Z 74 D 424196
Coming Back to Life!

Chapter 3 – Lotus Cortina, but Now in Chicago

I'm not sure what audience is reading this. If anyone has been following this saga on this site, they have un-doubtedly moved on, completed their own projects (suffering similar pains), or moved on to something a little less risky! So this must be for a new group of readers.

The last time I discussed this project, I had decided to move to Chicago from Knoxville, Tennessee, and although some may think that was a really stupid idea, I had my reasons, mainly related to vintage racing.

And the best part of this re-location? I was moving to a house with a 3200 sq. ft. garage. The worst part of this re-location, was the garage was only rough framed...

That was all of 5 years ago. Between trying to get some foothold in the never-ending job of upgrading a 30-year-old house, finishing off the dream-garage any gearhead would love, and working a demanding career to pay for it all, it was 4 years before I could get past that self-made promise of not touching any major auto restoration work before finishing that garage.

Then the 2010 racing season started. To really make my life complicated, I decided to start my son Mark’s racing career at the same time. Mark had just started a college life after 3 yrs. of active duty in the US Army Corps of Engineers in Iraq, and despite possessing a huge love of all things racing, at 26 he had never been behind the wheel of a real full-blown race car.

The 2010 racing season (which has just ended this past October) brought on two realizations for me- first, the Twincam Escort could still produce an incredible number of teething pains, and second, just how ridiculously fast Mark was in comparison to me, after he very quickly adjusted to racing my Cooper S!

It was a year of broken parts and repairs, that saw me destroy the Escort crown wheel and pinion, have all the exhaust valve inner springs of the Twinc disintegrate, have the Cooper suffer the exact same fate. (I am sure the cars were talking to one another in the workshop when I wasn’t there.) And finally, my season ended with both of us running a long endurance race in the Twincam Escort. And I personally suffered the experience of having my new-comer son Mark beat my best time in the Escort by ½ of a second (Ouch – and that left a big bruise...)

 

Back to Repairs on the Lotus Cortina

Rear Body – Chassis and Floor Area

If replacing all the front end panels, sills and part of the floor boards (front and rear) wasn’t enough, the rear end was an even bigger challenge. Between butchered “make it work” previous modifications related to turning a hard thrashed road car into a racer, and rust, the rear was a real “dog’s breakfast”.

As will be seen from the following photos and text, this summary is based on three major factors –

1. Past conversion of the original A frame suspension to leaf springs left a lot of scarring due to rough mods.
2. Past crude modification to the rear trunk area to allow installation of a Fuel Cell left even more scarring.
3. Very bad corrosion to the rear end sheet metal due to running on East Coast salted roads in winter.

Cortinas, and in particular the pre-airflow A frame cars were very prone to severe corrosion in the rear. The adaptation on the chassis rails for picking up the A frame was a really great rust collector, as was the rear chassis rail from the point where it passes over the axle backwards all the way to rear bumper.

The rails were badly rusted, but also, the floor under the rear seat and the trunk floor next to the fuel tank had suffered.

A few pictures speak a thousand words –

This what the RH floor (under the rear seat floor looked like once the completely rotted chassis rail and floor had been cut away, and the new fabricated floor section was about to be welded in place.

On the left-hand-side the rot to the floor was a lot less, but these photos demonstrate the extent of hidden rot under the A frame bracket, and the butchering that had occured in the attempt to fit the front leaf spring mount. (note professional (?) welding and fabrication!). And that left-hand-side was in better shape than the right-hand-side rail.

A pause for a moment ... Do not do what I did! Do not attempt to fabricate replacement chasis rail sections. The chassis rail, just where it rots, has turns in three dimensions, and unless you majored in metal fabrication, and love the challenge of the impossible – you should order the complete rear rail and chop off the piece you want. Note the double curvature in the photo, and realize that in the right angle axis it is also following the floor profile, which makes three curvatures. And remember, this is the better left-hand-side rail. The right-hand-side took 2 days just to fabricate a cardboard pattern.

