Leaky Valve Covers

[bigboi]

I have a set of knockoff Moroso valve covers. They look just like the high end $300+ Moroso aluminum covers except they are knock offs. They look great but the only problem with them is whoever fabricated them didn't grind the bottom aluminum piece that seals to the head very well. A corner on each valve cover is ground down a little too much.

I have a set of blue Moroso rubber gaskets on them, but I can't quite get the driver's side rear sealed perfectly and I am dripping a bit of oil down onto the header.



Am I pretty much out of luck on these valve covers or do you think I can bring them to a machine shop to make them perfectly flat? I have never brought something so minimal to a machine shop and don't want them to look at me and laugh.

I am not sure I can grind it perfectly flat myself or I would give it a shot. The piece is a solid piece of aluminum and I would need to ensure I got it perfectly flat for it to seal correctly.

Any thoughts / suggestions?

Brian

[justasquid]

how thick is the material on the lip? One of the problems I could see if a machine shop milled it flat would be not enough material to make it all flat. Keep in mind the rest of the cover may not be flat either. By the time get one end all the way to the other end flat, you may run out of material.

Also, holding the valve cover may posses some problems with the cover not being very rigid. They may be able to put the cover in a vise, but before clamping it in, have them place a piece of material (aluminum, maybe even wood), that fits very snug inside the valve cover then clamp it down. I think it may still chatter a bit, but as long as the cuts are small, it may work out.

Im not sure what a machine shop would charge though. I don't know if it would be cost effective.

Since they are knock offs, I would try a two part epoxy. Build up the low spots and then block sand the excess material flat. I'm not sure what to suggest, but there must be an epoxy of some sort that is heat and oil resistant.

[Josh]

The easiest thing that ususally works is RTV. Lay a good bead all the way around the valve cover, let set 10 minutes, lay rubber gasket on the bead then carefully install covers with very little tightening. You want just enough tightening to have the gasket make good contact with the head and thats it. Let dry fully, then tighten to regular torque value. This should "fill in" any gaps above the gasket and the gasket should be flat to the head now. Plus taking the covers on and off now is a breeze sine the gasket is glued to the cover.
Good luck.

[bigboi]

Yeh I tried some clear ATV and it didn't adhere to the valve cover at all although it stuck to the rubber gasket.

It made more or a mess than anything because once I took the valve cover off the rubber gasket came off and I had clear ATV on the rubber gasket with a mold of the valve cover.

Ugh... That's what I get for using knock offs. Need to spend the money and buy some real Moroso aluminum valve covers.

[Yoda4561]

If RTV doesn't stick then the surface wasn't clean enough, RTV adheres quite literally like glue to clean surfaces. Also, use an oil resistant grade of RTV, the package or tube will usually mention it. While clear works fine in a pinch the Blue/Black RTVs usually hold up better.

[Vegas69]

I agree, clean the surfaces with brake cleaner than apply the RTV and it should seal fine. It seals intake ends seals without a problem.

[CarlC]

You might be able to find a shop with a big belt-type sander that can grind the whole surface at once, similar to a header flange. Then glue a thick cork gasket to the sealing surface.

[Pro Stock]

You might be able to find a shop with a big belt-type sander that can grind the whole surface at once, similar to a header flange. Then glue a thick cork gasket to the sealing surface.

These sanders were used a lot in automotive machine shops a few years back, they were used for sanding head surfaces and would get the surface really flat, no clamping or or fixturing is needed, after you get them flat clean the gasket surface with laquer thinner, acetone or M.E.K. all of these solvents are oil free unlike most brake cleaning products that are petrolium based nowdays. After cleaning use a product made by Permetex called "The Right Stuff" which can be bought at NAPA, Autozone, Advance Auto Supply ect. Glue the gaskets to the valve covers, put the covers on the heads right away and tighten. If you have any other issues and need any repair work done on them PM me and I'll steer you the right direction.

Dale

[MonzaRacer]

Honestly best way to seal up valve covers for me would be ask around have local shop that uses the beltsander type give them quick scuff, little at a time. maybe even find low spot mix up some JB weld then go at the belt surfacer.
Now go to NAPA or local parts house, get the steel reinforced cork gaskets (look like 2 cheapies with thin metal shim inside) get a tube of 3M black weather strip adhesive, glue the gasket to the valve cover with it, do rest a bit of weight on them so you get good adhesion. THEN clean your heads dry with brake clean, spotless even, Now after valve cover/gaskets are dry, turn over, using your finger(you will need a few rags to clean hands)spread about 1/16" of Permatex Ultra Black, most itmes I just use enough to "slick up" cork gaskets ,,but,,,,.
Kind of like spreading peanut butter ,enough to cover the pore of the bread, but not the super thing amount that makes big mess.
Then pop the cover on while still wet, use good ,wide spreaders, and good hold down bolts.
when you have to remove these it WILL take nearly an act of God to get them off. IF you need to do periodic adjustments, make silicone little thinner, I use enough to make the cork gasket slick but not too as thick as above, LET skin over(this means it isnt still sticky but its still pliable). This will allow the covers to convorm to heads but not glue down.
Do this let it set for hr or so and start and warm up, and check for few days driving, as cork does have to take a set. Not too tight just so it wont wiggle or loosen.
This setup will not leak and my gaskets lasted for many years, and every time I removed them, I simply used finger nail to scrape the silicone off, re-silicon, and reinstall. The ones I got from NAPA were Victor, but Felpro makes decent ones, the victor seems to have smaller grain structure and lasted longer for me.

[bigboi]

Pro Stock - I am going to follow your advice and see how it works. I grabbed some "The Right Stuff" today - never saw that sealant before because they seem to stock it in a different place than the other crap.

I will take a sander flapper wheel and just scuff the surface, clean it up with some acetone, and apply the gaskets.

Hopefully they will seal up good. Tired of having the oil smoking on the header when I fire up the car.