My first LS4/F40 swap was built just for me and I went all out with a lot of performance parts and custom touches to make it truly unique (only thing left LS4 is the long block). So a couple of weeks ago, I purchased an 06 LS4 from an Impala SS to do another LS4/F40 swap. With this swap, I have several different goals I would like to pursue:
1. Do the swap in a manner in which others could copy. 2. Explore the benefit of modifying the stock LS4 intake and rear exhaust manifold vs. replacement. 3. Learn about the Gen 3 E40 ecm (compared to the E67) and see if DoD/AFM will work w/o the BCM on a Gen 3 engine. 4. Have quick access to a LS4/F40 for parts development (like the flywheel and starter bracket) - allows me to keep driving my LS4/F40 Fiero.
A few ground rules for the swap...
1. Only LS4 components will be used. I would like to dyno the car with it 100% stock, then start swapping out the stock parts with modified ones one-by-one to see how much the LS4 can be improved by modifying its own parts. 2. Keep things simple so others can copy. 3. Custom parts will be kept to a minimum.
This engine was a complete drop out, but I tore it down to just the engine so I could clean it. After its first trip to the car wash (still needs more cleaning):
This engine also came with a GM replacement transmission. I need to power up the ECM to get to the VIN # and find out when it was replaced. The engine supposedly has 92K on it, so the replacement trans should have much less than that. I still haven't decided if I will sell this off to recoupe part of the purchase price of the engine, or if I will keep it and use it in the LS4/4T65e-hd swap I am doing as well. Until I make the final decision, I will use this transmission to make a better (more precise) starter location fixture.
The areas I consider a restriction on the LS4 is the Intake and Rear Exhaust Manifold.
The intake had significant notch in it to clear the OPSU. This significantly reduces the diameter of the intake neck opening and likely costs hp:
Here is my proposed mod... enlarge the neck so it has a uniform diameter for its entire length.
The LS4 front manifold is quite good with each port dumping into the main log section. This main log is 2.3" OD and many people use this manifold for turbo LS applications.
The rear manifold is where the significant restriction is. In this portion there are 5 cylinders of exhaust flowing through a 1.8 x 2.7 OD ellipse. Which is about 14% smaller than the main log on the front manifold & there is 1 more cylinder pushing through it.
The main log for the other 2 cylinders on the rear manifold is also about 16% smaller than the front one after 2 cylinders.
The proposed mod is to cut open the rear manifold and add some sections of pipe to enlarge the exhaust passages for both sides of the rear manifold:
One of the first things I wanted to verify was if the F40 would clear the stock exhaust crossover. So while the engine was in the back of the truck, I installed the F40 and the crossover to see. In 1st (can't even get to Rev) there is interference between the counter weight on the shift arm and the heat shield.
Removing a section of the heat shield might help with 1st gear, but I doubt it would fix Reverse. So I will likely modify the counter weight. Right now I am thinking about scoring it on the top side and bending it down to it will clear, then weld up the scored opening. This would allow it to keeps its general shape/weigh, but fix the clearance issue as well.
I don't have a chassis for this swap at the moment, so the LS4/4T65e-hd swap will take priority. This swap will be progressing as the same time, but likely at a slower pace.
Another excellent build as always and we'll all be following along. Quick question, is it that the LS4 is easier to obtain than the LS1 or LS2? Or is this just your preferred engine of choice?
Originally posted by Lunatic: Quick question, is it that the LS4 is easier to obtain than the LS1 or LS2? Or is this just your preferred engine of choice?
The LS4 has the GM Metric bolt pattern which does 2 things.
1. Allows them to bolt to Fiero transmissions w/o and adapter plate (but you have to fab up a starter mount). 2. Keeps used prices quite low vs. the other aluminum block LS(x) engines. Since they don't have the SBC bellhousing pattern, they are of little use to most hotrodders, so demand and prices are quite low. You can buy a LS4 engine for 1-4K cheaper than the LS1/LS2 engines.
My LS4/F40 car dyno'd at 382 wph (~ 430 fwhp), so they can be built up to surpass the "stock" power levels of the stock LS1/LS2 and get very close to the stock LS3.
Hey guru. I'm curious about the interference with the counter weight there, as I'll be using a crossover pipe on my car, though I'll be building a custom exhaust for it. Can you give a measurement from the top of the counter weight, to the bottom of the LS2 throttle body (since I'll be using the LS2 as well, and I'm not sure if the bottom is lower than the LS4 TB or not) on your finished car?
My current plan is to have that section of the crossover be 2.25" OD. I'm not sure what the stock crossover diameter is with/without the heat shield either.
