RENNTECH AIXRO XR50 User manual

RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL

INTRODUCTION!!!!!!TECHNICAL SPECIFICATIONS
1.1!preface!!!!1! ! 7.1!data!!!!13
1.2!state of development! ! 1! ! 7.2!torque specs!!!13
1.3!target readers!!!1! ! 7.3!fuels!!!!13
1.4!copyright info.!!!1! ! 7.4!carburetor !!!13
! !!!!!!7.5!ignition and spark! ! 14
PRODUCT DESCRIPTION!!!!!7.6!clutch!!!!14
2.1!functions of the rotary engine!2! ! 7.7!starter !!!!14
2.2!area of application! ! 3! ! 7.8!fuel pump!!!14
2.3!identifying components! ! 3
! !!!!!!TIPS AND TRICKS
ASSEMBLY PROCEDURES!!!!!8.1!RENNtech faq!!!15
3.1!cooling system!!!4
3.2!engine assembly!!!4
3.3!chain tensioning!!!6
3.4!fuel and fuel lines! ! 6
3.5!electrical connections! ! 7
3.6!exhaust manifold! ! 7
3.7!exhaust pipe!!!7
3.8!starter !!!!8
INITIAL OPERATION
4.1!check-up!!!9
4.2!starting the engine! ! 9
4.3!test run!!!!10
4.4!after the test run! ! 10
OPERATION
5.1!warm-up and break-in! ! 11
5.2!driving!!!!11
5.3!switching off!!!11
MAINTENANCE AND WARRANTY
6.1!wear and tear items! ! 12
6.2!issue of warranty! ! 12
6.3!warranty procedures! ! 12
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
CONTENTS

1
INTRODUCTION
1.1
PREFACE
RENNtech would like to thank you for your purchase of a new Aixro XR50 rotary powersports engine. By
doing so, you have helped set new standards for performance and environmental responsibility.
Before you get started, it is imperative that you read and understand the instructions and procedures
outlined in this operator manual. Inside, you will find information to help you with the initial setup and
maintenance of your Aixro, as well as prevent potential damage.
Again, thank we’d like to thank you - and wish you luck in all your adventures!
Sincerely,
Hartmut Feyhl
president, RENNtech INC.
1.2
STATE OF DEVELOPMENT
The procedures and instructions outlined in this manual represent the most current data available at the
time of publication. Some printed specifications may deviate from actual specs. due to advances in
production methods or design changes.
1.3
TARGET READERS
This operator manual is intended for anyone who intends to install, operate, or service the Aixro XR50
rotary engine.
1.4
COPYRIGHT INFO.
All rights reserved.
The circulation or duplication of this document, in part or in whole, is not permitted without the express
permission of RENNtech INC. and /or Aixro GmbH.
TITLE: RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL

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PRODUCT DESCRIPTION
2.1
FUNCTIONS OF THE ROTARY ENGINE
Aixro’s XR50 is a 4-cycle rotary piston engine based on the Felix Wankel patents. Like other
racing 2-cycle and 4-cycle rotaries, the XR50 is lubricated by a 40:1 fuel/oil mix.
The XR50’s rotor revolves around an eccentric crankshaft, which eliminates oscillating masses
to produce a unique, vibration-free experience. The rotor spins at 1/3 the rotational speed of
the eccentric shaft, igniting one of its three chambers each revolution.
Rotary engines offer many special advantages when compared to conventional piston engines.
These include vibration-free running (due to evenly balanced rotating masses), very compact
construction, outstanding power-to-weight ratios, outstanding low-rpm torque, and very low
emissions.
The primary components of the Aixro XR50 include:
•water-cooled casing (called a trochoid, due to the shape of its interior outline)
•rotor and gaskets (similar, in function, to conventional pistons and rings)
•eccentric shaft (similar to a conventional crankshaft)
•water-cooled side plates
The XR50 makes use of a carburetor to deliver a 40:1 fuel/oil mix (approx. 2% oil). Due to the
high operating temperatures of the rotary, the oil burns completely without the environmentally
harmful residues normally associated with 2-cycle engines.
At low rpm, fresh air and fuel (pre-mix) passes through a side plate before going through the
rotor and into the opposite side plate, cooling the rotor, bearings, and eccentric shaft. From
there, the air flows into the combustion chamber.
At approx. 5500 rpm, a vacuum-actuated valve opens, and the air/fuel mix is able to flow
directly through the periferal port and into the combustion chamber. This increases efficiency
at high rpm by allowing more oxygen into the chamber, which adds to the enormous
performance of the XR50.
