TR2/3/3A Alloy valve cover. pros/cons

[mmgwhite]

Thinking of changing out my stock valve cover on TR3A
Hard time getting it to seal well and it leaks.
I note that there are a few options for color and style but mostly wondering whether
I need the one with the air intake pipe on the side or one without that. If there is no intake pipe on the side
how does it breath? The pictures I can find look like the oil additive opening/cap doesn't breath.
None of the parts companies give any details.
Any suggestions?
Thanks

 

[bobhustead]

There is nothing like opening the bonnet and seeing that big chrome valve cover.
Bob

 

[trglory]

If the chrome is good on your current valve cover you should buy an alloy cover and send the chrome one to me (They are very easy to fix. Make sure the mating surface is flat, get a good cork or neoprene gasket and use hold-down nuts with rubber washers or O-rings.). If you get the alloy cover, you want the one with the oil filler cap in the front and no breather pipe. Breathing is done via the vent pipe down by the slave cylinder.

 

[TR3driver]

The stock 3A cover has vents in the cap, nothing else. The original covers with the tube on the side are from later cars (TR4/4A) and take a different sealed cap.

To get the stock cover to seal, you may have to start by doing a little sheet metal work on it. Get the sealing surface as flat as you can, as well as the top around the mounting nuts.

I have one of the Justin Wagner silicone gaskets, but I don't think he sells them any more. Might be worth trying the silicone gasket from ARE, though (which is a different design).

With the original cork gaskets, the trick is to glue the gasket to the cover with RTV, then set the cover on a flat surface (like a sheet of MDF) while the RTV cures. That way the RTV fills in the gaps due to the cover being distorted and the bottom of the gasket is more nearly flat. Then use Hylomar (or some use axle grease) between the gasket and the head. This setup can be reused several times, until the cork starts to break up.

The factory fiber washers (at the mounting nuts) never seemed to work very well for me, I suggest some sort of rubber sealing method instead. Justin supplies these

but I think these are better suited
https://www.mcmaster.com/#93781a037/=wtqmr3

Or, what I use are the thumbscrews with O-rings that A.R.E. sells
https://www.the-vintage-racer.com/index.php/categoryhome/engine-components/product/52-vsd-t26
but they are a bit pricey and I found that the oil filler cap would foul on the front one (so I added a spacer inside the cap to make it ride just a bit higher).

 

[Darrell_Walker]

Besides checking for the cover to be flat, check that the long sides haven't bowed out, particularly the taller side. Over tightening the nuts can cause the sides to bow out.

 

[Geo Hahn]

TheThe factory fiber washers (at the mounting nuts) never seemed to work very well for me, I suggest some sort of rubber sealing method instead...

I was in the restroom in an old Mexican restaurant in Patagonia AZ - saw that someone had been working on the toilet and upon reassembling left the old pair of rubber washers that had been used under the metal washers where the tank attaches to the bowl.

That was several years ago and they still do a fine job of sealing the holes in the valve cover w/o requiring over tightening of the nuts.

 

[mrv8q]

I bought a nice alloy cover way back when TRF had a good sale. I use a good cork seal with Hylomar; no leaks, no runs no error. On my 3A, no side draft air intake necessary.