Ecotec, Fastback, T-Top Build. (Page 16/22)
LornesGT JUN 02, 11:47 PM
Thanks for posting in such detail of your mods and repairs. Wish I had all you tools, especially the lazer cutter.

Lunatic JUN 26, 08:29 AM
To those wondering, the 88 fuel tank physically fits into the 84 chassis with ease. Since I didn't want to mess around with old, rusty fuel tank straps, I went and picked up some really long ones. These are made by Spectra and the part number is: ST125 as seen.


While they are too long, they required some modifications. Chop, cut, rebuild. Here are the results.




Of course some black paint was in order.




After the cutting, grinding and painting of the straps, I then installed the fuel tank. I also added some thin rubber between the straps and the tank in order to reduce creaking and general noise.
The next step will be to clean and install the filler tube.




Now that the fuel tank is in for the last time, I had to install the filler tube. It was in nice shape but I decided to paint it black.


I also decided to install new rubber elbows as mine were old and weathered.


As you can see, the 1.5" ID hose comes longer and must be trimmed to fit.
The copper plumbing elbow was used to enlarge the ID on the smaller hose as it was very tight on the plastic 90 that I had.
PS-These are proper "fuel rated" hoses.


After trimming.


Installed on the filler tube.




The filler tube was then wiggled into place and secured to the car. For the smaller hose, I simply cut it in half, installed the fuel rated plastic 90 and trimmed to fit. I'm glad that's done.
Lunatic JUL 08, 07:03 AM
When I started this swap, I didn't have an 88 cradle. Not knowing if I'd be able to find one, I built a cradle with square tubing. While there is nothing wrong my square tube cradle, I've chosen to put it aside for now. After stumbling onto an 88 cradle from a local member, I decided to mount the Ecotec and F23 onto it instead.
Knowing the benefits of using jigs, I decided to make a cradle jig using material that I had on-hand. This will accurately index all the suspension mounting points and other critical mounting locations that I need. This will also hold the side rails in place while I make and modify 2"x3" tubing for the cross members. It will also get some legs so I can work at a more suitable height. With this jig, I will then be able to place the entire engine and trans combo right on top of it. This will allow me to position the drive train wherever I want more easily.

Here's a few pic's of the jig.


















The green tape, with the blue line, is the axle centerline.


I held the camera a little sideways. This jig is actually square.


Here is the Ecotec and F23 sitting roughly in place.


From this angle, you can see the diagonal down tubes. These double as supports to hold the axles. This is beneficial for measuring purposes.


From there, I started on the rear 2"x3" cross member. I chose to place it just under the rear sway bar. There is clearance for the bar to move and if I need more, I can slightly raise the sway bar.
I used thin cardboard, from a cereal box, and wrapped it around the tube. Then, I taped it together and trimmed to fit the contours as required.








Using a paint marker, I traced the outline required. The yellow stands out nicely on the steel. I still chose to use a black Sharpie and retrace on top of the yellow. Using a thin cut-off wheel, I removed the material not required.
















I will tack this in then start on the front cross member.

[This message has been edited by Lunatic (edited 07-08-2016).]

fieroguru JUL 08, 09:45 AM
I really enjoy reading fab intensive threads and this one has a few sections that bring back memories my prior swaps.

A couple of suggestions on the cradle fixture:
1. I would suggest you treat the axle center-line as a fluid dimension. It will change as the relative output locations on every transmission are different in relation to the crankshaft center-line (some more than others). If you lock down the axle center-line location, then the engine placement would shift slightly and change the mount dimensions based on transmission application. Additionally, When you deal with the physically larger engines (mostly V8s) or engines with the 4T65E-HD they have much less available space to move the engine/transmission combo to line up with the factory axle center-line. Besides, you want the axles to have some angle to them to keep all the balls and rollers moving around in the grease.

2. You might want to incorporate a method of raising all the cradle and suspension mount locations. There are several reasons you might want to do this. 1. The bottoms of the 88 cradle are not real precise and I have seen some that a welded section sticks down about 1/8" further than normal so it wouldn't directly fit the fixture. 2. You never know when you might want to build a cradle that has a lower base to allow lowering the engine placement and still keep everything protected, or raised suspension attachment locations to improve geometry on a lowered vehicle. 3. It more closely replicates the loading of the cradle as installed in the chassis - with the cradle only supported by the front and rear bolts.

Keep up the good work!
Lunatic JUL 09, 04:44 PM

quote
Originally posted by fieroguru:

I really enjoy reading fab intensive threads and this one has a few sections that bring back memories my prior swaps.

