Rtv vs. Gasket

[ChryslerKid]

Ive always used gaskets as opposed to rtv when I can help it with good results. There are certain applications where I add silicone. A very thin film around intake ports, timing cover just to hold it to the block, BB valley pan hold down bars, PITA thermostat housings etc.. with the magnum motor im building I decided to pull old junkyard LA bolt ons as opposed to buying new ( not much cheaper), partially out of habit and partly because I enjoy cleaning and using old factory parts. I find it enjoyable having a beer and scrubbing old parts, its satisfying to me in an odd way. That being said here is my question. Is there any downside to using rtv on pieces like timing cover and water pump? The gasket surfaces on these aluminum parts arent terribly pitted but they definately aren't what they used to be and im not a fan of using gaskets and silicone together.

 

[WileERobby]

I use

... as I've been doing for 50 years. No leaks.

 

[ChryslerKid]

Ive seen this plenty of times in shops but never used it. This is applied to both sides of the gasket?

 

[Geoff 2]

I think it was 1987 I stopped using gaskets...or was it 1988.

I only use a few gaskets, head & intake, that is about it. Around the intake port openings, I use 518 gasket maker. NOT silicon. [ Silicon will turn to jelly in the presence of petrol, good way to remove old silicon is to immerse the part in petrol ]. I use silicon everywhere else. The surfaces need to clean & corrosion free. Things such as t/covers, oil pan rails etc, I wire brush with an electric drill. Final wipe withy lacquer thinner.

 

[dvw]

I use Ultra grey and gaskets on nearly every thing. Why a gasket? Without one it's nearly impossible to pull the pieces apart. If you use RTV without a gasket it's a good Idea to put a notch in it for a screwdriver to get between the 2 surfaces. My upper intake is like this. Just had to wrestle with the extension housing on my 5 speed truck trans. It was sealed with RTV without a notch. I ended up drilling a few 1/16" holes side by side just off the gap between the trans case and tail housing. Then busted the small piece out with a screwdriver to get the parts apart.
Doug

 

[PlymCrazy]

If it came with a gasket, I put a gasket back in. A light film of RTV is all I'll ever use on cork gasket applications. Rubber gaskets I'll typically install without RTV. Straight RTV without a gasket can be quite a challenge sometimes when trying to disassemble, in particular with thinner parts that can bend easily like oil/transmission pans and valve covers. When deciding on what to use upon reassembly, whether it be RTV, a gasket or both, think about the next guy who may have to take it apart. Because you just might be that guy.

 

[HEMI-ITIS]

I use a skim coat with the right stuff.The only place I don't use a gasket are the headers.I have not found s company that makes one for my raised port heads.
All my gaskets are SUPERFORMANCE except the head & exhaust.

 

[WileERobby]

Ive seen this plenty of times in shops but never used it. This is applied to both sides of the gasket?

Yes. The way the old-timer in the garage told me way back...butter a nice film on the part surface, apply the gasket, butter a nice film on the gasket,wait a minute or so to get tacky, then install, tighten snugly all around, then tighten to torque.

 

[PlymCrazy]

I use View attachment 1332223 ... as I've been doing for 50 years. No leaks.

Works great on freeze plugs too

 

[gkent]

On parts with no flex I prefer a gasket with a light coat of Permatex gasket spray. On things with flex - like stamped timing covers and oil pans I prefer the grey gasket maker.

I try to avoid RTV anywhere that it could fall into the motor on disassembly.