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MG MGA - Wanted: Period Al. Rocker Cover

Been a while since I asked about this, so figured it is worth a try. I'm restoring my dad's MGA, and am reusing the cast aluminum rocker cover that he put on it sometime back in the mid '60s. It isn't like the ones that are available today, and it is kind of a pain since I have to re-polish it, and make a special gasket (I'm currently making a template so I can make replacements) since the standard ones don't fit right, thus it has always leaked. But, I want the car like it was when my dad had it, so it's worth doing, at least to me.

Now, my brother also has an MGA project, and he's expressed an interest in making it look like dad's plus we like having matching stuff. 8^) So, I'd like to find him the same rocker cover, if possible. The only other one I have ever seen, was in a picture of the "MGA Hawk" racing special (the one with the studebaker grill) on Barney's site. But, where there were at least two made, there were probably others, so I am hoping that somebody here will have one sitting in a box somewhere that they would be willing to sell me.

You'll probably be doing yourself as big a favor as you'd be doing me, since as mentioned, the standard gasket doesn't fit right, and also there is less interior clearance for the rocker assembly than the stock cover has. I'm attaching a picture to this image so you can see what it looks like. Anyway, I know this is a long shot, but thanks for looking and reading this far.



Del Rawlins

That is a lovely period piece and I hope your brother will find another one. I personally have never seen one the same.
But I am wondering about the gasket? the mating surface on the cylinder head has not changed so I assume the cover needs to marry up to that surface on the standard cylinder head so how can a standard gasket not fit?
Robert (Bob) Midget Turbo

It is more rounded at the corners. The stock gasket is just barely usable, but it is difficult to get a good seal since it isn't making a lot of contact at the corners. I wasn't able to find the correct normal thickness of cork gasket material locally, so since I had to order a sheet, I got some 3/8" thick cork gasket material (original is 1/4" or 3/16" I think)and am using that to gain a little extra internal clearance for the rockers. I also relieved the inside of the cover slightly with a carbide burr on one end, where there was evidence of it having fretted against the end of the rocker shaft, in addition to cleaning up some of the residual flashing where they didn't do a good job of cleaning up the casting originally. I think that as the rubber seals around the hold down hardware failed, that allowed the cover to shift slightly and wear against the end of the rocker shaft. It is fairly thick, so I don't think there is as much room in there as inside the stock stamped cover.

And, I am hoping that the cork I bought is actually gasket material. It was listed as such at the industrial supplier that I ordered it from, but it sure looks a lot like cork bulletin board material, without as much bonding compound amongst the bits of cork as I am used to seeing. I'll be kind of annoyed if it doesn't work, since the smallest size they carried was one square yard, and I had to have it shipped to Alaska. On the other hand, if this stuff seals okay, I can make plenty of extras.
Del Rawlins

Del, - I don't have one, but maybe I can help a little. Since I didn't have this part on my MGA Accessories list, I have just added a web page for Alloy Valve Covers. I have posted your photo and your request at top of page. Let it stew in public for a while, and we might get lucky. See here: http://mgaguru.com/mgtech/accessories/at126.htm
Barney Gaylord

Thanks, Barney. It also looks like I am going to have to find some different gasket material, since I can blow 80psi shop air through the cork material I purchased, despite it being 3/8" thick. That kind of makes for an expensive bulletin board.
Del Rawlins

Del-
Really nice cover, and v California I'd say. I've seen similar covers on American engines; maybe worth contacting Bill Smith at Speedway Motors, one of the experts on old timey speed equipment. In fact, among the street rod guys there is now a whole constellation of such experts, some of them the actual guys who made the parts. Look at the magazines in a grocery store (maybe not in AK!).

Such gasket material is usually porous, unless it is rubber bonded, as the best cover gaskets are. Most are not, and they swell with oil and get compressed by clamping, so they don't leak. If you are really worried about it, paint the inside edge with Permatex liquid as a barrier.

FRM
FR Millmore

Del, Lovely period rocker cover - much better than the horrible modern ones sold by Moss etc. - don't blame you for wanting to keep it and add another to your brother's car - good hunting - cheers Cam
Cam Cunningham

Del, look at the old 1950s Fords. The 292 and 312 had a two bolt valve cover (rocker cover) and it may be that that is an american cover fitted to your MG. Just a chance.
Mike Parker

Del,
Many auto stores sell rolls of rubberized cork gasket material. I used it to make gaskets for my lifter covers since the ones in the engine kit were crap. It's not quite as thick as normal rocker cover gaskets, but I think it will do the job.
Cheers,
Gerry
G T Foster

Del,

Have you thought about casting a duplicate using yours to make a sand or plaster mold?

Ken
k v morton

I've thought about it, but my desire to present my brother with one doesn't really justify that sort of effort. Besides, when using an original as a plug for a mold, there are issues such as shrinkage to consider when making a new casting. I've never done any foundry work, but it's my understanding that to really do it right, you have to make the plug oversize by a relatively precise amount, to account for shrinkage as the molten metal solidifies and cools.

