• Hey Guest!
    Do you enjoy BCF? Is our forum a useful resource? Do you want to ensure we can stay online?
    Please consider supporting us by **Upgrading**
    [Silver & above members qualify for a BCF email address... Click for Details
    (PS: Subscribers don't see this banner)

Cylinder Head Input/Exhaust Circlip/Split pin


Obi Wan
Country flag
64 BJ8. When I received my rebuilt engine, it didn't have any Circlips aka Split pins in the Collets.
I'm assuming the rebuilder forgot to install them?

Moss #73 Circlip
Workshop Manual #39 Split Pin
Workshop Manual #38 Collet

What is their purpose?
Should I buy them and install?


  • 2805AFF0-A42E-46E5-9F84-CC90FFDC90FC_1_201_a.jpeg
    3.3 MB · Views: 20
  • A8F68B58-90D5-479A-A8BF-626B87438811_1_201_a.jpeg
    1.2 MB · Views: 18
  • 193375ED-C2AD-410F-8381-B30FABEBCE08_1_201_a.jpeg
    1.6 MB · Views: 19
  • A95E2E86-4235-4317-9A00-B887592A9ED5.jpeg
    1.9 MB · Views: 20
Last edited:

John Turney

Country flag
My valves, in the aluminum head built by Denis Welch, don't have them either. Looking at the construction, their purpose seems to be to hold the two cotter pieces in place while the valve springs and valve cap (Moss #69) are assembled. Once assembled, the cotter/collet is held in place on the valve stem by the cap and springs.


Obi Wan
Country flag
Thanks John. Makes sense.
Moss catalogue show quantity required as 12.
Would they also serve as a safety clip, leave them on?
Similar threads
Thread starter Title Forum Replies Date
AUSMHLY Cylinder Head Studs Austin Healey 1
KVH General Tech Rusted Cylinder Head Freeze Plug--WOW Triumph 16
AUSMHLY BJ8 Cylinder Head Installation Austin Healey 6
T TR2/3/3A cylinder head ,valves and springs Triumph 0
K TR2/3/3A Oil leaks at two front cylinder head studs? Triumph 3
AUSMHLY BJ8 Cylinder Head Re-Torque Austin Healey 26
S MGB Mgb with nissan cylinder head. I am a new member, introduction and help MG 1
R TR2/3/3A Cylinder head threaded plub Triumph 6
R BJ8 Cylinder Head Gasket Austin Healey 38
M Alloy cylinder head Austin Healey 5
HealeyRick For Sale Bare 29F Block, Cylinder Head and Manifold Austin Healey Classifieds 2
B General Tech Cylinder head costs MG 7
J For Sale TR 2, TR 3 TR 4 cylinder head Triumph Classifieds 6
J TR2/3/3A TR 4A cylinder head on TR 3 engine Triumph 15
M Planing a Jaguar cylinder head Jaguar 4
RJS TR4/4A Cylinder Head Install - Questions Triumph 16
C Wanted - 3000 cylinder head - uk based Austin Healey Classifieds 0
E Wanted Wanted: TR6 cylinder head- '72 or before Triumph Classifieds 4
RJS TR4/4A Broken Cylinder Head Stud Triumph 10
T Wanted 3.4 Cylinder Head Jaguar Classifieds 3
T TR4/4A Can you proof read this please | TR2-4a Cylinder head stud length chart Triumph 20
T TR4/4A How do you go about reinstalling cylinder head? Triumph 7
PeterK TR4/4A Here's what my NOS 511695 cylinder head looks like, unboxed Triumph 10
HealeyBN7 Is this a 100 Cylinder Head? Austin Healey 4
T TR4/4A Does the water pump need to come off to remove the cylinder head? Triumph 5
DornTRoriginal TR2/3/3A Head Gaskets and Shaved Cylinder Head Triumph 9
SherpaPilot TR6 Cylinder Head Stud Question Triumph 6
T TR4/4A Seems like a bad cylinder head or head gasket but what do you think? Triumph 19
K TR2/3/3A Cylinder head valve springs? Triumph 3
K TR2/3/3A Aluminum plug intop of cylinder head... Triumph 5
KVH General TR Cylinder Head Gasket: Stay Simple? Triumph 9
KVH TR4/4A Cylinder Head Time For More Tools? Triumph 28
BOBBYR Cylinder head for sale on ebay Austin Healey 2
S Procedure for cylinder head removal and re-installation - BJ8 Austin Healey 11
S TR2/3/3A Cylinder head stud methodology Triumph 11
RedTR3 TR2/3/3A How to check for cylinder-to-cylinder head gasket leak Triumph 7
K TR2/3/3A Cylinder Head and Compression Ratio Triumph 0
B BN2 Cylinder Head Stud Thead Size/Replacement Austin Healey 0
TRspitfirefan TR4/4A Cylinder head issues? Triumph 5
K TR2/3/3A Can porting a TR3 Cylinder head be a DIY job? Triumph 6
M Healey 100-4 Piston Crown Clearance needed to Cylinder Head Austin Healey 3
S SaxMan's Cylinder Head Overhaul / Head Gasket Replacement Thread Spridgets 135
B Cylinder Head - Need advice Spridgets 5
G TR2/3/3A TR3/TR4 Cylinder Head Gasket SElection Triumph 2
C General TR TR3B Cylinder Head Triumph 7
S TR6 Suggestions: cylinder head won't release from block Triumph 10
glemon TR6 TR6 Cylinder Head Questions Triumph 31
M Proper torque for cylinder head nuts Triumph 20
angelfj1 TR 4-cyl exhaust manifold to cylinder head nuts Triumph 4
I oil spitting out of hole on Cylinder head Spridgets 6

Similar threads