Weber carb on a 78 fj40

[Eli Heimer]

So I’m running a Weber carburetor on my i6.
I just rebuilt my manifolds.
When I put the two risers on from the intake up to the carburetor I used fiber gaskets.
It seems as if they’re not the right ones, no matter how tight I get the Allen screws there are tiny air leaks getting in between the riser and intake.
Is there a better option for gaskets?

 

[charliemeyer007]

Not a Weber guy. So are the mating surfaces clean and flat? When ever I put on any fiber gasket I soak it in warm water for like a half hour - this softens it up enough to let the high spots dig in. Maybe some sort of gasket compound.

 

[Grayscale]

I always question the hardware on these things. The Allen head cap screws that are part of the Weber adapter plate sandwich are questionable in my mind. I wouldn't tighten them so much as I would use thread locker with them. If you over-tighten, then it might be pulling too hard on the aluminum intake manifold.

It is very likely that the adapter plate is not perfectly flat, after you tighten it for the carb and the manifold. I wouldn't blame the gasket. I'd use some kind of silicone to make up for a possible untrue surface, post assembly.

I thought that I'd try a Weber, so I got the milled Weber adapter plate from JTO - it is a solid one-piece unit, not a sandwich.

 

[brian]

Is there a better option for gaskets?

yes there are!!

 

[JohnnyC]

The adapter plates screws bottom out unless you use thick gasket or something like ultra copper on both sides

 

[65swb45]

The adapter plates screws bottom out unless you use thick gasket or something like ultra copper on both sides

Occums razor

 

[JohnnyC]

Occums razor

lol yes

Usually I’m going the buckminster fuller route of less is more with an emphasis on function over form however weber thought otherwise on their adapters lol

Never went to the one piece (on my wish list of things I’d most likely not get to ever)

 

[brian]

lol yes

Usually I’m going the buckminster fuller route of less is more with an emphasis on function over form however weber thought otherwise on their adapters lol

Never went to the one piece (on my wish list of things I’d most likely not get to ever)

if i still have one and can find it, i'll give you one if you tell me you'll actually put it on.

 

[Grayscale]

My career as a machinist was influenced by a coworker who was a machinist in the Navy. He taught me practical engineering. One lesson was about shop-geometry: three points compose a plane, but four points rarely do. So, whichever corner is screwed-down to full-torque first, will create a triangle-plane with two other points. And even if the fasteners are all similar in tightness/tension, it may not be a parallel interface between the two parts due to the tightening sequence and where the gasket compresses/yields first. At best, treat them like wheel lug nuts, where it is done in an alternating-pattern, not in a circle.