CONSTANT FLOW NOZZLES
Constant flow systems are very flexible and cost effective for many types of racing, engine configurations, and fuels. They are capable of supplying a very wide range of fuel requirements. The system can be easily configured and tuning is accomplished by increasing or decreasing the systems operating pressure.
A constant flow system uses a mechanical fuel pump to increase/decrease the supply flow to the injection unit directly related to engine rpm. This variable flow creates pressure against the fixed orifices of the main bypass jet and the nozzles. Using a barrel valve assembly the idle and the part throttle fuel rate is controlled. Kinsler can supply additional bypasses and enrichment circuits to give added flexibility.
Basic components of a constant flow fuel injection system :
A) Air control - individual runner (I.R.) manifold or throttle body.
B) Kinsler Fue Injection manufacturrer's throttle linkage. Special jackshaft kits (like the one shown above) are available for most manifolds.
C) We stock heavy duty Morse throttle cables and shut-off cables. We also offer S.S. quick and bolt down release mounting clamps.
D) Barrel valve assembly - barrel valve houses the spool. The spool controls fuel for idle and part throttle. There is a selection of spools for different engines and fuels.
E) Nozzles - fixed orifice in the runner or plenum of intake manifold. Sized for specific engine and fuel being used.
F) Nozzle lines - connects barrel valve or distribution block to nozzles.
G) Main bypass jet can - houses poppet and spring for basic idle fuel pressure, holds main bypass jet.
H) Main bypass jet - this orifice works in conjunction with pump and nozzles to set the overall fuel delivery of the system. It can be quickly changed to adjust the base fuel rate.
I) Fuel pump (mechanical) - positive displacement pump.
J) Fuel pump drive - typically setup to run fuel pump at 1/2 engine rpm. Can be mounted to camshaft or belt drive.
K) Fuel shut-off valve - stops fuel flow to barrel valve to allow the engine to be shut-off.
L) Fuel filter - filters the fuel to protect nozzles, bypass valves, and barrel valve.
Optional components :
M) Secondary bypass valve - allows tuning flexibility of part throttle.
N) High-speed bypass valve - allows tuning flexibility of higher rpm fuel delivery.
O) Electric lean-out or enrichment valve - special function valve to allow tuning of a specific area or range of the fuel deliver.
P) Kinsler Jet Selector Valve - holds eight main bypass jets. Allows main jet to be adjusted while engine is running.
Q) Kinsler Vapor Separator Tank (VST) system - typically used when the main fuel tank is mounted too far away from the mechanical pump and a transfer pump is required. Kinsler specially designed system keeps a constant feed pressure to the mechanical pump to prevent cavitation.
NOZZLE DISCHARGE STYLES :
'A' type : fuel is discharged at 45 to body through notch cut in deflector, commonly called 'whistle' or 'notched'. 'AS' type : fuel discharged in line with body through a diffuser screen, commonly called 'screen tip' or 'shot-gun'.
K-TYPE JETS :
Even a perfect fuel injection unit is of little use to the owner unless he has a good set of jets to use with it. When using commercially made jets, it is not unusual when going .005" smaller in jet size (in an attempt to richen the unit) to actually find no fuel rate change, or perhaps go grossly rich, or even to go a bit leaner! This makes it impossible to "tune in" the engine for best power and consistence.
EACH K-type jet is precisely machined and stamped with the "KINSLER" name to identify it. It has a reamed orifice controlled within .0002", a precise radius leading to the orifice, and a regulated finish.
Every K-type jet is tailored on the flow bench to within 1/2% of the flow rate of the master reference jet of its same size. Therefore, even though the increments between the K-type jets are very small (.002" available), the change in flow rate between each jet is the same. Every jet of the same size flows the same, if one jet is lost, an exact duplicate can be shipped immediately.
A) Because of the larger radius entrance to the metering orifice in the K-type jets, you must start with a K-type jet that is about .008" smaller than the conventional jet that you are replacing, if you want to retain your present fuel rate.
B) Always install the jet so that the number is facing up as you drop the jet in, then the fuel will flow into the radiused side of the jet. After the jet can has been assembled, the number will be facing toward the poppet.
C) Make sure the jet can end has an o-ring receiving groove and that an o-ring is in place for the jet to sit on. Note: the jet sealing o-ring should be replace periodically to make sure that the compound has not "dried" out.
We can make variations of these nozzles and special nozzles just call us. Also see pg 10 of main handbook.
per nozzle .72 sp. gr.
gasoline at 0 psi
+ or - approx. 4% from flows shown at left Crower and Enderle nozzle size (they code their inserts differently)
'A' Type: Fuel discharged at 45 degrees to body through notch cut in deflector: commonly called 'whistle' or 'notched'.
'AS' Type: Fuel discharged in line with body through a diffuser screen: commonly called 'screen tip' or 'shot-gun'
Nozzle Venting Vents let air premix with the fuel inside the nozzle for better atomization.
Externally Vented : For normally aspirated engines (unblown). Vented to the atmosphere. Use #5020 KFI nozzle vent filter biscuits for protection against dirt.
Internally Vented: For normally aspirated engines. Vents frow inside the runner of the manifold or cylinder head.
Non-Vented & Z-type : For supercharged or turbocharged use were the nozzle exit sees the manifold boost.
Vent location and quantity One and three vent nozzles drip into the engine on shut off are the safest. Four and six vent nozzles drip outside on shut off present a tiny-fire hazard but prevent any possible cyl. washdown.
Constant flow nozzle
For nozzles, bypass jets, carb jets
A sharp edge at the orifice entrance causes the flow stream to converge, the smallest flow cross section being termed the vena contracta and is the point of lowest pressure. The vena results in less flow through a given hole size than a piece with a rounded entrance.
The particle of fuel coming straight down a bit off to the left or in at an angle at the right both find their way into the hole.
This design is the least sensitive to machine marks, but the blend of the radius to the bore is very important Not easily damaged, as nicks from handling tend to be on the top surface.
The particle a bit off to the left tends to hit the top surface; may bounce off to the left, or into the hole. The particle coming in from the right will go into the hole.
This design is quite difficult to make, as the sharp edge must be the same on all the holes, with no nicks. It is easily damaged by nicking the edge.
The particle a bit off to the left will not enter the hole. The particle coming in from the right may not enter the hole.
You would never really see this design in a jet, but it is exactly like a ramtube without a bell. The top edge is easily damaged.
We use only fully radiused type orifice approaches in all our nozzles and jets. Every nozzle and jet we make is done with great care, but they still don't all turn out properly. Each piece is flowed at three different pressures, then compared to the master flow sheet If it isn't within tolerance, it is scrapped. Testing at three pressures is important because some pieces will flow perfect at low flows, but then go turbulent (due to imperfections on the surface) at high flows.... we call this a "shift" in the flow. All of this quality control costs more money, but it assures you of receiving the best possible peices in the industry.
Flow through an orifice
Pressure rises as the square of the flow through an orifice, so to double the flow through a jet nozzle takes four times the pressure:
If we know the flow of a jet or nozzle at some pressure , we can figure out the flow at a new pressure: