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-   -   No leak valve cover gaskets? (https://www.corvetteforum.com/forums/c3-tech-performance/2993894-no-leak-valve-cover-gaskets.html)

marshal135 02-02-2012 09:04 AM

No leak valve cover gaskets?
 
If there is such a thing I'd like to know about them.:toetap:
1968 427 w/ orig covers.
Current gaskets permit dripping down the exhaust manifolds dirtying up my engine:willy:
Thanks,
Marshal

oneshot 02-02-2012 09:17 AM

Might want to look at some Felpro gaskets. I know they make a oil pan gasket that has a metal core so you can tight them up but not pitch the gasket. They might make one for valve covers.

Surfer69 02-02-2012 09:42 AM

I have to say I've tried everything, cork, rubber, tall short, new valve covers and my AFR heads would still leak at the rear corner.
Even with or without a dab of sealant. And at $10 a pop or more it becomes a real pain.

But I noticed that there was always this more expensive set from Felpro (I think, can't remember now) around $20 and it's made of rubber with kind of fins going around it. At the fastener locations they have metal rings so you can't overtorque the thing. I've had these 6 months now with synthetic RP and no leaks.

I'm pretty sure I found the perfect valve cover gasket.:thumbs:

jcloving 02-02-2012 09:45 AM

I have some felpros on my engine. They are injection molded rubber over steel. They recommend applying them on a dry clean block and valve cover with no sealant. I have used them for over a year with no leaks.

I believe these are ones I have:

http://shop.advanceautoparts.com/web...___#fragment-1

They are a bit more pricey but are reusable and work for me!

qwank 02-02-2012 11:23 AM


Originally Posted by jcloving (Post 1579899615)
I have some felpros on my engine. They are injection molded rubber over steel. They recommend applying them on a dry clean block and valve cover with no sealant. I have used them for over a year with no leaks.

I believe these are ones I have:

http://shop.advanceautoparts.com/web...___#fragment-1

They are a bit more pricey but are reusable and work for me!

:iagree:

I use these on my '81 with great success also

anips 02-02-2012 11:34 AM


Originally Posted by jcloving (Post 1579899615)
I have some felpros on my engine. They are injection molded rubber over steel. They recommend applying them on a dry clean block and valve cover with no sealant. I have used them for over a year with no leaks.

I believe these are ones I have:

http://shop.advanceautoparts.com/web...___#fragment-1

They are a bit more pricey but are reusable and work for me!

first of all you have to make sure the V.C. rails are straight specialy at the bolt holes, I use either FP #1604- $33 or Mr Gasket ulta seal $23. they are both 5/16" thick with a steel shim, I use 3M spray adhesive to glue to the cover, and just a smire of rtv and I mean JUST a lite smire on the gasket-head side, and make sure the head rail is clean and dry before bolting on, never a leak, and later when you might have to remove the cover you might have to tap the cover to get it to come loose from the head,after that just bolt em back on.

BarryK 02-02-2012 12:11 PM

for what it's worth... when I was re-doing the motor and engine bay on my '78 a few years back I decided to use a set of expensive Felpro gaskets for the valve covers since I already had them new in the package. These were a "sandwich" type of gasket with a thin piece of metal sandwiched between rubber. Sorry, don't remember the model number..
These expensive gaskets leaks like a sieve all over my fresh and newly painted motor and nothing I did would get them to stop leaking.
I'd always used the basic cork gaskets on my '65 and never had a leak from the valve covers at all so I got another set of cork gaskets for the '78, put them on, and the motor hasn't leaked a drop out of thr VC's ever since

billla 02-02-2012 12:15 PM

I have personally never had a problem using the "old skool" cork gaskets. I Permatex them to the cover, and then tighten *just so*.

For stock and mild engines with tin covers, the most common cause of leaks are bent rails (or dimples at the bolt holes), over-tightening or failure to install the spreaders. They don't need to be brutally tight!

BarryK 02-02-2012 01:06 PM


Originally Posted by billla (Post 1579900994)
I have personally never had a problem using the "old skool" cork gaskets. I Permatex them to the cover, and then tighten *just so*.

For stock and mild engines with tin covers, the most common cause of leaks are bent rails (or dimples at the bolt holes), over-tightening or failure to install the spreaders. They don't need to be brutally tight!

:iagree: too many people overtighten the bolts and it causes leaks. just snug them down lightly

marshal135 02-02-2012 02:37 PM

Thank you everyone for your time and responses.
I think the area on the VC's around the bolt holes is probably dished in from overtightening in the past.
I'm going to check the rails when I pull em off.
I like the idea of adhering them to the VC and dropping in place.Some of my spreaders must have gotten lost because there are several bolts with round washers under them.
I'm going to order a new set of bolts with spreaders for a cleaner look.
I think cork replacements are on it now and are letting some oil sneak by on the lower edge of the head. I read the torque value for valve covers is like 10inch/lb so not allot needed to seal them.
BarryK, I enjoyed your timing article. I learned allot and read it like 4 times so I'm ready to tackle the timing this spring with the article on the fender next to me:eek:
Marshal

billla 02-02-2012 02:52 PM


Originally Posted by marshal135 (Post 1579902340)
I think the area on the VC's around the bolt holes is probably dished in from overtightening in the past.

