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Interesting cylinder head

Posted: Wed Nov 06, 2013 10:23 pm
by bmcecosse
Very interesting cylinder head on ebay. I remember reading about these efforts way back....to achieve best economy and low emissions. The combustion chamber is shaped to maximise squish -and to unmask the inlet valve. Can't say I am willing to pay £200 for it - but it's well worth a look. http://www.ebay.co.uk/itm/MINI-998cc-EX ... 1c3855fb76

Re: Interesting cylinder head

Posted: Wed Nov 06, 2013 10:33 pm
by Jaywhy
BMC - would there be any better performance fitting it to a standard 1098 mm?

Re: Interesting cylinder head

Posted: Wed Nov 06, 2013 10:43 pm
by bmcecosse
I doubt it - but there is no indication of the valve sizes, although they look to be pretty much 'standard' for a 998 Mini (same as 948 Minor). I guess it didn't really work - they never used the design in production cars - this is very much a one-off special/experimental head. The inlet valves must be longer than standard - and the exhaust valves must be shorter.

Re: Interesting cylinder head

Posted: Thu Nov 07, 2013 9:20 am
by IslipMinor
Very interesting indeed. It looks like it has spark plugs screwed into the head in the conventional places, but where do they come into the combustion chambers? And what are the 3 holes in the first picture? They are only in No. 3 chamber by the looks of the other pictures?

Is this head for flow development purposes only? With no plug protrusion, can it actually run?

Re: Interesting cylinder head

Posted: Thu Nov 07, 2013 10:30 am
by bmcecosse
I'm guessing the holes were/are for sensors - although no sign of them on the upper surface. The head has been run, there is carbon deposit - I'm assuming the plugs are hidden from view in the depths of the swirl chamber around the exhaust valve. Although this was post Minor production - it's the sort of thing a Club (maybe MMOC? but more likely a Mini Club) should buy and preserve.

Re: Interesting cylinder head

Posted: Thu Nov 07, 2013 11:13 am
by IslipMinor
Yes, now looking at the 3rd picture again, the plug threads look like they are at an angle pointing towards the exhaust valves, and on one of the other pictures of the combustion chamber, there could be a hint of a hole above the exhaust valve?

Re: Interesting cylinder head

Posted: Thu Nov 07, 2013 2:21 pm
by bmcecosse
I also suspect the valves may be slightly further apart than normal.

Re: Interesting cylinder head

Posted: Thu Nov 07, 2013 7:33 pm
by JOWETTJAVELIN
I wonder what valve gaps one would use with this? Same as we are used to or different?