Is there anyone out there who knows about rotary valve heads for OHV engine conversions or heard about them if not try these pages....
I also have an article from 1962 wheels mag mentioning 10 years of holden 6 mods and how one of the best was engineer David Dunstan's rotary valve head conversion which transformed it to a 10,000 rpm capable monster but unfortunately he died and Repco waggot inferior modified iron heads were marketed for ease of production in those days and also because they didn't want to produce the competitor's design after his passing away or something of the like.
Its good to know in case someone smart and with the right cash is thinking of designing a new head for an aftermarket a series!
haha I wish or maybe we can be the test bed for Coates design if we partition and get some made up by them for our a-series (dreaming again I know but wait to you see these things!!!)
http://www.coatesengine.com/eGallery/pages/RotaryValveSystem.htm

also check out:
http://www.coatesengine.com/t10_eDynamic.htm

and check out:
http://www.geocities.com/aspinvalve/

and:
http://www.lortim.demon.co.uk/aspin/

I have tried to get my mind around the rotary valve concept but can't seem to get it to work. I read an article about it some ten years ago in Road and Track or Car and Driver, I don't remember which. I though it might be one of their April fool issue things since I never heard anything else about it. I'll check out those site you mentioned and see if they can make it make sense. If it could be made to work, the sky's the limit on revs!

I just went to the three sites above and that is a totally different design from what I had seen before. What I had seen, and tried to "improve upon" in my mind, used a shaft through the head like a cam. It had scallops in it that intersected the bore and the intake or exhaust ports as it rotated. It did the same thing as Aspin's design above, but the axis of rotation was the same as the engine, not ninety degrees to it.

I dont know which is better in design except I know that from the early articles on Australian wheels magazines there was a David Dunstan engineer dude in 1955 who could make an antique crappy 6 cylinder pushrod small capacity 6 rev to 10,000 rpm. Sadly its always the innovators who get left out and after his death no one continued his work the others stuck with the tried and common iron head and just modified its ports. Im not saying a rotary valve head is easy to make but Im sure it's simpler to make than a new twin cam head due to its concise principals.
I hope someone with some tooling facilities and a love for datsuns has a go. ;))