since im repulling my intake manifold for the third time due to wrong silicon (i used gasket maker - copper) whats the real stuff im supposed to use that seals the china walls and the intake manifold? is it black RTV? and should i let it the one hour to let it dry? or even the fulll 24 hours to let it cure?

 

Black. For something like the intake, i'd let it cure 24 hours. The next day run the car as normal, let it cool off, then check the torque on the bolts, tighten any that came loose from the heat.

 

Don't use the "china walls.

The trick is:

Clean everything immaculately clean with lacquer thinner. Make your last pass with a clean towel with fresh thinner. Not gasoline, not diesel, not mineral spirits, not spray carb cleaner, not denatured alcohol, not generic "paint thinner"; use lacquer thinner. The only acceptable substitutes would be acetone, toluene or methyl ethyl ketone. Make sure it's absolutely spotlessly perfectly immaculately clean: any dirt or oil or residue will cause leaks.

Lay the manifold on the engine dry. Put couple of the bolts hand tight in each side. Scribe the block across the back and front of the manifold, holding the scribe tight against the manifold. Smear a smear of silicone across the block from the scribe line about ½" inward, and up the front and rear of the heads, making especially sure to get it down into the corners. Smear a thin smear on the intake gasket, both sides, around the water ports only. Lay the manifolds in place, tape them with clear mylar box tape, and smear them at the corners about ¾" up their edge. Lay about a ¼" tall bead of silicone all the way across the surfaces of the block, just to the inside of the scribe line; let it taper out to nothing about ¾" up the surface of the heads. Let it sit for about 30 minutes. Smear a smear of silicone on the mating surfaces of the intake, and about ¾" up the front and rear ends. Set the manifold straight down onto the block; DO NOT put it in the wrong place and then slide it to where it goes, you will create leaks. Put the bolts in using Loctite PST (thread sealer with Teflon) on the threads and under the bolt heads. Tighten the bolts to about 8-10 ft-lbs. Wait 10 minutes. Torque the bolts to about 30-35 ft-lbs; tighten the center ones first, then the outer ones. Go over the whole intake 3 or 4 times until they don't turn any more to get them to 35 ft-lbs. Don't touch the bead of sealer. It should make a pooched out kind of strip uniformly all along the intake. Just leave it like that. Wait about 2-3 hours before you start the motor up, for the silicone to harden some more. If it's below 70 degrees when you do it, wait about one more hour for every 10 degrees below 70.

Use the Ultra whatever silicone. It doesn't matter which color you use. If your motor is black, use black; if it's orange, use copper. If it's blue use blue. If your intake is bare and you want it invisible, use gray.

 

thanks, i sent my mom to the store to purchase me some ULTRA black so basically, i clean up the china walls and intake real well.. then apply a .25" bead of silicone over the china walls and around the intake bores on the gasket itself, then lay the intake down, bolt it to 35lbs, let it sit an hour to cure?

 

don't use the china walls, just use silicone like RB suggested.

 

I was reading in some car mag that 100% silicone is actually better since RTV is mainly silicone and makes sense to use it pure. Anyone ever heard of doing this? I was thinking about trying it myself.

 

what do u mean dont use the china walls? i thought that was just the term used to the front and back of the block? if its some kind of gasket, then i didnt use it, i only used a nice .25" bead of ultra black silicone... the manifold has been layed down and torqued.. i am now letting it dry, i will elt you all know how it is afterwards.

 

ok after an hour now, is it safe to set the timing and take it on a test drive to warm it up and retorque the bolts?

 

If I were in your shoes, I wouldn't take the chance and just let it cure for 24 hours.

That is just me.

 

i use the china walls and never had a leak, if the engine is out of the car. if it's in the car i use ultracopper rtv and never had a leak. i think any rtv would work for the intake. i'd have to look at waht permatex has to say to be sure.

 

I believe RTV Black, RTV Grey, or RTV Copper should be up to the task. I used RTV Black and did not use China wall gaskets and did not have a problem.

#1) Clean,clean,clean.
#2) Lay bead and go over the edges on the sides.
#3) Torque it down following the specs going a little at a time.

If you used RTV Copper, it should have held (unless I'm mistaken). I'm thinking you must have done something else wrong. I would try to figure out what that is.

 

it was not rtv, it was just a copper "gasket maker"

 

hey travis get it running yet

 

Travis:

Aren't they all RTV's considered gasket makers?

http://www.permatex.com/products/pro...=Gasket+Makers

I thought Ultra Copper was supposed to be better than Ultra Black for everything.

I know I find this confusing. Sometimes they say to use RTV as a sealer, then sometimes as a gasket, etc... Sometimes I just put it on and hope it works! So, I know what your fighting against! :-)

 

RTV = "Room Temperature Vulcanizing", meaning it will cure at room temperature without elavated heat or pressure.

The typical RTV is a silicone product. Some add other things, some don't.

"Gasket Maker" is a Permatex buzz-term.

(You "sent" your mom??? )

 

Yeah, he sent his Mom!

Just giving you a hard time 57Kid! I've been there! It was quite a while ago though!!!!

Still, you don't have to put it on the message board. You could have been more creative and said... I sent my parts runner to pick up some RTV Black for me! (Then typically that would translate to your girlfriend or something!!!) LOL!

 

i dont htink it was ultra anything.. just some copper gasket maker .. same comapny that makes black rtv sealer. when i took off the manifold again, the crap was saturated with oil and chunky.. not what its supposed to be, so i cleaned it all up, applied the black rtv. and now im home from work.. leak free

so a job well done and thanks for your advice guys.

really cool part is.. at mid rpm, half throttle, theirs a whistling sound of the intake

 

 

Good job on getting the intake to seal.

Whistling?? Sounds like a vacuum leak I had on my TPI setup. I had a bad leak at the trottlebody-plenum joint that would whistle. It gave it a jet engine type sound. Are you sure your TBI is tight and that you don't have any other vacuum leaks?

You better investigate some more!

 

well all three times i installed my new intake manifold and test drove it, the same sound was their. i seriously would have no idea to check, all the tubes running to my TBI is plugged in all the way and stuff like the brake booster is plugged in as well.

 

The chunkyness may be due to the fact that the RTV wasnt given enough time to cure. you should give it at the very least overnight or if its really cold out several days to cure before use. Once cured the RTV should be pretty much impervious to oil.

 

dp...