Intake Gasket and "Valley Pan" Install Q's

[Chris 69]

Got my rebuilt 440 from the shop. The intake manifold they used was too tall for the hood, so I'm swapping it out with a shorter one. When removing the intake, I noticed that there are no gaskets installed between the intake and valley pan, and the valley pan and head. I also don't see any evidence of sealant between the valley pan and intake and valley pan and heads. The front and back ends of the valley pan have sealant. This motor has not been run since it's been rebuilt (i got it back about a month ago).

Is this the correct installation? Head are 906 cast iron. Valley Pan looks to be a Fel-Pro 9546 (I cannot seem to find this model online)

All the valley pans I see online look to come with 4 gaskets!

Any recommendations on how I should proceed with installation??

Thank you, Chris

[BLK 68 R/T]

Sometimes the gaskets fit...sometimes they don't. Depends on what has been machined and lots of other variables. Usually start with the metal and sit the intake on. Look down the bolt holes and see how centered they are. More towards the top of the intake you might be able to squeeze one paper gasket in on each side. Just have to play with it to see what works. I usually seal the ends and lower corners. Very light coat of sealer around the intake ports.

[Bronzedodge]

... I usually seal the ends and lower corners. Very light coat of sealer around the intake ports.

Agreed.  The bottom of the intake port can suck oil or leak at the ends if no sealer is used.  Indy or someone had a tech page about using fine wax strings to check the 'crush" around the ports when test fitting.

[metallicareload99]

All good points above, looks like a Fel-Pro MS96000, as has been mentioned, see what fits best with 1 or 2 pairs of gaskets.  Intake too low, I like to add gaskets between the head and valley pan, still too low add a pair between intake and valley pan.  I also put a little bit of sealant on the intake manifold bolts

[Chris 69]

Thank you for the advice. I'll verify how centered the new intake manifold's holes are with the heads.

I thought that the middle hole in the head was for coolant to get into the intake. Research in the Internet is indicating that the RB intake doesn't have coolant. What is that middle hole for in the head?

[5wndwcpe]

The middle hole is for exhaust gas.  It heats up the air under that carb for quicker warm-ups.  Personally, I use the valley pan that blocks off this hole as the extra heat discolors the paint on the manifold and contributes to vapor lock with todays fuel.  Fel-Pro 1412 I believe is the part number.

Also, I don't usually run the paper gaskets but do put a thin bead of silicone around the intake ports for good measure.

[BSB67]

Chris-

Here are some key observations and take aways regarding your question:

1) The factory just used the pan, and they sealed fine.
2) Occassionally, aftermarket intakes don't seal with just the pan.
3) Ocassionally factory intakes don't seal after a rebuild due to machining.
4) Often times an aftermarket aluminum intake will seal just fine even after considerable rebuild machining.

In the end, it comes down to the angle and parallelism of both the intake and head surfaces, and the pan does not have much tolerance for much misalignment of either.

The paper gaskets will help assure a good seal.  Unfortunately, unless the rebuild and associated machining anticipated the use of paper gaskets, there is a good chance they will not fit.

Recommendation:
1) Get the thin paper gaskets (0.015" thick) install all 4, and see if you can get the intake bolts started.  If you can, use them. If not
2) Use 2 paper one on each side installed on the head, if not
3) Use your favorite gas resistant sealant and go with just the pan.

Diagnosing a small intake leak at the intake head surface is usually difficult for the less experienced hobbyist.    Folks run around with leaking intakes all the time and don't even know it and just assume that this is how the car is suppose to run.  If the car does not run smooth and clean at an idle, just remember that a leak at the intake could be one of about 20 reasons an engine does not run good and clean at an idle.

The gaskets that come with the pan are likely too thick (0.030") and will not work.  You'll likely need to purchase the thin gaskets from another source like Superformance.

[Chris 69]

The middle hole is for exhaust gas.  It heats up the air under that carb for quicker warm-ups.  Personally, I use the valley pan that blocks off this hole as the extra heat discolors the paint on the manifold and contributes to vapor lock with todays fuel.  Fel-Pro 1412 I believe is the part number.

Also, I don't usually run the paper gaskets but do put a thin bead of silicone around the intake ports for good measure.

Thank you for the info. That makes me feel much better that that wasn't an un-gasketed coolant port.

[Chris 69]

Chris-

Here are some key observations and take aways regarding your question:

1) The factory just used the pan, and they sealed fine.
2) Occassionally, aftermarket intakes don't seal with just the pan.
3) Ocassionally factory intakes don't seal after a rebuild due to machining.
4) Often times an aftermarket aluminum intake will seal just fine even after considerable rebuild machining.

In the end, it comes down to the angle and parallelism of both the intake and head surfaces, and the pan does not have much tolerance for much misalignment of either.

The paper gaskets will help assure a good seal.  Unfortunately, unless the rebuild and associated machining anticipated the use of paper gaskets, there is a good chance they will not fit.

Recommendation:
1) Get the thin paper gaskets (0.015" thick) install all 4, and see if you can get the intake bolts started.  If you can, use them. If not
2) Use 2 paper one on each side installed on the head, if not
3) Use your favorite gas resistant sealant and go with just the pan.

Diagnosing a small intake leak at the intake head surface is usually difficult for the less experienced hobbyist.    Folks run around with leaking intakes all the time and don't even know it and just assume that this is how the car is suppose to run.  If the car does not run smooth and clean at an idle, just remember that a leak at the intake could be one of about 20 reasons an engine does not run good and clean at an idle.

The gaskets that come with the pan are likely too thick (0.030") and will not work.  You'll likely need to purchase the thin gaskets from another source like Superformance.

Thank you for the write-up/explanation. I just ordered the 0.015" gaskets from Mancini.

[Kern Dog]

Also, for all of the intake manifold bolts, use a non hardening sealant since they thread into holes that are open to the lifter valley. Oil will migrate up through the holes of no sealant is used.

[rollo1504]

The middle hole is for exhaust gas.  It heats up the air under that carb for quicker warm-ups.  Personally, I use the valley pan that blocks off this hole as the extra heat discolors the paint on the manifold and contributes to vapor lock with todays fuel.  Fel-Pro 1412 I believe is the part number.

Also, I don't usually run the paper gaskets but do put a thin bead of silicone around the intake ports for good measure.

What this gentleman says

I used this felpro 1412 on my 73 charger with the heat crossover block and I did NOT use any gasket. I just used Black RTV Silicone.

Ron (firefighter) was so nice and guided me through this procedure and I followed his suggestions and it works flawlessly:

I've allways used just the valley pan....no paper gaskets. I use rtv on both sides of the valley pan. I also use the rtv on both end rails between the block and valley pan gasket. I put just a little dab in the corners to fill in any potential void.

- make sure all surfaces are clean and dry
- put the rtv around the cylinder head ports
- put a bead along the bottom of the head casting from end to end (underneath the intake ports)
- put a bead on the ends of the block with and extra dab in all 4 corners and then install the end straps & bolts. Just snug the bolts down enough to keep the valley pan in place.

**You're halfway done**

- now you put rtv around the intake port  openings
- carefully set the intake manifold in place and install the bolts just snuggig them up enough to hold everything in place


Let the rtv cure overnight before tightening everything down. The idea is to allow the silicone to harden up enough so that it won't be pushed out.

If you tighten everything down before the silicone has a chance to cure properly it won't seal properly and just get pushed away from the surfaces and make a mess.


Credits to Jon!!!