 400-500lb-ft in front of it? I have lost track of most car things after 1974. It doesn't have to bolt up. I have a complete CNC machine shop. I can fabricate adapters for just about anything.
Answering my own question, GM 6-Speed 6T80 MHM: https://gmauthority.com/blog/gm/gm-transmissions/mhm/
- CaptainHindsight
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Some pics of the body.
Was the factory using polyurethanes by '85? It acts like a urethane vs a lacquer. What's left of it anyway.
Was the factory using polyurethanes by '85? It acts like a urethane vs a lacquer. What's left of it anyway.
- CaptainHindsight
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- Joined: Tue May 11, 2021 3:29 pm
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
This site says it is the GM 6-Speed 6T70 M7W for the front wheel drive version. Thanks! Good to know.
https://gmauthority.com/blog/gm/gm-transmissions/m7w/
Found in:
Vehicle Engine
Cadillac SRX 3.6L V6 LFX NA
Cadillac XTS 3.6L V6 LFX NA
Chevrolet Equinox 3.6L V6 LFX NA
Chevrolet Malibu 2.0L I4 LTG Turbo
Chevrolet Impala 3.6L V6 LFX NA
Chevrolet Impala Bi-Fuel 3.6L V6 LFX NA
GMC Terrain 3.6L V6 LFX NA
Buick LaCrosse 3.6L V6 LFX NA
Buick Regal 2.0L I4 LTG Turbo
Buick Regal GS 2.0L I4 LTG Turbo
https://gmauthority.com/blog/gm/gm-transmissions/m7w/
Found in:
Vehicle Engine
Cadillac SRX 3.6L V6 LFX NA
Cadillac XTS 3.6L V6 LFX NA
Chevrolet Equinox 3.6L V6 LFX NA
Chevrolet Malibu 2.0L I4 LTG Turbo
Chevrolet Impala 3.6L V6 LFX NA
Chevrolet Impala Bi-Fuel 3.6L V6 LFX NA
GMC Terrain 3.6L V6 LFX NA
Buick LaCrosse 3.6L V6 LFX NA
Buick Regal 2.0L I4 LTG Turbo
Buick Regal GS 2.0L I4 LTG Turbo
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- Peer Mediator
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
What engine are you looking at for use with this transmission?CaptainHindsight wrote: ↑Thu May 13, 2021 4:26 pm This site says it is the GM 6-Speed 6T70 M7W for the front wheel drive version. Thanks! Good to know.
https://gmauthority.com/blog/gm/gm-transmissions/m7w/
Found in:
Vehicle Engine
Cadillac SRX 3.6L V6 LFX NA
Cadillac XTS 3.6L V6 LFX NA
Chevrolet Equinox 3.6L V6 LFX NA
Chevrolet Malibu 2.0L I4 LTG Turbo
Chevrolet Impala 3.6L V6 LFX NA
Chevrolet Impala Bi-Fuel 3.6L V6 LFX NA
GMC Terrain 3.6L V6 LFX NA
Buick LaCrosse 3.6L V6 LFX NA
Buick Regal 2.0L I4 LTG Turbo
Buick Regal GS 2.0L I4 LTG Turbo
The 2008 Saturn Vue with LZ4 engine had either MH2 or MH4 6T70, which would have the GM Metric bellhousing pattern. The 6T70 is decently strong already, but you could probably build one with 6T80 parts and have it bolt up to LS4, Northstar, turbo LZ9, (Caddy 4.9 ). If I were going to build an automatic Fiero, that's what I'd be looking at.
https://www.irv2.com/forums/f85/towing- ... ost1560751
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
So with a traditional automatic transmission, there is no power interruption, you are instead feathering in/out different bands/clutches to make the shift happen.
From what I have read, it becomes tricky on automatic transmissions with more than 4 speeds to manage the engagement/disengagement of the different parts all at the same time. Not DIY-friendly...
Get it wrong and the engine speed flares up during the shift, you burn clutches, or you bind the transmission.
Do your own research though, I just had a cursory look at this.
From what I have read, it becomes tricky on automatic transmissions with more than 4 speeds to manage the engagement/disengagement of the different parts all at the same time. Not DIY-friendly...
Get it wrong and the engine speed flares up during the shift, you burn clutches, or you bind the transmission.
Do your own research though, I just had a cursory look at this.
- CaptainHindsight
- Posts: 117
- Joined: Tue May 11, 2021 3:29 pm
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
If the factory can control it then I can most likely control it. The more difficult aspects of automotive controls are having to RE things on CAN bus and similar where the makers don't like to share info with those not blessed by the factory with some license fee or subscription.
Worse is what tractor co's are now doing by putting encryption into the controllers so that you have to have access to factory tools and pay for access to them.
https://www.resilience.org/stories/2017 ... -solution/
https://www.vice.com/en/article/kzp7ny/ ... -to-repair
https://www.thetruthaboutcars.com/2020/ ... ohn-deere/
i have no plans to use something other than the 4t65e for the moment. But my interests might change in the future.
