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Ecotec 2.2 Mid Engine conversion

After lots of thought and many different considerations I have decided to build an Opel GT with a 2.2 FI Ecotec DOHC aluminum block motor. I think for ease of installation I will go with the 4 spd Automatic. My thoughts are to find a 03-05 Chevy Cavalier that is totalled in the rear. Remove the motor, tranny and suspension as a single unit (transaxle assembly). Then cut the engine compartment out, including the firewall, strut towers, frame rails and inner fenders. Then cut out the Opel until all of the Cavalier drive (transaxle assy and firewall, strut towers..) fits into the rear of the Opel.

The rear axle width on the Opel is around 52.5 inches and the Cavalier is 57.5. But the Cavalier wheels seem to have alot of offset with the lugs almost flat to the outside of the wheel, while the Opel seems to be inset several inches, this should be enough to keep the tires inside the stock fenders. By using the firewall, strut towers, frame rails and inner fenders from the donor car, it should make mounting the entire setup pretty simply.

I figure I will mount the radiator in the front nose section and run long hoses back to the motor. At the same time keep the stock heater core with remote hoses. I think I will leave the stock transmission tunnel for running cables, wires and hoses. I will convert the engine compartment to a trunk of sorts.

I think the Gas tank can stay in its original location. That puts alot (all) of the weight in the rear of the car. This is not such a bad thing, it would be real easy to pull away from a light with the front wheels off the ground. Hydraulic wheelie bars would keep the car from flipping over. I think it would hurt the handling quite a bit although having Independent rear suspension should be a huge plus.

To combat the light frontend I will put the radiator, battery, brake booster and anything else I can in the front of the car. I was also considering adding some ballast weight to the front, but it would have to be adjustable and how would I be able to adjust it on the fly. One thought I had would be to mount a 20 gallon tank in the front and fill it with water/coolant and then mount 10-12 gallon tank (empty) in the rear over the gas tank. Setup 2 eletric pumps, one at each tank, then I could move upto 12 gallons to the rear and then move it back for handling. At 8.34 pounds per gallon thats 170 lbs added to the front and 100 lbs that can be moved to the rear with a flick of a switch.

I am now looking locally for a wrecked 03-05 Cavalier or Sunfire with a good front end. I have a lead on a good GT but it is 2000 miles away. If anyone knows of one for sale a little Closer to Maine, please let me know.

I am open to any suggestions and ideas anyone might have that could help out. Like what to do to make the front and rear wheels match. Cavalier has 5 lug and GT has 4. At this point I planned on keeping the stock frontend. Stock steering, I don't think I will need power steering with the engine in the back. I can also increase the foot room in the front by reducing the size of the transmission tunnel.

The 2.2 Ecotec is the Only motor I will consider using and the choice of the Cavalier/Sunfire is based on the Narrowest width wheel to wheel.
 

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I started merging this thread with the earlier one regarding the 2.2 Ecotec swap. Then I read about the mid-engine spin. Can't say I have heard that idea before. There might be a reason for that, but I don't know of one for sure.

OK, so the entire Cavalier front suspension/engine clip is installed in the rear of a GT, facing the original direction. The engine will be forward/on top of the wheel centre-line. Are the suspension mounts part of the "clip" or are they McPherson struts, attached to the Cavalier's unibody? I believe it's the latter, so that will be a challenge. One of many.

I guess the steering rack can be dispensed with by just fixing the tie rod ends. Unless you want to add a modicum of "all-wheel steer" (ala '88-'90 Prelude). Nah, dumb idea, since the direction will be all wrong. And the extra steering take-off would be too complicated to work.

Will the engine clip fit between the inner fenders at the rear? The GT is pretty darn narrow back there. If not, then MAJOR structural (as if this isn't major enough!) changes will be needed to accommodate the transplant.

I think the issue of wheel stud pattern will be the least of your worries. My first reaction? Not good. The "wheelie bars" kinda make me choke a bit, as did the water transfer idea. But I recall a few mid-engine Corvairs back in the '70's that were QUITE successful, so maybe with some sound engineering, and good execution, this could work. But if you are just a 16 year old kid with a sketch pad, please do us a favour and don't send another GT to the scrap yard. I hope for the former...
 

