How do you seal your small block intake?

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rmchrgr

rmchrgr

Skate And Destroy
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This subject has been a touchy one for me. Last intake I did leaked. I have been trying to finish up my 416 build and have been stuck on two things - the intake and oil pan. I will address the intake here, I'll start another thread for the oil pan.

So again, the last intake I put on was a leaker. I had coolant coming from the left side passage and running down the front to the top of the timing cover and pooling there.

So being a little uneasy about this since my last time was a fail, I want to make sure I get this right before the motor goes in the car. What I am looking for is a DEFINITIVE method to prevent leaks.

Couple things first - cork gaskets or not? I mocked it up and saw that I can not really use the cork gaskets. I know most guys toss em' but I wanted to see if it was feasible to use them since I am not a big fan of using tons of silicone. Unfortunately with the cork end gaskets in place, the intake is way off on one side or the other, like almost an 1/8" between the intake mating surface and head which obviously won't work.

Conversely, there is a pretty big gap between the bottom of the intake and the block surface without the cork end gaskets, again, like an 1/8". I presume this is par for the course and where the silicone is used to make up the difference. So OK, we've established that I need to use the silicone which is fine.

The next concern is the corners where the intake gaskets meet the block. I believe my leak last time came from a lack of sealant around the coolant passage in the head. Again, I am not a huge fan of silicone so I may have not used enough. Exactly what is the best procedure here though? Do you put the silicone around the coolant passage and then lay the intake gasket on top of that? I am planning on using sticky tack stuff to set the gasket in place so it stays put so if I put that down first, then what happens with the silicone around the coolant passage? Do you smear inside the gasket around the port? This is the part that has my panties all in a bunch, just can't get a good grip on that part.

My last concern is the little tabs on the head gaskets. I know they are supposed to interlock into the cork end rails but if you're not using them, then what happens with those? Do you cut 'em off or leave 'em on buried by sealant? Seems like a perfect place for a leak to happen if you don't seal them up perfectly. And then, how far up the head does your sealant go? Does it go on top of the intake gasket or smear it underneath?

When I was working on engines at the dealership, we would smear the gray stuff pretty good from the point where the head meets the block. We'd put a big bead in the corner then smear upwards. I don't recall how it worked with the intake gasket though.

Sorry to split hairs but I need straight forward instruction. I tend to overthink this crap and need to keep it simple. Pics would be super helpful as well.

BTW, I have "The Right Stuff" that comes in the Cheeze Whiz can or Ultra Black.

Here are some pics. First is the intake installed on my previous motor that leaked, then where I am at now and my areas of concern. Thanks for any input.
 

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so - I just took the top off of my 360. There were no leaks from the intake anywhere. The previous builder had used a set of thicker intake gaskets that did not have the port seals and a thin bead of sealant on the head side only. Those tabs were still there, they had some sealant under them. The end gaskets were not used on either end - just a copious amount of orange RTV - it filled the gaps to overflowing - it looked sloppy but absolutely worked 100%. The intake is a Victor series.. though I doubt this makes too much difference. I'll be doing this too fairly soon - gonna keep an eye on this thread.
 
In the second picture from the bottom It looks kike you have the alignment pin still in the block. If it is, you HAVE to remove it, or them, there are two of them one in the front and one in the back. VERY important. Intake wont seat properly if you leave them in, after market intakes don't have the alignment hole in it.
 
i put rtv around the water ports on both sides of the gasket...i put Permatex high tack gasket sealer around the intake ports on both sides of the gasket...then I use RTV on the ends....
 
I use gaskacinch on both sides of the gaskets, both the composite and cork, then a bead of silicone in the corners. Been working for decades for me....
 
The little head gasket tabs get neatly trimmed.
the cork gaskets go in the trash
A generous, but not ridiculous bead of silicon takes their place.
The head to intake gaskets get coated with a gasket maker like indian head or permatex. NOT silicon.
 
In your top photo, right where the harness loom / hose? goes down past the corner (lower left) SOME intakes (Ed?) have a gap there in the corner of the head / intake / block. Make CERTAIN you get that full of RTV. Like others I don't use the end gaskets.

You have to be aware in this used day and age, of whether the block / heads have been milled, and that affects how the intake "sits." Evidently there is now a QC problem even with Ed and other 'murican intakes fitting correctly.
 
Thanks for the replies. Just to note - the block was decked. Heads are RHS/LAX which are Magnum based. Intake is an old Holley Strip Dominator.

On the dowels - I took the time to measure their height with a caliper and the alignment holes in the intake are deeper than the amount the dowels stick up. Seems like they would be OK to leave in? No big deal to remove them, just less work if not necessary.