Originally posted by lateFormula: Guru, here's another possible solution for the small diameter region on the rear manifold:
That's and option, but I am pretty sure mine would flow better. Having two opposing exhaust streams is rarely good for flow. With mine they remain angled toward the exit which helps both sides flow into the exit.
quote
Originally posted by dobey: Can you give a measurement from the top of the counter weight, to the bottom of the LS2 throttle body (since I'll be using the LS2 as well, and I'm not sure if the bottom is lower than the LS4 TB or not) on your finished car?
Stock LS4 crossover OD is 2.1", but the point of interference is more on the heat shield around the expansion joint section which is wider. With the shifter in R (highest possible position) there is only 3" of vertical clearance between the counterweight and the bottom of the LS2 TB. They are offset from each other some so the maximum clearance is 4 1/8" if the pipe passed through them at an angle.
Just an FYI, most guys with intake swaps have to angle their TB's for clearance to the Doug Thourley Headers (and probably the eBay knockoffs).
About that counter weight mod... there is only about 1/4" between the counter weight and the transmission case in 5th gear, so not much room to push it down. I might just have to trim the point enough so it will clear and weld back on the part on the outer edge (or just leave it off and see what happens).
[This message has been edited by fieroguru (edited 08-03-2014).]
Originally posted by fieroguru: Stock LS4 crossover OD is 2.1", but the point of interference is more on the heat shield around the expansion joint section which is wider. With the shifter in R (highest possible position) there is only 3" of vertical clearance between the counterweight and the bottom of the LS2 TB. They are offset from each other some so the maximum clearance is 4 1/8" if the pipe passed through them at an angle.
Just an FYI, most guys with intake swaps have to angle their TB's for clearance to the Doug Thourley Headers (and probably the eBay knockoffs).
About that counter weight mod... there is only about 1/4" between the counter weight and the transmission case in 5th gear, so not much room to push it down. I might just have to trim the point enough so it will clear and weld back on the part on the outer edge (or just leave it off and see what happens).
Thanks! I don't think I'll have a problem getting the crossover pipe at an angle. And I'll be using v-bands to connect it all together, so I won't have to worry about the big ugly 2-bolt flanges interfering with things.
As for the counter weight, does it clear if you remove the heat shield? Maybe the crossover could be ceramic coated or something to keep the heat in, rather than using the shield? Might be an option if it gives enough clearance.
The final drawing for the flywheel was sent to the machine shop yesterday for quoting. The last one I had was 2-3 years ago and I added 3 bolt holes to the backside so I can use tabs to ensure the ring gear stays put (never had any issue with mine being press fit only), but almost all available aluminum flywheels have these tabs, so I added them.
It will be 1-2 weeks for the quote to be returned. Once i have it, I will approve production of the first flywheel so I can verify the machining program and tolerances. I will also start a thread in the Mall for those interested in getting in on the first batch. All I will be looking for is a number of people ready to buy so I can size the first run appropriately. No one will pay or send $$$ until I have the flywheels in hand and ready to ship.
I have also asked the machine shop about having some made with different crankshaft bore/bolt patterns for the 60* V6 and the N* applications. The main questions is if I order say 10 flywheels, and have some of each version made, do I still get the volume discount for the 10 flywheels.
Just been in the parts gathering stage for this swap (work on the accessory drive in the LS4/4T65e-hd thread).
The connectors for the fiero clutch line and HTOB are in, just need tested.
Also have the wear strip and ring gear for the flywheel:
And a stock clutch for use to verify the machining on the flywheel when its ready. This one was about $100 and the Spec Stage 4+ is a $575 flywheel. As part of this swap, I might install a lower level clutch since to see if I can find one that holds the power, but isn't as expensive.
If you still would like me too, I can talk to my co-worker about the two sets of LS7 exhaust mani's he has. I know you used them on your other build. Let me know.
What do you plan on doing for axles? Are you going to try to put the alternator in the stock fiero location on this swap? I think you mentioned on the other swap you wanted to try there. Do you intend to sell any of the brackets for the swap? other than the starter bracket.
Haven't though much about the axles, but will likely start with the Cobalt tripods vs. the G6 ones. The DS will likely be a custom axle shaft, but I am hoping to find a stock axle for the PS.
Its still a toss up on which swap will get which alternator setup. I have to get both done first.
As for selling other parts in the swap, that might be a possibility, but I have to come up with a design I like, review the mfg costs vs. market pricing, and determine if I can be competitive.
Originally posted by fieroguru:I don't have a chassis for this swap at the moment, so the LS4/4T65e-hd swap will take priority. This swap will be progressing as the same time, but likely at a slower pace.
I'm totally jealous of your ability to even get ahold of such an engine, let alone at a presumably reasonable price. If one ever showed up around here, they'd want as much as a car that age is worth for it.
All this LS4/F40 stuff and much, much more is still in storage. The house we purchased has a 3 car garage, but with my wife's instance that she park in it, I won't be able to pull everything out of storage. I am currently working on the shelving and unpacking lots of stuff in the new garage in hopes to fit as much in it as possible.
