Sealer on intake manifold

[Jt1776]

I'm installing my intake manifold on my rebuilt 350. Do I need to put gasket seal on the gasket. I hear yes and I hear no. Can someone help me out. Thanks

 

[Arkansas_V8]

I never have. I always use spray adhesive to keep all the gaskets in place though.

On the ends you do use RTV. Those cork gaskets dont work at all.

 

[WFO]

I never have. I always use spray adhesive to keep all the gaskets in place though.

On the ends you do use RTV. Those cork gaskets dont work at all.

Me too, except I do use a little sealant around the water passages.

 

[DoubleDingo]

I do the copper spray sealant on the side gaskets, and black silicone on the ends. Don't use the blue, black or gray is best the ends. I've used the blue and had oil leaks out the back. Sealed with black and no leaks.

 

[Arkansas_V8]

This stuff has never let me down. I highly recommend it.

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[Frankenchevy]

Dry fit the manifold with intake gaskets in place and check your gap at the China wall. Compare that gap to what your rtv says it’ll span. If the gap is too much, you’ll need the China wall gaskets plus rtv.

 

[K5_489]

My way for years has been to start with a good gasket, such as a Fel-Pro (doesn't have to be Fel-Pro, just avoid the bottom of the barrel parts store generics), and clean/chase the threads of the intake bolt holes to ensure they can be easily run down with fingers. Make sure your block and manifold are clean, and free of any major corrosion (especially with aluminum manifolds..major corrosion/pitting of the manifold can cause problems regardless of what gaskets or sealer you use).

Set the intake down without any gaskets or sealer in place, and finger tighten a couple bolts on either side. Check your distance between the block walls and front/rear of intake manifold. Barring any major milling of the intake/heads/block, this should be less than 1/4".

A thin film of RTV around the water jacket ports on both sides of the gasket, otherwise no sealers on the gaskets themselves. 1/4" bead of RTV on the front and rear walls, and just barely up on to the heads..kind of creating a "shelf support" for the gasket ends to sit on, and keep it aligned with the ports/bolt holes. Let it set up for 15 minutes or so. Set gaskets in place, making sure to have the bolt holes already lined up here (this is where that RTV "shelf" comes in handy)

Carefully set the intake straight down, avoiding as much movement as possible. Loosely seat the bolts down finger tight, and then walk away. Preferably for 24 hours (as this is the cure time of the RTV), but at least 8 hours/over night. This sets full contact across the block walls and the RTV, as well as between the RTV and manifold.

After the waiting period, come back and torque the intake bolts down to spec, in two stages - 20ft-lbs on round one, 30ft-lbs on round two. Fill 'er up with your coolant of choice, purge the air, and go!

Using this method, I've never had any gasket related leaks on a SBC or BBC intake. I've heard of guys using a ***** punch to "golf ball" the block walls and intake manifold, and I understand the thinking, but I've never needed to do it.

 

[Turbo4whl]

Me too, except I do use a little sealant around the water passages.

Use Fel-Pro Perma-torque gasket kit. I use a very thin coating of #2 Permatex around the coolant passages and the RTV on the ends as @K5_489 stated. I do torque immediately then wait for the sealants to cure before filling coolant.

 

[DoubleDingo]

@Turbo4whl I usually torque them down right away too, but I don't fill the engine with fluids until the next day.

 

[80BrownK10]

Use Fel-Pro Perma-torque gasket kit. I use a very thin coating of #2 Permatex around the coolant passages and the RTV on the ends as @K5_489 stated. I do torque immediately then wait for the sealants to cure before filling coolant.

Directions if you read the silicone say to do as 489 says. You have to wait for silicone to set up, then torque. If not your not compressimg it after it set up, your just squishing the silicone out of the gaps.

 

[DoubleDingo]

@Turbo4whl I usually torque them down right away too, but I don't fill the engine with fluids until the next day.

In my earlier response I hurriedly wrote it out not noticing that I forgot the "R" in torque. I just noticed it and corrected it prior to quoting it here, but check out what "TOQUE" is...lol...


toque
noun\ ˈtōk
, ˈt(y)ük \
Definition of toque
1 : a woman's small hat without a brim made in any of various soft close-fitting shapes
2 : tuque
3 : a tall brimless hat worn by a chef
— called also toque blanche

 

[DoubleDingo]

Directions if you read the silicone say to do as 489 says. You have to wait for silicone to set up, then torque. If not your not compressimg it after it set up, your just squishing the silicone out of the gaps.

Good stuff. I learn something each time I come on this site.

 

[idahovette]

All of this info is great ,BUT if you are working at a dealership or even just a generic shop you usually do not have the luxury of waiting for things to set up. Time is money and back in the day I guess we trusted ourselves and our gaskets more.

 

[bucket]

All of this info is great ,BUT if you are working at a dealership or even just a generic shop you usually do not have the luxury of waiting for things to set up. Time is money and back in the day I guess we trusted ourselves and our gaskets more.

Exactly.

I've never ever ever had time to sit around and wait for RTV to skin over, let alone wait till the next day to fill with fluids. Leaks and comebacks were never an issue for me. It always worked in the shop, and has always worked for me at home as well. A quality RTV will do it's job even in less than ideal conditions.

I'm sure following the instructions is technically best, but by no means is it absolutely necessary.

 

[80BrownK10]

Exactly.

I've never ever ever had time to sit around and wait for RTV to skin over, let alone wait till the next day to fill with fluids. Leaks and comebacks were never an issue for me. It always worked in the shop, and has always worked for me at home as well. A quality RTV will do it's job even in less than ideal conditions.

I'm sure following the instructions is technically best, but by no means is it absolutely necessary.

But most of us have these squares as toys. Unless your daily driving yours (you can still plan a repair for a day your don't go anywhere or a weekend) there should be no reason your that pressed for time. It is hard for me to wait on it though. If I can wait I do. And your correct, no shop waits over night or all working day to torque the bolts and then the next day to fill with fluids.