TRX450R Cylinder Head Extreme Race Service BeCu Seats DLC Valves

Description

Fastheads deals exclusively in motocross cylinder heads and valve train components for all brands.  We machine, repair and service worn or damaged heads with the latest high tech equipment designed for high RPM multi valve heads.  Old school methods of valve seat re-facing or grinding will not work on these new heads!  Our primary goal is incredible reliability and reduced valve wear while maintaining stock or more power.  We do this by using compatable alloys, DLC type valve coatings and precise machining for perfect valve to seat concentricity.  We offer economy trail to full on race options depending your needs.
This package services and upgrades all years TRX450R to our reliable race specs for motocross and desert.  P
remature intake valve wear is eleminated without using power robing Stainless valve kits.  This service solves all wear problems inherent with the Honda unicam heads.
Your head
will be returned ready to bolt on with new Chromium Nitride coated intake valves, Beryllium Copper intake seats, Bronze Manganese exhaust guides, Stainless exhuast valves with a specialized hard coating, new springs and viton seals.  Race seat face profiles are cut perfectly concentric and blended/ported into the bowls and professionally assembled and tested.  04-05 head gain 2hp just from the use of Ti intake valves.
Specs can be modified to suite your motors needs upon request.  If you have a big bore we can fit larger valves.  The specs in this package is for motocross and offers a good usable powerband from low to high rpm.  Specs can be altered for peak hp associated with wide open drag racing.  We can also adjust the valve shims for .  Complete porting for another 5 when purchased with this package.  PICTURES may not represent this particular model.
Short report from Fastheads, MX Head Machining 101 at bottom of this page.  Why old school machining methods don't work.
9 package
includes:
Removing valves, soda blasting, inspect for all needs, replacing intake seats and exhaust guides, cutting all seats with a multi angle high flow profile, assembled with parts in list below, spring and stem heights are checked and corrected and the head is vacuum tested for quality.  The
stock intake seats are machined out and new Beryllium Copper alloy Seats are installed.  These seats are 100% compatible with lightweight Titanium valves and last much longer than the the stock OEM setup.  This alloy wicks away the valve heat much faster, will not corrode, adds a padding effect to the valve without loosing material from micro welding.  This package also includes replacing the exhaust guides with a Bronze Manganese alloy.  Most all TRX heads we receive for repair have worn exhaust guides due to the rocking action from the rocker arm.  Bronze Manganese guides can run half the clearence of stock, pull heat out of the valve through the stem and lasts much longer when properly honed.  To keep the cost down and still make a better than new head, we only replace the parts that wear.  In the Unicam head the intake seats and exhaust guides are usually all that is needed.  Cutting the stock exhaust seats is a must after replacing guides to maintain concentricity and performance.  Honda uses steel exhaust valves as they need stronger stems when using the exhaust rocker arm.  Stainless is compatable with the stock seat material and usually just needs to be re-cut.  The exhaust and the intake seats are then blended / ported up to the guides as seen in the picture.  This is the critical area that creates 75% of all flow obstacles in the port.  You you will notice extra power throughout the powerband.  WE CAN BUILD A HEAD TO SUITE YOUR NEEDS WITH OVERSIZED VALVES, ALL TI OR SS, ETC.  JUST GIVE US A CALL.
Installed parts in this package.
Beryllium Copper intake seats.
Bronze Manganese exhaust guides (Set up a half the std clearance)
Viton low friction guide seals
Exhaust Valves with black Nitride or hard chrome coatings (Reduces guide wear)
CrN Coated Ti Intake valves.  (package price can be reduced 0 with OEM Ti)
OEM intake springs
OEM R exhuast springs
For  more we can adjust your valve shims
.
OUR GUARANTEE
you will get our general head service
free
with this package for life, if it ever needs it!  (orginal customer only)
We can supply all your top end needs including gaskets, pistons and cams.
Unicam Motocross valve trains come with Ti intake valves for a reason!  They are race engines and they loose 2 to 3 hp and rev slower with Stainless valve setups.
If you have decided to go with steel valves and heavier springs for wearability and lower cost (which we sell in our ebay store) you will loose more power than you can gain back from porting or cams.  If you what to maintain maximum power, RPM and acceleration you have to use Titanium valves as originally designed.  Especially on 250cc machines.   Honda only use SS exhaust valves due to the extra strength needed from the rocking action of the rocker arm.  We use Ti valves and lighter springs on the exhaust for full race needs but they are expensive and need replacing more often.
For 9 we do the above machine work including the seats and guides but no assembly, parts or porting.
For 9 you can have the above installed into a new head.  A complete port and polish job is another 0.00 when done in conjunction with any of these packages.
Send heads and engines to:  Fastheads 1141 E 540 N #7, Saint George, UT 84770
Download Repair order on our web site.
If we find any other problems in your head we will estimate and give you a call.   This package is the same price for TRX450R, CRF250R, CRF450R, CRF250X and CRF450
We use the new race developed and proven Rottler SG7 seat and guide machine specially designed for accuracy and tooled for the power sports industry.
Please note:  Modern valve faces can not be cut due to the hard facing.  For this reason we only assemble with new valves.  If you want an endurance or the Ultimate race head we can build it.   Dealers and race teams are welcome.
With the economy in shambles, hanging on to your current machine and keeping it in prime condition is the new standard.  We can keep you running and updated!
Please check out our ebay store for motorcycle tools, rebuild kits and rebuilding services.
We operate one of the largest mail order style service for complete engine, transmission and head work for off road race bikes.  It's our specialty so we can save you money and headaches.  See us at the WORCS races and other events around the west.   Brent Kirk has raced and has been involved with the technical aspects of engine building for the last 39 Years.  His sons race on CRF 250's.
HEAD MACHINING 101:
CURRENT STYLE HIGH RPM MOTOCROSS HEADS REQUIRE NEW MACHINING TECHNIQUES.  OLD SCHOOL METHODS DO NOT WORK.  WORN VALVE SEAT FACES HAVE TO BE PERFECTLY MACHINED WITHIN TENTHS OF A THOUSANTH IN ORDER MAINTAIN PERFORMANCE, EASE OF STARTING, REDUCE VALVE WEAR AND VALVE BREAKAGE.
This is everything you need know in order to grasp the concept of how and why valve seat concentricity is extremely critical.  Specialized machining techniques have been developed in order to cut concentric seats in heads that use very small valve stem diameters which require very small pilots that are more prone to flex.
All valve seats are cut by installing a pilot post in the guide in which a cutting tool centers and revolves around.
The seat has to be accurately cut horizontal and vertical to the centerline of the valve guide.
Concentricity is how perfect this measurement is.
Poor concentricity will let one side of the valve land on the high side of the seat face first.
Depending on the severity of the seat face offset the valve may always be open on the low side or may flex or slide to center from the force of the valve spring.
Guides wear oval front to back and may let the pilot move in the same pattern which can also create poor concentricity along the seat radius.
Imagine now, how non-concentric seats can affect the ability for the valve to seal under pressure, how it increases valve wear, how it decreases the ability for the valve to transfer heat to the seat and how the valve stem being flexed every time the valve closes can create it to break.
The following is a description on why it is nearly impossible to maintain concentricity using old machining methods on newer race heads.
1.
Valve stems and the guides are much smaller in diameter.
They have gone from 7-8mm to 4-5.5mm.
The smaller pilot shaft needed to fit in the guide decreases its ability to withstand flex thus allowing the cutter to follow the old seat face.
2.
The distance from the top of the guide to the seat face has increased due to a much larger port which allows the pilot to flex even more.
3.
Some race seat face profiles require the cutter to cut more surface at one time along its cutting edge which creates more force against the pilot more.
4.
Valve guides that are worn or damage have to be replace before cutting the seats.
Guides wear in an oval hour glass shape and won’t hold the pilot from moving in an in the same pattern.
Whenever a guide is replaced its center line changes slightly.
Seats have to be re-cut to be concentric with the new center line.
Modern machining equipment has been created to overcome the pilot flex problems.
Most early four strokes were low rpm utility engines and had large enough pilot to enable the use of hand operated cutters and grinders with some degree of accuracy.
They would run and start even if the concentricity was off compared to the tolerances required in race motors.
Most motorcycle shops cut valve seats using these hand tools such as a “Neway cutter” and grinding stones.
When they tried using these methods on heads with small pilots and not realizing the need for perfect concentricity their work immediately started to fail.
Except for race technicians most mechanics don’t even know what a seat concentricity gauge looks like.
One major cure was to use stiffer pilots made of carbide instead of tool steel to reduce flex.
This still didn’t give us the needed concentricity requirements with hand operated cutting tools.
The only way to make concentric cuts with small pilots is to support the pilot from the top and guide side.
This requires the purchase of a ,000 or more air float seat and guide machine.
Very few shops can justify the expense in purchasing this type of equipment and most mechanics if they are educated on the importance of concentric seats will send them to a professional race machine shop.
A human hair is two thousandths thick .002”, good concentricity is a quarter of that .0005”
On Apr-05-08 at 17:49:47 PDT, seller added the following information:
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