So I am a little confused on the method you guys are using around the intake ports. Some say to put sticky stuff on BOTH sides of the gasket? Do I need to? Again, I was planning on spraying the back of the gasket with the red sticky crap, then laying it down in place so it does not move. My heads are ported so the gasket sits right on the edges of the ports. Do I need to put RTV around each port under AND on top of the gasket? What happens if you need to remove the intake? Seems like a big mess to clean up?

What is the preferred gunk to use on the end rails, Right Stuff or black RTV?
 
You might have well as asked what's a good oil or something, because you are going to get a hundred different oppinions.


Cork only works worth a crap with factory cast manifolds in my opinion, and even then I won't use them because they always end up seeping oil.

With those PrintOseal type gaskets tightening a little at a time on each bolt until it is all the way tight should work, but if it doesn't for you for whatever reason it is fine to put a thin layer of RTV on both sides of the intake gaskets anyway. (I do all the ports, water and intake both and on both sides of every intake gasket I use no matter who makes it or it's composition.)

On my own engine you can't see anything at the front and back of the intake, as a matter of fact it looks like there is nothing there to seal it because of where the RTV bead is.
After the gaskets are on I use the same red hi temp RTV about 3/8 thick bead on the top of the rail toward the inside of the block, from right in the corner where the heads meet the block and one continuous bead all the way across.

You have to watch the left front corner because the intake and the rail where the cork would have gone comes kinda close to not matching up, and if you set the intake on without the gaskets on you will see what I mean in that corner. (another reason to stay towards the inside edge of the rail with the sealant)

Once the RTV is on the rails I like to get that intake on there ASAP so the RTV doesn't skin over.
I like it to actually be stuck to it instead of the intake just sitting on top of the RTV

Put the intake on as straight down as you can, and do not try to reposition it once it's down any more than you have to. You don't want those silicone beads to be disturbed any more than is necessary. I watch a bolt hole for lining it up as I set it down on the engine.

Temporarily start two bolts, one on each side in the center of the intake to keep it lined up and add the rest.

Intake bolts can leak in two places (around the threads or at the head) so I like to get all the bolts in and tight, then take out one at a time for sealer.
I apply sealer to the threads AND at the bolt head/shoulder under the washer.
This seals both areas, and not sealing them when you first put them in keeps the RTV around the shoulders from getting all messed up when the bolts are being turned a lot pulling the intake down into place.

Any extra little bit of RTV showing gets wire brushed off. (toothbrush sized brush)

RTV is some real good stuff if used correctly, but using it correctly for the application seems to elude most people.
I see post ALL the time about thermostat housing and intake leaks and I just don't understand.
I don't use a gasket at all for thermostat housings and never have, also never have leaks no matter what housing I use.

Getting gobs of silicone everywhere is people using WAY more than is needed, and not cleaning any extra up right away.
On gaskets a thin film that you can almost not even see the color of it is plenty.
Like I said, big messes are people using WAY too much for the app.
 
67Dart273 said:
In your top photo, right where the harness loom / hose? goes down past the corner (lower left) SOME intakes (Ed?) have a gap there in the corner of the head / intake / block. Make CERTAIN you get that full of RTV. Like others I don't use the end gaskets.
Click to expand...

Those cork POS gaskets go in the trash. As another mentioned, I trim that head gasket tab off.

Look at the bottom of your intake in the corner Del wrote about. The sealing surface is back from the leading edge of your intake. This is the corner that usually gets people. I also clean off the surface, place intake down, outline end seal surface for applying silicone. Watch the pass front corner... :)
 
johnnymac2k6 said:
The little head gasket tabs get neatly trimmed.
the cork gaskets go in the trash
A generous, but not ridiculous bead of silicon takes their place.
The head to intake gaskets get coated with a gasket maker like indian head or permatex. NOT silicon.
Click to expand...

That's interesting because I only ever use RTV and NEVER have leaks
IMO that gasket maker stuff makes a much harder mess to clean next time.
 
Throw the cork end ones in the garbage...i prefer the "right stuff" put a nice fat bead on both ends of the block surface,then i install the intake gaskets putting a bead of "the right stuff" around each water jacket on the heads and lay a bead in each corner of the mounting surface too put the intake in place tighten it down..then i like to let it set up over night been doing it this way for years..as far as intake gaskets i like the ones Edelbrock sells..
 
I have always put some RTV around both sides of the coolant ports, and used the cork ends also with RTV on both ends and never had any leaks.
 
TrailBeast said:
That's interesting because I only ever use RTV and NEVER have leaks
IMO that gasket maker stuff makes a much harder mess to clean next time.
Click to expand...

