I kind of figure from talking to some of my friends who know about this project that you guys will either love them or hate them LOL! Feel free to respond to the poll above. The photos below show the first pair of valve covers, and what one of them looks like mounted on the 428CJ that is currently on my dyno. The covers are not yet complete; more on that farther down the page.
I've been thinking about doing these for a long, long time. After our kids were born and my wife went back to work, I spent a lot of time in the house babysitting the kids when I wasn't at work. Because I couldn't spend time in the shop I started on the radio control model airplanes; I could build them on the dining room table while I was watching the kids (much to the wife's chagrin
). I got into that pretty heavily over the years and started doing a bunch of scratch built planes, and in order to make parts like canopies and gun turrets for some of the more complex models I wanted to have a vacuum forming capability. In the back of my mind I was also thinking about vacuum forming car parts, like valve covers... So, back in 2004, just as I was transitioning back to cars, I bought some plans and all the materials required to build my own vacuum forming machine. Shortly after all the parts arrived, my Mach 1 came up for sale on ebay, I bought it, and got completely immersed in that project. So the vacuum forming machine sat in pieces, awaiting fabrication and assembly, for about 8 years.
Fast forward to this fall, and I was cleaning up my shop after last year's unsuccessful Drag Week thrash, and kept having to move all the vacuum forming machine parts around as I was cleaning. I finally decided at the end of November just to put the freaking thing together. This turned out to be a fairly arduous task, involving lots of cutting, welding, plumbing, wiring, woodworking, etc. Took me a whole month, but over the New Year's holiday I finally finished it, and tested it with success on a clear plastic canopy for a 1/5 scale AT-6 Texan.
Of course, now I didn't want to do airplane parts, I wanted to do valve covers. Starting with 428CJ valve covers as a guide, I built a plug that I thought would work, and then shopped around some for the right plastic. I finally settled on 1/8" thick Lexan, which is supposed to stay hard up to 280 degrees, and was rigid enough to make a decent cover.
My first experiments with vacuum forming Lexan were not all that successful, but as I learned I modified the valve cover plug and my technique until I got better results. This has been kind of a back burner project because of the work I've been doing on the CVR water pump adapters and the FE intake adapters, but finally this weekend I got a passable valve cover off the vacuum form machine.
Here's a photo of the vacuum forming machine, with the valve cover plug on the forming surface (called the platen), and the plastic attached to the frame and up in the heating position.
From below, you can look up through the clear Lexan and see the heating elements in the top of the vacuum forming machine:
When the plastic gets hot enough it starts to droop, and when it droops to a certain point the frame holding the plastic is pulled down over the plug and stretched onto the platen. Then a valve is opened feeding vacuum to the platen, and sucking the plastic down onto the plug. It happens really fast. The challenge then is to get the plug back out of the plastic, but after working it for a while you can do this if the plug is designed correctly. Mine gave me some trouble at first, but I finally got it working.
Next steps are to machine a couple of valve cover rails that will sandwich the Lexan, and bolt together with an O-ring seal to provide a leak-free, rigid frame to bolt the valve covers down with. This will ensure that sealing to the valve cover gasket isn't an issue. I also plan to machine a fitting that bolts to the top of the valve cover and will accept a factory breather. Then I want to develop a light kit that fits into the aluminum frame, and will turn on some LEDs when energized. Finally, when I've got all that worked out I think I will put a set of these on an FE car for testing over the summer, to see if the Lexan really will hold up to underhood temperatures. If they look like they will survive without any trouble, I may start building them for sale this fall.
I've also given some thought to doing a set of covers based on the pentroof design. It is a difficult process to build a plug for the vacuum form machine, but if these covers last the summer without durability problems I think I may give that a try. One of the real distinctive things about FE engines is the valve covers, and the pentroof covers are a real signature piece, so I think I may have to give those a try. I've also thought about an SOHC version, but that would be REALLY tough, with the spark plug tubes coming through the valves covers. On the other hand, I like a challenge...