gasket or no gasket? SBC question

I'm replacing the intake gasket on my 350 Chevy and I'm torn between using the rear rubber gasket or not using it. It's weird, but my Indiana friends say not to use it, while the Illinois boys say I should. What says the HAMB?

The IN argument is that the replacement gaskets leak and you're better off with a big fat, glob of a line of RTV. The IL argument is that you need a gasket, the kit comes with one for a reason, so use it.

Both claim 100% success with their method, and failure with the other method.

 

Listen to your friends fron Indiana. Throw the end seals away and use a bead of RTV.

 

Here at the dealership, the trained GM monkeys that we call technicians just use RTV as a front and rear intake seal.

 

throw those gaskets away and use RTV , intake gaskets for the newer chevy engines do not even come with the end gaskets, they just come with a small tube of RTV and the instructions tell you to run a bead of RTV .

 

Back in the mid 90's, I worked heavy line at a Chevy dealership. GM published statistics about this very subject. It was something like 80 percent decreased warranty oil leaks when the quit using the end gaskets. Use the silicone only.

 

I say get new friends...

I still prefer the seals with a dab of silly cone at the corners where the cork meets the gasket. One of my good friends uses silicone for everything.

 

I used them with the dark grey permatex (that never really hardens) in the corners where it's most likely to leak. Hasn't leaked yet.

 

If it's a stock intake, nothing on the engine has been milled, and you like making things complicated, use the end gaskets. Othewise just run a bead of silicone...especially with an aftermarket intake or milled heads/decked block.

 

Ah, no consensus on the HAMB either.

I should've mentioned that it's a stock '78 350, but has a Edelbrock Performer intake.

If I don't use the gaskets, should I let the bead of RTV set up first, or just drop the intake on right away?

I have orange high temp stuff. Should I use the silver instead?

Sorry Mike, I keep trying, but they keep following me.

 

I put the intake on right away, I've seen other guys let it set up a bit. Make sure it's thick enough and goes a tad past the end of the surface on the block.

Toss the orange, get black, it looks better

 

Silocone only

 

AWW... get the blue goo. Nothing makes an engine look better than blue goo squeezed out of every gasketed joint. Unless you can peel off a half a pound of the stuff when you're done, you haven't used enough of it!

 

We just put an SBC together for Faye and did not use gaskets in the front or back, just the goopy stuff.

Stacey

 

RTV only with aftermarket intake. On a few non-chevy engines I have had, I fought vacuum leaks because of those stupid end seals.

 

if you ever get any of that **** in your oil you will never use it again. I use the gaskets and put some sealant on the corners,been doin that for ever.

 

I haven't used a gasket in 20 years, and haven't had a leak since the last time I used a gasket! Don't use any of that colored **** you buy from Auto Zone, I have torn apart too many engines that have an oil pump pick-up screen full of it. I always use G.E., Dow Corning, silicone, like a tube you can put in a calk gun. Make damn sure that you wipe the block and the mating surface on the intake with laquer thinner and set it down with the RTV wet. Make sure the bead is think enough to fill the gap but don't get carried away. After it dries overnight you can trim off the squeeze-out, because if you plan to paint the engine, paint won't stick to the RTV.

 

That would be my answer as well.

I always use the end seals, with a dab of black RTV where they meet the intake gaskets at the corners, and a THIN film helping to hold them in place. If you use QUALITY intake gaskets such as Fel-Pro, the end seals won't go anywhere using this method.

The only time the end seals might be an issue is with the cheapie intake gasket sets that just give you a flat piece of cork cut to the squiggly shape of the ends with no tangs or nubs to hold them in place.

But...if your heads and block have been resurfaced or milled, I would recommend a neat bead of GOOD quality black RTV.

 

I was a line technition for 25 years and the best RTV I've used was from Toyota. 'Form in place gasket' I used it on everything. It's the best stuff I've tried. Not cheap but it won't leak.

 

Ive had great success with using this Fel-Pro gasket.It comes with embossing around all the ports & good cork end-rail seals.
I usually pucker the end-rails on the block with a centerpunch,& also the bottom side of intake manifold.
Make sure the block end-rails are clean & dry(Laquer thinner).
The cork seals have sticky backs on them.
Use Gaskacinch on the intake gaskets to hold em in place on the heads,& just stick the cork ends to the block.A thin film of white grease on the face of the gasket where it meets the manifold doesn't hurt either.
A small dab of HighTemp(red) silicone in the corners,& you're done.Ive pulled the manifold at least 3 times using the same gaskets.
Re-torque the intake after you warm the motor.
My 2cents.
Fel-Pro part # is 1205

 

I've always used rubbers and have never had a leaker yet...................Oh, we are talking intakes here.....Yeah , rubber with a dab in the corners.

 

Dump the front and rear gaskets and use the RTV and you will have no regrets.

 

i 've done it both ways , and never had a leak. if i use the end seals , i glue them down with gasket ADHESIVE first , then let them dry before ***mebly

 

I use adhesive only.

You can't just say "silly-cone" and know it's going to work.

Different adhesives are rated for different max thicknesses.

I knwo the **** GM uses is similar if not the same to the dark grey Permatex listed above.

put you runner gaskets on dry, set the intake on, push down and measure the gap.

Get on the web-site and make sure the product you want to use is rated for that much gap.

Pretty sure Permatex has all this info on theirs. It's been a while since I worried about it because it seemed the grey Perma-tex will take care of all I ever worried about.

I also seem to recall that the blue is not recommended as a gap filler as it was designed to be a gasket "dressing". I have seen the blue blow out of the are you speak of. It's what sent me in search of all I just told you.

Place it wet so it will adhere to the intake.

 

I used that set a few weeks ago on the new SBC in my daily driver. I have used RTV in the past, but I decided to give them a try. I liked the way they are held in place by the adhesive backing. I'll probably buy the same set next time.

Slonaker

 

I used a FelPro gasket set with the RUBBER ends and had no vacuum leaks and this is a aftermarket intake. I used a thin layer of orange RTV on both sides of all the gaskets and it was OK, but I keep hearing that I shouldn't use the ends that's why I asked

 

to be perfectly honest, there is no right answer here (or really no wrong one)

the rubber sometimes leaks due to the fact that the block usually gets a die grinder taken to it to remove the old gasket which creates tiny little "ditches" in the metal and the rubber does not get into them. the cork gaskets work okay, but you should "dry fit" the intake and try to slide them in or out. if they don't have much grip, chunk 'em and use silicone.

the whole "rtv only" thing is a by-product of milling heads and intakes. you mill the heads a bunch, have the intake cut to match and presto! the end seals no longer fit.

but yeah, they all work.if you ain't leakin oil on a chevy intake, it probably needs a quart,anyway.

 

On later model GM engines they only used the sealer on the ends no gaskets at all.

 

For whatever it's worth, I'm NOT using any more of those gaskets! Not even if there made by Felpro! I'm "tubing" my tri-power intake with RTV on the 283 I'm prepping for my next build! I'm sick of the leaks, and apparently not smart enough to avoid the problem! IMO, the black color is the best choice! Good Luck Dude!



No more three on the tree, out on a limb!

 

We just went through this a week or two ago:

http://www.jalopyjournal.com/forum/showthread.php?t=92879

For my money, you should stay away from silicone only unless severe milling renders your cork unusable...but that's just me.

 

.....silicone.......just like my girlfriends ***s