leadfoot4

iTrader: (1)

I just received my new issue of 'Super Chevy' magazine, which as many know, rolled GM High Tech performance into it. Anyway, they're doing an LT1 build, and showed something I haven't seen in a long time...a gasket at the ends of the block, where the intake manifold interfaces with it, instead of the now "normal" bead of RTV.

Anybody have any recent experience with this? Think it would work better than just the RTV?

Kevin Blown 95 TA

Those of us that don't want it to leak use the Right Stuff on the china walls. No crappy SBC gaskets. Those of us that really don't want it to leak make a groove in the ends of the block or manifold or both to help hold the gasket stuff in there.

93M6Formula

I've honestly never had mine leak. I just use a about a 3/16" tall bead on the china wall and call it good. The biggest key is setting the intake straight down on the motor, sliding it back and forth can move the silicone out of place.

leadfoot4

iTrader: (1)

I'm just curious, as I was thinking that this was some new and improved gasket......

I'm old enough to remember when there was indeed a gasket used there, BEFORE the invention of RTV. Then RTV became the widely accepted sealant for that location, and the gaskets went away. I've been using RTV for years.

SS RRR

iTrader: (2)

Meh, I've never found it necessary to deface the block to keep the sealant in place. A thick bead, setting the manifold on straight and letting sealant cure for a good 24 hours before any startup and checking the torque on the manifold bolts after a weeks worth of heat cycles has always worked.

myltwon

iTrader: (1)

I've reinstalled the intake plenty of times and the biggest determining factor for proper sealing has been letting the RTV cure for me. Only time(s) it ever leaked was from not waiting long enough to run the motor

leadfoot4

iTrader: (1)

That's most likely why the dealer had to fix mine twice, under warranty. The first time, I dropped off the car after work, one day, and they called me before I left work, telling me the car was ready. They couldn't have let the RTV set more than an hour, or so....

Catmaigne

iTrader: (6)

I've always used The Right Stuff. Make sure the surface is clean and dry, then lay a bead down the ends of the block. Let it sit for a minute or two to skin over and then plop the intake down. Seat it first, then torque the bolts to spec with the proper sequence. Permatex says it cures immediately but I always give it at least an hour. 0 leaks.

Never had good luck with regular black RTV. Stuff is garbage.

camar0corey

iTrader: (22)

I've never had any issues and I usually just use the permatex black rtv. Sometimes the tube of stuff that comes with the gasket set if I don't have a large tube of the permatex laying around.

Same deal though, I usually let it sit over night before I fire the car up. When I do a water pump on these cars also, I'll wait at least 4 hours before startup and overnight if I have the time.

SS RRR

iTrader: (2)

Ultra Black? When my **** is running that's how it's held together.

superspirit

Another vote for Ultra Black, that's all I ever use. the key is to clean both surfaces with brake cleaner and apply a skim coat on each surface and rub it in with your fingers. then apply the bead and drop the intake in place. as a tech I've used this method for over 20 years and never had any recheck's for leaks.