Getting a bit carried away with the pictures at the moment so hope you don't mind. Tend to do that when covering something new for the first time.
Just thought I would show a mock up of how I make a 'fair' curve. Just use a thick stainless ruler and place magnets to hold the curve I am after that intersects a start and finish mark as well as the depth of the curve I want.
So here is my first use of the bead roller. It is a reversed version of what was there on the original firewall. The two vertical ends match up with where the hinges will go on top of the cowl to give extra strength.
Want to tidy up the ends of the bead. Picked up this trick from one of the forums where you just notch out a piece of pipe where its ID matches the OD of the bead
Just placed it on the table and gave it a hit and much neater now. Tried it over some rubber as well but straight on the bench gave the best result.
Had to raise where the bead had been run over in the other direction. Clamped a curved hammer face in the vice and used a small soft headed mallet to get the crease out.
I tried a square outside corner first using some notched SHS, but decided on the same tube trick with only a 1/4 left to curve the bottom corner.
Now to use the tipping wheel for the first time. Tightened in down into the wheel about 3 turns.
First pass I just guided the wheel through to mark the line and start the bending.
Next pass I lifted up on the side of the piece as it passed through increasing the bend.
Forth pass and is far as I can go. It is touching the bolt head as well as the side of the washer. An extra turn can give a little more but was close enough to hammer and dolly the last bit.
Use a small soft mallet and steel dolly to tip the last bit.
The tight corner as caused it to bend. The outside edge needs to be shrunk to get it straight
Just used a shrinker to get it straight at the ends. Can see the cheap soft mallet I used for the tipping and other tools for correcting it until perfectly flat.
Bottom edge was tipped and needed very liitle work afterwards. Only the bottom corners where I couldn't get all the way to the end with the tipping wheel
I needed to make an extra curved tip to the flange in the middle of the bottom section. Found some scrap under the house and quickly made these T dollies in different diameter rods.
One fitted perfectly the curve I needed. This lip turns up to give clearance to the back of the engine cover.
The first part had to stay flat and then the curve was needed. Used a soft mallet as didn't want to stretch it while bending it over.
Fits in quite nice.
Just dropped in place without clamps. Only a slight gap at one end which I corrected later. Was only the bit done by hand and must have missed the mark when bending it with pliers.
Cowl sides and top tested to make sure it all goes together. Better than expected but I did remember to take off the material thickness twice when adding on the flange width to the template.