IMO it makes a mess because it remains tacky and seals well because of this. I've seen RTV peel off like a sticker many times, Which to me says it wasn't adhered extremely well.
To each his own. You and a million other guys prefer RTV, i like my gasket maker. Just like alot of guys like the edelbrock gasket slime, and i truthfully dont care for it much.
po-tato
po-tat-o
:)
 
Throw away the cork end pieces and use a high quality silicone rtv. There will be a million arguments about what brand is best, but if you use a good quality name brand you will be fine.
 
Alright, here is my plan. I am taking most of the advice here, I am sorry if it seems like I might be ignoring any suggestions that work for you, just trying to make it as simple as possible.

1) Re-clean ALL surfaces with solvent, wipe down and dry with air. Might take a Scotch Brite pad to some of the spots that flash rusted too. In a nutshell, clean.

2) Trim the head gasket tabs

3) Put a bead of Ultra Black RTV in the corners where the head meets the block, smear with a finger up the side of the heads around the coolant passages.

- still not sure whether I need to smear the RTV on top of the gasket around the coolant passages after the gasket is laid down. Please advise on that.

- also still unclear as whether I need to smear some under the gasket around the intake ports. I don't think I need to do this but please advise either way.

4) Sticky-tack the intake gaskets on one side, lay over intake ports on heads.

- I have the print-o-seal gaskets, just don't think it's necessary to have the gaskets sticky on both sides. Please advise either way.

5) Run a bead of right stuff on the front and rear rails of the block.

6) install the intake, toque bolts in proper sequence.

7) it will be left to 'cure' for a while, not going to be starting it tomorrow.

Am I missing anything? Thanks again for all the help.
 
I do as others have stated with the RTV on the ends instead of cork. I don't put RTV around the coolant passages, I use copper coat spray on the entire side gaskets. Seals great, and they become tacky which helps them stay put during assembly

Joe
 
One of the important things you need to do if you use RTV is clean and wash the surface with brake cleaner or CRC. RTV doesn't stick to anything that has oil residue on it. I always clean the hell out of the mating surfaces then spay them with brake cleaner and scrub real good with rag soaked in RTV. If the metal surfaces are bone dry the RTV will stick real good. If let the RTV "set up" a little it will help retain it volume/height before you ease the intake onto the engine. It's better to use too much RTV than not enough.
JMO........
treblig
 
rmchrgr said:
- still not sure whether I need to smear the RTV on top of the gasket around the coolant passages after the gasket is laid down. Please advise on that.

- also still unclear as whether I need to smear some under the gasket around the intake ports. I don't think I need to do this but please advise either way.
Click to expand...

Do it now, or after it leaks you pick. :D

Ultra RTV blows in my opinion. (way too soft)
The hi temp I don't necessarily use because of the hi temp part but more for it's dried consistency.
The hi temp dries harder and is quite a bit tougher than regular or ultra. (a lot like Right Stuff)

Here's a mind blower for you that I never told anyone because I don't want their opinion.
I use the all metal intake gaskets with an aluminum intake and STILL don't have leaks.
One of reasons why is that the bolts line up with the holes better and the intake sits lower between the heads making that front and rear gap a lot smaller.
A thin film of RTV around all the ports of the heads and intake both and the metal gaskets only.
 
Yep I put rtv/right stuff around all ports on head before gasket goes on. Then I'll turn on some music roll a left hander and forget what the hell I was doing. Fire up fabo, another lh'er and look for help. Lol
 
Been there done that soooo many times, tried every 'new evolution'
of the best & greatest ... Sooo many wasted $$$$.

Sikaflex, aka the 'grey goo' !
Originally designed for Diesel app's ,--- huge temp changes--- huge vibration--
huge thermal expansion movement ---

Singular drawback, a 48 hr cure/service time.

P,s. DO NOT CHALLENGE THAT :)
 
I believe I have the same gasket set you do, with the cork gaskets that have the adhesive side on them. I used the cork end seals with plenty of silicone in the corners (Ultra Black) where the end seals and intake gaskets meet, and a smear of ultra black on the top surface. It has not leaked at all. The cork will compress as you tighten the intake. This is with an Edelbrock Super Victor EFI intake.

Previously, I had a performer RPM air gap manifold and basically the same thing was done. That never leaked either.

I also use Acetone to remove any oily residue and gasket material.

No RTV around the intake ports, the stuff really isn't made for gasoline compatibility. Plus, you bought the good gaskets with the raised sealing surfaces.
 
Straight from Felpro. I used the printoseal and followed instructions and no issues.
 

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