Worse is what tractor co's are now doing by putting encryption into the controllers so that you have to have access to factory tools and pay for access to them.
https://www.resilience.org/stories/2017 ... -solution/
https://www.vice.com/en/article/kzp7ny/ ... -to-repair
https://www.thetruthaboutcars.com/2020/ ... ohn-deere/
i have no plans to use something other than the 4t65e for the moment. But my interests might change in the future.
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Glad to see you joined up and posted over here! This will be an interesting build to follow, I'll be following along closely!
"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."
- CaptainHindsight
- Posts: 117
- Joined: Tue May 11, 2021 3:29 pm
- Location: Comaville/Chicago Area
Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Did anyone ever find out of the LS7 1.8 ratio rockers work on the LZ9/LZ4 heads?
12577695 - LZ4/LZ9 1.7:1 Ratio Straight Rocker, Intake and Exhaust
12579615 - Ls7 1.8:1 Ratio Offset Intake Rocker
12579617 - Ls7 1.8:1 Ratio Straight Exhaust Rocker
12577695 - LZ4/LZ9 1.7:1 Ratio Straight Rocker, Intake and Exhaust
12579615 - Ls7 1.8:1 Ratio Offset Intake Rocker
12579617 - Ls7 1.8:1 Ratio Straight Exhaust Rocker
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
I can tell you aftermarket LS rockers are too wide. I have an idea of how to make them work, but no time to work on it at the moment.CaptainHindsight wrote: ↑Sun May 16, 2021 10:37 pm Did anyone ever find out of the LS7 1.8 ratio rockers work on the LZ9/LZ4 heads?
12577695 - LZ4/LZ9 1.7:1 Ratio Straight Rocker, Intake and Exhaust
12579615 - Ls7 1.8:1 Ratio Offset Intake Rocker
12579617 - Ls7 1.8:1 Ratio Straight Exhaust Rocker
"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."
- Shaun41178(2)
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Gotta use the exh rockers only if you arr gonna attempt this. The intakes have an offset that prob wont work.CaptainHindsight wrote: ↑Sun May 16, 2021 10:37 pm Did anyone ever find out of the LS7 1.8 ratio rockers work on the LZ9/LZ4 heads?
12577695 - LZ4/LZ9 1.7:1 Ratio Straight Rocker, Intake and Exhaust
12579615 - Ls7 1.8:1 Ratio Offset Intake Rocker
12579617 - Ls7 1.8:1 Ratio Straight Exhaust Rocker
I have not tried the 1.8 rockers exh rockers to see if they roll well on the valve. Buy one exh rocker and try on both valves
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Might need to buy two to make sure they'll fit next to each other (and under the valve cover)
ETA: Also curious as I'm looking at LZ9/F23 for the Storm Trooper
ETA: Also curious as I'm looking at LZ9/F23 for the Storm Trooper
- CaptainHindsight
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Rocker ordered.
LZ4 Head - rockers
Looks like there might be enough space between them. I can always make some new valve covers.
Not much room left for bigger valves though.
LZ4 Head - combustion chamber
LZ4 Head - rockers
Looks like there might be enough space between them. I can always make some new valve covers.
Not much room left for bigger valves though.
LZ4 Head - combustion chamber
- CaptainHindsight
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
Just some numbers for posterity.
Cam lift: 0.271" +/- 0.001" (not measured, info from other threads)
Edit ** Update 0.271" +/- 0.001" measured**
Valve lift with 1.7:1 rockers: 0.4607"
Valve lift with 1.8:1 rockers: 0.4878"
0.0271" difference, 5.88% increase
Is there enough clearance using 1.8:1 rockers from valve to piston with the stock pistons and full range of VVT?
Is there enough valve spring clearance with 1.8:1 rockers with stock springs?
Cam lift: 0.271" +/- 0.001" (not measured, info from other threads)
Edit ** Update 0.271" +/- 0.001" measured**
Valve lift with 1.7:1 rockers: 0.4607"
Valve lift with 1.8:1 rockers: 0.4878"
0.0271" difference, 5.88% increase
Is there enough clearance using 1.8:1 rockers from valve to piston with the stock pistons and full range of VVT?
Is there enough valve spring clearance with 1.8:1 rockers with stock springs?
Last edited by CaptainHindsight on Tue May 18, 2021 12:56 am, edited 1 time in total.
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
And the higher ratio rockers will increase duration slightly and area under the curve a bit as well.
- Shaun41178(2)
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Re: LZ4 + 4T65-E Swap Into an 85 Using rusEFI
As far as I know noone else has done this. I dont think the answers are out there. Please let us know what you findCaptainHindsight wrote: ↑Mon May 17, 2021 4:59 pm Just some numbers for posterity.
Is there enough clearance using 1.8:1 rockers from valve to piston with the stock pistons and full range of VVT?
Is there enough valve spring clearance with 1.8:1 rockers with stock springs?