In this "instance", your wife has made her insistence clear.
Patrick- now you are in trouble... Didn't you know that you are considered to be a sociopathic sadist on this forum if you help others with spelling or grammar?? Try pointing out that plural nouns do not use an apostrophe- Fieros, not Fiero's, and you will be crucified
If a member posts that he owns a 1983 Fiero with a stock 2.4L engine, it will get corrected within minutes by others. However, if the same person posts that he owns two 1983 Fiero's and that he loves his car's..... You will be booted from the forum if you try to help him improve his grammar or spelling skills.
Back on topic- I hope one day Guru can offer a kit for these motors... He does great work and this motor would be awesome. Maybe he can make enough money to kick the wife out of the garage and let her park in one of these http://www.costco.ca/12-ft....oduct.100229034.html
[This message has been edited by cam-a-lot (edited 01-30-2016).]
An LS engine is my dream engine, but I would need substantial help from someone to put one in. From what I understand they are no simple matter. I feel like I'm "settling" for a 3800SC when I would really prefer an LS4, or even an LS3.
An LS engine is my dream engine, but I would need substantial help from someone to put one in. From what I understand they are no simple matter. I feel like I'm "settling" for a 3800SC when I would really prefer an LS4, or even an LS3.
If you want an auto, an LS4 is really no more difficult than a 3800 swap.
Well it looks like the biggest piece of this puzzle is about to find it's way to my door. Have located an LS4 engine and trans with wiring harness and ECM from a 2007 Impala SS. The wrecker will let me separate the trans from the package to save a little money and the pain of getting rid of it later, but I get to keep the starter. They did not keep the gas peddle with the package but after checking the part # they seem to be all the same for all engine options on the Impala from 2006 to 2011. So they can just grab one from another car in the yard and toss it in with the engine. I am not sure what the BCM looks like, or how much I need it. Does anyone know if it is the same on most of these cars also? Guru did you ever find any standard axles for the cobalt ss parts to hook up the fiero rear wheel hubs? Or are we still looking at cutting a couple of fiero axles to length then cutting new splines on them. Also any progress with this project in general? Would be good to have a simple version of the LS4 - F40 swap Just to get a car running, then upgrade it as time and budget allow.
I do finally have the two LS4 engines, 4T65e-hd and F40 transmissions in the new garage, but I am staying busy filling orders for current products and doing upgrades to my LS4/F40 fiero to get it ready for some more autocrossing this summer as well as long hauling the hotrod power tour.
I haven't done any additional work on the axle front. Probably the simplest way is to just get new shafts made that use the proper inboard and outboard joints.
I like this.... Thanks for doing this.. One thing I'd do off the bat is move the coil s (packs) off the valve covers.. just for looks.... grind down the stands and then paint the v/c red..
They do make covers to hide the coils under them (fake v/c's) but I'm thinking trapping the coil heat isn't a great idea
I know you listed under ground rules, to learn about the genIII ECU over the other type.. but the ECU type you used in your 1st swap.. how hard is it to program, tune, adjust as you add /change/update the set up?? and if it's not that hard to do, from the eyes of a newbie (not a person that can tune a g.m. ls tune in their sleep) . What would the pro's and cons be of using the factory ecu over say.. the holley H/p ecu..
[This message has been edited by E.Furgal (edited 04-17-2016).]
Always enjoyed seeing Paul's build take shape, may have to take a journey up that way just to take a gander.............
An LS4 with an auto might not be a bad thing...........
Especially if it already had Guru's tweaks.
------------------ Ron
Isn't it strange that after a bombing, everyone blames the bomber, his upbringing, his environment, his culture, his mental state but … after a shooting, the problem is the gun?
My Uncle Frank was a staunch Conservative and voted straight Republican until the day he died in Chicago. Since then he has voted Democrat. Shrug
I like this.... Thanks for doing this.. One thing I'd do off the bat is move the coil s (packs) off the valve covers.. just for looks.... grind down the stands and then paint the v/c red..
They do make covers to hide the coils under them (fake v/c's) but I'm thinking trapping the coil heat isn't a great idea
I know you listed under ground rules, to learn about the genIII ECU over the other type.. but the ECU type you used in your 1st swap.. how hard is it to program, tune, adjust as you add /change/update the set up?? and if it's not that hard to do, from the eyes of a newbie (not a person that can tune a g.m. ls tune in their sleep) . What would the pro's and cons be of using the factory ecu over say.. the holley H/p ecu..
However, smoothing the valve covers isn't that simple... when you grind down the stands, you are left with holes in the valve cover that need to be welded up. Welding aluminum is not in the skill set of most DIY, so that isn't the direction for this swap. Simple, relatively inexpensive, and repeatable by others.
