Im about to re do my intake gasket since it leak from the back

That was my first try and by the result i think that i didnt do it correctly so a couple of questions:

-Can i damage something if i make a really large bead of rtv(dont wanna do it a 3rd time)?I think that it leaks from the back because i didnt put enough of it...

-After applying it do i need to wait a couple of minutes to let the rtv dry a little so it would be less liquid?

-Do i need to apply some rtv on the intake gasket(both side) to prevent leaks?

-Wich rtv should i use?(black/red/copper/name it

Thanks

 

No, don't put RTV on the sides of the gasket.

 

To be honest, you need to let the intake sealant dry longer. Some say 24hrs just to be safe. It makes sense since there is some kind of pressure under the intake. Get the High temp rtv. Some have used something else called great stuff or right stuff not sure, with success.

It is very important to drop the intake down correctly when placing it on your rtv beads(front and back). Some use guides ( is saw a pencil used in a guide somwhere) where the bolt holes are on the block.

Hope this info helps. Just do this job on a weekend where you can get away with letting it dry for a while.

 

I've done my intake manifold twice successfully. To do it right, buy the copper hi temp stuff - Permatex brand. My Haynes manual also recommends putting a very small bead of silicone around the port openings on the gaskets, I can't remember which side now. If you don't already have one, buy a Haynes manual.

Just put a bead of silicone about the width of the sealing surface on the front and back of the engine at the sealing areas. Run the bead partially up on the heads. At the back of the engine, you have a fitting to contend with, I think the EGR?, make sure you have a continuos bead of silicone from left to right. Also, cleanliness is next to godliness! Make sure the surfaces are completely clean on both the engine and manifold, wipe them with alcohol before applying any silicone or gaskets. Spray the intake manifold with throttle body cleaner or something to remove all the oil that's inside and let it dry. I have used both factory and Fel-Pro gaskets with success.

Don't wait for the silicone to dry before putting the manifold on. Put it on immediately, making sure everything is square. Put some silicone on the bolt threads as well, then torque them down according to the sequence in the Haynes manual. I always wait at least 24 hours before starting the engine to let the silicone dry. Good luck.

 

I used Permatex copper. I also put a little bit on the gaskets. I let it set for about 48 hours before starting the car. It didn't leak, but I haven't really driven the car, so I can't say how it's holding up. We also torqued the bolts to 38 lbs., as opposed to 35. I hope that's not going to cause problems.

 

Felpros instructions for the gasket specifically say to NOT apply RTV to their gasket. Apply a consistent bead on the front and rear of the clean block. Once the RTV is applied, carefuly lower the intake such that you will not have to reposition it. Another nice trick is to run your finger along the edge where the intake mates to the block, once the intake is seated. Not only will this rid of access RTV, but push RTV into any voids you may have missed.

 

I put the intake on while the silicone is wet, so it sticks to both sides well. But I don't tighten it down, just start all the bolts. Then once it's dry the next day, tighten the bolts and it compresses the silicone seal.

 

Interesting. So you get a good seal this way? I might try that next time.

 

I've done probably 7 or 8 LT1 intakes over the years due to different setups, different cars, etc, and I've never had a single one leak on me.

I've used black RTV, grey RTV, copper RTV, even the stuff that FelPro includes in their kit.

I make sure the surface is nice and clean, lay a rope bead along the block edge and about 1/2" up the head near where the gasket ends (it will overlap a bit). I let the RTV set for about 5 minutes.

I use a pencil snapped in half in each corner of the intake bolt holes to set the intake down flat after the 5 minutes are up. I tighten all the bolts down immediately to spec.

I then wait overnight before starting up the car or 24 hours if I can.

 

Never done intake on an LT1, but the intakes that I have done like GMs v-6s from 3100 to the 4.3or some thing like that, smear some silicon on the gasket to keep it on place, then for front and back, make a nice thick bead of silicon overlaping the the gaskets a little bit, so you get a good seal between the gasket and the silicon.

 

No need to smear silicon on LT1 gaskets, they (the gaskets) come with little plastic locaters that fit into the head.

 

LT1 gaskets have tabs that hold them in place.

OOOPS, a little late.

 

I recommend going to your local GM dealer and picking up GMS RTV. The tube will run you around $13. This is the only stuff I will use on any engine. If you cannot make it to your chevy dealer go with Permatex Right Stuff.

These recommendations are coming from years of experience!

 

I tend to use "the right stuff" for my end seals. I run about a 3/8" bead acrossed the rail even up onto the head where the intake gasket lays a bit. Then I sit the gaskets on and press them into that. I also like to put a little bit of gasket sealer or weather strip adhesive around the ports not alot but a line around all intake ports especially the bottom i do this to both sides and i never have problems with sucking oil. When I put the intake on i screw a couple of short pieces of threaded rod into one head at the ends and slip the intake onto those to get it flat and even. The rest is just tq'ing it down. After that heat cycle it a time or two and tighten the bolts again. Then drive it a couple of weaks and hit em again, after that it should be tight but i still check periodicly.

 

forgot to tell you, get the block and intake perfectly clean. Once this is done apply a steady bead across the block and up onto the intake gasket. If you use GMS assemble in about 5 minutes. If you use right stuff assemble right away. Use blue loctite and torque the intake to 25ft.lbs. Change your oil and try to wait 24 hrs. before you start you engine. If you are careful it will not leak.