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just off the top of my head
+side : opel did it with the gt2 using the opel kadett/vauxhall cavalier 8 valve ohc engine from a front wheel set up[but this was a concept car only]
-ve side :you will have a very light front end at speed as the gt gets a little lift due to its shape
if you do it then for your own safety put the tank in the front out of harms way as an engine and tank in the same place are not a good thing
the front suspension/handling will be terrible as you will loose all the weight its designed to have there and a transferable water system sounds like a recipe for disaster (go to your local fire station and ask a tender driver [thats the 1 with water onboard ] what happens to it if you drive fast with a part load in a water tank ) any car driven at speed will have baffles to slow the fluid down and stop it moving from side to side in a corner and if you empty 1/2 a tank from front to back you will set up a system that gives you unpredictable understeer/over steer [dont know the yank terms think under steer is push?]
+ all the weight of extra water would need yet more power to move it
the wheel offset is for the cav which is front wheel drive and designed to put the center of the wheel over the center of the hub
much better to get a dead caddy Catera and use the eco inline in the front (remember the gt is a front mid engine layout)

if you give azzi a holla im sure he would be pleased to tell you what you need as hes just done this [from opel /vauxhall parts]
 

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Not just another kid ... I have owned 9 GT's in the past. 69 1100, 72 Auto with AC, and many 1.9's with 4 speeds. I went threw 4 speeds like water. I could change the tranny or clutch by myself in 3 hours. I have rebuilt solex carbs so many times it isn't even funny. I gave up the habbit (GT's) 15 years ago on a 20 below zero day, driving my 69 1100 to work. When I got to work I couldn't walk, my gas pedal foot was FROZEN. I believe it was a ripped rubber boot around the steering column or gas pedal. Bought a BMW that day and never drove an opel again. I hate the stock drivetrain, my personal opinion from having worked on them for years. I even purchased some of my parts from C+R.

I have been looking for a sports car and had 3 in mind. A 73 Saab Sonett, a Cosworth Vega or an Opel GT. I had a Sonett and that was a FUN little car but it is made out of plastic and can't really do anything with them. The Cosworth Vega was always a car I liked and I found a Original with on 8K miles and in near mint condition for $9000. The only problem with that is IT'S A VEGA !!!! You have to first convince someone that it IS a nice Car .. Really it is !! Then there is the Opel GT, My personal favorite. I bought my first one in 1980,yellow rust bucket for $200. That car never made it onto the road (legally :D ). But I could put down 25 feet of 2 tire rubber in my driveway. I was SOLD !!

And now I want another Opel GT but with the sole intention of FUN and not a daily driver. I don't want any 1970's original drivetrain parts left when I get done. I want it to be reliable enough to drive daily if I want, but really would like a Tire Fryin, Wheelie Machine that I can beat on and still have it hold up, unlike the original drivetrain.
 

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Discussion Starter #6
kwilford said:
OK, so the entire Cavalier front suspension/engine clip is installed in the rear of a GT, facing the original direction. The engine will be forward/on top of the wheel centre-line. Are the suspension mounts part of the "clip" or are they McPherson struts, attached to the Cavalier's unibody? I believe it's the latter, so that will be a challenge. One of many.

Yes install the same direction and the engine is more forward of the wheel centerline. It has struts that attach to the unibody. I was thinking that I would strip the clip down to only the escentuals leaving the engine mounts and unibody frame rails with the strut towers attached. The firewall from the old car would be left to tie the side in for alignment and make a barriers behind the engine. That whole clip would then be welded in to the GT body. The drivetrain is attached to a subframe and would then bolt into the GT body from undernieth. see attached pic for example.

I guess the steering rack can be dispensed with by just fixing the tie rod ends. Unless you want to add a modicum of "all-wheel steer" (ala '88-'90 Prelude). Nah, dumb idea, since the direction will be all wrong. And the extra steering take-off would be too complicated to work.

no 4 wheel steering .. I would just tie them off and use the for camber adjustments. I think it's camber

Will the engine clip fit between the inner fenders at the rear? The GT is pretty darn narrow back there. If not, then MAJOR structural (as if this isn't major enough!) changes will be needed to accommodate the transplant.

on the orginal post I have a graphic with and GT frame overlaid with the cavalier engine bay clip. Looks like a nice fit with excellent engine placement behind the seats. My only concern is the fitment of the top of the struts. I may have to tilt them in a little for hight purposes. But I will make them fit.

I think the issue of wheel stud pattern will be the least of your worries. My first reaction? Not good. The "wheelie bars" kinda make me choke a bit, as did the water transfer idea. But I recall a few mid-engine Corvairs back in the '70's that were QUITE successful, so maybe with some sound engineering, and good execution, this could work. But if you are just a 16 year old kid with a sketch pad, please do us a favour and don't send another GT to the scrap yard. I hope for the former...

Overall I think that with the mid/rear engine mount and the independent suspension, lightening up on the front spring(if I even keep the stock front suspension) and adding a few pounds to the front will yield a very good handling car with alot of power to spare.

