Glueing plenum down with hi temp RTV

[Thomas]

Hi Guys,
I am at the stage of fitting the plenum to the engine and I am concerned about using hi temp RTV to stick it in place. I know how hard it is to remove this stuff if you ever need to get at the engine. I read somewhere on the forum but cannot re-find the post, of using aluminium tape to seal and I wondered how this solution worked in use.
Bruce

[Pete D]

I have installed and removed a lot of plenums using the red/orange high temp RTV. I have never had any real issues.

There are a couple of techniques for taking the plenum off. Usually I use a couple of different knifes to cut through the RTV and then pull the plenum gently. You can also use a piece of string like rip stitch cord, one end inside, one end outside like a saw to cut through it.

Once the plenum is off you just cut most of the big lumpy areas of the RTV off and put a smaller fresh bead of RTV right over the top of the old bead. It sticks very well to itself especially if you make sure there is no oil on the surfaces.

Generally my experience with the foil tape has been it does not span gaps well. It will quickly fracture when its used across seams and once baked on is very hard to get off.

You can also find high temp RTV (I think Loctite brand?) that comes in black. Sometimes looks a bit better against the black plenum.

[Dan L]

Hi Guys,
I am at the stage of fitting the plenum to the engine and I am concerned about using hi temp RTV to stick it in place. I know how hard it is to remove this stuff if you ever need to get at the engine. I read somewhere on the forum but cannot re-find the post, of using aluminium tape to seal and I wondered how this solution worked in use.
Bruce

I put Teflon tape on my plenum, put the high temp sealant on the engine and bolted the plenum in place. Once it setup I removed the plenum and then peeled the tape off. The reinstalled the plenum. Now the plenum will come off easily and there is a full seal between the engine and plenum.

[Pete D]

The RTV is what holds the plenum tight to the engine across the front and the back. Keep an eye on the plenum if it is not stuck down, I have seen stress cracks in the gel coat especially in the front area that leads me to believe the plenum flexes and lifts up when its pressurized. If it can flex up and allow air out from under it then it is not doing its job of directing the air through the cylinders and oil cooler.