Author Topic: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY  (Read 484 times)

Cape T/A

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I figure ill make a post in here summarizing my LS swap I started (and finished) last year. 

here is my car before the swap.
More of the build and engine swap by nathan kluesner, on Flickr

More of the build and engine swap by nathan kluesner, on Flickr

and here it is 8 months later

Untitled by nathan kluesner, on Flickr

Untitled by nathan kluesner, on Flickr



I came across this 70k mile g8 pull out on facebook, I offered a little more than asking price so I could get all accessories, harness, computer, gas pedal, fans and I'm sure a few other things, I got it for $3,700. For those that don't know, the g8's came with an L76 and 6L80e trans, which is an aluminum 6.0 with ls3 style heads, displacement on demand, and a 6 speed automatic transmission. 

More of the build and engine swap by nathan kluesner, on Flickr

So i started pulling the original pontiac 350 out.  It ran good, just didnt have power, got 10 mpg, and had a lot of leaks.

More of the build and engine swap by nathan kluesner, on Flickr

I ordered up a pile of parts for the new engine from Scoggin Dickey.  A cam spec'd for boost, and DOD delete kit.

More of the build and engine swap by nathan kluesner, on Flickr

Next i took the heads off, cleaned them up, and put the new hardware on.

More of the build and engine swap by nathan kluesner, on Flickr

Engine going back together

More of the build and engine swap by nathan kluesner, on Flickr

ready for paint

More of the build and engine swap by nathan kluesner, on Flickr

painted

More of the build and engine swap by nathan kluesner, on Flickr

dropping my test block in place.  I am using BRP engine and trans mounts, and I am very pleased with them,  they keep the engine very low.

More of the build and engine swap by nathan kluesner, on Flickr

next i stuck the transmisson on to see if it would even fit with the mounts.  i was fully ready to cut the trans tunnel to make it work.  It fit though with no issues.

More of the build and engine swap by nathan kluesner, on Flickr

More of the build and engine swap by nathan kluesner, on Flickr

now that the transmission is on, i was able to put the accessories on and check their fitment.  i wanted to keep the low mounted alternator and A/C compressor because i hate how they look up high and with the relocation brackets they tend to look like an afterthought.  as suspected i need to notch my frame for the alternator and a/c compressor.

More of the build and engine swap by nathan kluesner, on Flickr

More of the build and engine swap by nathan kluesner, on Flickr

i started cutting back the unused wires of the stock harness.  all that i kept past the firewall was for the lights, horn, wipers, and starter coil.

More of the build and engine swap by nathan kluesner, on Flickr

engine ready to go in

More of the build and engine swap by nathan kluesner, on Flickr

since i got g8 fans with the engine i bought a g8 radiator from ebay.  it took A LOT of work and test fitting to make it fit, but in the end it turned out very good.

More of the build and engine swap by nathan kluesner, on Flickr

vintage air kit came in, so now i can figure out my exact ac compressor placement.  turns out the brackets vintage air would send for low mount dont keep the compressor close enough to the block for what i needed.  So i ordered dirty dingo brackets (which needed modification to work)

More of the build and engine swap by nathan kluesner, on Flickr

here is the dirty dingo setup

More of the build and engine swap by nathan kluesner, on Flickr

here is where i needed to notch the frame for it

More of the build and engine swap by nathan kluesner, on Flickr

frame notch in progress

More of the build and engine swap by nathan kluesner, on Flickr

test block set back in, bolted to trans, accessories put back on, and checking for clearance.

More of the build and engine swap by nathan kluesner, on Flickr

More of the build and engine swap by nathan kluesner, on Flickr


1971 lucerne blue Esprit

Cape T/A

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #1 on: May 17, 2018, 08:01:38 PM »

test block removed for notch finishing.

More of the build and engine swap by nathan kluesner, on Flickr

i had to end up trimming the front edge of the engine frame mounts to clear the notches, no big deal though.

More of the build and engine swap by nathan kluesner, on Flickr

frame is finished and painted, now the fire wall can get painted body color.

More of the build and engine swap by nathan kluesner, on Flickr


A friend came by and painted my firewall and radiator support for me.