With all of the drivetrain as a single unit installed in the rear, I dont have to worry about twisting the body or adding frame rails. Since the whole unit is designed to hold that power the GT will "just be along for the ride" sort to speak.
 

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Discussion Starter #7
here is an illustration showing the part of the cavalier frame section I would be using. It is approximate for lack of other way to explain it.
 

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Fiero loving

I think you will save yourself a lot of time if you hunt down a fiero first as your starting point. They were designed to use a Citation front suspension and drivetrain in the rear and a Chevette front suspension in the front. That means the rear suspension should mate up with cavalier parts, as they are mostly the same, and you should be able to put your more modern Ecotec motor in without much trouble. They utilize a nicely removable subframe back there that might just free you up some roon and save you a ton of engineering work.

I had similar thoughts myself once, after hearing tales from my Father of a Bug/ Toronado hybred he worked on once, but I haven't ever had a Gt in just the right condition to not feel bad cutting it up and still have enough to work with.
 

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ok I'm not sure where to start but the Fiero was a true mid design with the seats and everything moved forward and a firewall behind the passenger compartment. The X19 was a similar design but those 8 foot throtle cables are not easy to get.
Where is the fire wall?
a tank to shift the weight would be where in the back?
300 pounds of water in the front is...
A shifter linkage just below what was the gas inlet
 

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Am I right in believing that when you say MidEngined, you mean placing the Engine transverse in the rear of the GT?

If thats the case, I think you'd better look at this, If it can be done in the rear of a Nova, the same technique and subframe could be used easily in the GT.

Why reinvent the wheel when you can just rip off someone elses idea. ;)

The ecotec engine is the same as the C20LET engine in this conversion, I have to admit that I also toyed with this idea before but couldn't bring myself to have no engine in the front or wanted a transverse engine in the front of the GT to make it twinengined.

But if your asking me if its possible .... Well everythings possible, But would you really want to do it.

Enjoy the reading.

Boost Beast Page 1
Boost Beast Page 2
Boost Beast Page 3
Boost Beast Page 4
Boost Beast Page 5
Boost Beast Page 6
 

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"I don't want any 1970's original drivetrain parts left when I get done. I want it to be reliable enough to drive daily if I want, but really would like a Tire Fryin, Wheelie Machine that I can beat on and still have it hold up, unlike the original drivetrain."

the opel drivetrain holds up extremely well, i have a 71 GT with all origional drivetrain with power mods, i'm 16, i beat the living **** out of this car, and since i threw that solex across the garage its NEVER left me stranded or give me fits of trouble whatso ever. i have driven this car daily, and racked up over 12,000 miles between mid april and early november. i can roast them through frist and grab second gear very very well, i can leave a 8 foot 2nd gear patch. she sees 5,000RPM every few days or so, seen 6 grand more than it ever should, yet it'll do 121 MPH, something the cavalier drivetrain will be hard pressed to do. granted my 4 speed is not liking all the new power, but i think a 5 speed swap would be much easier, cheaper, and more fun in the short or long run. i just dont see a rear engined GT working out well at all as a few members already gave the same opnion also. if your gonna do it atleast get a rough one, dont cut up perfect bodies, as once they're cut they never go to origional, and solid bodies should be for Opel Opels.
 

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Tire Fryin GT,

I commend you for your creativeness in choosing an approach for an engine swap. Most seem to just want to bolt in a V8, but this is much more interesting.

In general I see no technical obstacle that couldn't be overcome here. I think it's going to come down to your own determination, which no one knows better than yourself, except maybe your spouse:) As long as you realize that this is going to be a substantial project and you have the needed tools and skills, I say go for it!!!

Here are my suggestions/comments

1. Watch the weight distribution. I'd have to do further research to determine what has been proven to be 'too much' but my gut instinct is telling me 60% max. RallyBob could probably comment further. In any case, expect to have to play with springs, sway bars and shocks, both front and rear, to get it to handle right.

2. Move the gas tank to the front, not only for weight distribution but also for safety

3. I'm not sold on the idea of bringing that much of the cavalier chassis over. I'd have to see more of the chassis to know for sure

4. I don't see the struts shown in the pic below working out. You should be able to angle them in somewhat using the camber adjustment in the struts, but I doubt it would be enough. Worst case scenario would be to fabricate upper control arms and add a coil over or something similar.

5. Bail on the water pumping idea. I see that being a PITA and not that beneficial.

6. Have you thought about servicing? Is there access room to change the timing belt, oil, spark plus, water pump and so on. It may end up that it's easy enough to just drop the transaxle for things like the timing belt, but it's better to work those things out in the beginning.

