intake manifold sealant

[82g]

purchased the edelbrock performer 289 intake manifold today, what is the best rtv sealant to use on this, thanks

[dynodon64]

I never use RTV in place of the front and back cork or rubber gaskets. The only place to use it is in the four corners where they meet the side gaskets. Just a dab in the corners on top and bottom to seal the two pieces together. They will also be others that say they never use the front and rear gaskets, and only use RTV instead. If you do use the cork or rubber end seals, never use RTV on top of or bottom of the gaskets. It will only make them squeeze out when your torque it down. Always put then in dry with only the corners sealed with RTV. The best kind to use is the black or gray oem type. Blue, orange or red high temp I never use for this purpose.

[JACook]

If you use the production Explorer style expanded graphite gaskets, those require no sealers, other
than the aforementioned dabs of silicone at the corners. The Explorer style end seals are -very- nice.

What you do -not- want do use are the soft Felpro 1250 'Print-O-Seal' gaskets. They are, shall we
say,... temperamental.

[Walking-Tall]

Ultra Blue.

[82g]

Ultra Blue.

most people i talked to say dont use the gaskets on the ends, just a good bead of rtv works best?

[JACook]

Most people have not experienced the Explorer style end seals. But a bead of RTV does work too,
IF you prep the surfaces properly. I've seen as many silicone bead end seals leak as I've seen the
gaskets leak, mostly because people tend to think silicone is an acceptable substitute for proper
surface prep.

[82gt50]

Personal preferences.
I use Felpro gaskets and Permatex sealants. High tack sealant on both sides of the end gaskets and dab of Ultra Black RTV in the corners. Always worked for me. Proper surface prep and torque sequence is critical.

[gr79]

Personal preferences.
I use Felpro gaskets and Permatex sealants. High tack sealant on both sides of the end gaskets and dab of Ultra Black RTV in the corners. Always worked for me. Proper surface prep and torque sequence is critical.

When i worked at the Ford engine plant (1970's), that is how we did FT engines. 330, 360, 361, 390, 391.
Brushed on high tack which was yellow like weatherstrip adh
The cork had one red side, prob like red high tack.
Dabs of RTV.
My job was mainly to prep and secondly install intake gaskets when relieving co-workers for break.
Line did not stop for breaks, only lunch and shift change.
The intake was dropped on a few minutes in next work station after gasket install. RTV was still wet.
Side gaskets were installed dry.
Intake bolt threads were dipped in brown stuff similar if not the same as Indian Head Shellac.

If no cork is used, would not the manifold sit 1/4" or so lower?
All RTV would be a bitch if the manifold had to come back off.

Soak Scotchbrite pad for old end gasket surface to remove any trace of old material and junk.
Clean block surface with a rag soaked in brake cleaner or similar oil remover.
Side gaskets install dry or per instructions with gasket.

Later on in the 2000's, was involved in new GM Gen III and IV V8 and V6 shipments to the assy plants.
4.3, 4.8, 5.3, 6.0, 6.2. Car, truck, marine, industrial.
For sure, the 4.3 V6, iron intake, had gray RTV only, no end cork gasketing.
The V8 used composite intakes with o-ring type sealing already installed before assy.
Times and manufacture procedures have changed.
They used to hot test production engines, but only leak test them now.

[Walking-Tall]

most people i talked to say dont use the gaskets on the ends, just a good bead of rtv works best?

I wasn't going to elaborate, because some peoples' dander gets up with the end seals subject, lol

What's always worked great for me, without a hitch of any kind, is a thin layer around both sides of gaskets' cooling system ports, ~1/4" beads front and rear on the block rails, lay the side gaskets in position on the heads with their tips into those ~1/4" bead beds front and rear, add a dab more to each bottom corner topside of the gaskets if necessary. NEVER without good clean prep of all surfaces as others have mentioned. A good practice also, if all the intake fasteners are bolts, is to get or make at least two, but preferably four studs for when setting the intake down, so that it goes down nice and and even and straight.

[Mgino757]

I used Permatex Ultra Copper RTV for my end seals. Laid a good size bead, laid a thin layer around the coolant ports, sat the manifold on, installed the bolts finger tight until the RTV started to squeeze out, let it set up for about an hour or two, then torqued the manifold bolts to spec. It's been working great for me for over a year now. Surface prep will make or break you. Get it really clean.

Give the sealant a good 12-24 hours to cure before refilling the coolant.

[82g]

I used Permatex Ultra Copper RTV for my end seals. Laid a good size bead, laid a thin layer around the coolant ports, sat the manifold on, installed the bolts finger tight until the RTV started to squeeze out, let it set up for about an hour or two, then torqued the manifold bolts to spec. It's been working great for me for over a year now. Surface prep will make or break you. Get it really clean.

Give the sealant a good 12-24 hours to cure before refilling the coolant.

so i got the felpro intake gasket kit with the cork end seals, so what is the best method for these end seals, thanks

[82g]

so i got the felpro intake gasket kit with the cork end seals, so what is the best method for these end seals, thanks

can anyone recommend a intake manifold gasket kit?, other than explorer? felpro 1250 any good? thanks

[Mgino757]

I didn't use the provided end seals at all.