More of the build and engine swap by nathan kluesner, on Flickr

now the real engine can go in

More of the build and engine swap by nathan kluesner, on Flickr

my son posing for this proud moment!

More of the build and engine swap by nathan kluesner, on Flickr

getting the transmission ready to go in now.  fluid and filter change, and some paint.

More of the build and engine swap by nathan kluesner, on Flickr

More of the build and engine swap by nathan kluesner, on Flickr

there it is all put together!  That is an F body oil pan by the way.

More of the build and engine swap by nathan kluesner, on Flickr

accessories put on.

More of the build and engine swap by nathan kluesner, on Flickr

very tight clearance on passanger side (G8) manifold. I used manifolds because i plan to turbo the car soon and didnt want to waste money on headers that will be eliminated.

More of the build and engine swap by nathan kluesner, on Flickr

Radiator and fans mounted.

More of the build and engine swap by nathan kluesner, on Flickr

my custom speedhut canbus gauges came in

More of the build and engine swap by nathan kluesner, on Flickr

mighty mouse catch can

More of the build and engine swap by nathan kluesner, on Flickr

2" hole in the firewall for the engine harness

More of the build and engine swap by nathan kluesner, on Flickr

laying out the PSI harness.

More of the build and engine swap by nathan kluesner, on Flickr

harness finished

More of the build and engine swap by nathan kluesner, on Flickr

time to work on the vintage air.  what a pain in the ass this was.

More of the build and engine swap by nathan kluesner, on Flickr

More of the build and engine swap by nathan kluesner, on Flickr

trying to get a game plan for all of the under dash wiring and figuring out the best way to do it.
More of the build and engine swap by nathan kluesner, on Flickr

gauges wired up

More of the engine swap by nathan kluesner, on Flickr

More of the engine swap by nathan kluesner, on Flickr

my cruise controls.  This still isnt working to this day, i think i can get it to work, just am not really motivated to dig all my wiring apart to do it.  the issue is i am using a g8 gas pedal and its designed for an ls3 pedal.

More of the engine swap by nathan kluesner, on Flickr

the wiring gettting even more complicated.

More of the engine swap by nathan kluesner, on Flickr

current state of the engine bay.

More of the engine swap by nathan kluesner, on Flickr

both inner fenders on, ebay $50 99-07 truck intake installed, and fuel pressure regulator installed

More of the engine swap by nathan kluesner, on Flickr

fuel lines tied in
More of the engine swap by nathan kluesner, on Flickr

my custom slip-spline driveshaft finished.  i had to use a bolt on th400 yoke in the trans and had to have it milled to fit.

More of the engine swap by nathan kluesner, on Flickr

my tanks inc efi tank and my Chris1313 dual 450 pump setup.  this fuel pump setup is only $650 and good for 1200 hp.  since boost is in the plans i didnt want to do this twice, so fuel will not be an issue for me!  this pump is designed for a 4th gen so some (a lot) of modification had to be made for the tank. in the end i have had trouble keeping it sealed up to the tank, i have tried to fix this 3 times now without a solution.  my latest attmept was to weld a 4th gen lock ring onto the tank and use the 4th gen gasket and it still leaks, not as bad though, and only when the tank is first filled up.

More of the engine swap by nathan kluesner, on Flickr


1971 lucerne blue Esprit

Cape T/A

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #2 on: May 17, 2018, 08:03:29 PM »


marking out where to cut the hole

More of the engine swap by nathan kluesner, on Flickr

More of the engine swap by nathan kluesner, on Flickr

g8 gas pedal mounted

More of the engine swap by nathan kluesner, on Flickr

vintage air controls done

More of the engine swap by nathan kluesner, on Flickr

sorting out some wiring

More of the engine swap by nathan kluesner, on Flickr

panel i made for the glove box to do all the wiring.

More of the engine swap by nathan kluesner, on Flickr

cruise control is mounted to the back, which turned out to be a bad idea now that its not working and dakota digital wants me to do voltage readings at the terminals.

