In my previous article, I was discussing things that I did around the firewall and the dash, before installing the subframes got in the way. But the time has come to install the frames.
I had installed the frames previously before painting. And by “subframes” I mean the two engine frames, the “picture frame”, and the bonnet support frame. This did two things. It established any “fettling” required to get the frames to line up. There was almost no fettling required. I did enlarge one hole slightly at one connection plate on the firewall. It also allowed me to hang the bonnet and get it all lined up. Then everything got taken apart and spent quality time in my paint booth getting the final paint applied.
First let me say that although I am doing this article, I found the OwenAuto article linked below which does an amazing job of explaining this evolution in detail with great pictures. And there is also the article by Steve Kemp about which bolting goes where that is incredibly useful.
And there is the article I did a few weeks ago:
I made one last check of the captive nuts on the firewall and thread chased any that did not spin in a bolt easily. After research determined that the bolts required to assemble the frames would have been black, I had sent all the proper bolts to Industrial Electroplating in Gastonia, NC to be zinc plated with a black overlay coating. I was fortunate to find 98% of the original bolts I needed, including the odd ones for the steering rack attachment. Original captive nuts were plated in clear zinc by the same firm.
You may wonder about washers and lockwashers. In this case let the Spare Parts Catalougue (SPC) be your guide. Once you get used to the format, it is in my mind the final determinant to these kinds of questions. The bolting hardware is rarely shown on the Plate drawings but if you locate the item number for the piece you are bolting and go to the parts list for that item, the SPC will always list the required hardware underneath the item. And in this case, with two exceptions we will talk about, there were no flat washers or lockwashers used.
Some folks ask about gaskets or such between the frames and the firewalls. In all my reading, I have never found anything to indicated a gasket was used at any of the connections involved in this assembly.
First I made up the engine frames to the firewall. I started with the very large and somewhat large bolts “down low” where the torsion bar reaction plate goes and worked my way out from there. All bolts should be loosely assembled until the very end. The bolts that go through with nuts inside the footwells get flat washers under the nut. On these you will need an assistant to hold the bolt head from turning as there is no good way to be in both places at the same time. And with final paint and plating, my standard trick of holding the head with vicegrips is not a good plan!
Once the two engine frames are loosely installed, continue with the installation of the picture frame. Most of the “tricks” I would offer are discussed in the Steve Kemp article. Be sure and see his Notes. The installation of the bonnet support frame is largely coincident with that of the picture frame but if you look there are a few bolts that make up just the picture frame that will get your alignment started without the added complexity of lining up a the bonnet support frame holes. As I have noted before, my engine frames and my bonnet support frames came from EtypeFabs in the UK and in general fitment was very good. That said, there were a few places where I had to use a proper sized drift to get the holes in alignment. I did not have to use bar clamps but don’t rule this out if you see it will help.
For this step you will install a set of suspension fulcrum attachment blocks. These should be all cleaned up and ready to go, as it will be very hard to install them later. Since I had the parts detailed and ready to go, I went ahead and installed the anti-roll (sway) bar and the steering rack. Here I found a few clear zinc plated bolts that I had missed on my black plating order. Rather than hold up the job, I used a more traditional chemical blackening dip that I had purchased from Caswell Plating. Dicsussed in the article here.
The bolting on the steering rack is wierd. I consulted the SPC, which was confusing with reference to special washers, plain washers, distance tubes, and very long setscrews (fully threaded bolts). I made reference to several internet articles and I think I got it figured out. The confusing bolts/distance tubes/washers are used in a “safety” application to hold the rack mounting plates in position should the rubber support plates fail. On the passenger side mounting plate, there is the other use of flat and lock washers, as well as non-captive nuts. I removed the rubber bellows on the rack to get best access to the bolts.
After I had all these items loosely assembled I proceeded to final tighten all the fasteners. I use the “calibrated arm” approach to tightening these bolts, based on years of experience. Using a torque wrench with captive or nylock nuts is not going to be effective. I started with those on the firewall, in a loosely symetrical pattern and finished up on the picture frame. There are a lot of bolts to tighten. I suggest going through them all intially as “hand tight” and then swinging back around for final tensioning. Stay focused and avoid interruptions, as you can easily miss a final tension otherwise. On my track car, I would mark each final torque with yellow nail polish but not appropriate here!
Then stand back and admire your work. This represents a major milestone in your project. Next I will install the bonnet and proceed with final alignment on it.