ORDER DESK 661-256-7309

CYLINDER HEAD COMPONENTS

Big Bore Thumpers offers the ultimate CR450R and CRF250 R/X cylinder head solution with APE stainless*** valve conversions. These conversions completely eliminate the problem of oem valved beating themselves into the seats and the lash tightening up. Install APE conversion and spend more time riding and less time working on the motor. World famous APE valve springs are made from premium chrome silicone wire for consistant pressure and excellent fatigue life. Racers as well as street riders have come to depend on APE springs for winning performance. We have had over 30 years experience designing valve springs for the most high-performance motorcycle engines. APE valve spring retainers are CNC machined in-house from aircraft quality titanium bar stock. Special gauging fixtures allow dimensions to be held close to provide exact installed heights when assembling the cylinder head.

PDF instructions for setting valve springs using assembled height method.


STAINLESS STEEL AND TITANIUM VALVES

APE is a leading supplier of high performance and racing valves for motorcycles. APE stainless steel*** valves are precision manufactured from aircraft quality Inconel based stainless steel***. This special material offers excellent resistance to heat and distortion. APE stainless steel *** valves are designed to be used in the most extreme racing applications including the use of exotic fuels, or will give many miles of trouble free street use. They present an outstanding value. In most cases you can upgrade to APE stainless steel*** valves for less than the cost of replacement stock valves. All oversize stainless steel valves feature hard chrome stems for extra long stem to guide life.

Click HERE to see a complete listing of valves for your motor.


***These valves are a very high tensile strength SAE HNV3 steel, used because the factory seats on these models are too hard to get good valve face life with stainless steel.

$24.96 EA. - ORDER THESE VALVES ONLINE -

HONDA CRF 250R (2004-2007) PART NO. TYPE HEAD DIA. OVERALL LENGTH DESCRIPTION
98329 EXHAUST 26MM 82.15MM STD. SIZE / 4.97MM STEM
98331 (THRU '09) INTAKE 31.1MM 83.40MM STD. SIZE 4.98MM STEM

HONDA CRF 450R (2002-2008)

TRX 450R (2004-2009)

PART NO. TYPE HEAD DIA. OVERALL LENGTH DESCRIPTION
98305 INTAKE 36MM 84.6MM STD. SIZE 5.49MM STEM
HONDA CRF 450R (2002-2006) PART NO. TYPE HEAD DIA. OVERALL LENGTH DESCRIPTION
98308 EXHAUST 31MM 84.25MM STD. SIZE 4.965MM STEM
HONDA CRF 450R (2007-2008) PART NO. TYPE HEAD DIA. OVERALL LENGTH DESCRIPTION
98801 EXHAUST 30MM 84.25MM STD. SIZE

STAGE 1 - CRF 250/450 INTAKE ONLY KIT

Consist of APE stainless steel*** valves. High performance "Gold Stripe" valve springs, specialy matched for ultimate valve control. Manufactured from "super clean" chrome silicone wire. Titanium valve spring retainers and steel spring bases

CRF450 and TRX450 Quad (2002-2004) #H450HS-1 - $105.00

CRF250R/X #H250HS-1 - $99.95

STAGE 2 - CRF 250/450 INTAKE AND EXHAUST KIT -

Same as stage one, with the addition of special stainless steel*** exhaust valves, made from premium "turbo grade" material to better resist heat, and featuring hard chrome stems for extreme wear resistance. Exhaust side matched valve springs and titanium retainers.

CRF450 - #H450HS-2 - $199.95

CRF250R/X (2004 - 2007) - #H250HS-2 - $199.95

CRF450R (2007-2008) - H450HS-2-08 - $199.95

CRF450 "GOLD STRIPE" VALVE SPRING KIT

APE introduces it's premium valve spring kit for the Honda CRF450R. This kit features their exclusive "Gold Stripe" valve springs. APE is a leading manufacturer of racing valve springs for the powersports industry. APE springs are world renowned in drag racing, road racing and endurance racing. This same expertise is used in the design and manufacturing of these new CRF springs. Manufactured from the finest super clean, chrome silicone valve spring wire, for reliable, long life service. Exclusive titanium valve spring retainers are manufactured in APE's state of the art CNC facility, from premium aircraft grade Titanium. APE is the only company that manufactures titanium retainers and builds cylinder heads. We know what works and what doesn't. Kit includes spring bases. LOOK FOR THE "GOLD STRIPE".

APE also does private label titanium retainer manufacturing. If you are a cylinder head shop with your own special retainer requirements, contact our engineering dept.

CRF450R/X - #VSKH450 $99.95 (order this item online)

CRF250R/X (2004 - 2007) - VSKH250 $99.95 (order this item online)

TRX450R Thru '05 - #VSKH450TRX $99.95 (order this item online)

TRX450R Thru '06 - '09- #VSKH450 $99.95 (order this item online)

DRZ400/ LTZ400 HIGH-PERFORMANCE VALVE SPRING KIT -

This valve spring kit comes with APE's famous silicone wire valve springs and titanium valve spring retainers. Order as a kit (shown) or just the valve springs. Fits the following bikes and ATVs:

SUZUKI
DRZ400 (2000-2004)
DRZ400E (2000-2007)
DRZ400S (2000-20009)
DRZ400SM (2005-2008)
LTZ400 (2003-2009)

KAWASAKI
KFX400 (2003-2006)
KLX400 (2003-2006)

ARCTIC CAT
400DVX

#VSKS400 - Valve springs and titanium retainers - $97.50
#VS400S - Valve springs only - $39.95

STAINLESS STEEL AND TITANIUM VALVES

APE is a leading supplier of high performance and racing valves for motorcycles. APE stainless steel*** valves are precision manufactured from aircraft quality Inconel based stainless steel***. This special material offers excellent resistance to heat and distortion. APE stainless steel *** valves are designed to be used in the most extreme racing applications including the use of exotic fuels, or will give many miles of trouble free street use. They present an outstanding value. In most cases you can upgrade to APE stainless steel*** valves for less than the cost of replacement stock valves. All oversize stainless steel valves feature hard chrome stems for extra long stem to guide life.

Click HERE to see a complete listing of valves for your motor.

BRONZE VALVE GUIDES

APE valve guides are designed to take the abuse of today's modern high horsepower engines. They are made from special bronze alloy to resist wear and heat. No other valve guide that you can buy will out-perform APE guides. Fact is we supply our guides to nearly all of the top cylinder head shops.


CRF250R '04-'07 Exhaust - #VGH250-7E
CRF250X '04-'15 Exhaust - #VGH250-7E
CRF250R '04-'09 Intake - #VGH250-7I
CRF250X '04-'15 Intake - #VGH250-7I

CRF450R '02-'08 Intake - #VGH450-8I
CRF450X '06-'09 / '12-'15 Intake - #VGH450-8I
TRX450R/ER '06-'14 Intake - #VGH450-8I

CRF450R '09-'15 Intake - #VGH450-15I

CRF450R '02-'15 Exhaust - #VGH450-15E
CRF450X '05-'15 Exhaust - #VGH450-15E
TRX450R/ER '06-'14 Exhaust - #VGH450-15E

$10.95 each.


***These valves are a very high tensile strength SAE HNV3 steel, used because the factory seats on these models are too hard to get good valve face life with stainless steel.
358.93.35