Tilton Flow Control Valve (98-1280) - Manual

IntroductIon
Shock loads created during shifting events can have two very detrimental
effects. They can cause the drive wheels to lose traction and they can dam-
age drivetrain components (broken axles, transmissions, etc.). A shock load
is the result of an abrupt clutch engagement when the crankshaft and input
shaft speeds are not precisely matched. The Tilton flow control valve reduces
shock loads by allowing the clutch to slip slightly during engagement. This is
accomplished by restricting the return flow of the hydraulic fluid by a tunable
amount. Fluid flow is not restricted during disengagement. Therefore, shift
times are still quick and the feel of the pedal is not altered. This valve will have
an effect on quick clutch actuations only. It will not alter fine clutch modula-
tion (small pedal movements).
SelectIng the orIfIce SIze
1. The three digits on the piston indicate the orifice size. For example, ‘040’
indicates .040".
2. A larger orifice creates a more abrupt clutch engagement. A smaller orifice
softens the engagement a little more by allowing the clutch to slip a few
revolutions.
3. It is generally recommended to start with the largest provided orifice size
and work your way down. The size you need depends on the clutch spring
force, the number of friction plates, the clutch diameter, the weight of the
vehicle, front drive vs. rear drive, tire size, and a few other factors. There-
fore, a little testing may be required.
4. Assemble in the order shown in the diagram. Torque the two halves to-
gether at 50 lb-ft (68 Nm).
5. If the orifice size is too large the engagement will still be very abrupt.
6. If the orifice size is too small you will see signs of excessive heat buildup or
wear in the clutch.
InStallIng the ValVe
1. Make sure that the fluid system is without contaminants. Flush the system
if in doubt.
2. Find a location. This valve will work anywhere in the hydraulic line between
the master cylinder and the hydraulic release bearing. Each end of the
valve has -3AN fittings for use with most Tilton master cylinder ports and
-3 hydraulic lines. Threading directly into the master cylinder provides an
easily accessible location.
3. Free flow is required in the direction of clutch disengagement (while
depressing the pedal). The arrows next to the word ‘FREE’ must point away
from the master cylinder.
4. Install the valve in the line. These fittings seal best without the use of pipe
tape or sealing compounds. Torque the fitting to the line or master cylin-
der to 15 lb-ft (20 Nm).
5. Bleed the clutch system as you would normally bleed it.
Flow Control Valve
INSTALLATION INSTRUCTIONS 98
-12
80
Tilton Engineering, Inc. 25 Easy Street • PO Box 1787 • Buellton, CA 93427 • www.tiltonracing.com