Ecotec Swap
 

Straight Forward Plan: Swap an Ecotec Engine into a FB, keeping front end suspension parts "stock".

Ecotec's make between 160 and 180 hp, Similar amounts of Torque. Readily available parts all over the place, support for Turbo/Supercharger from Cobalt Forums.

Technically this engine was offered in the Solstice/Sky in a longitudinal RWD setup. If you are doing a swap for a street car this is likely the way to go.. Since we will be racing, Spare parts are easier to find/cheaper if you use the Miata Transmission.

Total Swap will likely cost about 3k to do.

Parts List (To Be updated throughout Build):
2.4 EcoTec "LE5" - Craigslist in Michigan, $650$ w 70k miles.
2.4 Ecotec Engine Controller (HHR, Pontiac G5, Cobalt, Saturn Sky, Pontiac Solstice) ($$Included in engine sale$$)
NA or NB Miata Transmission (5 Speed NB Recommended)
EcoMiata Bellhousing Adapter Plate
EcoMiata Flywheel Adapter
NA/NB Miata Flywheel (Doesn't need to be ultra lightweight) with matching Clutch "Stage 1" for ~ 180 hp.
4:10 Rear gear for FB (Allegedly you can use a Miata ring gear)

Those engines seem fairly popular with the guys building "Locost 7" style cars. Will be interesting to see it in an FB...

Another rear end option for you is the Kia 4.78's from the front of 95-02ish Kia Sportage's...

Good luck with the build :)

You know that you can install the RX7 tailshaft housing on the Miata transmission and have it bolt right into the car. I am running a Miata center transmission section with an RX7 bell housing, and tailshaft housing, the closer ratios really help.

Let me know if you need any spare parts for the FB stuff.

RARE Rx7 Parts, Race Parts, and Integra Part Out

Hi All, Thanks for the feedback so far.
Cost of Engine = 650 Bucks, 60k miles.
Today, picked up two Ecotec LE5 engines out of a 2010 and a 2012 Malibu. The Harnesses and fuse boxes were intact, and the basic measurements of the engine look like it will take up a significant amount of longitudinal space and height in the FB engine bay. I will post a few photos with the exact dimensions.
This is going to force us to move the Radiator forward ~ 5 Inches. Modification of the Rad Shroud, should allow us to still use the stock radiator, and still get decent air flow.

@mhr650 - That information on rx7 the tailhousing for the Miata trans is very helpful . Link to a write up would be great for the thread!

Yes! Please! I was under the impression the input shaft had to be machined down,believe saw this on Mazdatrix'website.

This can get confusing - In order to use the miata transmission gearset on a rotary, you would need to have the input shaft modified, and install the gearset into a FB transmission case.

What we're talking about here is different. He is going to use a Miata transmission, on an ecotec engine and put it in an FB. To make things go easier, he can use the tailshaft housing (back section, with shifter tower on it) from an FB trans, and bolt it onto his miata trans without modifying the Miata trans. This will allow him to easily bolt the transmission into an FB using an FB transmission mount etc. It would also allow him to use an FB driveshaft.

Again, the input shaft on the Miata trans would only need to be modded if you're wanting to use the miata gears behind a Rotary.

I'm very interested in watching the progress on this. I've been on the hunt for a cheap engine to swap into my drift car so I can keep the rotary as a spare for my street FB cars. My wife used to have a cavalier and I can attest to the Ecotec's longevity :)

My only reservation with using a Miata gear box would be strength. Several of us have killed them behind street ported rotaries. Which is a higher HP engine with no torque. The Ecotec would have torque.

What about a GM trans out of a Sky/Solstice?

If you do the Miata box with the RX7 tail shaft housing, you need the housing and the shift rail out of the RX7 transmission.

You can use the Miata rail and shifter turret on the RX7 tail shaft but there is some machine work required and it moves the shifter forward about an inch in the car. I currently have an RX7/Miata transmission with the Miata shifter turret on it in my race car. It shifts allot better than an RX7 box.

have you gotten anymore work done on this? is the engine in the car?

Hey All,

Right now, I am working on a wiring harness layout (Diagram and actual harness) for the car and getting the 12A out and sold- to fund the adapter parts.

Allegedly the NA/NB 5 Speed Transmissions will hold more than 220+ hp and about 200 ft lbs without destroying themselves, based on my Miata friend's Knowledge.

Theres currently a team called "Apocalyptic racing" in Lemons, who run a 2.2 Ecotec in a old Celica. They were the ones who suggested the Eco-Miata swap kit. I think they get a new trans around every season, but I have seen them lose gears before.

The Sky/Solstice Transmission is significantly more expensive. If I were doing a street car, The I would just use that GM trans. Since its endurance racing, Its ultimately lower cost for the long run to use the Miata 5 spd since they are quite cheap.

Wait.... Eco-Miata swap?!? that sound fantastic.... If my wife ever gives me her miata I'd drop an ecotech in to pump it up.

Update! March 2017

We got a NB Miata 5 Speed Transmission- on Craigslist for 300 bucks with a stock clutch and Flywheel.

