IMO if using rtv you don't let that partially dry either. You want to "stick" the two parts together. Probably why those who insist on using "the right stuff" have better luck with it, because they're using rtv wrong.

If you're going to let it partially cure before putting the intake on you might as well use rubber gaskets on the end.

 

You don't let RTV partially dry either. For these intakes some guys including myself like to let the RTV partially set up before final torque. But the parts need to be assembled before the RTV skins. The idea behind letting it set up is that it will have some springiness when you final torque it that will help it seal.

 

All good info and I am glad I found this thread. I too am going to reseal the intake on the 94 LT1 and am in agreement of using "The Right Stuff". I bought the Fel-Pro gasket set and was about to buy the sealant, but noticed that "The Right Stuff" comes in different colors. Gray and black if I am not mistaken. Does anyone have a preference on what color, or are they all the same?

Thanks in advance...

 

bought it to day, dont wont to do job twice!
thanks
wayne

 

The key thing Ive learned over the years isn't what you use to seal it as much as letting it sit over night to cure. Sure using the right sealant helps but letting it sit up before use is the key to working right. Especially on valve covers.

 

thanks
wayne

 

Get this.

 

Bring this back...

Gonna be tearing off the Super Ram this spring soon again. The past 2 times I've used the black RTV. Each time I made sure that everything was super clean. I did not dimple but think I may this time. I keep getting the leak in the same spot. Passenger side rear. Def. not from valve covers or switch and sensor.

I'm going to look for "The right stuff" to use this time. Need clarification on when to put the intake on. Let it set up? How long? Or put it down right away...

Thanks guys!

 

Run your 3/8 beads from and rear china wall and carefully set intake straight down. No need to let set.

I dimple the china walls and also the underside of the intake to mate with china walls. Never a issue.

 

And dimpling the underside of the intake and the china walls only takes a few minutes and it won't harm anything. I don't understand when someone says they wouldn't "waste" the time doing it.

One suggestion - if possible have someone assist you in setting it in place. I did it myself and though it turned out well, it would have been a lot easier with a second pair of hands. Even though it's aluminum, it gets a little heavy and unwieldy when I'm bent over trying to set it down in place without messing it up.

 

not trying to get into a pissin' contest with anyone, but dimpling the china walls, and now i'm reading the underside of the intake, IS just a waste of time - an old wives tale, or some sort of urban legend. not sure how it got started, but it's been around for years, most likely, left over from the "china wall gasket" days. granted, it probably doesn't hurt anything, but it doesn't alieve the fact that it's still a waste of time. the key when using the right stuff or RTV is to have BOTH, mating surfaces squeaky clean, and I mean SQUEAKY clean using some sort of cleaning solvent. RTV works just fine if you let it cure properly - 24 HOURS! engine heat does not "fast cure" this stuff. the real advantage with the right stuff is the faster cure time. I personally use RTV, cause I work real slow - thus my RTV has plenty of time to cure. in a nutshell, squeaky clean and pay close attention to the cylinder head/china wall corners, use plenty of product and apply it about 1/2 inch up on the intake manifold gasket surface. set the intake straight down with minimal alignment giggle, sealant on hardware, and torque to spec (i always use a 3-step torque procedure). let cure. the last time I had an intake manifold/china wall leak was from using a gasket, and that's been a long time ago. BTW, that's my procedure and my 2-cents....

one final question to the pro-dimpling folks - what is the technical advantage to dimpling the china walls or for that fact, any gasket surface?

 

But you are trying to get into a "pissin contest". One final question what is the technical disadvantage of dimpling?

 

no on the pissin contest - you can do pretty much what you want - I could care less, that's why I said, my 2-cents -

just trying to find out why people dimple china walls. if there's no advantage or DISADVANTAGE, then why do it? BTW, using "disadvantage" is a clever way to put a spin on the topic without answering the question. have a good one....

 

Not spinning at all - you're previous post just stated an opinion with no backup of facts to support your position so I just turned it around.

 

wasn't aware I had to support an "opinion" with facts. how can anyone have supporting facts on something that has neither an advantage or disadvantage? that doesn't even make sense. I would continue this "pissin' contest" with you, but it's really not worth the effort. BTW, it's "your" but i'm sure you know that -

 

I used Ultra Black RTV on my china walls. I think it is made by Permatex......and i have done the dimpling of the wall and the bottom of the intakes. Gives more surface area for the RTV to adhere to. Just let it set for a few long minutes, and let it all cure for a day or 2 before starting. Never had any problems, on 2 different TPI engines.....

 

I use GM engine sealant. It has worked great for me. 👍

 

The idea behind it is that the RTV will grab better. Rather than a smooth surface where the RTV can move around, the dimples mean that some RTV is "below the surface" making it more difficult for it to squeeze out or for oil to squeeze under or over (in the case of the dimples being on the intake).

Personally....I've never dimpled. I swear by "The Right Stuff". My '96 was over 500hp, saw a LOT of track days (road course so hours of sustained high rpm) and the intake never leaked.

If someone wants to do it, so be it.

 

Joe, like I mentioned above, I even go one step farther then dimpling the china walls and the intake...I drilled 1/8th" holes all along the front and back walls and intake..What this does is allows the sealant to push down into the holes when the intake is set, this gives the sealant anchor points all along the china wall so the sealant can not be pushed or moved out of place...Is this neccesary for a car on the street? "Maybe not" , but it is used extensively on the track cars..Pete Kane, the guy that built my 383 motor is the one that suggested doing this on my engine , so I have done it to all my engines when I have to remove the intakes...Why not do it, it only takes a few minites, and makes the install just a little bit more secure.There are many things we do on our cars that are just done to make them more resistant to failure...For me, this is one of those things........WW

 

- if people have the idea that it's beneficial, so be it. if it makes one feel good about their build or rebuild, I say go for it. if it gives one, peace of mind, that's good! knock yourself out! however, when you say "...the RTV can move around," well, why will it move around? if you're saying oil can seep past it, then it's not an efficient or effective sealant. awhile back, Cliff Harris posted a very good pic -

- it shows how the RTV forms a bead on both sides of the seal. if by some chance the seal was "floating," the bead or beads would tend to hold it in place. as far as oil seeping over or under the seal, well, a few dimples is not going to stop anything. if oil could seep around this stuff, it would tend to make the use of RTV as a gasket maker pretty useless. if RTV is applied to, two clean, dry, mating surfaces, in sufficient quantities, it will not move, stick like glue, and by the nature of this stuff, impervious to oil, thus making it an effective seal.

show me one factory service manual, tech manual, shop manual, application or usage manual, technical data sheet, or anything on the use of RTV as a sealant, that has a dimpling step in the procedure. if dimpling had any validity, it should be referenced somewhere.

this will be my last post on the subject - that should make some of you happy - - posting on some of these threads is like beating your head against a wall - it feels so good when you quit!