Weber Cold Air Box Mods.
Posted: Thu Jun 30, 2011 3:40 am
The very first time I was involved with fitting the cold air box
to the Webers I came across the first cause of frustration, IE
the bolts would not readily line up with the threaded
spigots attached to the backing plate, the bolts not
having some sort of guide meant a bit of fiddling
around to find the threaded spigots as shown in Image #1:
Image #2:
So, I set about fixing this problem, first job was to machine
two small hat shape spigots from aluminium, which were
clear-drilled 1/4" ID, these were to act as bolt guides and were
aligned and fixed over the air box bolt holes with F/glass on
the inside of the air box.
Image #3:
Attention was then moved to the backing plate, four small
extra reinforcing straps made from sheet metal were brazed
to each spigot, and to the outer corners of the A/box as shown,
the idea of the straps was to spread the bolt tightening tension
load over a wider area of the air box, also, with the standard
set-up, if the bolts were ever over tightened, the sheet metal
backing plate could possibly be pulled away from the front face
of the Weber, creating a small air gap & allowing a small amount
of unfiltered air into the air box.
Most air box bolts probably wouldn?t be over tightened,
but if the gasket was not sealing properly, the temptation
to over tighten is there.
Image #4:
Provides a close up detail shot showing the alloy spigot
fixed to the inside of the air box.
The set up explained here has been a permanent feature
of the cold/cold air box system on my twink for the past
twenty-six years.
BTW, the sealing gasket also shown here on the air box is
a rocker cover gasket from the early K series
Toyota Corolla, and is almost a perfect fit.
Neither the backing plate nor the cold air box are
original items, they were both fabricated in our workshop
during the early 80s not long after I acquired the basket
case S2 elan.
CeeJay.
to the Webers I came across the first cause of frustration, IE
the bolts would not readily line up with the threaded
spigots attached to the backing plate, the bolts not
having some sort of guide meant a bit of fiddling
around to find the threaded spigots as shown in Image #1:
Image #2:
So, I set about fixing this problem, first job was to machine
two small hat shape spigots from aluminium, which were
clear-drilled 1/4" ID, these were to act as bolt guides and were
aligned and fixed over the air box bolt holes with F/glass on
the inside of the air box.
Image #3:
Attention was then moved to the backing plate, four small
extra reinforcing straps made from sheet metal were brazed
to each spigot, and to the outer corners of the A/box as shown,
the idea of the straps was to spread the bolt tightening tension
load over a wider area of the air box, also, with the standard
set-up, if the bolts were ever over tightened, the sheet metal
backing plate could possibly be pulled away from the front face
of the Weber, creating a small air gap & allowing a small amount
of unfiltered air into the air box.
Most air box bolts probably wouldn?t be over tightened,
but if the gasket was not sealing properly, the temptation
to over tighten is there.
Image #4:
Provides a close up detail shot showing the alloy spigot
fixed to the inside of the air box.
The set up explained here has been a permanent feature
of the cold/cold air box system on my twink for the past
twenty-six years.
BTW, the sealing gasket also shown here on the air box is
a rocker cover gasket from the early K series
Toyota Corolla, and is almost a perfect fit.
Neither the backing plate nor the cold air box are
original items, they were both fabricated in our workshop
during the early 80s not long after I acquired the basket
case S2 elan.
CeeJay.