Depending one where you are in Maine, I may be willing to give you a hand if you get in a pinch, or just want to bounce your ideas off someone else once you get all the parts in. I'm in Southern NH BTW.

Good luck!

-Travis
 

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Discussion Starter #14
Travis said:
Tire Fryin GT,

I commend you for your creativeness in choosing an approach for an engine swap. Most seem to just want to bolt in a V8, but this is much more interesting.

Thanks, I had one with a 289 in it and it was too much weight in the front.

In general I see no technical obstacle that couldn't be overcome here. I think it's going to come down to your own determination, which no one knows better than yourself, except maybe your spouse:) As long as you realize that this is going to be a substantial project and you have the needed tools and skills, I say go for it!!!

I have built several Harleys, Boats engines etc.. and have pretty good access to all the tools I need to do the job.

Here are my suggestions/comments

1. Watch the weight distribution. I'd have to do further research to determine what has been proven to be 'too much' but my gut instinct is telling me 60% max. RallyBob could probably comment further. In any case, expect to have to play with springs, sway bars and shocks, both front and rear, to get it to handle right.

2. Move the gas tank to the front, not only for weight distribution but also for safety

I am still up in the air on moving the tank forward. I think I can leave the tank in the stock location and the engine will be plenty far enough away. Plus there will be a firewall between the tank and the motor. But with that said I am not dead set on leaving it there. I know I will have some weight distribution to deal with and the tank would be the easiest to move.

3. I'm not sold on the idea of bringing that much of the cavalier chassis over. I'd have to see more of the chassis to know for sure

For ease of installation, I think starting with the cavalier chassis and removing metal until it fits would be alot easier that trying to recreate the motor mounts, tranny mount, suspension supports and strut towers. Ithink I can do it and make it look good too.

4. I don't see the struts shown in the pic below working out. You should be able to angle them in somewhat using the camber adjustment in the struts, but I doubt it would be enough. Worst case scenario would be to fabricate upper control arms and add a coil over or something similar.

I assume you are looking at the pic of the engine/transaxle assembly. That is just an example pic and is actually from a Corsica with the old style motor. The pic was just to represent what the typical assembly would look like. In the Cavalier the strut towers are not that high and I suspect they will fit in at a slight angle. Still just guessing, I am working on finding a totalled Cavalier so I can make more accurate guesses.

5. Bail on the water pumping idea. I see that being a PITA and not that beneficial.

The water idea was a just an idea, I think it is also unrealistic to try to use. I am sure I will need ballast of some type, maybe a bucket of lead in the front.

6. Have you thought about servicing? Is there access room to change the timing belt, oil, spark plus, water pump and so on. It may end up that it's easy enough to just drop the transaxle for things like the timing belt, but it's better to work those things out in the beginning.

I think Access will be good overall. you should be able to get to the plugs, oil and misc. from the inside the car. I plan on making a cover for the motor that would still allow the use of the rear view mirror/rear window. It should be removable from behind the seats. As for other difficult to get too items, the whole motor/transaxle assembly should be very easily removed from under the car.

Depending one where you are in Maine, I may be willing to give you a hand if you get in a pinch, or just want to bounce your ideas off someone else once you get all the parts in. I'm in Southern NH BTW.

Thanks for the offer. I grew up in southern NH and am in that area all the time. All my previous Opel GT's I owned while in NH. Opels and New England don't mix well. Most of my GT's were rust buckets. But if you hear of any for sale in that area, Please let me know. Right now the best one I can find for this project is in Minnasota and thats going to be a lond haul to go and get.
Good luck!

-Travis

I passed on a 2.2 ecotec motor with 5K miles for $1000. I found a place today that thinks they can find me the entire drivetrain for the same $1000 and after they strip the sheetmetal they want, I can cut out any of the chassis parts I want. Sounded like a good deal to me. I am in no rush yet as I still need to find a Solid GT to start with. But if the right deal comes along for the Cavalier, I am all over it.
 

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nobody said:
ok I'm not sure where to start but the Fiero was a true mid design with the seats and everything moved forward and a firewall behind the passenger compartment. The X19 was a similar design but those 8 foot throtle cables are not easy to get.
Where is the fire wall?
no the gas tank won't be smart under a motor
a tank to shift the weight would be where in the back?
300 pounds of water in the front is...
A shifter linkage just below what was the gas inlet
.
There will be a firewall between the motor and the seats as the motor will need to have sound dampening and to make sure it is sealed off from the "air" inside the car.

