Square four Mk2 valve collett

[Andyozz]

Gents..... HELP..
I have never seen this before but the damn thing has now managed to throw a new problem at me... one of the valve colletts broke in 2 and dropped a valve. this then dislodged the valve guide which will need to be replaced along with piston. however, i am in desperation to locate a new valve collett.

Drags no longer stock them so out of desperation i am asking..... a long shot i know if anyone would have a pair or just one valve collets they would be prepared to part with..... Part number is 640-55. OR details on materials and heat treatment of the colletts so i can make one

As a side point does anyone know who supplies oversize valve guides?

Thanks all in advance.... Regards Andy

[john.whiting]

A broken collet should stay put.............the only exception I can think of is some Ford motors had loose collets so the valves could rotate freely.........nevertheless,any collet trapped in a tapered cap ,will stay put ..........there is some other problem here ,and I suggest you identify it ,before other valves meet pistons.

[john.whiting]

In answer to your other question...make a collett from 4140HT...........i hesitate to say this ,but assuming correct assembly,a common cause of dislodged collets is over revving .

[paul.jameson]

Try Bruce Longman.

[pappleton]

Britbits Barrack Rd Christchurch have been very helpful to me in the past. Digging through their stock to find me collets to fit a G.S. inlet valve and Ariel spring retainer
BR, Paul