These and other special processes (unique to rotary engine architecture) produce a fraction of
the harmful emissions of comparable 2-stroke engine, and are on par with some of the best
racing 4-strokes.
For even cleaner performance, the XR50’s high operating temperatures allow it to be fitted with
a catalytic converter.
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PRODUCT DESCRIPTION
2.2
AREA OF APPLICATION
Aixro’s XR50 is designed exclusively for use in racing go-karts. Any use or development of the
XR50 for other applications is strictly prohibited, except with the express, written consent of
Aixro GmbH and/or RENNtech INC.
2.3
IDENTIFYING COMPONENTS
1. !trochoid
2. !eccentric shaft
3. !rotor, gaskets
4. !carburetor
5. !ignition module, spark coil, and spark plugs
6. !clutch
7. !starter
8. !vacuum-actuated valve
9. !throttle valve
10. !fuel pump
11. !side plate ignition side with static pinion and bearing
12. !side plate output w/ bearing
13. !exhaust manifold (aka “header”)
14. !exhaust pipe (aka “silencer”, or ”muffler”)
15. !water supply
16. !kill switch
17. !encasement
18. !engine mount
19. !engine support
20. !bell housing
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL

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ASSEMBLY PROCEDURES
3.1
COOLING SYSTEM
The XR50 is a liquid-cooled motor that uses an external water pump driven by the rear axle to
cycle water and coolant through the radiator. The radiator and cooling systems can be installed
on the left side of the kart without strain or stress on the chassis.
Water hoses should be free of any sharp bends or kinks, and run from the bottom connector on
the radiator to the central connector of the water pump (inlet). The hose should lead from the
pump outlet to the front engine connection. The engine’s water exit (next to the exhaust mani-
fold) takes up the hose leading back to the radiator. (see pg. 5)
The cooling system should be filled with a mix of water and coolant.
Routine checks should be made to ensure tightness*. Route the return hose in a sufficient dis-
tance from the exhaust pipe. Check that there are no sharp bends in the hose connections and
that the hoses do not touch any rotating parts.
Fasten all hose connections with hose clips while allowing suffecient movement
Should insert a water temp during this installation
!TIP: a small amount of antifreeze prevents corrosion.
!TIP: place water temperature sensor as close as possible to the exhaust port, or (ideal) directly
into engine housing.
3.2
ENGINE ASSEMBLY
Assemble the engine mount (torque to 26 Nm).
Remove the clutch cover.
!TIP: place the engine on the chassis and align the chain / sprockets.
ATTN: DO NOT DISABLE VACUUM SOLENOID
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RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL

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ASSEMBLY PROCEDURES
(continued)
3.3
CHAIN TENSIONING
Generally, the engine should be mounted as close to the rear axle as possible to achieve the
shortest chain length (in this case, approx. 33”). Be sure to choose a suitable rear sprocket for
your racetrack, such that engine rpm does not exceed 10500 at your kart’s top speed on the
longest straights.
!TIP: if the gearing of a 100cc racing kart for your track is 10/82, subtract 37 from the large
chain ring - this will give some indication of the correct gearing (e.g., 82 – 37 = 45). Note that
this is merely a guide, and it is important to closely monitor engine RPM (while driving) to adjust
sprocket/gearing accordingly.
At the tightest spot on the chain, it should be possible to move chain (slack) approx. 10mm.
Once the chain is tensioned correctly, assemble the clutch cover.
!TIP: over-tightening the chain will damage the clutch and bearings.
!TIP: do not use a chain lock or master link - the chain must be riveted. RENNtech recommends
Regina O-ring chain (available from RENNtech for 89.00USD). Clean and lube chains regularly,
using O-ring safe cleaners (such as WD40). Stronger cleaners (brake cleaner, etc.) will dry out
and damage the O-rings.
3.4
FUELS AND FUEL LINES
The Aixro XR50 can be run using 91 octane “premium” unleaded without problems. RENNtech
recommends a 93 octane “premium” (determined with the formula: (MOZ+ROZ) / 2, where MOZ
is “motor octane”, and ROZ is “research octane”). Petrol-resistant rubber fuel lines should be
used at all times, and a fuel filter should be mounted between the fuel tank and the inlet to the
XR50’s fuel pump. The fuel line for connecting the fuel pump to the carburetor’s float chamber
is pre-assembled.