Also just bought the ecotecmiata.ca "Transmission Adapter Kit" - around 670 all shipped, Comes with everything you need to get the trans bolted to it.

Ecotec Miata Engine Swap Kits


This Adapter kit has a thermostat housing spacer that you need to use to clear the bell housing adapter.

Purchased a c6 corvette accelerator pedal for the throttle.

Also got a alternator from Craigslist for the Ecotec from a J Body.

More pictures to come.

Update, April 2017.

We have reviewed the OE Ecotec Oilpan vs the stock Rx7 subframe. Ecomiata also sells a oilpan which is super low clearance and comes baffeled but its damn expensive at about 700$$$?!!?!

The Ecotec uses a front sump in an aluminum pan. It will be difficult to Baffle, but I do know some good welder buddies who will do it for a 6 pack of craft beer.

I believe we will have enough room to run it, if you flip the subframe backwards, similar to what guys do with the granny's speed shop 5.0 swap. See the detail on the link attached.

GrannysSpeedShop.com

Next up is engine mount fabrication. Ill post photos once I get into the actual fab.

EcoMiata has about a 3 week lead time on their bellhousing adapter, so we are still waiting on it before mocking the trans and engine into place.

https://cimg7.ibsrv.net/gimg/www.rx7...64974cccf3.jpg
here's a photo of the le5 for dimensions.

I see why you went Ecotech. It's the power of suggestion. I see Ecotouch Pink on your insulation in the background.

@Jeff20B..

Good eye! You win a free broken apex seal.. Ill even throw in the corner piece! hahah

Send me your address in PM to claim your prize :D

A Thread from another ECOTEC User, This has great info on the wiring harness.

Electrical Archives - the bowtie6 blog

http://www.custombuiltmotors.com/ima...%20Harness.pdf

Update June '17
 

Well, the engine is finally living in the FB.

We needed to modify the front subframe quite significantly to fit the OE Ecotec Oilpan.

It now sits nicely between the steering rack and front crossmember, and the Miata transmission lines up perfectly in the stock trans tunnel.

We used the OE GM Solstice Mounts, about 35 bucks made of cast aluminum and bolts right up to the engine block.

We are going to be running a 3/4" Poly universal engine mount for compliance on the engine and trans.

https://cimg9.ibsrv.net/gimg/www.rx7...e442f6b4b2.jpg


The Coolant Lines need to route behind the engine, so we needed about 2" to the firewall. Worked well with the trans location.

https://cimg1.ibsrv.net/gimg/www.rx7...3d2b637554.jpg

This was the early mockup for clearancing the subframe to the oil pan. The Pan sits between the steering and subframe now.

https://cimg3.ibsrv.net/gimg/www.rx7...9e3d3409fe.jpg

You can see the ecotec manifold gets close to the brake lines/master. About .75" from the MAF as we have it sitting.

That's gonna be a hell of a hose to get the coolant back up front from the bell housing.

That's a cool looking swap. subbed.

September Update
 

Update, The car is running and moving under its own power!

Latest steps have been finishing the exhaust, vacuum line routing, and diagnosing some issues with starters.

For the cooling system, we ended up running an the Rx7 Radiator (we have a aftermarket-ebay 3 core).
- We flipped the rad upside down to use shorter hoses, and added a in-line filler and cap.
- The hose coming from the back of the engine, around the bell housing and up to the radiator is still at least 2.5 ft long!

Using the Rx7 subframe, and our Eco-miata adapter for a 94 Miata transmission, The Prop Shaft was custom made at 40- 5/8 "

We chose to use a 4.77 Rear Gear from a Honda S2000, this put our top speed at about 135mph with a 225/45R15

More pics to come!

https://cimg4.ibsrv.net/gimg/www.rx7...d1d64e6d52.jpgLooks good with the Ecotec in, Needs some modification to hood to fit..
https://cimg8.ibsrv.net/gimg/www.rx7...5aea200707.jpgThis is the side exit exhaust. Had to oval the pipe around the side to pass the frame rail. Very simple routing, similar to stock past the trans.
https://cimg1.ibsrv.net/gimg/www.rx7...c71e48593e.jpg4.77 R&P from a Honda S2000 fits right into the Rx7 rear diff.

Fuel Cell Pics
 

https://cimg5.ibsrv.net/gimg/www.rx7...5bd07d0574.jpgThis is a mock-up for the Ute style rear end! This covers the fuel cell for rules.
https://cimg7.ibsrv.net/gimg/www.rx7...d32a8f56c9.jpgThis is a cage we made for the fuel cell. Its pretty simple. We used foam-3M tape on the edges that touch the cell to make a tight fit.
https://cimg8.ibsrv.net/gimg/www.rx7...f68c71cb69.jpgHere the cell is, with the spare tire tub cut out. In Hindsight it would have been better to have the attachment points horizontally across the car, but this worked out too.
https://cimg9.ibsrv.net/gimg/www.rx7...c9e0cc36e9.jpgBreather, Pump and Return all wired up. We put a Summit- brand fuel pump in the stock location for the Rx7. Filter is in line.