Shop US-made Kibblewhite valves, valve guides, valve springs, pushrods, bushes and thrust washers for classic Triumph, Norton Commando and BSA twins. Kibblewhite Precision Machining (KPMI) of Pacifica, California, has made engine parts since 1939 and is known for its Black Diamond stainless steel valves and C630 bronze valve guides. Every listing shows the original part numbers and available sizes. We offer free shipping to the lower 48 states.
BSA A65 A70 Inlet and Exhaust C630 Valve Guide 1971-72 Kibblewhite PN# 71-2300 C
$27.17 – $49.03Price range: $27.17 through $49.03
BSA A65 A70 Inlet And Exhaust Valve Guide 1971-72 Kibblewhite PN# 71-2300
$27.17 – $49.03Price range: $27.17 through $49.03
Triumph 650 750 Kibblewhite Black Diamond Inlet Valve(s) PN# 70-4603 BD
$30.52 – $78.59Price range: $30.52 through $78.59
Norton 750 Commando Kibblewhite C630 Exhaust Valve Guide(s) PN# 06-3527 50-0410 50-0411 50-0412
$26.13 – $47.01Price range: $26.13 through $47.01
Norton 750 Commando Kibblewhite C630 Inlet Valve Guide(s) 1968-74 PN# 06-2725 50-0403
$25.12 – $65.85Price range: $25.12 through $65.85
Triumph 650 750 Kibblewhite Mn-Brze Inlet/Exhaust Non-Seal Valve Guides (2) PN# 70-2899 M 70-2900 71-3294 71-3295
$33.69 – $37.79Price range: $33.69 through $37.79
Triumph 650 750 Kibblewhite MN-Bronze Inlet/ Exhaust Seal Valve Guides (2) PN# 70-2899 S 70-2900 71-3294 71-3295
$37.79 – $37.82Price range: $37.79 through $37.82
Triumph 500 650 750 Layshaft Thrust Washer(s) 1963-1982 Kibblewhite PN# 57-1607 K
$22.78 – $40.55Price range: $22.78 through $40.55
Kibblewhite Triumph 500 650 750 Valve Keeper Split Collet(s) PN# 71-3748 K 99-0062 WE259 A
$12.09 – $31.74Price range: $12.09 through $31.74
Triumph 650 Kibblewhite C630 Non-Seal In/Ex Valve Guide(s) PN# 70-2899 CN STD 70-2900
$21.42 – $37.82Price range: $21.42 through $37.82
Triumph 500 ’67-74 T100 Kibblewhite Black Diamond Exhaust Valves (2) PN# 70-6854 BD E6854
$78.59 – $109.66Price range: $78.59 through $109.66
Triumph 500 1967-1974 T100 Kibblewhite Black Diamond Inlet Valves (2) PN# 70-6853 BD E6853
$109.66 – $148.15Price range: $109.66 through $148.15
Triumph 500 T100 Kibblewhite MN-Bronze Valve Guide Pair (2) 1958-74 PN# 70-3208 70-6301
$33.69 – $60.30Price range: $33.69 through $60.30
Triumph 650 750 Kibblewhite Black Diamond Valve and Manganese Bronze Valve Guide Set Complete 1964-1978 PN# 70-2904 70-4603 71-3295 S
$187.56 – $211.07Price range: $187.56 through $211.07
Triumph Norton Universal Valve Stem Seal(s) Kibblewhite PN# TBS-10-0012
$7.35 – $13.75Price range: $7.35 through $13.75
Norton Commando Intake Valve(s) Kibblewhite PN# 06-4034 50-4092
$35.21 – $66.41Price range: $35.21 through $66.41
Table of Contents
Kibblewhite Precision Machining: Valvetrain Specialists Since 1939
James L. Kibblewhite founded Kibblewhite Precision Machining in 1939. His son William F. Kibblewhite took over in 1989 and greatly expanded the range (KPMI: About). The family’s British bike roots run deep. A 1965 Cycle World article describes Jim Kibblewhite and partner Gerald Young running “Precision Machining” from a shop in Pacifica, California. It also tells how they turned Jim’s Norton street bike into a dirt-track racer and then a dragster (Cycle World, March 1965).
Today KPMI stocks more than 3,000 valvetrain parts for motorcycles, ATVs, snowmobiles and watercraft. It runs eleven CNC lathes across five locations (KPMI: About). Its registered brands include Black Diamond, White Diamond, Tensilite and Spin True. KPMI says its replacement guides, valves and spring kits are made to exceed original equipment durability (Kibblewhite Precision Machining).
