1992 Miata, LS1, then LS3 swapped

[mazpower]

I don't know where else to put this but I wanted to share it so here you go. I started this project in '09, I wanted more power out of my '92 Miata and figured why not. First swap was with a junkyard LS1 which spun a bearing the first day I drove it. Then I built a 383 LS1 for it, which ran 12k miles and broke a rod at a track day due to quench being too tight and mechanical overrevs...thanks T56 shifter! The latest build is a 415 cubic inch LS3, running strong!

Copied and pasted from another forum, forgive any weird inconsistancies...

I bought my '92 Miata back in '98. In the 11 years I've owned it, its been turbocharged (Greddy kit), put back to stock, and sat in storage for almost 3 years while I focused on my '93 RX-7 single turbo and other numerous projects. The goal was for my dad to get the car, which is why it sat in storage, but after that didn't work out I got it running with the replacement engine and pondered what the next mod would be. While I love the Miata's handling, I've never liked the weak power. Since its already been turbo'd I wanted to do something different.

So I bought a LS1 out of a '99 Camaro with 80k, along with a T56 6-speed transmission. I went with the V8 Roadsters conversion kit which requires modifications to the transmission tunnel. This kit places the engine farther back, so the shifter lines up, and you can use the Miata style radiator. I currently run a Mishimoto aluminum radiator so I'll be able to keep that as well as the stock fans. The kit requires that the oil pan be cut and rewelded to clear the tubular subframe - aside from gathering parts, this will be the start of the project and should be done by next weekend. That's where the pictures will start as well.

The other stuff...I'm going with a LS7 flywheel and clutch kit along with a V8 Roadsters master cylinder to work with the T56's slave. The exhaust will consist of Sanderson block-hugger headers and true dual piping & Borla mufflers. The infamous '90-'93 rear end is being replaced with a Getrag LSD 3.60 unit out of a CTS, along with the V8 Roadsters rear end kit with beefier axles, driveshaft, and mounts for the diff.

A Walbro 255 pump will feed the bigger engine and instead of running the stock electronics to control the engine, I'm going with a Haltech E11v2 and custom harness for engine management. I've been working with Haltechs since '01 and have installed 30+ in personal and customer's cars. I figured if I had to buy a software program to work with the LS1 ECU for $500+ and modify the GM harness, I might as well just go with the Haltech.

So there it is. I'll keep this thread updated, with pictures of course.

[mazpower]

LS1


T56


New tubular subframe, frame rail reinforcements, tranny mount and hardware

[mazpower]

And here's the car that its going in...this is an older picture, I don't have any recent pics with the 15" wheels I'm running now, but the car looks pretty much the same otherwise...

[mazpower]

Made some progress on the swap over the weekend.

So the first order of business was modifying the oil pan to clear the custom tubular crossmember. Since the oil pan was coming off, I ditched the shitty stock rod bolts for some ARP pieces. Anyways on to the oil pan.

As it looked, coming off the engine.


After media blasting and baking for 1 hour at 400 degrees to pull any hydrocarbons out of the pores for a decent weld. Outlined is the section that needs to be removed.






Cutting done!




Okay big disclaimer time! I'm not a welder by trade, to be honest I bought my first welder - a Miller Diversion 165 TIG - back in April. I know my welds look like shit. But please keep in mind that this is the second functional aluminum piece I've attempted to weld. The first is a shifter extension for my SC300's R154 and it looked much worse than this but it worked. I am open to criticism so let me have it.

After first pass, before grinding.




Inside.


End result. All pinholes sealed, it held water for 30 minutes without so much as a drop. It took me a few hours of testing, drying, heating & welding, cooling, and refilling to reach this step. It doesn't look pretty but it holds liquid, it'll clear the subframe and bolt up to the engine, and I did it myself. I'm proud of it.



I'm waiting on a new oil pan gasket and oil pickup tube o-ring, then I'll seal the engine up. Also still waiting on the flywheel & clutch combo to get the engine set ready to go in. That's when the Miata comes apart and goes under the knife.

[mazpower]

Epic progress this weekend!

Old engine comes out...




Look at that dirty transmission LOL...162k miles will do that I guess.


Empty engine bay


Dashboard and HVAC yanked, carpet pulled back...


Firewall ready for cutting. See those braces at the top of the tunnel, on both sides? Remember those for later...


And the cutting begins! Plasma cutters are fun. Much better than cutoff wheels and the like. Well until you shoot sparks through the steering shaft hole and set insulation on fire on the floorboard of the car. I wet everything down real good, got a wet towel to cover up the seat and insulation, and continued flame-free for the rest of the day.


