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MG MGA - Cast rocker cover revisited

I got the head on my engine and spent some time futzing around with the "mystery" cast aluminum rocker cover I posted about in this archive thread:

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&mode=archiveth&archiveyear=6_2006.dat&access=&subject=6&subjectar=6&source=T&thread=2006112206555624801

The first interesting thing that I noticed, is that the footprint is slightly smaller than the factory stamped cover, such that getting a good seal with the standard gasket would be a bit of a pain, especially at the corners. Second, due to the thickness of the metal, there really isn't a lot of clearance inside for the rocker components. The cork gasket is 1/4" thick, and I think it needs all of that in order to maintain adequate clearance for the rockers. At one point, it was either installed slightly misaligned, or it drifted in use and there are wear marks where the front of the rocker shaft worked against the inside of the cover. Since the metal is pretty thick, I may relieve that area with a die grinder for more clearance. And if I can find some suitable
material, I am going to make my own gasket.
Del Rawlins

Hi Del. I have an alloy cover that was also dimensionally a bit small. The rocker shaft was hitting the inside of the valve cover at the front. I carefully ground out the contact area wth a dremel tool, and coarse grinding stones. I had to remove a fair bit of metal to get the valve cover to fit properly. When grinding out metal, bu sure not to leave sharp corners that could promote cracking. Instead, gently radius all ground corners to relieve internal stresses. Good luck with your valve cover reclamation project! Cheers, Glenn
Glenn

Thanks for the input. Any other car, and I'd probably just use the stamped cover off the spare engine, but the cast cover was first installed on the car during the mid 60s by my dad. I looked on MSC's website (www.mscdirect.com) and found cork gasket material in thicknesses up to 1/2", and I'm thinking about getting some in 3/8" thick to gain a little more clearance for the rockers. I think it would actually be easier to make the gasket out of the thicker cork because I could probably rough cut it and then sand it to exact shape on my belt sander. I'm just glad I didn't spend the money on a silicon gasket from Moss before I discovered this.
Del Rawlins

I am using a Roadster Factory neoprene gasket on my car. It is much more durable than cork and should have enough give to seal in less than ideal conditions
Rich McKIe

The problem is the cast cover has a slightly different shape to the gasket surface than a factory cover, so any standard gasket isn't going to fit quite right, regardless of what material it is made of. My dad managed to make the standard gaskets work, but I'd rather spend a little time and money making it right. Maybe if I keep looking, I can find a source of thicker neoprene or silicon gasket material than MSC stocks.
Del Rawlins

If you go too thick with a silicon gasket it will just squish out sideways as they are very flexible. Your thicker cork gasket solution sounds more feasible.
R J Brown

As a side note, I would love to find another one of these, so I could give it to my brother for his MGA. He's going to finish the 1600 which our father was restoring at the time of his death, and wants to make it as close to being a visual twin of dad's (my) 1500 as much as possible.
Del Rawlins

This thread was discussed between 06/12/2006 and 11/12/2006

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.