As for the gasket, a friend on another forum provided me with a NAPA part number for 1/4" rubberized cork material, so I am going to get some of that and use it instead of the stuff I already have. I did check at NAPA when I was looking locally, but if they don't have something on display, it isn't something they can look up by make and model, and you don't have a part number, usually you'll just get a blank look at those sorts of places. Or, worse, they'll waste your time by asking for more information that they won't understand anyway.
Del Rawlins

For you valve cover gasket has you considered using the Slicone valve cover gasket that Moss sells? Part # 296-425? They are very flexible and might fit.
Keith Lowman

I was just at a foundry this morning in NH that makes one off parts for old car restorations (in particular, one guy is restoring a 1910 steam car and needed a water pump).

The cost to make a mold and cast one part is about $500 to $600. Pretty spendy. If you wanted to make 10 and could sell the others, it would be do-able - about $90 each once the first mold has been made.

JIM in NH
AJ Mail

I was envisioning melting beer cans over the BBQ and pouring the results into a box of sand. I guess it's not that simple. And if you sold ten of them to pay the NH foundry to make the mold, then everyone you know with an MGA would have one, and it wouldn't be so special...

Ken
k v morton

Actually, I'm starting to wonder if that isn't how this cover was originally produced. I started getting serious about polishing it today, and it quickly became apparent that while I could eliminate the dings and scratches easily enough, the pitting is another matter entirely. There is apparently enough porosity in the casting, that no matter how much metal is removed, there is always going to be some amount of pitting present, so I decided not to get too carried away with sandpaper, and just made it look good, within reason before taking it to the buffer. I painted the finned area MG engine red, and left the machined surfaces polished. Once the paint is harder, I'm going to work on it with some Happich's paste and then call it good.

I got the real Fel-Pro 1/4" cork material from NAPA yesterday, and made another gasket from that tonight, which I think is going to do the trick. I'm already glad that I went to the effort of making a gasket template out of some .063" aluminum, since I'm on gasket version 3.0 at this point. A potentially useful tip, is that a stationary disk sander works very well for shaping the thick cork material, and then I cut out the interior with an x-acto blade.

When I get it on the engine, I'll post a picture here. I think even though it won't be perfect, it will still look pretty good.
Del Rawlins

There must have been a few of them made; at least yours and the one on the MG Hawk. Have you tried posting a note on the MG Vintage Racers web site? http://www.mgvr.org/
It might be worth a try.

Ken
k v morton

Del:

I have resisted posting that I have one of these valve covers because I do not have any intention of parting with it. It was given to me decades ago by my best friend when he sold his MGA and, like yours has priceless nostalgic value to me. In addition to yours, and the MGA Hawk, I have only seen one other and that was on an eBay car for sale posting a few years back.

Since you mentioned the difficulty you had polishing, I thought that I would pass on my experience and a picture. I had mine professionally polished at the same time I had a Judson valve cover polished. Of the two, the polisher told me that he had the most difficulty with the non-Judson unit like yours.

As you can see from the picture, the filler cap is different on mine. Mine is like the Hawk version and the one eBay that I mentioned. Originally, it had a flat rubber gasket, but I had it machined for an O-ring.



Steve Brandt

Thanks for posting, and I don't blame you a bit. Since I have no intention of ever visiting new york, your cover is probably safe from me. 8^) I don't know what gasket the cap originally had, but there was a homemade flat rubber gasket that my dad evidently made at some point, it was most likely a piece of inner tube It was starting to harden, so I made a new one out of some 1/8" cork that I had.

Ken, I may do just that. Realistically, it will be several years before it is needed, so I do have time to locate one. Be funny if I had to buy another MGA to get the cover, swap on a stamped unit, and re-sell.
Del Rawlins

Del-
It would be a better reason than some of us can produce for the stuff we drag home!
Steve, you are not that far from me!
Porosity in sand casting is a common thing, so much so that nowadays they are routinely vacuum impregnated with epoxy to prevent leakage through the walls. You can approximate this with Loctite 290 (wicking) on a very thoroughly degreased part. Polishing such a part will always show pits and waves, the waves being a result of polishing the pits. The correct way is to sand it flat, smooth and clean, then polish without high local contact pressure. If you look at the pics recently posted re the air inlet manifold, you can see the pits and waves, but Geoff's filed one is excellent.

FRM
FR Millmore

Well, I was going to drag the engine out and take a picture in front of a better background, but my brother is here visiting, and he snapped his picture with his iphone while I had the engine uncovered. The rocker cover is just setting in place with the hardware snug; I haven't glued the gasket or anything yet:

http://www.rawlinsbrothers.org/mga/images/shiny.jpg

Not sure why my browser isn't letting me upload the file directly to this BBS at the moment, Firefox died today and I had to switch to Safari.
Del Rawlins

Hi Steve ,

I can imagine that your Judson valve cover is not for sale too ?

I need one for my Judson Supercharge that i just buy .

Jules


jdesb@videotron.ca
Jules Desbiens

Del, that valve cover looks very cool all polished up with the top ribs painted. I REALLY like it!

Jules, did you buy the Judson that was just recently on eBay?
Andy Bounsall

Sorry Jules:

I sold my complete Judson a couple of years ago. The valve cover from that unit is pictured on Barney's site:

http://mgaguru.com/mgtech/accessories/at126.htm

and on Dominic's site:


http://www.clancy.ch/Judson_Components.html

Steve
Steve Brandt

Andy ,

Yes its the one that i bought a week ago . I don't recieved it yet .

Jules .
Jules Desbiens

This thread was discussed between 07/11/2009 and 28/11/2009

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