More of the engine swap by nathan kluesner, on Flickr

engine harness fuse box mounted underneath and my fuel pump and fan relays are up top

More of the engine swap by nathan kluesner, on Flickr

More of the engine swap by nathan kluesner, on Flickr

More of the engine swap by nathan kluesner, on Flickr

gauges lit up

More of the engine swap by nathan kluesner, on Flickr

working on my Pypes 3" exhaust x pipe kit

More of the engine swap by nathan kluesner, on Flickr

driveshaft finished

More of the engine swap by nathan kluesner, on Flickr

READY TO BE STARTED!!!!!!  I couldnt get it to start though, computer had it locked out, so my friend came by and flashed a tune on it.

Finishing the engine swap by nathan kluesner, on Flickr

loaded and heading to the exhaust shop to get the exhaust finished from the manifolds to the x pipe.

Finishing the engine swap by nathan kluesner, on Flickr

new hood getting painted at the body shop

Finishing the engine swap by nathan kluesner, on Flickr

back from the body shop and with Trans Am stripes too.  you can see how much higher the front end sits with the aluminum LS engine vs the old pontiac.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

shaker scoop installed, its just on the hood for now.  eventually ill mount it to the engine.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

getting the ac charged.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

working on fitting the g8 seats.
Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

seat tracks modified to bolt down using factory seat holes

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

both seats finished, about 18 hours of work went into this.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

its all about the details.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr


trans am nationals is 1 week away, so i cut the springs to bring the front end down, i cut 1.5 coils off, in hind sight i should have cut 1.25, its very low, looks agressive though.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

wiring finished.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

pulled the old shocks off with helper springs to bring the back down.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

alignment time, just a few days left before trans am nationals

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr


1971 lucerne blue Esprit

Cape T/A

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #3 on: May 17, 2018, 08:04:36 PM »


getting the back window tinted, and this bird is ready to fly!

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

or so i thought, my transmission pan is 1 1/2" off the ground now that the car is at ride height, so i had to make a skid plate with just a few days before a 1100 mile trip.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

skid plate done

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

fuel punp leak fix attempt #2, the day before trans am nationals

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

cleaned up and ready to go!

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

and here we go!  deadline!  8 months from when i bought the ls engine, we (my girlfriend and i) are leaving from missouri to go to ohio for the Trans Am Nationals!

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr


179 test miles before we leave.

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

we made it with no issues, other than smacking that skid plate about 30 times.  then at the Tipp City cruise in we won Best Of Show!!! what an honor!

Finishing up the firebird build and trip to Trans Am Nationals by nathan kluesner, on Flickr

While at Trans Am Nationals I also got a photoshoot for Timeless Muscle Magazine, very cool stuff.

Untitled by nathan kluesner, on Flickr

Untitled by nathan kluesner, on Flickr

Untitled by nathan kluesner, on Flickr

Untitled by nathan kluesner, on Flickr

ended up getting 22 mpg with the A/C blowing cold on the trip!

here is the magazine article for those that care to give it a look, make sure to watch the video!!!

http://www.timelessmuscle.com/features/car-feature-modernized-2nd-gen-firebird/





1971 lucerne blue Esprit

ryeguy2006a

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #4 on: May 18, 2018, 08:17:33 AM »
So cool man! Congrats on the article.  8-)

1976 Trans Am LS1, 6 speed, C5 12.8" Brakes, LS1 rear 12" brakes, 17" Aluminum Rims, and much more...SOLD
My Build: http://transamcountry.com/community/index.php?topic=24465.0

New project: 1968 Camaro with 6?.?0?  5.3 w/ Z06 cam/T56
http://transamcountry.com/community/index.php?topic=74591.0

Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #4 on: May 18, 2018, 08:17:33 AM »

Cape T/A

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #5 on: May 18, 2018, 08:37:32 AM »
Thanks ryeguy!!!


Here was my skid plate after the trip, it was smashed up against the trans pan.  I ended up pulling it off, adding some more welds to it, and putting new hardware on it. 

Untitled by nathan kluesner, on Flickr


so as I see it, I have 3 options. 

1- pull the engine and trans, re do all the mounts, cut the trans tunnel out, and make it sit about 2-3" higher in the car. 
I'm not a fan of this idea as id be messing up everything i've done to this point.

2- switch the 6 speed out for a 4 speed.
I am also not a fan of this, as I purposly searched for a 6 speed auto setup to run, I love how strong these transmissions are, their quick shifting, tunability, and fuel economy.