!TIP: the engine MUST BE RUN WITH A FUEL/OIL MIX, approx. mix ratio of 40:1.
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ASSEMBLY PROCEDURES
(continued)
!TIP: use only self-mixing, high-quality synthetic two-stroke racing oils with high flash-points
(Motul is recommended).
3.5
ELECTRICAL CONNECTIONS
The XR50 can be switched off using a red STOP button (included), which can be mounted on a
kart’s frame or steering wheel (recommended). From there, a wire (with connector) leads to
the engine casing, and is plugged in to the corresponding connector.
!TIP: when mounting the STOP button to a steering wheel, it is important to leave enough slack
to allow the wheel to turn, lock-to-lock, without pulling or binding the wire.
STARTER WIRE: SEE STARTER, 3.8
3.6
EXAUST MANIFOLD
The XR50’s exhaust manifold is fastened with 3 nuts, torqued to 25 Nm. copper-coated, self-
locking nuts are used to secure the header pipe.
ATTN: THERE IS NO EXHAUST GASKET
!TIP: you may use a high temp. silicon “liquid gasket” (sparingly).
3.7
EXHAUST PIPE
The exhaust pipe (or muffler) is fastened to the exhaust manifold with tension springs (2 incl.
with XR50 engine package) in a manner similar to other racing karts.
!TIP: replace the intermediate plastics in the exhaust mount with a strong compression spring
(due to extreme temperatures).
ATTN: EXHAUST PIPE MUST BE ASSEMBLED WITHOUT STRESS LOADS
ATTN: THE EXHAUST RUNS VERY HOT, AND TYPICALLY GLOWS RED - BURN HAZARD
!TIP: use 2 support brackets (due to added weight of exhaust system).
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ASSEMBLY PROCEDURES
(continued)
3.8
STARTER
The standard XR50 engine is started using an external starter placed over the clutch fastening
nut (with a 22 mm socket) or started with an optional on-board starter.
3.8.1
OPTIONAL ON-BOARD STARTER
RENNtech’s optional on-board starter is intended for use in short start intervals. Under normal
conditions, the motor should crank and start almost immediately.
3.8.4
ELECTRICAL CONNECTION
The optional starter motor is a 12V system, controlled via relay.
ATTN: DO NOT CRANK MOTOR USING STARTER FOR MORE THAN 10 CONSECUTIVE SECs.
!TIP: on-board starter should not be used for initial start-up during break-in period. External
starter is recommended until engine “loosens up” and starts easily.
!TIP: check all positive connectors and shield against accidental grounding.
3.8.2
EXTERNAL (or “REMOTE”) STARTER
ATTN: DO NOT CRANK MOTOR USING STARTER FOR MORE THAN 10 CONSECUTIVE SECs.
!TIP: once the engine starts, remove the starter socket IMMEDIATELY to avoid nut loosening.
!TIP: check central nut for tightness after each run when external starter is used.
!TIP: complete COLEMAN starters available through RENNtech INC.
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INITIAL OPERATION
4.1
CHECK-UP
!TIP: use the following as a basic checklist before heading out onto the track.
Is the engine properly secured to the chassis?! ! ! ! _
Have the following connections been properly tightened?
!1.!cooling system!_
!2.!fuel system! ! _
!3.!exhaust pipe! ! _
!4.!STOP button! ! _
Are hose, pump, and float chamber of the carburetor filled with fuel?!_
Is the fuel / oil properly mixed? (40:1, or approx. 2%)! ! ! _
Does the carburetor slide easily from idle to full throttle?! ! ! _
Has the air filter been properly mounted?! ! ! ! ! _
Has the chain been properly aligned?!!! !! _
Are the brakes (front and rear) functioning properly?! ! ! _
Is the starter battery fully charged?!! ! ! ! ! _
4.2
STARTING THE ENGINE
!1.!engage the choke
!2.!bring fuel slider in idling position
!3.!start the engine
!TIP: engine should start within first 10 sec. do not run starter for intervals longer than 10 sec.
without “breaks”.
!TIP: pay close attention to rpm using tach (because of the low frequencies involved, it is often
difficult to gauge rpm “by ear” with a rotary).
ATTN: MOST TACHS ARE TOO SLOW TO READ EXACT RPM, AND (UNDER LOAD) CAN BE 200
TO 300 RPM “BEHIND” ENGINE. ON A STAND (FREE-REVVING) A TACHOMETER CAN OFTEN BE
3000 TO 4000 RPM BEHIND
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INITIAL OPERATION
(continued)
4.3
TEST RUN
!1.!idle the engine with choke for approx. 1 minute, then disengage choke.