The gas tank wouldn't be under the motor it would be FEET behind it and there would be a firewall between the tank and motor. I might even have to mount it in the front.

a tank to shift the weight would be where in the back?
300 pounds of water in the front is, well just special
that isn't even close to what I suggested. And it was just an IDEA... you have to start somewhere or are all your idea's perfect from the moment you get them?

A shifter linkage just below what was the gas inlet
Of course the shifter would not be mounted in the rear of the car. Most shifters are cable or linkage, both of which could EASILY be put back on the tranny tunnel in the stock location.
 

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Discussion Starter #17
Travis said:
Any idea on the weight of the transaxle?

I assume you've already seen this, but I thought I'd throw it out there anyway. It's truly hard to tell if it's too nice to cut up or not.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4515975485&ssPageName=STRK:MEWA:IT

-Travis
Travis,

Truely amazing response ... merely minutes after I suggested that I am looking for one, you find one in my back yard. Get that guy a beer and put it on my tab.

I am going to email them and go check it out. My biggest fear is that it has 114000 miles in Maine on it. Common rust area's like the rocker panels and the shock support on the front suspension rust bad around here and it seems to be very dificult to find a Solid body. I have had 2 front suspensions colapse on the road and it isn't any fun.
 

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hey 'tf' i know it sounds like we are all getting on your back but its not really so just trying to give you a good idea of the work involved
we all have our ideas im in the slow process of doing a cut and shut between my gt and my jag to give me a V12 gt
i also am of the thought that putting in bits from the donor is the easy way
so im going to take the body off my jag floor ,shorten it by 5" to get the wheel base right then weld the gt onto the jag floor
i think you will be doing the clip? rails the hard way as i think it would be easyer to just fab the new mounts onto the rear chassis rails with a couple of cross braces for and aft the tank could have a good enough clearance at the back of the engine but would really help put some grip back to the front if its put in the new trunk @ the front
as mentioned about the fiat X1/9 and 8' throttle cables then just go to your nearest cycle shop and buy a lenth of brake cable its the same thing and comes on a roll
 

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you know, the more I think of it, the more this sounds attainable.

You may have to fit a flip rear to get access to the new transmission (A'la GT40) but its not as if your invading any real space in the rear as there is no rear seats. And witht he flip rear, you'll be obviously making a firewall to protect the passenger compartment.

There will be more than enough space to fit an exhaust and have it coming out in the standard position and there more than enough room for the injection plenium.

It would even work out having a more usable boot space under the bonnet, apart from the Tank, Radiator and spare tyre.

Its a hell of a lot of work, but go for it.
 

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Discussion Starter #20
azzi said:
you know, the more I think of it, the more this sounds attainable.

You may have to fit a flip rear to get access to the new transmission (A'la GT40) but its not as if your invading any real space in the rear as there is no rear seats. And witht he flip rear, you'll be obviously making a firewall to protect the passenger compartment.

There will be more than enough space to fit an exhaust and have it coming out in the standard position and there more than enough room for the injection plenium.

It would even work out having a more usable boot space under the bonnet, apart from the Tank, Radiator and spare tyre.

Its a hell of a lot of work, but go for it.
It's a neat idea but that would be too much structural work. I think this can be a relatively simple project if kept simple. The engine will be completely enclosed from the driving compartment with an access panel, much like a small hood inside the car. It would give access to the spark plugs, checking the oil and general easy access items. To do any larger jobs you would have to drop the motor and suspension out of the bottom to work on it.

baz said:
i think you will be doing the clip? rails the hard way as i think it would be easyer to just fab the new mounts onto the rear chassis rails with a couple of cross braces for and aft the tank could have a good enough clearance at the back of the engine but would really help put some grip back to the front if its put in the new trunk @ the front
as mentioned
I will give that alot of consideration. Here is what I was thinking. If I don't use the clip from the Cavalier, all the mounts for the engine, transmission, suspension and all the support equipment, like the computer and the strut towers have to be fabricated. If I use the clip all the mounts for everything as well as the locations for the strut towers will be in perfect alignment.

The gas tank could easily be mounted in the front. But remember as you use gas the front will get lighter. Now with the gas tank in the back, behind the wheel centerline and with the engine infront of the wheel centerline, as you use gas the frontend will actually get heavier. Where the tank is now, in it's stock location, will be wasted space if you move the tank to the front. Another consideration would be moving the tank to the front. Then cutting out the rear window and making an accessable trunk, like a hatchback. I have attached a pic for example. I would then use the Gas cap as a trunk release, locking also. I could also gain access to the back of the motor and tranmission if I did this.
 

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