OK, I have this oil leak resonating from the driver's side valve cover at the rear corner near the #7 cylinder. This is my second chrome valve cover and third set of gaskets. Last gasket is felt with high-temp silicone on both sides and let it set for 2 days before starting. The head is brand new Summit 2.02/67 cc heads. I am wondering if the leak could be from the head itself as I can't imagine it is still the valve cover. The cover is mounted with T-handles and hold down bars. The other side is fine. I have lost my patience with taking this apart and am open to any suggestions. Has anyone had this problem and if it is the head how can I make sure it is. I am at wits end!

If you haven't done it already, swap the valve covers and see if there's a difference. Leak in the same spot may indicate a head sealing issue. Leak on opposite side is probably a valve cover issue. Oil pooling or leak thru the bolt hole are possibilities - especially if your PVC setup doesn't pull a lot and you have blowby issues.

If those "chrome" valve covers are the thin stamped kind, that is your problem, they SUCK!
I'm not ruling out a head sealing issue but I would bet that is the problem over anything else.

Invest in a set of heavy cast type covers, fabricated aluminum, anything but stamped flimsy stuff.

Also, don't over torque the bolts, tightening the bolts even more to avoid a leak doesn't solve the problem, it causes the valve cover to flex even more.

Jack, when you say leak through bolt hole are you talking about valve cover bolt? I like that idea of switching valve covers.
I got these valve covers from Summit, they're Proform GM Performance Stamped Steel and they seem like heavy guage and they said these greatly reduce leakage around the flange area but they were only $46 so....are these the flimsy ones you are talking about?
Maybe I'll clean up the original ones and put them back on, wanted to dress the motor up with the chrome. This is really frustrating and I really don't want to pull that dam head off.

Proform generally have cheaply made stuff in my opinion, their carbs are good, but I question some of their dress up kits. Can you post a link of which ones they are?

The ones I run are from proform (came in a gmpp box?) but are die-cast aluminum, they are heavy and will not flex or leak: http://www.summitracing.com/parts/PRO-141-108/

I have seen at least 20 different motors in person that run the same type, they are a tad expensive but look good and don't leak.

These are the ones I have, although I bought the chrome dress up kit: Proform GM Performance Parts 141-102 - Proform Stamped Steel Chevrolet Valve Cover. They're not the ones you have, stamped steel has no color.

http://zteiyw.blu.livefilestore.com/y1pu1NoRmtwtKepE-CoAgQ0iFINSFb8kjfh8jCzbQ5TBbx9Z9f-j90hqu6gVXkYwVmPmqZAYDOQ5NtOrdgu0pXMG3kZZCY6n-gb/valve%20cover.jpg

Mine were leaking thru the bolt hole opening. The AFR heads I have pool oil under the rear outside bolts. I sealed the hole with silicone and put the coverson wet. This made a kind of sleeve seal around the bolt and stopped the leak.

I don't think the bolt holes are leaking, it is leaking at the corner, I can see it pouring down from there. I'm thinking that the covers just "suck" but not sure why it leaks, they look fine.

I have a set of GM licensed Chevrolet chrome valve covers that were pretty cheap and look like the ones you posted in that link. I have had them off and on probably five times in the last few months with the same gaskets. They have not leaked once.

Personally, I don't like the T-handles. I think they look good, but I don't like them for a fastener. It's too hard to get uniform torque on them.

Here's how mine are installed:

Get a set of valve cover studs. Clean the holes in the head with brake cleaner and install the studs with Loctite.

Use RTV only on the valve cover side of the gasket after cleaning the valve cover with brake cleaner. I use the cork/rubber gasket. Make sure the RTV is just a very thin coating and that it goes around the bolt holes in the valve cover. Too thick and the gasket will just slide on it. Put the gasket on the valve cover and let it sit for an hour.

Clean the edge of the head with brake cleaner. Install the valve covers (NO RTV on head side). Install a set of valve cover hold down clamps. Make sure they are installed right side up. Install the washers and nuts that came with the studs. Torque the nuts to NO MORE than 8 foot pounds. It doesn't feel like much but don't go any more.

Run the motor up to operating temp and let it cool. Re-torque the nuts at 8 foot pounds.

I have a pair of the cheap, stamped steel chrome valve covers and never have had an oil leak issue!.....The trick is to purchase a pair of the rubber valve cover gaskets and glue them to the valve cover flanges with a good adhesive then install the valve covers dry, do not use any silicone sealant!....You also must not overtighten the valve cover bolts or you'll bend or warp the flanges!.....Just snug the bolts up with your 3/8" ratchet!

I have tried the rubber gaskets as well, have used silicone and also tried that gasgacinch sealer. Why would the T-handle be different than a nut, would think you would have the same pressure. Just getting tired of taking it off and putting it back on.