!2.!idle the engine without choke for approx. 30 sec.
!3.!press STOP button.
ATTN: DO NOT TAMPER WITH VACUUM SOLENOID
ATTN: DO NOT FREE REV ENGINE ON STAND OR WITHOUT LOAD
ATTN: DO NOT MAKE ADJUSTMENTS TO ENGINE WHILE IT IS RUNNING
ATTN: DO NOT MAKE ADJUSTMENTS TO ENGINE WHILE IT IS ON STAND OR WITHOUT LOAD
4.4
AFTER THE TEST RUN
Once the XR50 cools down (could take several minutes) check to ensure that all bolts are still
securely fastened (engine mounts, etc.) and check coolant levels (coolant check will not be
accurate if engine is still hot).
Once all checks are “passed”, the Aixro XR50 is ready for operation.
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OPERATION
5.1
WARM UP AND BREAK-IN
To properly warm-up the Aixro XR50, drive the kart slowly, increasing rpm with gentle throttle
movements. Do not rev the engine beyond 8500 rpm during its first hour of operation.
Break-in your Aixro rotary just like you’d break-in other powersports engines, by starting at low
rpm and low load, steadily increasing rpm and loads. Your engine will be fully broken in after
approx. 1 hour.
!TIP: gear your kart for your track, keeping 10500 as your “peak” rpm.
ATTN: DO NOT MAKE ADJUSTMENTS TO ENGINE WHILE IT IS ON STAND OR WITHOUT LOAD
5.2
DRIVING
Most drivers need some time to adjust to the performance of the Aixro XR50, and may need to
adjust their driving styles
!TIP: build speed slowly, and avoid driving faster than you’re really able to.
!TIP: optimal engine temp. is approx. 150 deg. F; +/- 20 deg.
ATTN: IF ENGINE TEMP. REACHES 180 DEG., STOP ENGINE IMMEDIATELY
5.3
SWITCHING OFF
Run a full cool-down lap at low speeds, keeping throttle inputs to a minimum. Try to avoid time
spent idling in the paddock.
ATTN: PRESS STOP BUTTON IMMEDIATELY UPON REACHING THE PADDOCK
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MAINTENANCE and WARRANTY
6.1
WEAR AND TEAR ITEMS
-!spark plugs
-!oil seals
-!air filters
-!chains
-!clutch and clutch parts (check and lube every 4 - 5 hours)
-!fuel lines
-!carburetor jets
-!carburetor gasket
6.2
ISSUE OF WARRANTY
In general, there is no warranty on racing parts of any kind. This is a racing motor, designed for
go-kart racing. Only Aixro GmbH is authorized to issue warranties on XR50 engines and engine
components. Aixro GmbH guarantees the faultless function of these engines when they are
properly used and handled.
The buyer is obligated to document the date of purchase, correct assembly procedures, proper
break-in, accurate number of operating hours, correct handling, and that appropriate steps
against engine damage were taken.
Over-reving and overheating issues (running engine too lean, without water, etc.) is not covered
under any circumstance. Typical signs of over-rev include separation of magneto from flywheel.
Typical signs of running too lean include damage to (or failure of) rotary piston’s needle bearing
due to extreme temperatures.
6.3
WARRANTY PROCEDURE
In the event that a warranty claim is issued, the complete engine must be made available to
Aixro GmbH and/or RENNtech INC. After checking the engine and determining that the cause of
failure falls within the scope of warranty, damaged parts will be repaired or replaced free of
charge.
The reassembly of the XR50 can be performed by RENNtech INC.’s regional representative or at
RENNtech INC.’s location in Lake Park, FL, at the discretion of RENNtech INC.
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TECH SPECS
7.1
TECHNICAL DATA
TYPE! ! ! ! 4 stroke, single-rotor Wankel-type rotary
OUTPUT! ! ! 48 @ 8500 rpm
TORQUE! ! ! 34 lb-ft @ 4500 rpm
WEIGHT! ! ! approx. 30 lbs
CHAMBER VOLUME! ! 294 cc
MAX RPM (recommended)!10500 rpm
CLUTCH! ! ! 2-disc centrifugal dry clutch with RENNtech press. plate
DRIVE! ! ! ! 0.5” 428 o ring chain
IGNITION! ! ! magnetic ignition with variable timing
CASING! ! ! water-cooled, Nicasil-coated rotor housing
END PLATES! ! ! water-cooled steel alloy
7.2
TORQUE SPECS
CASING BOLTS! ! M6! ! 15 Nm
NUT, MAGNET BRACKET!M20 x 1.5!40 Nm
NUT, CLUTCH! ! ! M14 x 1.5!30 Nm
SPARK PLUGS!! ! M10 x 1!12 Nm
EXHAUST NUTS! ! M8! ! 22 Nm
7.3
FUELS
FUEL! ! ! ! 91 or better octane unleaded (93 pref.)
