I need to replace my valve cover gaskets, Mac's has rubber and cork for my 400.

Q1: Which is better?

Q2: What sealant/sealer should I use with the new gasket to make the best seal?

 

I like cork and a thin coat of high temp red Permetex. let it tack up to hold the gasket. Make sure that surface is clean. Use a flat edge steel ruler and flat ck the under side edge of the valve covers themselves. Folks tend to overtighten the bolts and bend the area around the bolt holes. Can be tapped back to flat.

 

I personally like the rubber gaskets. I use gaska sinch on the valve covers.

 

I've got rubber on there now and they are both leaking. Not sure how the PO installed them but I'll give the cork/permatex a try. Rich - thanks for the tip on checking valve covers!

 

The torque is technically something like 3 to 5 foot pounds. Not very much. Retorque after a couple hot cold cycles.

 

I run rubber and line em up super carefully and dab some RTV to hold them in place. No leaks. I hate cork personally... Will replace cork with rubber any time I get the chance.

 

I think I've used all of them over the years on my 1976 F350, 460, and they all leaked. Finally switched to Moroso Perm-Align steel core valve cover gaskets and no more leaks. You don't use any sealers with these. I found it was helpful to install them using a couple of studs to keep everything aligned. They're not Ford blue, but they are blue.
The part number for the 460 gaskets is Moroso 93065.

 

Only thing I don't like about cork is trying to clean them up after a lot of use. They tend to stick well!

Never had issues with either. Trick is the 3-5 lb. as mentioned. Over tightening will kill any gasket. If I don't have a torque wrench handy I use an extension with knurl and just tighten with a socket by hand.

 

Keys are making sure the contact surface on the cover is dead flat (or as close as possible), and making sure the gasket does not roll or displace during installation - I have had very good luck putting a bead of blue or black Permatex on the cover, letting it sit a few minutes, then carefully putting the gasket on the cover, making sure it is aligned, then letting the permatex cure for an hour or so. If the gasket is firmly affixed to the cover, either cork or rubber will work fine (even on the lifter cover, which is a flaming pain to seal sometimes.) Be glad we have new stuff; I remember trying to get cork side cover gaskets to seal using Indian Head...that was almost an art form.

 

thanks HoustonDave for the tips on gasket prep, I'll use that method.

vettman - I can't find a Moroso for my 400, is this an equivalent?

https://www.summitracing.com/parts/s...view/make/ford

The plan so far:

1. Clean both surfaces
2. Check valve covers for flat (77&79F250)
3. gasket - Cork/Rubber/Other TBD
4. Permatex on cover, wait - gasket on cover, wait (HoustonDave)
5. 3-5lb (Tedster9, gittinwidit)

 

I prefer rubber over cork anywhere and everywhere. On valve covers, though, most leaks I've encountered are actually due covers that are warped from being overtightened rather than being an issue with gasket material; be sure they're straight before installing them, and pay attention to torque specs. As indicated above, it's just a few foot-pounds.

 

I'm okay with either rubber or cork. Prep and installation technique seems to be more important than the material.

However, I prefer Fel-pro over Mr. Gasket gaskets... the latter's cork tends to be more dry and crumbly. Crummy binder agent?

 

HIO is right. FEL-PRO are the best. Available at NAPA.

 

I've tried several and usually have best luck with Fel-Pro cork. As mentioned, making sure cover sealing surfaces are straight first is key and don't overtorque.

I sometimes use adhesive between the cleaned up cover and gasket for convenience... or not. I don't think the adhesive helps much with leaks.

 

You guys are going to think I am nuts. My 1979 F150 (original owner) with a 400 never had valve cover gaskets installed at the factory, just a grey sealer that appeared to be the same as silicone. I wondered if Ford stopped using valve cover gaskets at some point later in production. When I dismantled the engine for the first time for some head work, I never installed valve cover gaskets. I just polish the head and valve cover mating surfaces then wipe them down with acetone to remove any residue before applying a small bead of my favourite silicone, allow it to skin and bolt them on. No leaks! The good thing about not using gaskets is it is virtually impossible to bend the valve cover flange. Ever since seeing that, I have stopped using valve cover gaskets on engines unless the valve cover is recessed for a gasket and there is a space that needs to be occupied by a valve cover gasket.

I just checked a Ford parts manual, and it definitely shows that valve cover gaskets were used. Weird. Really, really weird.