Needless to say the most critical part of totally rebuilding the mounts for the A frame, is ensuring (before the final welds go in place), that the A frame is dead true with the center line. The positioning “fore to aft” is controlled through the brackets butting up against the notch in the car floor where the rails end. But ending up with the correct distance between the mounts, and the relative position on the rail to get the mount exactly central in the body, are both absolutely critical. And do not assume that there is any symmetry to this car... – There just simply is not!

Another tremendous pile of rust is found at the chassis rail stiffener over the axle (Lotus only or possibly GT also). As can be seen once the rotted stiffener portions have been cut away, the chassis rail underneath is equally damaged, and in this case on the right-hand-side, the rust has spread into the floor and even the inner wheel well.

Repairing the Trunk Area of the Cortina

So having sorted out the critical, but unseen underpinnings of the body it was time to start moving outwards to the better know rust areas around the rear wheel arch and outer rear panels. Not only had it suffered the usual lower outer wing wheel arch lip rot, but in a bad attempt to repair it, it was decided to flare the wings a little – all but destroying the outer panel lip. So this necessitated replacing both the outer half of the wheel arch, and also the entire outer wing itself.

As with nearly every Cortina, the spare wheel well was totally rotted out, and the battery shelf and lower rear wing inner panel had been very roughly repaired. Along with the trunk floor panel having suffered as mentioned earlier, the right-hand-side rear brace tube had somehow been bent and kinked beyond repair – the latter can be seen in the very early photos of the rear trunk area.

After examining the outer half of the wheel well, I decided that this is a serious piece of work. The biggest headache is that the two halves are roll-welded together – not spot welded. So rather than the joint having a spot weld every 1 inch or so, the welds are almost literally 1/8th of an inch apart! Separating the outer half can really only be done by cutting along the seam edge, and then carefully and patiently grinding the joint lip down to the point were it can be pealed off the inner half of the wheel well.

Fortunately, the outer half (portion being removed) is laid over the inner half from inside the wheel well, so it is accessible from the outside (wheel side) of the well rather than the trunk area side.

Replacing the trunk floor, is a major piece of surgery. Not only are you dealing with a very large area of the body, but once the floor panel and side areas are cut away, you are dealing with a very large (4 foot x 4 foot) hole, so that with only two chassis rails running through the space, the body has suddenly lost the “3rd dimension of strengthening”. In other words, once you cut away the trunk floor panel, spare wheel well, and battery platform, the back end gets r-e-a-l-l-y wobbly.

That was a major motivation in picking up the rear Spit mount points of multiple points – specifically the top of the strut towers, and the rear (leaf) spring pick-up points.

This achieves two things – It minimizes the loading on the end of the chassis rails (the more traditional “bumper mount points”) and at the same time triangulates the chassis rails somewhat to the shock towers, to help keep them in check when you cut away the trunk floor panels. The only fly in the ointment – once you have cut the rotten / offending old panels away (in pieces), you have to put in the new panel complete, and that means temporarily removing the rear strut mount to put the new panel in place. But what could have been a major problem... was not. As the spit mount had been made strong enough, it trued up the chassis rails to the rest of the body dimensions as it was put back in place.

In the first photo that follows, the piece of 2X4 in the photo is to provide leverage to turn the body on the spit.

You will notice that in the first photo the LH spare-wheel well panels have already been replaced. In the second and third photos, you can see the spare-wheel well panel from the outside.

Replacement of the lower rear quarter panels

Once the rear trunk floor is in place it’s time to start putting the “outer skin” back together. The initial part of this is rather like playing a game of chess. A lot of planning takes place before a move is made.

