The use of RTV and permatex sealants with gaskets - what do I use?

[Firetodd]

I have a 67 Charger with a 383.

Among various leaks that I need to fix before the cruising weather comes around, I have a valve cover that is leaking down the passenger side onto the exhaust. I have new gaskets (Felpro vs50145r) and was wondering if I should put permatex black RTV on the gaskets or just use the gaskets alone.

Additionally, I have a vacuum leak on my intake manifold drivers side. I replaced the manifold last year and the valley pan looked good and I thought was well sealed, so I left it alone. I had trouble with tuning the carb due to low vacuum, but did the best I could. Now I find the vacuum leak  So I have read differing opinions on using gaskets with the valley pan or pan by itself, or using some RTV. I have a new valley pan, some edelbrock gaskets, and hylomar blue. What is the consensus? Use gaskets, or just the valley pan? Do I use the hylomar sealant as well?

I'm tired of leaks.

[crj1968]

Well you'll get differing opinions but I finally got my valve covers to stop leaking with cork fel-pro's and a thin coating of some RTV (blue permatex)

Cant say for sure if the RTV helped but it's not leaking.

As for the intake I've just used the Valley pan and only RTV at each end(where this is no raised seal.  But with aftermarket or milled heads, it may not be enough.

[firefighter3931]

I like the Permatex "Ultra Copper" high heat silicone for engine sealing duties 

On the valvecovers ; I use a skim coat on the cover side only to hold the gasket in place. Clean thoroughly and put a small bead on the VC and install the gasket. Let it set up overnight to cure and install the next day. Don't overtighten the valvecovers....just enough to compress the gasket slightly and seal. 

On the intake manifold I use the Ultra on both sides of the tin valley pan around the ports and along the lower edge of the pan where it makes contact with the head surface. I also put a bead along the end rails with a little dab in the corners for good measure. Again....just snug the intake down and allow it to cure overnight then tighten the next day. Make sure you criss-cross when tightening down the intake bolts starting from the center working out to the ends. 


Ron

[Firetodd]

Thanks guys, I guess I will get to work!

[ACUDANUT]

I like the Permatex "Ultra Copper" high heat silicone for engine sealing duties 

On the valvecovers ; I use a skim coat on the cover side only to hold the gasket in place. Clean thoroughly and put a small bead on the VC and install the gasket. Let it set up overnight to cure and install the next day. Don't overtighten the valvecovers....just enough to compress the gasket slightly and seal. 

On the intake manifold I use the Ultra on both sides of the tin valley pan around the ports and along the lower edge of the pan where it makes contact with the head surface. I also put a bead along the end rails with a little dab in the corners for good measure. Again....just snug the intake down and allow it to cure overnight then tighten the next day. Make sure you criss-cross when tightening down the intake bolts starting from the center working out to the ends. 


Ron

Ron is the Bible here. Always has great advice.

[crj1968]

I like the Permatex "Ultra Copper" high heat silicone for engine sealing duties 

On the valvecovers ; I use a skim coat on the cover side only to hold the gasket in place. Clean thoroughly and put a small bead on the VC and install the gasket. Let it set up overnight to cure and install the next day. Don't overtighten the valvecovers....just enough to compress the gasket slightly and seal. 

On the intake manifold I use the Ultra on both sides of the tin valley pan around the ports and along the lower edge of the pan where it makes contact with the head surface. I also put a bead along the end rails with a little dab in the corners for good measure. Again....just snug the intake down and allow it to cure overnight then tighten the next day. Make sure you criss-cross when tightening down the intake bolts starting from the center working out to the ends. 


Ron

Ron is the Bible here. Always has great advice.

Yeah take his advice over mine. I'm just a backyard bolter-together guy-  good luck !

[Firetodd]

On the valley pan and intake manifold, do you use gaskets as well?

[polywideblock]

x3 on the ultra copper   

[firefighter3931]

On the valley pan and intake manifold, do you use gaskets as well?

I've never used them...and have had zero leak issues using the outlined method.

Another tip ; put some Copper RTV on the threads of the intake manifold bolts. Oil can work it's way up the threads and leak out onto the intake manifold....seen it a few times. 


Ron

[ACUDANUT]

 Off topic, but the valley pan's always seem to get surface rust on them.