3- Air ride suspension-
This is the route I am going to take, the car currently has all stock suspension that needs replaced.  So once i can save up the 4-5k to pay for it, I'll be adding the Ridetech shockwave system to my car.  It uses air bags with a double adjustabe shock built inside of them ( like a coil over), it 4 links the rear axle, and ill be using their Air Pod which is a pre made pump, tank, relay, and controller setup.  It will give me a remote toutch screen with several pre set settings on it.  So ill be able to raise the car up when going down the high way, lower it down when cruising slow in a car show or where ever id like, and then put the car real low when parked. 

I'm buying a house next month so that will be taking up most of my money along with my 2010 GMC lost oil pressure, so firebird is on the back burner for a bit.


1971 lucerne blue Esprit

Cape T/A

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #6 on: May 18, 2018, 08:56:33 AM »
So once I fired up the engine I noticed my A/C belt kept jumping off one rib to the back.  No matter how many times I put it back to the correct spot it would immediately jump off once the engine was started.  So this winter I corrected that problem.  After some measuring I found out that the compressor was 5/32" to far forward.  So I had to cut, drill, and add some spacers and was able to get it right where it needed to be.  I have since put several hundred miles on the car and many WOT pulls and the belt has stayed put!

Untitled by nathan kluesner, on Flickr

Next I noticed my balancer was very slightly wobbling.  The bolt was tight as I had followed the GM torque sequence, so I concluded that the rubber was working out of it. 

I had my friend Aaron at SDPC send me a new balancer and ARP bolt (along with all the components to build the rear axle).  The new balancer is straight as an arrow when running.

Untitled by nathan kluesner, on Flickr

not really LS related so ill skip the details, but here is my axle I built and finished a few weeks ago.  3.23 Richmond gears. eaton tru trac, mouser 31 spline axles, and 4th gen disc brakes.  The car runs so much better with this setup.  And I still only turn 2k rpm's at 75 mph.

Untitled by nathan kluesner, on Flickr

So on my 3rd attempt to fix my fuel leak, I got a 4th gen plastic tank, cut the lock ring out, melted the plastic off, cut it down to height, and had a friend Tig weld it to my tank.  Using a 4th gen gasket this seemed to seal up really well, and I thought it would fix my leak when the tank was freshly filled up, it did not though, as it still drips, unless my leak is coming from somewhere else?

Untitled by nathan kluesner, on Flickr

Untitled by nathan kluesner, on Flickr

axle and tank back in the car

Untitled by nathan kluesner, on Flickr



« Last Edit: May 18, 2018, 10:07:39 AM by Cape T/A »

1971 lucerne blue Esprit

Cape T/A

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #7 on: May 18, 2018, 09:04:20 AM »
Fast cars have to stop good right?  I got more money back from my income taxes than I thought so I decided to finish my brake upgrades since I had already started on the rear.  I ordered up a cpp C5 brake kit.  That kit has got to be the easiest big modification ive made to my car.  It took way more time to paint it all up than to actually install it.

Untitled by nathan kluesner, on Flickr


Untitled by nathan kluesner, on Flickr

Untitled by nathan kluesner, on Flickr

And the wilwood master cylinder.  works great and makes the engine bay look so nice!

Untitled by nathan kluesner, on Flickr


So that brings me up to date on all of my LS related mods to the car.  I initially thought I would be putting a turbo on the car by now, but the swap cost me a lot more than I intended, and the Ridetech suspension is more than double what I thought id spend on suspension as well.  So it will be several years before this car sees boost, but it will happen! 

1971 lucerne blue Esprit

Dreamn2

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #8 on: May 18, 2018, 12:05:35 PM »
Very Good Job Nathan, Love the car!
79 Fire Am
76 Fire Am
78 Fire Am

scarebird

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Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #9 on: July 23, 2018, 09:02:13 PM »
Nice work.  I saw your upper radiator hose and ran out to see if it would work with mine - nope, 3's have the outlet on the drivers side  %$#@&!

I noted your water pump hoses exit about 1-1/4" lower than mine, most likely why your trans cleared and mine did not...

Re: 1971 Firebird LS (L76) swap with 6L80e 6 speed auto, PICTURE HEAVY
« Reply #9 on: July 23, 2018, 09:02:13 PM »
You can help support TAC!