Need Advice on Intake Install (Poly 318)

[Evan Frucht]

I just removed and painted my intake and valve covers because they looked terrible and were leaking. I have some questions for some seasoned mechanics on what the best methods, or any tips and tricks that can be used, to install it again.

My main concern is the intake. I've never installed a large V8 intake like this. I have a good idea of the process but its more the details I don't want to get wrong.

I got a Felpro intake gasket set for my Poly 318 which includes: two metal compression side gaskets, two small rubber/neoprene gaskets (almost foam like) for front and back engine block, and a small tube of black RTV.

Should I even use the little rubber/foam pieces OR only use black RTV to seal the front and back--- or a combination such as using a bit of the RTV to glue those gaskets in place? I've watched some videos and read that people don't use those gaskets altogether (only RTV) because they don't like to stay put during install, and also leak over time due to shrinkage and cracking... has anyone experienced this who could give me advice?

Also seen a few videos where people put a small bead of silicon around the water passages.
Would that be a good idea or is it overkill, obviously I don't want the water passes to leak. I usually stay under the assumption that gaskets should not be combined with RTV but maybe this case is different.

Thanks in advance !

 

[khryslerkid]

I'm no "Poly" expert but I'd remove those pieces of material from the heads before you sit the manifold on!

(Sorry Evan, couldn't resist)

 

[threewood]

You can use those gaskets as is or seal them with Gaskacinch or Ultra Grey. The intake is wet so it has coolant passages so I would apply Ultra Grey around the passages.

Throw those foam end pieces away. Use Ultra Grey on the front and back. How big of a gap is there between the intac and block? Mine was about 3/16" so I filled it with Ultra Grey.

 

[khryslerkid]

On a serious note, I don't like silicone, it's for rain gutters. Call me old school but I prefer Permatex #2.

I'd use Copper Coat spray on the runner gaskets, a light spray on both sides of the end gaskets. Use a small bead of Permatex #2 around the water passages and in the corners where the gaskets meet. If the bolts go though into the valley, use #2 on the threads to keep oil from wicking up.

Set the manifold down squarely without moving it around. Install bolts at each corner loosely to square it up. Install the rest of the bolts loosely then snug them all down by crisscrossing. Then do your torque patteren and torque amount per your FSM.

 

[khryslerkid]

Those foam end gasket could deteriorate over time so what threewood said might be better.

 

[Evan Frucht]

You can use those gaskets as is or seal them with Gaskacinch or Ultra Grey. The intake is wet so it has coolant passages so I would apply Ultra Grey around the passages.

Throw those foam end pieces away. Use Ultra Grey on the front and back. How big of a gap is there between the intac and block? Mine was about 3/16" so I filled it with Ultra Grey.

Would ULTRA BLACK be fine to use instead of ULTRA GREY. I already have an unopened tube of the black stuff. It says "maximum oil and gas resistance" or something like that and goes to 500F

I guess I'm asking, in your opinion how similar are the two sealants and would the black work just as well here

 

[Evan Frucht]

I just read on the Permatex website Ultra Black and Ultra Grey BOTH have the suggested application "intake manifold end seals." I guess that leaves me more confused as to which is "best," lol!

also as a side note, what might be a good to way to block the heat crossover, I don't think I need it, the weather doesn't get too cold here... but I'm willing to hear an argument saying I should leave it alone

 

[69Bee]

Throw the "Ultra Black" in the garbage, and use the "Ultra Grey". The black and others dries to a slick rubber that can peel off easily. The Ultra Grey dries hard, and is a bitch to get off. I ONLY use Ultra Grey, and do NOT have leaks. Use brake kleen on a paper towel (not a shop towel), and wipe down the block, intake, and head surfaces to remove any oily residue, and apply the grey. Put a 1/4" bead on the front and rear rails, and a small bead around the water ports on the intake and head. Finish up with a small bead in the 4 manifold corners where the head-intake-block meet. Spray both sides of the metal gasket (intake ports and exhaust crossover only) with copper spray, wait a minute and then put the gaskets on the head. Then carefully drop the intake on and start bolts. I use ARP thread sealer on any bolts going to oil, and oil on any blind holes (possibly the 4 corners only). Follow the torque specs, and in the proper order, and tighten in 3 steps to bring the manifold home evenly.

 

[Don Frelier]

Clean the sides of the heads and intake with a razor or good sharp scraper. Then scrub with a good solvent lacquer thinner, brake cleaner, acetone work well. Do not use sandpaper!
A scrotchbrite pad is OK if you need it, but a coarse cloth usually does the job.
The Ultra Black should be good.
On the valve covers I use Permatex High Tack on the top of the gasket and valve cover side. It's like contact adhesive you paint it on, let it sit for 5-10 minutes then put the gasket in the cover. Good stuff.
On the valve covers check that the bolt holes are not caved inward toward the head.
If they are you can flip them over set a small socket below the hole and then tap with a ball peen hammer until they are flat again.
The engine looks real nice inside, good project.

 

[Evan Frucht]

ok good advice, ill take it!

also, my metal gasket pieces have little tabs that go into the bolt holes, basically that holds them in place. would the high tack be unnecessary then

 

[threewood]

I agree on the Ultra Grey being the best to use. I have never had an issue with it, whereas the blue and black look like bathtub caulk.

When I blocked my heat crossover on my poly. I used a 1/8" piece of steel with a step and a corrosponding step in the intake so it didn't fall through. A thin piece of sheetmetal under the gasket would work but was told it would fail at some point.

 

[khryslerkid]

I know on the Big Blocks, they offer intake gaskets that have the cross over holes blocked. Don't know about the Polys.

You don't have to use any sealer on the intake gaskets for the exception of around the coolant passages. I like to just for piece of mind.

 

[threewood]

ok good advice, ill take it!

also, my metal gasket pieces have little tabs that go into the bolt holes, basically that holds them in place. would the high tack be unnecessary then

I like it around the ports for that extra bit of sealing if the head/intake surface isnt quite perfect and it doesn't add thickness.

 

[Evan Frucht]

Clean the sides of the heads and intake with a razor or good sharp scraper. Then scrub with a good solvent lacquer thinner, brake cleaner, acetone work well. Do not use sandpaper!
A scrotchbrite pad is OK if you need it, but a coarse cloth usually does the job.
The Ultra Black should be good.
On the valve covers I use Permatex High Tack on the top of the gasket and valve cover side. It's like contact adhesive you paint it on, let it sit for 5-10 minutes then put the gasket in the cover. Good stuff.
On the valve covers check that the bolt holes are not caved inward toward the head.
If they are you can flip them over set a small socket below the hole and then tap with a ball peen hammer until they are flat again.
The engine looks real nice inside, good project.

Good advice thanks!
My valve covers were severly bashed up and dented inward! the sheet metal was weakened to the point where they would kind of loosen up over time--- no good!
So after I stripped the paint and cleaned, I smashed 'em back flat enough and welded in some 1/8" thick reinforcements!

 

[khryslerkid]

You wouldn't think we were having conversations with a guy in his early 20's.

You're ahead of your time Evan, nice work!

 

[Evan Frucht]

I agree on the Ultra Grey being the best to use. I have never had an issue with it, whereas the blue and black look like bathtub caulk.

When I blocked my heat crossover on my poly. I used a 1/8" piece of steel with a step and a corrosponding step in the intake so it didn't fall through. A thin piece of sheetmetal under the gasket would work but was told it would fail at some point.

when you blocked your heat crossover (not sure if you drove it before you did that, but...) did you notice any improvement in performance/ were you happy with the results?

 

[Don Frelier]

Any performance would be negligible.
But it would help with heat soak when you shut it off for 5-15 minutes.
Since you are in California a warm climate, probably a good modification.
I just folded up a piece of sheet metal and stuck it in the hole.
Not really an exact science...
What carb are you using?
A small AFB would be good. 500 CFM

 

[Evan Frucht]

Any performance would be negligible.
But it would help with heat soak when you shut it off for 5-15 minutes.
Since you are in California a warm climate, probably a good modification.
I just folded up a piece of sheet metal and stuck it in the hole.
Not really an exact science...
What carb are you using?
A small AFB would be good. 500 CFM

I like your style with the folded up sheet metal... your right its not rocket science I probably just overthunk as usual.

I like threewood's idea too, but I cant bring myself to hit the intake with a Dremel, even though I'm sure it wouldn't really affect anything and would work well

 

[David Hunt]

Built these motors and use red light temp silicon. No leaks, glue gaskets to valve cover, and glue to head . No leaks. Retorq intake bolts twice one cold, one hot. Glue intake gakets same as valve cover instructions. Good motoring David Hunt

 

[Evan Frucht]

ok thanks for all the help everyone. I'm gonna go to the auto parts store to get some supplies.

I pretty much decided I'm gonna use ULTRA GREY for front and back, and discard the foam stuff they gave me. Then shoot the metal compression gaskets with some Permatex copper gasket spray. I may also put a little Ultra Grey both sides around the coolant passage port on gasket just to be safe.