I have tried the rubber gaskets as well, have used silicone and also tried that gasgacinch sealer. Why would the T-handle be different than a nut, would think you would have the same pressure. Just getting tired of taking it off and putting it back on. Do you have just the T-handles or do you also have the hold down clamps to help distribute the seal.

I have tried the rubber gaskets as well, have used silicone and also tried that gasgacinch sealer. Why would the T-handle be different than a nut, would think you would have the same pressure. Just getting tired of taking it off and putting it back on.



Are you able to use a torque wrench on the T handle?

I had a high quality set of Edelbrock aluminum covers and T handles that always leaked. Now I have a cheap set of chrome covers with studs and proper torquing that don't.

Just saying....


And again, no silicone on the head side of the gasket. Only on the valve cover side with a very thin smear and let it set first before you try to install it. If it's wet it makes the gasket squish/slide out when tightening the bolts.

I have the same valve covers on a 350 in my 69 C/10 and they leaked with cork gaskets. I replaced the gaskets with some felpro rubber gaskets that have a steel shim in the center of the gasket and they do not leak anymore. The gaskets came with a set of load spreaders and I used those too.

http://i222.photobucket.com/albums/dd216/67SSand99SS/100_4128.jpg

Maybe the thread at the heads rear cover screw hole is not cut deep enough to tighten the cover to the head? or the "t'" handle thread is cut too long to adaquately tighten the cover?

Either the screw is too long or the thread is too short. Either way, it sounds like you cant tighten the rear valve cover enough to seal.

I thought that before I put them back on, it looked like I head enough thread to tighten them down but maybe not. Then maybe the studs with nuts will be better. I'm assuming Advance Auto or similiar would carry valve cover studs.

Chrome stamped steel covers are cheap and prone to leaking. I ended up replacing mine with OEM painted ones. I then used cork gaskets and soaked them in water overnight. Then applied shellac gasket sealer to both sides of the gasket. Then bolted into place. I think the torque setting is something like 20 ft/lbs. I didn't have a torque wrench that precise, so I tightened them a hair over "firm." Oh yeah, I also used those elongated washers that are made for valve covers to help spread out the force from the bolt.

Not as aesthetically pleasing as the pretty chrome ones I removed, but they haven't leaked for more than a year now.

Have you checked to make sure the oil is not coming from the oil pressure hole in the back of the block on the drivers side?

Porosity in the head casting at that corner? What does the surface at that corner look like? No chips or dings I hope.

alan

If you overtorqued the T-handles or unevenly torqued them, the damage is already done, the covers have been through a few heat cycles and are likely no longer straight and true.

I do believe the problem isn't solved by throwing more money at it (expensive valve covers) but it's the only way in this case. Even stock type covers leak, heck you should see my '97 vortec pick up, never had the covers off and they leak bad.

Even stock type covers leak, heck you should see my '97 vortec pick up, never had the covers off and they leak bad.

Hell, I was told that they were designed like that to let "bad oil" out.

Seriously though, I have NEVER been able to seal stamped covers without the process already spelled out before by Steiner. I also use the wide hold down tabs such as these MOR-68510/ (http://www.summitracing.com/parts/MOR-68510/)

The oil is definitely coming from the valve cover and not the sending unit, I can see it run down and onto my header flange. I have those hold down clamps except there summit's I believe. The cover on the passenger side is and has been fine, it is just this side which is aggravating to say the least.
The head is brand new and looks fine, no dings or anything like that. I will try using the studs that came with the T handles and use nuts instead with the hold down clamps and if that doesn't work then I am going to replace with one of the ones you guys have recommended (more money :hurray:).
Maybe it is not tightening down because of lack of thread, that seems to make the most sense here, therefore a nut would solve that. I'll let you guys know how this goes.

Get a set of those finned M/T aluminum valve covers. you can find them all day long at swap meets for pretty cheap, and they look super cool! Cheap to "restore" them too, clean 'em up and hit them with some textured black paint and then scotchbrite it off the top of the fins.

Steiner, you are the man! Replaced the T-handle with nuts and followed your advice and presto, no leak.:beers: If you're ever in CT I owe you a beer or 2!!! Thanks to all.

Just e-mail him one....jk:) He is a big help!

Steiner, you are the man! Replaced the T-handle with nuts and followed your advice and presto, no leak.:beers: If you're ever in CT I owe you a beer or 2!!! Thanks to all.


Great! All you did was learn from my mistakes. See my signature.

I spent three months in Stamford while on a project in White Plains several years ago.....Dec thru March. That was about enough CT for me, thanks. :p

Yep know what you mean, if I could find a job in NC we would be out of here too!