intake manifold install &PCV

[scott h]

during the motor reassembly i noticed that the previous builder had used some black RTV on each intake manifold bolt. I really don't see the need unless it is to help keep the bolts snug or to keep oil from migrating up the bolt holes. what is the consensus to RTV or not. i am looking at ways to set up a PVC. Will a 1" spacer fit under the hood in 351W with a victor jr. i could also make a fitting for the air cleaner but am not so sure about pulling the crankcase air thru the carb. Your 2 cents please!

[JeepSnake]

Scott -

I can't remember for a Ford without looking, but I know that on a Chevy you put thread sealer on the intake bolts because they thread into the water jackets.

On the PCV, you're going to have to get a hookup that is exposed to manifold vacuum. It can either go into a spacer plate or a decent-sized port on the carb. Or, if there is room on the intake, you can drill and tap a port of your own. It MUST be in the plenum area, however. If you put it in a runner, you'll screw up the A/F ratio to that particular cylinder.

(Going into the air cleaner with the suction side of the PCV system won't provide positive ventilation.)

[scott h]

no ports on carb, i will look for a spacer plate thanks!

[nolastyankee]

Not sure if you are running a BB or SB Ford, but on Windsors the intake manifold threads into the water jackets and needs sealer. You can use teflon thread sealer just as easily as RTV.

I'd be very surprised if your carb did not have any vacuum ports unless it's a full race-only version. Look on the front of the baseplate or the body. Every carb I have seen has 2 or 3 ports that will look like either a barb fitting (with a cap over it when not used) or a threaded hole (with a plug when not in use) where a barb or AN fitting will screw in. One of these ports will be above the throttle blades for metered vacuum, the other will be below the blades for full engine vacuum. You'll want the non-metered vacuum for the PCV.

[scott h]

its a small block, sealed up the bolts yesterday, the carb a holley HP has no ports, will play around to se if i have enough hood clearance for 1" spacer, if not i may try drilling the intake, or just not have any pcv

[Brent]

Never had any luck with sealing anything with silicone that was not compressed. Works good on two surfaces pushed together but no good on threads. Liquid teflon, tape, or Permtex aviation sealant.

[spd4me]

Scott
When you put on your intake, did you use a four piece gasket or did you use a 1/4" bead of RTV at the front and rear. I'm fixing to replace my Victor Jr. single plane with a RPM Air Gap dual plane. I have a 396Windsor. The instruction also say to use Edlebrock's intake sealer that comes in a can on the gasket. Permatex has always been a good sealer. Does Brent recommend the non-harding type for the bolts?
Bob

[Brent]

The stuff I have is Permatex 56521.
It is a white paste made for stainless, aluminum, etc. It resists fuel, oil, etc. It also lubricates the threads so you use the same torque settings.

[nolastyankee]

Sorry guys, when I said teflon thread sealer I was thinking the ARP teflon thread sealant, not the plastic tape. We have had good luck with the ARP thread sealant on everything from fuel to coolant.

[scott h]

i used permatex ultra black for front and rear of intake. I spoke with a rep from edelbrock ( i have edelbrock heads and intake) he said the bolt holes do mnot go into any water jackets and that the sealant was more as an aid to keep the bolts from working loose.

[spd4me]

scott
I got some of the same permatex ultra black. Did you have to use alot or just 1/4" high ridge.

[scott h]

i was told by my engine builder to set the manifold in place and check the gap, make your bead almost twice as thick as the gap, then you can use your finger to clean up the edges which will also help fill any minor voids.