What Kibblewhite Parts Do in Your Engine
Triumph, Norton and BSA twins are overhead-valve engines: the camshaft moves tappets and pushrods, which work rockers that open the poppet valves (Wikipedia: Valvetrain). Kibblewhite makes most of the parts in that chain:
- Valves: seal the combustion chamber and open to let mixture in and exhaust out.
- Valve guides: hold each valve in line with its seat and carry heat away from the stem.
- Valve springs, collars and keepers: close the valves and hold them shut.
- Pushrods: carry the cam’s motion up to the rockers.
Black Diamond Valves
Kibblewhite Black Diamond valves are one-piece forged stainless steel valves. A special German process treats the surface to improve wear and reduce friction. KPMI says this gives better corrosion and wear resistance than hard chrome or nickel plating (KPMI: Custom Valvetrain). Our Triumph 650 and 750 listing adds that the treatment goes .002″ deep and that the valves are made in the USA.
- Triumph 650 and 750 Black Diamond inlet valve (70-4603): standard 1.600″ head or oversize 1.660″ head, both with a .3105″ stem
- Triumph 650 and 750 Black Diamond exhaust valve (70-2904)
- Triumph 500 T100, 1967–74, Black Diamond inlet valves (70-6853), plus matching exhaust valves (70-6854)
- Norton Commando 750 and 850 Black Diamond exhaust valves, standard (06-5115)
- Norton Commando intake valves (06-4034 / 50-4092)
- BSA A65 650, 1966–72, Black Diamond inlet valves (68-0665) and exhaust valves (68-0663)
Valves must be lapped in to seal at the seat. For UK-made replacements to the original design, compare our G&S valves.
C630 and Manganese Bronze Valve Guides
Kibblewhite offers guides in two bronze alloys (KPMI: Custom Valvetrain):
- C630 nickel-aluminum bronze: the copper gives good heat transfer, the nickel adds toughness and wear resistance, and the aluminum work-hardens. It allows tighter valve clearances, which helps the valve seal at the seat and control oil. Its expansion suits aluminum cylinder heads. See Wikipedia: Aluminium bronze for more on the alloy.
- Manganese bronze: a lower-cost guide with the same tolerances but less wear resistance. It is easier to ream and hone with hand tools.
Guides we stock:
- Triumph 500 T100, 1958–74, manganese bronze guide pair (70-3208 / 70-6301): standard, +.002 and +.004 oversize
- Triumph 500 T100 C630 guide, +.004 oversize (70-3208 / 70-6301)
- Triumph 650 and 750 inlet and exhaust guides (70-2899 / 70-2900 / 71-3294 / 71-3295):
- manganese bronze, seal type, pair: standard, +.002 and +.004 oversize
- manganese bronze, non-seal type, pair
- C630, seal type, +.004 oversize, single
- C630, non-seal type, Triumph 650
- Norton 750 Commando, 1968–74, C630 inlet guides (06-2725)
- Norton 750 Commando, 1968–74, C630 exhaust guides (06-3527): standard and +.004 oversize
- BSA A65 and A70, 1971–72, inlet and exhaust guides (71-2300), in C630 or manganese bronze
- Universal valve stem seals for Triumph and Norton (TBS-10-0012), made from red Viton
New guides must be reamed to size after fitting. We stock the Kibblewhite .3115″ valve guide reamer, made for manganese bronze guides, along with an 8.00mm guide hone (TBS-3125) and a valve guide removal and installation tool set.
There is also a complete Triumph 650 and 750 set, 1964–78, with Black Diamond valves and manganese bronze guides (70-2904 / 70-4603 / 71-3295). If you prefer UK-made valves, the G&S valve and Kibblewhite bronze guide set covers the same 1964–78 engines.
Valve Springs, Keepers and Pushrods
- Triumph 650 valve spring set with collars (99-7037 K/650): for 1963–72 T120 and TR6 twins. The springs are chrome-silicon wire, heat treated and shot peened, and the kit suits stock cams and lift up to .415″.
- Triumph 750 valve spring set with collars (99-7037 K/750)
- Triumph valve spring set without collars (99-7037 K)
- Norton Atlas, 88SS and Commando 650, 750 and 850 premium valve spring set (06-7070 K)
- Triumph 500, 650 and 750 split valve keepers (71-3748 K)
- Triumph 750 T140 and TR7, 1973–82, chrome-moly pushrod set (71-3330 CM): seamless heat-treated tubing with hardened steel ends, ground to size after assembly
- Triumph 750 T140 and TR7 alloy pushrod set (71-3330 A), Triumph pre-unit and unit 650 chrome-moly pushrod set, 1958–72 (70-2620 A), and Norton Commando 750 and 850 chrome-moly pushrod set (06-7940 / 06-7941)
- Triumph 500 and 650 tappet guide block, 1946–65 (70-1477 K)
Kibblewhite makes thin-wall chrome-moly pushrods for Norton and Triumph engines because they are stiffer than the originals (KPMI: New Products; see Wikipedia: 41xx steel). Renew the pushrod tube seals at the same time with our Triumph pushrod tube seal kit. Valve spring kits from Hepolite are also available.
