With the basics of the VW bug front fire-wall complete, I can now focus on the rear engine cage bracing. The rear engine cage will be similar to the front fire-wall but it will be built to fit it’s location. This cage needs to be really strong to contain the MR2 3SGTE stroker motor.
Using the foam template I created the steel pieces to fit between the upper and lower fire-wall members. I then clamped them in place and welded them on. I completed the welding on the front side of each joint because I will be fitting a fire-wall plate on top of these joints.
To add frame support and triangulation, I will incorporate two angle pieces into the VW bug’s fire-wall. I have set the fuel cell in place to try and determine where these supports should be located.
With the VW bug’s lower rear fire-wall member tacked in place, I need to construct the upper fire-wall member. I used the same 1.5×1.5 inch 10 ga. tubing and cut a piece to fit. I tapered the corners a bit to match the angles of the plate fame before welding it in.
With the VW bug’s lower rear fire-wall member built, I have reinstalled it and tack welded it in. Everything is now bolted together and all 4 MR2 3SGTE motor mounts are in place. All I have to do now is complete the fire wall and rear engine cage bracing.
All I had to do after installing the anti-crush sleeves for the MR2 3SGTE’s front motor mount, was to weld the 1/4″ steel plate to the cross member. I completely welded not only the plate to the cross member but also the reduced ends so that the entire piece is now ready to be installed into the VW bugs custom frame.
Once I located the two remaining motor mount bolt holes in the VW bug rear cross member, I drilled them out. I will be using a couple of heavy wall steel tubes to act as anti-crush sleeves. I drilled out one side to fit the OD of the tubes and the other side to fit the OD of the bolts. I also recessed the larger holes a bit to be able to get more weld on them. This will allow me to torque down the MR2 motor mount bolts without crushing my rear cross member.
After cutting out the 1/4″ steel plate for the MR2’s front motor mount, I located and drilled out the bolt holes. I bolted the motor mount to the plate with the one bolt that goes only through the plate. I positioned the whole assembly in the VW’s frame and marked the motor mount’s location on the cross member. I will now drill out the cross member to incorporate the motor mount’s remaning 2 bolts.
As I stated earlier the VW’s rear firewall will also incorporate the front motor mount. With the lower rear cross-member fit in place, I can create this mount plate from 1/4″ steel plate.
After making sure the lower firewall member fits in it’s location at the rear of the VW bug’s main frame rails, I can now cut the ends to reduce the 2×2 inch tubing in one dimension making it 2×1.5 inch. The tubing will be cut like this to insure that the torque bar bolts can be removed and installed.