For those who have installed lower intakes - Silicone or block end gaskets?

[5spd GT]

Highly doubt the sanding for cleanup would cause any issue..I'm sticking with the idea that the sealant simply did not cure properly last time.

Well we let the RTV sit for 10 minutes to skim over and then installed the intake (with all the little tricks - dowels/gasket held in place, etc) and put the intake on...we then snugged it down a bit and then came back the next day (almost 24 hours later) and finished it up...did fine until a few months ago is when I seen the very first signs of it...

 

[DMAN302]

Retorque after a few miles..mine went from 18ft lbs to under 10flt lbs in only 100 miles.

 

[Daggar]

Highly doubt the sanding for cleanup would cause any issue..I'm sticking with the idea that the sealant simply did not cure properly last time.

You may also have just gotten a bad tube.

 

[5spd GT]

Retorque after a few miles..mine went from 18ft lbs to under 10flt lbs in only 100 miles.

Yeah I retorqued them when I redid the valve adjustments as well...they were loose (like they should have been) and I checked them a couple weeks later after the initial "retorque" and they were fine...and checked them a couple weeks ago (9 months later) and they were tight like they should be...

 

[Grn92LX]

I've done it both ways (cork ends and silicone) and never had a problem with either. The first time I used the cork then every time after that I used silicone. It doesn't matter what color as long as its 'ultra'. What I do is put a nice thick/neat bead across the block ends and a slight bit around the coolant ports on the gasket (both sides) and throw the lower on. No need to let it set, like 89sleeper said, let it bond to the manifold while its still 'wet'. I torque my lower to 22 ft/lbs I think. I go over the sequence many times.

 

[vristang]

The Fel-Pro intake gasket set I just put on my car included molded rubber end gaskets that are keyed onto the block and fit together with the intake -to-head gaskets. At first I was just going to lay a bead of RTV (which has worked well for me in the past) but I decided to put those rubber ends on instead. It hasn't leaked (granted, my car only has 6 miles on it since its been back together)

Do you know the Fel-Pro part number. I asked the parts guys at SCHMUCKS, but they are pretty easily confused without part numbers.

 

[5spd GT]

I also have some oil "lip" above my gaskets (underneath the valve covers) where it has very thinly seaped out...which I think is caused by the different lower intake gasket we used...it was thinner than the 1250 that I originally had...so I can't wait till I get some time to fix it...I love a "no leaker"

 

[jackchan]

a buddy and I owned a mustang shop locally back in around 97-98 and used both silicone and cork. I personally like the Black RTV silicone on both ends and cork or rubber on each side. I use 4 studs on each end (on the corners) and tighten it down. then install the bolts with correct torque sequence. Call me lucky but I havent had any leaks!

 

[vristang]

I stand behind the rubber end gaskets only because I tried silicone only, I tried the cork ones, I tried silicone w/ cork ones and I had problems w/ leaking all times. It could have been my prep/installation, but who really knows.

I would suggest the dowels to line the intake up. I got the rubber end seals that kinda have a "U" shape that sit over the block ends in a intake gasket kit I believe from auto-zone (I think I had to ask for the one w/ rubber ends) and I think you can get it from ford as well. I believe it's about $24-25. I think I put a little RTV on top of the rubber gaskets as well.

If you were to use the RTV only, I would let it set up for 10 min or something to kinda get set so it doesn't squish out all over the place.

Good Luck man.

Sorry, I missed this earlier
I will try Auto Zone, I think we have a couple around here
Thanks

 

[Mustang5L5]

When i have done intakes, i use all the gaskets as well as RTV. I use the Fel-pro kit.

At the four corners i use a big dab of RTV and run a thin bead below and on top of the end seal gaskets.

I've done 4-5 cars this way and no problems at all.

 

[5spd GT]

I got to looking (with what little visibility) there is and it appears the back RTV slid out somehow but how could that be possible. The "smashed" end is protruding...but the front doesn't look like that and it seeps some oil out in a very thin even amount...

 

[vristang]

I got to looking (with what little visibility) there is and it appears the back RTV slid out somehow but how could that be possible. The "smashed" end is protruding...but the front doesn't look like that and it seeps some oil out in a very thin even amount...

I looked a little closer at my Lightning intake when I pulled it and realized that the surface that the silicone would adhere to, is incredibly smooth. Very good machine work, but crappy for any type of adhesive. I will be scuffing that surface a little with some sand paper before the motor goes back together.