First section removed!




Cutting finished on driver's side, still need to bust out the grinder.




Time to cut up the passenger side!


Done!


*Almost* ready for a V8!


Time to cut the tunnel where it meets the firewall, so it can be expanded. This is where I had to stop yesterday. The braces I told you to remember above stopped me from continuing. My good friend Robert - a body tech - is bringing me a spot weld drill bit so we can pop the braces off and continue the cut...then after the tunnel is widened and rewelded, I can spot weld the braces back on.

Passenger side


Driver's side


Driver's side from the engine bay...you can see that the cut isn't quite high enough...it needs to go to the top of the tunnel but the brace is blocking that.



More to come tomorrow!

[mazpower]

Spot weld drills are wonderful things. Got the braces off so the tunnel can be reshaped. After the tunnel is welded back up, these braces will be spot & stitch welded back on.






Cuts extended farther up...




And the pounding begins! Reshaping the tunnel on the driver's side...




Shaping finished on driver's side...still a lot of cleanup to do and welding, but its basically there...


About to start on the passenger side...


Got the tunnel completely widened last night, went from 16" to about 21", which will allow dropping the T56 tranny without having to pull the engine, should the need arise. The passenger side needs more shaping, gonna tackle that on Wednesday and start the cleanup...

[mazpower]

More progress tonight...

Yanked the subframe after welding up the driver's side tunnel a bit and reshaped the passenger side tunnel. We mocked up the transmission and it fits perfect with plenty of room to spare.

[mazpower]

After a LONG weekend, made some really nice progress. I only took one picture.



Engine, transmission and crossmember are in. LM Performance made a boo boo on my clutch order and the flywheel wasn't included. But I bolted up the tranny anyways, after the engine went in. This way I could set up the frame rail reinforcements in the right spot as they double for the transmission mount bolt points. I also wanted to see if the tranny could go on with the engine in place, it does. I'm very happy with the clearances.

I also discovered that I got the wrong headers when I went to hook the steering shaft back up. I guess Sanderson has two different styles of block huggers for the LS1 and I got the wrong type. Hopefully they'll exchange them. Also found out that the headers can come out with the engine already in the car.

[mazpower]

Over the weekend I got the Haltech E11v2 harness wired in...







All sensors, coils and injectors are wired up. I still need to run some grounds for the coils and the power & fuel pump wires.

[mazpower]

So my flywheel finally came in yesterday! This is the same flywheel that should have come with my clutch kit, that I recieved a week and a half ago, but someone messed up and it never got shipped. Because of that I had to put the tranny on anyways, knowing that it would have to come back off when the flywheel came in...there's no way of aligning the frame rail reinforcements with the tranny mount if it isn't there. And I love doing things twice!

[mazpower]

Didn't get much done, only had today to work on the car after coming back from a family turkey day gathering. My Vette front engine pieces showed up but no headers.

New alternator bracket from a Pontiac G8, fresh from Australia. This places the alternator bracket 3/4" back to match the Vette harmonic balancer and water pump. Some "shaving" was needed to get the Camaro alternator to bolt up...with the new style alternator it would have bolted right up.


Corvette water pump on the left, old Camaro pump on the right.


Radiator and both fans in the car, along with all the new front engine pieces.


Passenger side fan showing clearance between fan and thermostat housing. I had to "trim" the plastic a bit on the fan frame to get it to slide up from the bottom.


Driver's side fan. Also the new alternator bracket with an alternator in it.


Picture from underneath. With the Corvette balancer, there's plenty of room for the Miata radiator and stock fans.


I had to move the sway bar forward about an inch to clear the balancer. I was told that it would bolt right up, but discovered otherwise. With a couple custom brackets, it was no big deal.


Close up of the badass brackets.

[mazpower]

I finally got the right set of headers from Sanderson yesterday. Only took 3 tries, my fault though.

Took a lot of pounding and massaging but the steering shaft fits!




Before starter, passenger side...




After starter...

[mazpower]

Loomed the harness tonight. No more spaghetti!

[mazpower]

Made more progress tonight.

Thermal tape/wrap is fun but the insulation makes my hands and arms itchy.

[mazpower]

And it begins...rear end swap time!!!

I pulled the stock diff and axles and mounted up the Getrag diff so I could figure out where the front mount needs to be welded. Tomorrow I'll clean the subframe, sand it, weld up the mount and install the axles and driveshaft. The car will be mobile tomorrow night!!! It still needs the exhaust before I can drive it though...that will come a week from Saturday.

On to the pics!