A couple of suggestions on the cradle fixture:
1. I would suggest you treat the axle center-line as a fluid dimension. It will change as the relative output locations on every transmission are different in relation to the crankshaft center-line (some more than others). If you lock down the axle center-line location, then the engine placement would shift slightly and change the mount dimensions based on transmission application. Additionally, When you deal with the physically larger engines (mostly V8s) or engines with the 4T65E-HD they have much less available space to move the engine/transmission combo to line up with the factory axle center-line. Besides, you want the axles to have some angle to them to keep all the balls and rollers moving around in the grease.

2. You might want to incorporate a method of raising all the cradle and suspension mount locations. There are several reasons you might want to do this. 1. The bottoms of the 88 cradle are not real precise and I have seen some that a welded section sticks down about 1/8" further than normal so it wouldn't directly fit the fixture. 2. You never know when you might want to build a cradle that has a lower base to allow lowering the engine placement and still keep everything protected, or raised suspension attachment locations to improve geometry on a lowered vehicle. 3. It more closely replicates the loading of the cradle as installed in the chassis - with the cradle only supported by the front and rear bolts.

Keep up the good work!




Hey Paul, Thanks for the excellent tips and information. I have two 88 cradles here and while these were similar in build, they both fit into this jig. I did see some variances between the two however. It seems as though GM was liberal in their tolerances on the cradles.

After cutting and fitting the front crossmember, it was time to weld it in fully. I had to think ahead before committing to a full weld though. In this case, I can say with certainty, I will have to slightly notch the front crossmember to clear the AC compressor bolt. No biggie and it'll happen the next time I get the welder out. If I used a 2"x2" tube, this wouldn't have been an issue. I'm very happy with the results and clearance of these 2"x3" crossmembers. I have excellent clearance around key components and the benefit of added stiffness. The worst part of this ordeal was removing the cradle from the jig to weld the bottom. The channels had enough room to get in there to tack the crossmembers in place, but not enough room for a full weld due to the stand the jig is sitting on.
Here are some pictures of today's progress.
















Instead of cutting a small piece of steel to fill this void, I just cut a small slot in the corner and hammered it down. A little bead of weld did the rest.






Here is the cradle as it sits right now. I've placed it back on the jig and set the driveline back in place. After I locate the final position, I will start on the mounts.
wftb JUL 12, 07:21 PM
Lots of great work going on here .I noticed you have your fuel pump assembly ready to go .Did happen to measure the assembly from top to bottom ? I need a ball park measurement so I can assemble my unit before I drop the tank .Or if you happen to know the distance from the hole in the tank down to the bottom will work as well .Thanks a lot . Steve
Lunatic JUL 13, 06:34 AM

quote
Originally posted by wftb:

Lots of great work going on here .I noticed you have your fuel pump assembly ready to go .Did happen to measure the assembly from top to bottom ? I need a ball park measurement so I can assemble my unit before I drop the tank .Or if you happen to know the distance from the hole in the tank down to the bottom will work as well .Thanks a lot . Steve




Hey Steve.
It seems as though we're both heavily involved in our projects. As for the measurement you require, sadly, I cannot assist you. I just cleaned up all the loose papers that I had on my desk last week. In that pile were the measurements that I had written down. I think you're on your own. Sorry bud.
wftb JUL 13, 08:54 AM
No problem , I will just leave the rubber tube off until I get the tank out .The assembly accordians up and down to fit a variety of GM cars , but the tube that flexes with it can't come off without ruining it .
Lunatic JUL 15, 06:40 AM
With having the driveline in place, I needed to come up with a way to mount it. I've chosen to use a three point mounting system (engine mount not shown) with a dog bone like anchor on the far right side of the engine. (Not shown.)
After a few minutes, I came up with the templates.


Which lead to.






The result are these pieces.


Lets set them in place and see how they fit.
















Now I will tack them in place and put the entire assembly back into the car and check for any issues that might arise.
I think I'll be good though.
Lunatic JUL 17, 08:29 AM
My goal, for the weekend, was to get the Ecotec and F23 sitting in place. Well, that task has now been completed.
I need a mount in this area.


By modifying the factory bracket, I bolted my poly mount there.


I then made a little shelf for this mount to sit on.


A few pictures to show the general idea.






The mount sits flat when the Ecotec is sitting in the Cavaliers and Sunfires due to the tilt of the engine. I my application, the engine is mounted straight up. I chose to leave the mount tilted since there isn't a lot of room due to the slope of the oil pan.


Here are some pictures of the other brackets.
Note: I pulled these apart slightly to ease the installation of the trans.








Success. The engine and trans are sitting happily on the 88 cradle.




There is plenty of clearance here. This is where I will mount the dog bone in time.




The transaxle is really close to touching the frame rail. I will clearance this in time.


While I have the stock exhaust manifold in place, I will review my options. I don't like the angle but I think I can work with it.