[dynodon64]

The paper work for the intake tells you what gasket set to use. Different gasket sets work with different intakes. They have different size ports and different locations on special ones. You have to use what is recommended by the maker or you risk having vacuum or coolant leaks. Look at the instruction sheet.

[Walking-Tall]

In case you haven't got paperwork to tell you what to do, use what you have (if you have some Fel-Pro's on hand now, use them), and if you want to use the cork ends, give them a fighting chance at staying put (the problem people have run into, them squeezing out of position, and/or variation of them sealing in oil vapor if there's been block/head machining, which is the blanket reason to use beads of silicon that address both of those potential issues) with a thin layer of RTV. Ditto at both sides of the gasket coolant ports. Otherwise, beads front and rear and corner dabs, or take your pick of the above methods mentioned.

[JACook]

can anyone recommend a intake manifold gasket kit?, other than explorer? felpro 1250 any good? thanks

Not sure why you wouldn't want the Explorer gaskets. Expanded graphite gaskets really are the best thing
to use with an aluminum intake against iron heads. (Why Ford made them that way.) The differential
thermal expansion rates cause coolant seepage on most of the other styles available. And no, the FelPro
1250 is the absolute worst choice for an engine that's not being regularly torn down and refreshed.

so i got the felpro intake gasket kit with the cork end seals, so what is the best method for these end seals, thanks

If the set you got came with cork end seals, I'm gonna guess you didn't get the best gaskets. Not that I
have any problem with cork end seals, but these days, typically that's what comes in the cheaper rebuilder-
grade gasket sets (well those, and the aforementioned 1250s...)

[82g]

Not sure why you wouldn't want the Explorer gaskets. Expanded graphite gaskets really are the best thing
to use with an aluminum intake against iron heads. (Why Ford made them that way.) The differential
thermal expansion rates cause coolant seepage on most of the other styles available. And no, the FelPro
1250 is the absolute worst choice for an engine that's not being regularly torn down and refreshed.



If the set you got came with cork end seals, I'm gonna guess you didn't get the best gaskets. Not that I
have any problem with cork end seals, but these days, typically that's what comes in the cheaper rebuilder-
grade gasket sets (well those, and the aforementioned 1250s...)

do u have a part # for explorer gaskets?, thanks

[84StangSVT]

do u have a part # for explorer gaskets?, thanks

fel pro MS95952

[82g]

fel pro MS95952

will these work on a edelbrock 21213 manifold, this car is carbureted, felpro list these gaskets as efi?, dont know if that makes a difference or not. thanks

[gr79]

Any fresh quality brand black, gray, white RTV gasket maker made for auto uses will work.
Tube in caulk gun or small squeeze tube.
For sure use the screw on tip and cut to desired bead size.

Aluminum intakes are lighter than iron but still weigh 15-20#
Dropping it slowly freehand dead straight onto fresh gaskets can be tough, especially in car.
Few can hold the weight of a bowing ball at arm length for very long.

I say this because i remember, when installing them on the line, felt some air being displaced at the final 'clump'.

We used an air op crane, since they were iron intakes.
On the line, the engines wiggled a little due to conveyor fixture. Intakes were 'dropped' the last inch or so.
The regular workers did it every day for hours. One engine a minute.
There were misses every now and then that had to be routed to the repair bay. Not good.
Pinched side gasket or more likely the end cork moved out of place.

Hovering 15-20# of metal can be hard on the back and hurry things.
Especially engine in car install.
That air pushing out can slightly displace any gasket that is not locked or glued good.
An arm fatique juggle in the last inch or so after committing to drop.
Especially when dressing gaskets with RTV.

Having the glues firm up a little should help with success in proper sealing.
A push test with finger would confirm that.
A long silicone bead needs to tack or firm up a little to support weight without squishing out to thinness, globs, or gaps.
Using just enough and waiting time is a little tricky.

[grabbergreen84]

will these work on a edelbrock 21213 manifold, this car is carbureted, felpro list these gaskets as efi?, dont know if that makes a difference or not. thanks

The difference is that it will likely come with gaskets for the upper EFI intake and the throttle body. You don't need those extra gaskets, but you will have to pay for them anyway...

[84StangSVT]

will these work on a edelbrock 21213 manifold, this car is carbureted, felpro list these gaskets as efi?, dont know if that makes a difference or not. thanks

Yes, they will. You won't need the upper intake gasket but the lowers and rubber seals will be fine.

[mmb617]

Aluminum intakes are lighter than iron but still weigh 15-20#
Dropping it slowly freehand dead straight onto fresh gaskets can be tough, especially in car.
Few can hold the weight of a bowing ball at arm length for very long.

For that very reason I made a set of alignment studs which really help.






I'm a fan of alignment studs so I made a set for the T5 as well. Much easier to slide into place using the studs.

[82g]

For that very reason I made a set of alignment studs which really help.






I'm a fan of alignment studs so I made a set for the T5 as well. Much easier to slide into place using the studs.

was thinking about that, what did you use?,thanks

[mmb617]

I went to Lowes and bought four 5/16x18 bolts that were 4 inches long, cut the heads off and rounded the ends a bit with a grinder. I didn't bother to cut screwdriver slots in them as I only put them in finger tight and they are easy to back out after the intake is in place.