Don't use the gaskets. Just use RTV. Make sure you get RTV in the corner where the head, manifold and block come together. I use the ultra black RTV.

 

Make sure the surfaces are complete oil free before putting on the RTV.

 

I use a product called "The Right Stuff" and no cork or rubber seals. Expensive, but it works very well.

 

what color do you use, I have ultra grey because that said it was for intakes, would black work better?

 

Without the rubber seals in place, measure the gap between the China wall and intake. Make sure you're at least an 1/8" to 3/16", 1/4"?, higher than the gap size when applying the silicone.

Some say to let it skim over, but that makes zero sense to me.

 

me say to let it skim over, but that makes zero sense to me.

Decades ago we used red and let it skim over and leak city.
I have used Ultra black and Ultra grey and the right stuff and none of those leak.

Black is more pliable and grey is stiffer and Right stuff is like concrete.

Hard to remove an intake with the right stuff on the ends ..you must cut through it then remove intake.

Now the way I do the end seals.

Everything clean and dry and oil free.
Intake gaskets in place.
I tamp sealant into the very sides/corners where the head meets the block on the china wall.

Tamp it in that crevice with your finger and I run a tad bit up to the point on the intake gasket.
I then lay a bead of sealant along the wall tall enough to fill the gap and a tick more.

Immediately stick the intake manifold on.

DO NOT let it tack up or skim over.

If it does then it will not adhere well to the intake manifold. This will cause the top of the sealant to allow oil to pass between it and the intake.

Yea does not make any sense to let it skim over.

Ultra grey is my choice and I have used it instead of the front timing cover bottom rubber seal.
Yes you read that right.
It was my own vehicle and I wanted to experiment as that area has a small gap and I thought it would work and it did.
10's of thousands of miles and still not leaking.

Many newer vehicles use only Ultra grey or something close to it as a pan gasket.

 

I use the permatex black ultra. I put a little dab where the rubber end gaskets go into the notch on the head part of the gasket (sometimes I will take a punch and put "peen" marks/dimples on the surface of the block where the gasket goes to help keep it from sliding out.) Then I put the intake on and don't tighten the bolts more than lightly snug. I then run a bead of the ultra black across the back and front from head to head covering the gasket from intake to block. Smoothe it out, but make sure you leave enough material to bridge across the intake to block opening. After it cures I torque the intake bolts. If you need to, you can paint it after torquing. Works great so far and I also use the ultra black as a universal adhesive as it will seal and stick almost anything. Robot or human?

 

I do not start the engine for 24 hours after applying silicone.

I will also add this.
Buddy had the same issue as you and I went to see what the issue was.
It was his rear oil sending unit leaking where it screws into the block.

Another friend had a lot of oil all on the front of his sbc engine and thought his end seals were leaking.

It was that bolt hole that is used to access the fuel pump pushrod. There was no short 3/8" bolt in it.

 

When I installed the billet manifold on my car the gap between the manifold and block was about 3/8". It was more than I expected. I ran a fairly thick bead first and let it cure for 24 hours. Then I ran another bead on top of that so it would seal the manifold. It's been on there 2 years now without any leaks.

 

Thank you all for the advice, give me a few days to redo the intake, I will keep you all posted on how it goes

 

Get a can of red brakleen and use it to completely clean all the mating surfaces where the rtv will touch. This will ensure a clean, oil free, leak free bond.🤘 I saturate a rag and wipe everything down.

Ultra grey or ultra black are my top choices. Grey cures to be harder (smidge thicker) than black but still flexible, they both seal great when the surfaces are cleaned correctly.

 

Get a can of red brakleen and use it to completely clean all the mating surfaces where the rtv will touch. This will ensure a clean, oil free, leak free bond.🤘 I saturate a rag and wipe everything down.

This is excellent advice and I will add before cleaning you should sand the mating surfaces. Just as in painting preparation is the most important part.

 

Permatex RTV Regular to Ultra instructions on the package clearly state to apply, immediately assemble finger tight, wait something like 1 hour, Torque to spec. Wait 24 hours before putting into service.
And more is not necessarily better. You don't want it gushing all over the place.
Many, many, many don't follow the directions and either have or don't have issues.

The Ultra line has better resistance levels and similar but slightly different instructions.

RTV is not to be used when gasoline is present.

If you need it to go into service sooner use Permatex The Right Stuff, 1 minute or 90 minute. Same as Ultra but has a fast cure agent in it according to Permatex.

Permatex has a guide on their website for the product you should use and they have a good Tech guy who will get back to you same day or within 24 hours. I have talked to Don several times.

 

Use any of the mention products, secret is to just tighten all intake bolts finger tight or no more than 1/2 turn after bolts seat. Let your sealer cure don't use full torque. What's happening your cranking down on your intake bolts and squeezing out the sealer your using. If you have the intake off drill small dimples on front and rear rails where intake meets China wall, help to hold sealer in place.

 

alright i just got done removing and reinstalling the intake, one observation i did make while pulling the intake off is that the intake came off really easily, that got me thinking the rtv did not adhere to the mating surfaces like they should, so i took a lot of time cleaning the surfaces, I also lightly scuffed each surface to give the rtv a little more to grab on to, then I took brake clean and wiped the surfaces until my cloth was completely clean after wiping it. I currently have it setting up for an hour before I can torque it down like it says on the instructions. Let me know if you see anything wrong in the process i used, because i can still take it apart at this point

 

Before you reinstall you may consider going along the china wall and putting dimples with a center punch. Both on block and manifold. Gives the sealent a place to bite and less likely to blow out.
I do a punch at each end and then every inch along the surface

If you blow up this pic some more you can see what I am talking about

 

Before you reinstall you may consider going along the china wall and putting dimples with a center punch.[/QUOTE]

Honestly with today's sealants\adhesives that old school trick really isn't necessary? How do you clean out the dimples when you pull the intake again? After first use they aren't very effective?

 

Ok I finished torquing everything down and got everything back together now it is a waiting game, It is raining where i am so i cant test my work until tomorrow

 

Well I have been running and driving it for a little bit now and I have yet to see a leak so I think my issue is solved

 

I've never dimpled the walls and intake myself and never had an issue. Only RTV and done.

 

brake Klleen thoroughly, then RTV! PS I have seen dimpled walls before however, can't hurt.