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A+ valves

Posted: Fri Dec 13, 2019 11:35 am
by midget
I am in the process of preparing a 1275 A+ head for unleaded conversion, and am surprised to find that the valves are triple cotter/double spring type.
I have built other A+ heads in the past but have not come across this before. It is a very late 1984 and looks to be totally original from factory fit. I am aware that there was some later engines from Mini/Maestro range that had these heads, but not from an Ital?

Need to know what to order for replacements. Any Ideas please?

Re: A+ valves

Posted: Fri Dec 13, 2019 12:16 pm
by philthehill
http://www.minispares.com/product/Class ... o%20search

Use the Minispares web site to determine the replacement valves required against head seat size. Quite a bit of information is available from their spares web site.

For the long term it may be easier and cheaper to fit single groove valves, top cap and collets.

If I remember correctly the angle of the contact face of the collet relative to the spring cap is different to the single groove collet so must be changed in complete units - that is collets and spring top caps.

http://www.minispares.com/product/Class ... |Back%20to

Re: A+ valves

Posted: Sun Dec 22, 2019 8:51 am
by philthehill
Further to above:-

The three groove collets have a 14 degrees cone taper whilst the standard collets have a 10 degrees cone taper.

The 14 degree valve spring top caps can be identified by a raised ridge around the collet hole.