This swap will use the E40 ecm from the (05-06 LS4s). This ecm is quite fast and advanced, but it still uses a traditional VE table for tuning and isn't as reliant on the BCM. The E67 (07+) ecm on my first swap was developed to enable VVT and GM switched from using a VE table to a series of coefficient equations. This used to make it tougher to tune VE, so many just ran MAF only. Now HP Tuners has virtual VE tables that make it easier to tune. The E67 is still much more reliant on the BCM for the brake position switch (case learn, cruise control, etc), which can complicate the swap.
I am not much of a fan with the aftermarket ecms. No aftermarket company puts in the same level of R&D and reliability testing as GM does with their ECMs.
I found the learning curve to be a bit steeper to understand and learn how to edit the scanner program within HP tuners, than the tuning package itself. Prior to my LS4/F40 swap, I had never used HP tuners or tuned an OBD2 car (just OBD1). I am not an electrical or computer person, my forte is on the mechanical side, so if I can learn it, many others can as well.
[This message has been edited by fieroguru (edited 04-17-2016).]
However, smoothing the valve covers isn't that simple... when you grind down the stands, you are left with holes in the valve cover that need to be welded up. Welding aluminum is not in the skill set of most DIY, so that isn't the direction for this swap. Simple, relatively inexpensive, and repeatable by others.
This swap will use the E40 ecm from the (05-06 LS4s). This ecm is quite fast and advanced, but it still uses a traditional VE table for tuning and isn't as reliant on the BCM. The E67 (07+) ecm on my first swap was developed to enable VVT and GM switched from using a VE table to a series of coefficient equations. This used to make it tougher to tune VE, so many just ran MAF only. Now HP Tuners has virtual VE tables that make it easier to tune. The E67 is still much more reliant on the BCM for the brake position switch (case learn, cruise control, etc), which can complicate the swap.
I am not much of a fan with the aftermarket ecms. No aftermarket company puts in the same level of R&D and reliability testing as GM does with their ECMs.
I found the learning curve to be a bit steeper to understand and learn how to edit the scanner program within HP tuners, than the tuning package itself. Prior to my LS4/F40 swap, I had never used HP tuners or tuned an OBD2 car (just OBD1). I am not an electrical or computer person, my forte is on the mechanical side, so if I can learn it, many others can as well.
Today I put the first test run flywheel from the machine shop together (been sitting in a box in storage or on the shelf for nearly 2 years). Once I am done verifying all the dimensions, I will be ready to order the first production batch of 5.
I also milled another starter bracket from a print I had created (again 2+ years ago) to confirm the dimensions are correct. I still have to make and print the mounting ears, and weld it up. Once the starter bracket is done and the transmission clearance work complete, I will mate the engine/transmission and flywheel to verify everything works as it should (and do a compression check on the LS4 engine). Then I will pull the starter bracket back off to make an assembly fixture. While sending the prints for the starter bracket and mounting tabs out for quoting from the machine shop.
Here is the starter mounting plate and the transmission mounted in the mill for clearance work. All that is left on the transmission clearancing is the notch through the case for the starter gear. I will mill it once I have the starter mount bolted to the transmission.
[This message has been edited by fieroguru (edited 06-25-2016).]
I'm glad to see you're back on this one. Is the LS4/F40 going to take priority over the LS4/4t65e?
Any chance you'll offer the starter pad with mounting ears only for those using a getrag w/ HTOB? I just picked up a billet LS4 flywheel cheap because they were manufactured wrong. The pressure plate bolt holes were off. Tough to pass on at the price. They have 3 left. http://www.ebay.com/itm/361...e=STRK%3AMEBIDX%3AIT
Originally posted by motoracer838: Guru, you have a PM. Joe
Answered.
quote
Originally posted by KissMySSFiero: Is the LS4/F40 going to take priority over the LS4/4t65e? Any chance you'll offer the starter pad with mounting ears only for those using a getrag w/ HTOB?
Since I don't have a fiero to install either the LS4/F40 or LS4/4T65E-HD (gave my 4cyl 88 GT clone to my nephew), I will likely bounce back and forth between them making the various parts. However, people have waited long enough for the LS4/F40 flywheel and starter mount, so they are at the top of the R&D list.
Yes the starter bracket will be available individually and you would need it unassembled for your project.
[This message has been edited by fieroguru (edited 06-26-2016).]
It was 92 degrees in the garage today... but I finished all the machine work on the F40 and welding up the starter bracket. So I pulled the engine out from under the sheet metal brake, installed the flywheel, and bolted up the transmission w/ starter.
Pulled the plugs, squirted some oil in the cylinders, hooked up the jump box, and turned the switch...
Guru, thanks for the quick response, the info is a big help. I'll probably need an unassembled starter bracket as well. don't expect to need it before late fall/ early winter.