There are two approaches to replacing parts of a panel with repair sections. Either the new panel is butt welded against the original, or the repair panel is overlaid and brazed or welded onto the original. I chose to use the overlay method, for several reasons. Butt welding two thin gauge panels together requires a very high level of welding skill. And you are confronting many challenges – the replacement panels are made from a thicker gauge of metal, and the older original panel has rust and paint on it despite careful cleaning. I also chose to use brazing, as the heat transfer is much lower, and therefore minimizes the warping of the panel. I used Cleco clamps to hold the two surfaces of the panels togethe. I slowly brazed sections of the edge until the entire edge is solid. A couple of hints – use the minimum of flame when doing the edge brazing, regularly beat the edge and surrounding panel flat, as it will warp constantly while working, and watch out for heating the Cleco clamps, the springs inside don’t like heat at all (I made little metal shields to go over them to avoid direct flame contact).

The repair involves five panels, all of which have to line up with one another. Starting from the front, the panel over the wheel arch, then the lower rear outer panel (in the photo, the one with the bumper body molding on it), the lower rear inner panel (under the battery shelf), the battery shelf, and the rear valance. Bearing in mind that the rear valance has to line up with the bumper holes, and the LH and RH lower rear ¼ panels, it’s good to start there and use it as an anchoring reference point.

Once the lower rear panel is cut away, the replacement panel has no reference point to position it vertically on the panel, unlike the repair panel over the wheel arch, which can use the lower inner wheel arch lip as a vertical reference point. So before finally cutting away the old panel, I cut away the panel face with the rear valance to allow me to place the repair panel flush over the original, and mark it’s upper reference edge. I also took the precaution of marking this reference on the original panel with a small cutting wheel every 1.5 inches, as the original marking will disappear with the application of heat.

Once the old panels are cut away (in my case, this was done before the trunk floor was replaced), it’s best to start by welding the battery shelf in first, as the inner lower rear ¼ panel is welded onto it.

With the rear valance positioned and clamped in place, it was time to get the lower wing section in position. I clamped the repair piece into place making sure it lined up with the top edge marking made before removing the old panel section. It’s a lot easier to work with the valance off, but before removing it, you first want to tack the other panels in place.

Once the outer repair panel was in place, I offered up the inner lower ¼ wing. In my case I discovered it needed a lot of edge trimming to get it to fit snugly. After tacking the inner panel in place, I finished the welding / brazing of the outer panel. I decided to do as much of the finish welding / brazing on the inner panel as possible with the original valance still clamped to it, to minimize the shifting of the new wing panels before removing the original valance and finishing it off.

Finally the rear ¼ panel repair piece over the wheel arch. This is a piece of the job I was least looking forward to! Due to the length of the panel, dealing with panel warpage is inevitable, and to make matters worse, the top portion (the piece that warps the most, needless to say) is right up against the rear seat back, and very difficult to beat into place. It ends up being a long and frustrating job to get it right.

I did not do the final trimming of the panel until I had completed the job of getting the lower portion of the rear ¼ completed, so that I could butt the two repair panels against one another with the minimum of a gap. The photos speak for themselves.

As mentioned earlier, the left-hand-side rear ¼ is much the same process as the right-hand-side, the photos will help tell that story.

With just the rear valance left to be welded into place, and some final touch up on some areas the bulk of the work on the main shell is finished. The car is going off to Redi Strip in Indianapolis to be dip stripped in a few weeks. Once it gets back to my shop any final finish touches to the body will be done, and the seams etch primed and sealed with body silicon seal. And then it’s off to the Paint Shop for my trusty body man to get it back to it’s original color scheme. in preparation for assembly.

A conversation with the fellow at Redi Strip regarding the doors, trunk lid and hood being aluminum-skinned, produced some useful information. He said that the worst thing I could do was media-blast the panels, as, based on his experience with aircraft panels, it would all but destroy the panels. He suggested using good old paint remover and elbow grease, with a final clean down using copper or brass wool (specifically not steel wool!) with acetone, followed by a final rinse with very hot soapy water. And here I had thought I could find the easy way round that...

Best Regards,

Peter Pentz

Now in Chicagoland
November 2010