A few careful moments with a ball-peen hammer and a scrap of 2x4 will fix that right up :)

birdsmith 02-02-2012 04:14 PM

A little trick that I invented was to check around the cover with a .0015" feeler gage as you slowly tighten it. Cork gaskets will not leak as long as there is no gap between them and the head mating surface. too often the valve covers are distorted from previous Bubbas. And I don't use RTV on them ANYWHERE. I glue the gaskets to the valve covers with yellow 3M weatherstrip cement, which keeps them tightly in place so they don't move around or creep while you are [carefully] tightening them. That is all...

forman 02-02-2012 04:36 PM

I use the felpro blue ones they have the metal in the middle , just make sure the valve cover edges are not bent or warped or they will leak like a sieve no matter what you do

Ironcross 02-02-2012 06:36 PM

One of my PRO tips
 
it really does not matter what brand of gasket used, Felpro, Victor, McCord or what ever...its the technique used and most will never follow this....do all the prelimination necessary, clean parts ect....use a hard setting sealer, your yellow 3-M trim cement is a good one {08011} I think...AND on the valve cover only, spread the glue all around the valve cover gasket lip until its real tacky but not quite dry...place the gasket on that surface and with whatever weighted objects hold the gasket in place several places so it will not move...When completely dry install the gasketed valve cover in place and put the screws back in....and do not over tighten....No silicone is necessary..ever and NOTHING on the head except some bearing grease...

MotorHead 02-02-2012 06:57 PM

I've had motors you could run with valve covers off with high rail heads.

The problems many of us face is the oil return on AFR heads. If you have ever looked closely at it, it is just below horizontal. What happens is the oil is not drained well from the head and collects in the corner and overflows the rails.

Any pinhole sized hole and you have a leak. I have had a leak on both sides on my AFR 227's since new. I have tried everything and every gasket I even put Permatex #2 on both sides of the gasket and it still leaked. Brand new heads, brand new valve covers, brand new gasket and oil on my garage floor.

What is the part # for the ribbed one with the washers ? :thumbs:

noonie 02-02-2012 07:25 PM


Originally Posted by MotorHead (Post 1579904672)
I've had motors you could run with valve covers off with high rail heads.

The problems many of us face is the oil return on AFR heads. If you have ever looked closely at it, it is just below horizontal. What happens is the oil is not drained well from the head and collects in the corner and overflows the rails.

Any pinhole sized hole and you have a leak. I have had a leak on both sides on my AFR 227's since new. I have tried everything and every gasket I even put Permatex #2 on both sides of the gasket and it still leaked. Brand new heads, brand new valve covers, brand new gasket and oil on my garage floor.

What is the part # for the ribbed one with the washers ? :thumbs:

Here are the good Felpro
They come with spreaders that are longer than stock (black)
The really long spreaders are oem GM (on cover) from around 1980.
No probs with these at all.

http://i74.photobucket.com/albums/i2...alveCover2.jpg

http://i74.photobucket.com/albums/i2...alveCover1.jpg

http://i74.photobucket.com/albums/i2...alveCover4.jpg

http://i74.photobucket.com/albums/i2...alveCover5.jpg

If you find that nothing works, use Permatex Great Stuff (???). I use that on problem tranny pans immersed in oil with never a leak.

Will's'74VetteL-82 02-02-2012 07:42 PM

I use Felpro cork gaskets with and RTV bead around the rim of the VC (which are aluminum L-82 valve covers). I currently have the normal thickness gaskets on, but I also bought another set from my Corvette shop that I use and they are thicker cork gaskets, both Felpro though. I used a 1/4 inch nut driver and tightened the bolts with that to a good torque to compress the gaskets, and I have no leaks since the install.

Will

C3 4ME 02-02-2012 08:40 PM

Just re-did mine last night for the exact reasons listed. I have stock aluminum covers, I placed both on a piece of flat glass, and both are dead flat. I tried Fel-Pro rubber gaskets this time. I have always put RTV on the covers only, so as to be able to remove them without damaging the gaskets. I had cork ones on before, so we'll see how the rubber ones do. I'm starting to think the only way to keep them from leaking is to not have any oil in the engine, lol.

billla 02-02-2012 09:03 PM

In aviation, we call this "automatic airfame lubrication" :-D

Steve2147 02-02-2012 09:30 PM

I would estimate that the single biggest cause of leaks, sweating, seepage from gaskets is failing to properly clean the surfaces.

In order for any of those gaskets to work the surface has to be free of any traces of oil. I use CR brand Brak-kleen (sp?) in an aerosol and spray liberally, then blow it off with air. If you have to glue the gaskets for ease of assembly I use 3M weatherstripping adhesive and glue the gasket the cover. The other side is left dry.

Same if you choose to use RTV sealant. If both sides are dry you don't even need bolts. Glass shops use that stuff to glue mirrors on. If you've ever had to remove covers that were siliconed on you know exactly what I'm talking about. The only thing they did any different was put it on clean dry surfaces.

Steve g


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