Specially
prepared B230 Inlet Manifold
by Anthony
Hyde
Outside and inside
pictures show the result of 55 hours dedicated hand crafting. This
Volvo manifold was prepared in advance of fitting a programmable
engine computer. All the effort better be worth a few extra
horsepower ! -
3 beaut pics below
Good lighting is essential
to see exactly what your doing way inside. Spend some time setting up
lamps at both ends of runners.
The biggest challenge is removing the
two casting joins in each tube. Machines can't get deep inside these
curved oval areas, so the most effective way is to scrape out casting
spots and irregularites in a controlled manner by using special hand
tool scrapers and burr bits. Progress
can be slow & tiresome, but
when you reach and clean up new areas, there is a feeling of
reward.
An 'S' shaped tool can be made using 1/4" copper tube, bent easily as
required. To hold the burr bit, drill a piece of round steel , then
tap the side for two small grub screws, then solder onto the copper
tube.
Radiusing the entry tubes (see pics) was
achieved with some fine half-moon type files and scraping (grind an
internal radius into a steel blade), and finished off by using fine
sanding discs attached to a Dremmel type tool.
Final
finish was with fine bead
blasting. When metal finishing is complete, thoroughly wash out
manifold using hot soapy water and a bottle brush. The
outside metal
surface is sealed with a furniture polish - best is 'Johnson's
Wax' wood polish (contains oil &
wax) to keep the bead blasted
alloy surface looking good for many years.
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B230
INLET MANIFOLD ANATOMY
This trick shot was taken
using a 'fish eye lens' on a digital
camera.
The view is from where the
throttle body attaches to the manifold plenum. Notice how
every edge and transition has been rounded off.
'Flow through' would be far
more laminar (smooth) than original casting.
Being manifold for a fuel
injected engine, fuel is injected elsewhere, so the manifold
serves to channel only air to the cylinder head. So the
smoother the flow the better. Eg, race cars use very smooth
carbon fibre for inlets and airboxes.
Thanks for visting,
Anthony Hyde
For fittment information
see:
B21/B23
to B230 Turbo Intake Manifold
conversion
- by Stu Spencer, TurboBricks
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THROTTLE BODY - being
machined (bored out) in the lathe. A face or mounting plate
needs to be made first.
At the same time, the
outside 'hose clamping surface' is machined round and a
clamp lip improved.
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