Bushes, Thrust Washers and Clutch Parts
Kibblewhite also makes engine and gearbox wear parts:
- BSA A50 and A65, 1966–72, crankshaft bushing, standard, plus the crankshaft thrust washer (68-0685) and wrist pin bushing (67-0298)
- Triumph 350 and 500, 1957–68, timing-side crank bush (70-4322 K)
- Triumph 500, 650 and 750 layshaft thrust washers, 1963–82 (57-1607 K)
- Triumph and BSA unit twin clutch thrust washers: early, 1963–69 (57-1735), and late, 1970–83 (57-3931)
- Triumph 650 and 750 clutch push rod, 1963–82 (57-1736 K)
- Triumph 500, 650 and 750 clutch spring set (57-1830 K)
How to Choose Kibblewhite Parts
- Start with your model and year. Check your Triumph parts book or workshop manual for the original part number. Each listing shows it.
- Choose your guide material. C630 bronze lasts longest and allows tighter clearances. Manganese bronze costs less and is easier to ream and hone.
- Pick the right oversize. If the head has been worked before, a machine shop should measure the guide bores and seats before you order standard or oversize guides and valves.
- Replace parts as a set. New valves need new or checked guides, and should be lapped into freshly cut seats. Replace the springs if they are worn, and fit new stem seals and keepers.
- Leave the machine work to a professional. Fitting and reaming guides and cutting seats need the right tools and skills. Shop Triumph manuals, Norton manuals, BSA manuals and workshop tools.
For the rest of the engine, see Triumph engine parts, Norton engine parts, BSA engine parts, and gasket sets for Triumph, Norton and BSA. Rebuilding the whole top end? Add Hastings or Grant piston rings.
Read our guides Triumph T100 Top End, Triumph Top End Sealing and What the Workshop Manual Doesn’t Explain, Eliminating Triumph Oil Leaks and Pattern Parts and Fettling to Perfection. Need help choosing? Contact our team.
Shop Kibblewhite Parts
Browse the Kibblewhite parts above, or see all the brands we carry. Orders ship free to the lower 48 states, and weekday orders placed before noon Mountain Time ship the same day (Shipping and Returns).
Kibblewhite Valvetrain Parts FAQ
Who makes Kibblewhite parts?
Kibblewhite Precision Machining, Inc. (KPMI), a family business founded by James L. Kibblewhite in 1939. His son William F. Kibblewhite has run the company since 1989. It is based in Pacifica, California.
Are Kibblewhite parts made in the USA?
Our Kibblewhite listings describe the valves, valve guides, pushrods and crank bushes as US made. KPMI machines its parts on its own CNC lathes in California.
What are Kibblewhite Black Diamond valves?
They are one-piece forged stainless steel valves with a special surface treatment. The treatment improves wear resistance, reduces friction and resists corrosion better than hard chrome or nickel plating.
What is the difference between C630 and manganese bronze valve guides?
C630 is a nickel-aluminum bronze. It is tougher and more wear resistant and allows tighter valve clearances. Manganese bronze guides cost less and are easier to ream and hone, but wear faster.
Which motorcycles do your Kibblewhite parts fit?
We stock Kibblewhite parts for Triumph 350, 500, 650 and 750 twins, Norton Atlas, 88SS and Commando 650, 750 and 850 models, and BSA A50, A65 and A70 twins. Fit varies by part, so check each listing’s years and part numbers.
Do new valve guides need reaming?
Yes. New guides are pressed in slightly undersize and must be reamed, and sometimes honed, to the correct valve stem clearance. We sell a Kibblewhite .3115″ reamer made for manganese bronze guides. Have a qualified machine shop do this work.
Do I need oversize valves or guides?
Only if your cylinder head needs them. If the guide bores or valve seats have been machined before, have them measured first. Many listings come in standard and oversize options.
Do Kibblewhite pushrods fit stock engines?
Yes. Our Kibblewhite pushrod sets are direct replacements for the Triumph 650, Triumph 750 T140 and TR7, and Norton Commando 750 and 850. Each set has four pushrods.
Should I replace valve springs when I replace valves?
It’s good practice. Old springs can lose tension. Our Triumph 650 spring kit includes new collars and base washers and suits stock cams.
Do you offer free shipping on Kibblewhite parts?
Yes. Orders ship free to the lower 48 US states. Weekday orders placed before noon Mountain Time ship the same day. Service tools such as reamers can’t be returned.