moehorsepower

iTrader: (3)

Always remember to let the RTV "Skin" over first, a lot put the RTV then immediately put the intake on and it either smears or will just push out leaving small voids when torquing down the manifold, I did this one time on my 95 and it never leaked again..

aroberson77

Good point, that should always be done when using RTV.

BALLSS

Few tips I follow and have not had any leaks after are:

1. Beyond cleaning all the old gasket material & RTV off, wipe block & intake mating surfaces liberally with acetone

2. Use FelPro "printo" type intake gaskets

3. Use Permatex Black Ultra RTV 3/8" bead across front & rear china walls that go up onto the heads 1". Let RTV skim over for about 15 min

4. have threaded studs about 3" long installed front & rear hole on one side of the block. You use these short studs to line up intake and drop it dead nuts in place. Remove the 2 short studs and install the intake bolts. Pieces of wood dowel would also work as guides.

5. Torque intake bolts per FSM order/TQ

Kevin97ss

Can't say I concur with that method. The "skin" cannot bond with the surface as well as it does fluid.

Smearing is a faulty install technique. If done correctly you should be able to "read the squish" and know its right. It will almost look like a good weld, perfect continuity and evenness with no dripping excess or burst air pockets.

moehorsepower

iTrader: (3)

Well I can tell you that from the engines I have built for years and years, big blocks, small blocks, I have used this method and have Never, had a leak, where as I have seen Many where they installed the RTV then immediately installed the intake and later had a leak due to a void, or where it dripped into the valley..

The "skin" cannot bond with the surface as well as it does fluid.

If the skin cannot bond with the surface then hows does gaskets bond? they are dry not fluid like material...

SS RRR

iTrader: (2)

IMO the most important step out of all of them is to let the sealant cure for 24 hours before starting the engine. Even more time in cooler temperatures.

moehorsepower

iTrader: (3)

Yes, thats the most important step.

Kevin97ss

I can agree with a fellow Jackstandicandian as well as moe that cure time is crucial before returning to service.

Moe, if you remember the days of "the great wall of silicone", true you had no choice but to let it skin. The gaps on an LT1 though, being ~1/4 inch....Oh, and that's why were having a discussion about silicone...cause the gasket didn't bond

moehorsepower

iTrader: (3)

Yup, I think back then people were using both the gasket and putting silicone and it would push the rubber gasket out of place..

SS RRR

iTrader: (2)

Just, whomever reads this who is doing research, if you see posts which state it's a good idea to dimple the block or take sand paper and "scuff up" the intake/block surfaces for sealant to "bond more betters..." and to keep the sealant in place, don't read any further. All you are doing is adding channels for oil to get through and out. Leave the surfaces the way they are. There is enough rough material already there for the sealant to bond just fine.

Kevin97ss

... We had more success with the cork and silicone sandwich when running the Buick heads...still sucked though.