Hey Guys, back in the early 80's, my car was converted to an a/c car by a previous owner. This year, I plan to convert it back to non a/c, loose several hundred pounds in weight, and a few tenths in 1/4 mile ET. We cut this firewall piece out of a junkyard '70 Chevelle. Any ideas on where to tie it in? It appears to have 2 pieces, 1 around the blower motor, and 1 heater core area. Also, will the Chevelle heater core case work? Looks to be the same as our Skylark's. Thanks in advance, Joe X.
I did this a long time ago to a skylark, but I can't remember where I made the cuts. I was going to do this to my Sportwagon but I ended up cutting the entire firewall off instead! :error:
I think you might just be better off completely patching the verticle hole cut for the AC box then cutting the horizontal hole back for the heater box. The assembly manual show good views of this.
For $125, I would not waste my time and effort splicing in the Chevelle piece. American Graffiti on Ebay sells a non-ac firewall box (engine side) to convert an AC car to non-ac. Up to you!
Thanks for the replies guys :TU: . The American Graffitti piece looks to large for me. I'm looking for a back to factory original look. I know it will be a lot of work, to get it looking just right for sure. Might be a good time to pull the engine out, and give it a check up. I've been pretty hard on it, in 1/4 mile increments, the last year. Thnx again, Joe X.
i just did that with my skylark, had a non ac firewall spliced in from a piece someone cut out. came out perfect, cant tell the car ever had ac allen
Looking at mine I think this is about where the cuts were made. Remember it's eaiser to cut more off than to add some back! Also this firewall metal is very thin and flat, so it warps easy. Weld a little at a time (1/2" or so) and cool it off with air before welding the next bead. I used MIG but TIG would be even better.
Here's a picture of the (never quite finished) lower section. In post #8 while drawing the red line I zigged when I should have zagged (around the dimple), but you get the idea.
Let me guess you are install about 6 flat screens displays, a dvd player, an Xbox and a Playstation in your car????????? :laugh: :laugh: :laugh: :Brow:
Not yet! ou: It has had a F.A.S.T. EFI controler, Altronics data logger with exhaust temp for 2 cylinders, Dakota Digital gauges and rich/lean gauge, 3 electric fans, nitrous, and a stereo! The F.A.S.T., rich/lean gauge, nitrous and stereo are no longer installed, and I'm not using the temp sensors right now. Maybe I should crawl up in there with a weed eater! :shock: :laugh: :error:
Thanks for posting your photos Alan. I've got my firewall repair piece down to about the size I need. There's a verticle seem that runs next to the blower motor hole, and is covered by the left fender. I plan to drill out the factory cowl(top) welds, as well as the other factoy welds on the piece, and Z-bend(overlap) the other edges, Mig/Tig weld them, and then filler, to hide them. I'll post some photos, as soon as I get my car back from Mc'D's, and get started. Here's my repair piece. Thanks Again, Joe X.
how badly did they mess with the old firewall when they converted it---meaning if they just did some selectived cutting/welding then you could easily reverse that process and with a little welding (ie to fill in the upper portion of the vertically oriented hole for the AC core) you might be able to put it back original. Of course, if they hacked out the old non-ac firewall and welded on the AC firewall piece then I see your point. Got any pics of the stripped, current firewall?
Platton, You may be right. It's been over 2 yrs, since I've seen just the firewall, with nothing on it. I did find a photo that shows a patch, covering the original non a'c hole, and a new up and down a/c hole, cut into the firewall. Guess I'll have to figure which way to go, when I get the car back. Joe x.
Yeah--that is what I was getting at Joe--take a close look--maybe strip the paint off the firewall first and see if it might be a whole lot easier to just "reverse" some of what they did VS. cutting out and installing a whole new piece. If they didn't go to crazy you may be in luck. Also--remember that the firewall metal heater box covers up a lot of this so having the exact rolled lip on the opening, etc may not be that critical as it may all be covered up. Good luck. If this is a race car and you aren't going back concours (yet :grin: ) then lay the box on there and see how much of the prior work is covered up. Patton
I agree with Patton Much easier to just weld some sheet metal back in where needed. Remember this is going to be a satin black firewall,pretty easy to hide the bodywork. The box covers alot, I've done this a few time's now. The Chevelle box is exactly the same, in fact I'm thinking that all GM car's from 64-72 use that same box, from compact to full size.
I agree--those boxes are generic and plentiful----at least there's one part that is findable in the salvage yards. I think GM even still sells these things new possibly.
