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Cooper engine valves
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Author:  Mick [ Wed Mar 01, 2006 1:03 pm ]
Post subject:  Cooper engine valves
Does anyone know of a reference table for A series valves?

I'm mainly interested to the valves fitted original Cooper S engines (Mk1 and 2).
Author:  EST-071 [ Wed Mar 01, 2006 1:24 pm ]
Post subject: 
This may help.
www.minis.com.au/cyl%20head%20data%20an ... bers_1.htm
Pete
Author:  Mick [ Wed Mar 01, 2006 1:33 pm ]
Post subject: 
Excellent, thanks 8)
Author:  Mick [ Wed Mar 01, 2006 2:43 pm ]
Post subject: 
Orright then,

I've got the head off the Cooper, and see that the valves over many years have receded into the head by about a millimeter. There's no problem, the head is working fine but I inquired about converting the head to unleaded. Apparently it's not a good idea to put the inserts into Mk2 S heads, and that I should consider upping the valve size to Mk1 S exhaust valves to compensate with newly cut valve seats.

My questions are:
1. Has anyone else put the inserts in with any problems into a Mk2 S head?

2. If I go up from 1.15" valves, should I go to 1.215" or is there another size I should consider?

thanks

Mick
Author:  drmini in aust [ Wed Mar 01, 2006 7:40 pm ]
Post subject: 
I've done it both ways.
Ha-Ha has the bigger 1.219" exhausts (these are MK1 head size, but 12G940 heads have longer stems).
I run bronze guides because these valves are 21/4N S/S with plain stems and will pick up in iron guides.

Barney the 1293A+ has Rover inserts, I got `em shrunk in with liquid N2... 8). Valves are all Rover ones with chromed stems, guides are stock cast iron. <edit> exhaust valves are stock 1.156".

I've had the big valves in Ha-Ha for about 10 yars now, no problem. I run Flashlube in it.

Not much to choose really, both work, there is no problem with the unleaded inserts for road use if properly fitted.
Author:  Mick [ Wed Mar 01, 2006 7:59 pm ]
Post subject: 
Thanks Doc,

I'm happy to use the additive, I don't do many kilometers anymore in the old girl.

Does fitting inserts mean you have to stick with the smaller exhaust valves (1.151")?
Author:  drmini in aust [ Wed Mar 01, 2006 10:07 pm ]
Post subject: 
Yes. There is no room there for bigger inserts. Some people in the UK manage to cram 30.0mm valves in but that's about it.

BTW the bigger 1.219" ex valves don't really give any more power- Greig Malaure's Nb racer is pushing 160HP at crank now from 1299cc, still has 1.156" exhausts in. :wink:
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