MG Sports Cars

I'm just an exhaust system installation away from driving my 302 MGB. So after spending years on my build and thousands on body work and paint I managed to do this a couple of days ago when I was installing the door parts - window assembly, vent window, etc. About a half hour after I completed the door work I was at my work bench and heard a pop, didn't know what it was until the next day when I saw it.

I feel your pain, Steve.
I've had the infamous COD on the passenger side for a few years now - it was painful to see it slowly materialize after a total ground up restoration, but after a few years and a few miles, you just come to accept it.

That's a pretty serious crack, I feel your pain. I'm ashamed to think of the stream of profanity that I would have yelled.

It's not a bad as the first photo makes it look. Here's a view of the entire door.
I'll fix it this winter. Maybe I'll stick a decal or emblem over it until then.

That sux. Was there a previous crack that had been repaired?

You could pull a Mikey and put a band-aid over it...

Jim

JWD
There was no previous crack that I know of, but I hadn't taken a real close look at it prior to having the body work and paint done. The passenger door had a crack that I repaired. Looking back I should have gone ahead and welded a support to it same as I did to the passenger door. Oh well.

Steve

Steve,

The reason I asked is that you said you heard a "Pop". It sounds to me like the previous weld let go. I was in the process of repairing my cracks (by drilling a hole to stop the crack, welding up the crack and added a substantial piece of metal behind the crack area) when a buddy stopped by who is a design engineer. We studied the cause of the crack and came up with a theory.
The crack seems to always start at the 90° corner at the base of the wing window which indicates a stress point caused by pressure being applied by the vent window/windshield seal area. Also, the inherent issue of "cowl shake" in all convertibles makes it worse and uni-body construction exasperates it. In summary, you have a stress point under pressure and a vibration to make it worse. The solution we came up with is to weld up the 90° corner so it's an arc instead of a sharp corner (this won't interfere with adjusting the vent window assembly) and to adjust the vent assembly and door so that area isn't under so much stress.

Jim

My recollection from the days when these cars were in use, is that it wasn't helped when people used the quarter-light frame to shut the doors.

Ivor

I welded a 3/16" diameter wire about 3" long into the lip to spread the stress over a larger area.

Jim

Before my car was painted I put new door skins on with the idea that starting fresh might be more durable in the end. This is very easy to do, the skins are held in place mainly by crimping; to remove just cut through the edges with an angle grinder, then cut through the few spot welds (maybe 4 or 6). The new skins are crimped in place by tapping with a hammer or else by using Eastwood crimping pliers. Install the door and bend it as needed so it fits flush all around its perimeter, then spot weld in a few places to stabilize it. Ten years ago the skins were only $55 each, I have not checked lately, but they are probably still reasonably priced.

Yes, that's a pretty simple thing to do and doesn't take very long, but you still should reinforce the COD area.

Jim