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when I upgraded my valve covers for aesthetic, I had used some silicone to create a gasket, and that lasted around 5000 miles before the left one started leaking oil onto the rear header.

took it to a shop, who replaced it with a cork one, saying that it was better, but still wouldnt probably last more than 5k miles as well.

well... after a couple months, I had to pull a valve cover as my oil breather baffle ripped off and was dancing on my valve springs - was hoping I didn't need to swap out the cork and it would still form a seal.... I dont know why i thought that.


so now i gotta replace it, again.


what are your preferred valve cover seal material ?
 

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Can't tell you the best, only what I do. Do your best to insure that the gasket surface on the valve cover is flat. Not tweaked a little from over tightening or ? I like the blue felpro gaskets (are they the best, who knows). I use a little rtv between the gasket to valve cover. Use NO rtv between the gasket and the cylinder head. Snug it down but don't over tighten. Snug it down again after a couple heating and cooling cycles.
 

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Mine are a steel core molded rubber. Designed to be reusable and they work well.

Cork works good too.
My technique is to use black RTV on the valve cover side and a light coating of oil on the head side. Get the RTV side set in place first.
Gently bolt them down. Too tight and the gasket will split and then you will have to do it all over again.
 

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I prefer the factory rubber 5.0 gaskets with the with the steel washers. You may need a different length VC bolt
 

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+1 for the Fel-Pro.
I am using the PermaDryPlus without any RTV. No leaks and it can be reused. In addition you don't have the pain of cleaning the valve cover and head if you work without RTV.
 

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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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I've grown to love the factory style steel-cored rubber gaskets. Be aware there are cheap copies out there. Some are just black rubber with no core. Some are a flat sheet of thin metal with a sheet of metal adhered to each side and then stamped out to size. (Apparently). No comparison to the OEM style where a piece of metal you can't see is engulfed in the rubber.

IMHO, cork is for wine bottles and bulletin boards and has no purpose in a car. Period. I also never put any silicone or sealer in my valve covers. If I ran mechanical lifters that needed to be adjusted twice a year or so I can see that. But as is I run hydraulic lifters and once the valve covers are on I see no need to have them back off again unless the engine blows up. Or I buy new and different valve covers.
 
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I glue rubber gaskets to the covers with ultra black RTV, drying with the gaskets down to a hard flat surface. Then grease the gasket to head surface. (cast, not stamped covers). Re-use dozens of times.
 

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Leave the cork to the wine bottles. Cork has no place as a gasket material anymore, it is brittle it leaks etc...

Like others the Felpro silicone or other similar brands are the way to go. Don't buy those no name loose ones that the guys sell at the swapmeets as they are too hard of rubber and don't seal well. Same gors for pan gaskets the felpro silicone ones are really good. For places that need sealant the right stuff RTV is really good stuff. The ultra grey and ultra black are up there too. I see no use for the ugly blue stuff that doesn't seem to hold up very well.

Another trick is if your heads are off have the gasket rail machined flat (for ones that are rough cast rounded). This makes sealing way easier but it does reduce rocker clearance a bit. Ideally you would machine those flat then get aftermarket aluminum covers with a thick flange and machine it to hold an O-ring.
 

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I use the FelPro corks on my 428 valve covers. I use the same method as the first poster Mike. I have learned the valve covers tend to warp with age so... I secure the rear most end and work forward. Go back and tighten. Works for me. Brian
 
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I’ve had good luck with cork and rubber with the metal inserts so it’s harder to over tighten and deform. Funny enough, but I currently have doubled-up cork gaskets for rocker clearance and zero leaks for 5 years now. Cast aluminum valve covers no doubt help with this.
 

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+1 for the Felpro, they do not need RTV, and seal perfectly.. trick is, DON'T OVERTIGHTEN the bolts.. simple..

Sent from my SM-G950F using Tapatalk
 

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Felpro 1684 rubber w/ steel core works for me. I've had the aluminum valve covers on and off a dozen or more times and they continue to seal perfectly every time. If I ever have to replace them, it will be with another identical set.
 

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To satisfy my own curiosity, I looked through my receipts and determined that my Felpro gaskets were purchased in 1999 along with my aluminum valve covers from a local engine builder (Jim Grubbs Motorsports). 20 years and still going strong! I don't think you can ask more of any gasket.
 

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This is an easy one... Rubber Valve Cover Gaskets all the way... Cork will break down over time and eventually you'll find it in your Oil pan and clogging up your oil pump...and even oil valleys under your intake...

Purists will still use cork on "Concours" restos though.... but who cares since its barely ever seen.

Rubber Fel-Pro Valve cover gaskets will perform a million times better than cork.... especially over time..

Rubber is the way to go..

When they came out with Rubber Valve cover gaskets in the 1980's I switched over and never looked back... I got tired of cleaning cork out of my engines... Also, It can be a bitch to take off too when you have to remove them...The rubber comes right off.. usually in one piece... Noone can say that about the cork ones... That's for sure..

:eek:)

Tony K.
 

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Mine are a steel core molded rubber. Designed to be reusable and they work well.

Cork works good too.
My technique is to use black RTV on the valve cover side and a light coating of oil on the head side. Get the RTV side set in place first.
Gently bolt them down. Too tight and the gasket will split and then you will have to do it all over again.
i use rubber gaskets, i hate cork with a passion. i also use RTV with the rubber gaskets, but only on the valve cover side, and just enough to hold the gasket in place. and i agree not to over tighten the bolts.

one thing you can do is find valve cover gaskets that have steel grommets in the bolt holes to prevent over tightening.
 

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Back in the day we used to glue them in place on both sides with Ford's Windshield & Trim Adhesive....
which sadly is no longer available.
For the last 20 years I've been using Victor Reinz VS38300HTC
Special cork with a steel shim section in the center. No leaks.

It does look like their perfection has led to their demise. I don't see that exact item available anywhere.
The $9 ones listed under that part number sure wouldn't be them.
(Victor Reinz was acquired by another corporation awhile back. Might be a result of that.)
 

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Back in the day we used to glue them in place on both sides with Ford's Windshield & Trim Adhesive....
which sadly is no longer available.
For the last 20 years I've been using Victor Reinz VS38300HTC
Special cork with a steel shim section in the center. No leaks.

It does look like their perfection has led to their demise. I don't see that exact item available anywhere.
The $9 ones listed under that part number sure wouldn't be them.
(Victor Reinz was acquired by another corporation awhile back. Might be a result of that.)
^^^ These. Victor-Reinz acquired by Mahle. Gaskets available through rockauto.com as #VS38300H.
 
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