Intake manifold gaskets

[Timwaiex0146]

I just had my heads and valves worked on and im reassembling my engine. I was wondering why no gaskets are called for between the heads and intake manifolds. The gasket kit contains two metal gaskets that seem to fit perfectly. I used permatex originally,but I seemed to be almost missing when I disassembled the parts. I’m considering Ez Turn for a gasket , has anyone used it to seal their intake manifolds ?

[Rynoth]

I've never noticed Permatex form-a-gasket missing, that stuff seems to stay where it's stuck for eternity. I'd say you had a very nice machined fit between your manifold and heads and the permatex just got (appropriately) squeezed out. Did you have signs of leaks?

FWIW, I believe the permatex is removed by ethanol, so if running fuel containing ethanol it's probably not the best choice.

Edit: My original Aerovee Turbo manual called for Permatex Aviation Form-a-gasket for at the intake manifold elbows, current/revised manual states Red RTV.

[SNX1508]

My $.02.....

Per Permatex tech support, the following products are NOT compatible with the chemicals present in 100LL:
Permatex® High-Temp Red RTV Silicone Gasket Maker Product Code 81160
Aviation Gasket Sealant #3 Product Code 80018
Permatex® PermaShield™ Fuel Resistant Gasket Dressing & Flange Sealant Product Code 85420

And I had the following email exchange with Sonex tech support regarding the metal intake manifold gaskets:

On 9/3/18 8:25 AM, Terry L Cooper wrote:

I am wondering why the AeroConversion engine does not use the metal gaskets for
sealing the intake elbows, as opposed to using sealant as specified in the
assembly manual? I know as an experimental builder I can choose the method of
assembly, I am just curious why the sealant was chosen over the metal gasket
supplied in the gasket kits. See attachment for a picture of the metal gasket that I am referring to.

Thank you,

Terry L Cooper
Sonex #1508
AeroVee #0736

********************

AeroConversions Technical Support <techsupport@aeroconversions.com>

Subject: Re: Intake Metal Gasket

Priority: Normal Date: Tuesday, September 4, 2018 8:22 AM Size: 4 KB

Hi Terry,

We've gotten a better seal using the RTV than we have with the metal gasket.
Blue Skies....

Kerry

Sonex Aircraft Tech Support

[Rynoth]

My $.02.....

Per Permatex tech support, the following products are NOT compatible with the chemicals present in 100LL:
Permatex® High-Temp Red RTV Silicone Gasket Maker Product Code 81160
Aviation Gasket Sealant #3 Product Code 80018
Permatex® PermaShield™ Fuel Resistant Gasket Dressing & Flange Sealant Product Code 85420

That's interesting, I just looked back and my original Aerovee Turbo manual called for Aviation Gasket #3 for the intake manifold elbows. I checked the current manual and it calls for High-Temp Red RTV now.

[Klimek]

As a retired VW technician and Service manager I have rebuilt literally hundreds of air cooled engines and several water cooled. On the type III there is a plastic spacer between the head and intake manifold that has a very thin attached paper gasket on each side. The spacer is replaced anytime the intake is removed. When installing a thin coat of VW case sealer is used as a sealant.......1970’s........
Fast foreword 2015......I matched my intake manifolds to the heads by scribing the head then the intake mating surfaces using one of the steel gaskets as a guide. Then a die grinder was used to remove material from heads and intakes so to make a smooth transition reducing turbulence and effectively increasing the airflow. Using the steel gasket as a guide, a gasket was cut out of the thinnest gasket material I could locate, to prevent compressive settling, and installed with aviation permatex on the head and manifold surfaces.
Take this for what it’s worth, but I have never had a leak.
I’m NOT an engineer, just experienced.
As far as the SOS Beer Venture thing, it’s a stiff neck against greed. It could be worked out if both sides can talk and don’t let the lawyers enter the room.
My technique and opinion and they both probably stink.

Frank
ONEX 090
1970T
flylite@cox.net

[Area 51%]

If there are sealing issues with the metal gaskets supplied, it probably has more to do with the intake manifolds having rectangular ports and the heads having round ones. I have one of each in my hand right now, and the stamped bead on the gasket does not lie completely outside the Aeroconversion's intake port; which is necessary to crush the bead correctly and make an airtight seal. (I have Great Plains intakes on my engine because of that mismatch) Can 13 million VW engines be wrong?

Not sure how detrimental ethanol fuel is to Aviation grade Permatex. They do list denatured alcohol as a thinning agent, but not all alcohol is created equal. (Water based paint is water proof after it dries, go figure)

I would personally use nothing (assuming good machine work) as opposed to any of the RTV sealants on an intake. Gasoline will attack and dissolve everything from bathtub caulk to marine 5200. I personally am a fan of the paper gasket.

[pappas]

Remember, the proper way to use rtv gasket sealants is to place a bead around the area to be sealed and then only tighten to about 5-10 inch pounds. the idea is to NOT squeeze all of the rtv out by tightening it right away. After the RTV sets up and turns into more of a rubberlike substance, then you tighten it to the proper torque. the time between application and final torque could be as much as 24 hours depending on the product used.

It is likely that what appears to have been the rtv mostly missing could be that it was mostly squeezed out when torqued before it could form into a rubber-like gasket. I have only had problems with leaks when I have been too impatient to let the sealing material set up before torquing to final specs.

Lou Pappas