OIL! ! ! ! full-synthetic 2-stroke racing oil (Motul 600, etc.)
FUEL:OIL RATIO! ! 40:1 (approx. 1.6 fl. oz per gallon, or 25 cc per liter)
COOLANT! ! ! 30:1 water/coolant (approx. 2.1 fl. oz per gallon)
7.4
CARBURETOR
Std. carburetor for the XR50 is the Bing type 84/32/150, with a main jet (164-168) and a idle
jet 42. Recommended carb setup can be found in FAQ section (pg. 14).
!TIP: use the K&N RC 2320 air filter (included) or get the available airbox adapter.
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TECH SPECS
(continued)
CARBURETOR SETTINGS
STD. EQUIPMENT
TYPE! ! ! ! Bing type 84; 84/32/150/00
MAIN JET! ! ! 164 - 166
IDLE JET! ! ! 42
JET NEEDLE! ! ! 8M1
NEEDLE JET! ! ! 2.74
AIR CIRC. BOLT! ! opened 1/4 - 1/2 rotations
GAS SLIDER SCREW! ! 2 revolutions of UT gas slider
AIR FILTER! ! ! K&N RC 2320
7.5
IGNITION AND SPARK
IGNITION! ! ! IDM with variable ignition timing
SPARK PLUGS!! ! DENSO U22 ETR 4 2 0 1
7.6
CLUTCH
Std. equipment clutch is Horstman 0.5” Greased Lightning HD unit, with 11 tooth, 0.5” drive
pinion (428 chain pass).
!TIP: RENNtech recommends using 3 weights per clutch (12mm nuts/bolts, no washer). This
can be changed to adjust for track, kart weight or driver skill, but deviations could lead to some
additional clutch wear.
7.7
STARTER
RENNtech’s on-board starter option for the Aixro XR50 uses 12v, 9 amp-hour sealed lead-acid
powersports batteries, or a Coleman external starter (similar to other TaG kart batteries).
7.8
FUEL PUMP
Std. equipment fuel pump is a Mikuni DF 44-18.
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TIPS AND TRICKS
8.1
FUEL:OIL RATIO! ! 40:1 (approx. 1.6 oz. per gallon or 25 cc per liter)
FUEL!!!!93 pump octane
!TIP: using higher-octane racing fuels will not significantly improve engine performance
OPERATING TEMP! ! 150 deg. F
!TIP: use a mix of water and coolant to protect against corrosion and extreme temperatures
ATTN: DO NOT IDLE ENGINE ON STAND OR IN PADDOCK
JETTING!!!a change of 1 jet (ex.: 166 - 168) usually makes a difference
CHAIN!!!!loose, approx. 10 mm of play
!TIP: RENNtech recommends Regina 428 O-ring chain
TIRES!!!!10 - 12 psi
MAX RPM!!!10500 rpm (engine can be over-revved, so watch rpm closely)
ATTN: TACH MUST BE SET TO 2-STROKE SETTING
CLUTCH PLATES! ! should be replaced every 40 - 50 race hours
!TIP: use three (3) clutch weights - bolts and nuts, no washers, recommended
!TIP: pipe is extremely HOT, and may glow red in dim light
!TIP: lube clutch bearings frequently
!TIP: avoid any engine “blueprinting” or modifications to chamber volume - chamber volumes
are already at maximum efficiency, and any mods will result in power loss
ATTN: DO NOT MAKE ADJUSTMENTS TO ENGINE WHILE IT IS ON STAND OR WITHOUT LOAD
ATTN: DO NOT DISABLE VACUUM SOLENOID
ATTN: RUNNING A NON-OEM EXHAUST WILL CHANGE RPM CURVE
ATTN: USE CAUTION WITH NON OEM PARTS; HIGHER RPM WILL SHORTEN ENGINE LIFE
RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL

RENNTECH / AIXRO XR50 ENGINE OPERATOR MANUAL