TIMING
Timing is one of the most important fundamentals behind nitrous
oxide setup. Unlike naturally aspirated or forced induction engines
we can not run timing advanced. Due to high cylinder pressure we
have to retard to prevent detonation.
Typically the rule of thumb is for every 50 hp addition of nitrous
oxide you should retard your timing by 1-1/2 to 2 degrees.
IGNITION
You should at least have a stock ignition system but the better
the ignition system the more power your engine will make.
High performance wires, larger coil and spark plugs with one heat
range colder with stock gap should be used (unless specified by
kit). It would be a good idea to purchase a high performance ignition
box with rev limiter and a timing controller this way you wouldn't
have to manually adjust your timing every time you use or don't
use nitrous!
BOTTOM END
Nitrous
motors need to be built for strength, not high rpms. It would be
a good idea to get the block machined and balanced by a machine
shop if not in newer condition. Also a stronger crank, rods and
pistons would allow for more power.
TOP
END
Intake
Manifolds
On
carbureted motors you have two choices dual plane or single plane
manifolds. Dual plane intakes raise bottom end torque in return
losing horse power at higher rpms. Single plane intakes are meant
to pump up high rpm horse power without considering the loss of
low end torque. Either way the colder the manifold the more nitrogen
oxide your can pump into your head this is were raised or air gap
manifolds work best.
Heads
Nitrous
oxide adds so much oxygen that a large intake port is not desired.
The larger the intake ports the lower the velocity. This causes
the nitrous to slow down giving it more time to turn from a liquid
to a gas. Larger ports let less nitrous oxide into the cylinder.
Now exhaust ports are the opposite. Due to the extreme pressure
in the combustion chamber, exhaust valves should be as large as
possible. You might even have to reduce the size of the intake to
allow room for a bigger exhaust valve.
The combustion chamber should be free from all sharp edges (prevent
detonation) and polished. Exhaust rocker studs should be also upgraded
to stronger or larger ones, because of the increase in exhaust pressure.
Camshafts
Camshafts
for nitrous oxide engines should be matched to the heads. A duel
pattern cam can accomplish this by incorporate a short duration
and small lift on the intake, but longer duration and higher lift
on the exhaust. By opening the exhaust valve earlier this starts
bleeding off some pressure before the piston starts moving up the
bore.
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