the best engine by far is not available in australia but in much higher numbers in europe and it ####s all over the honda s2000 even though it has the same technology four piece alloy design. But it kills the huge s2000 for weight, quantity, size, design, power and budget. Sorry to offend some of you datto diehards but Ill always love my dat 1000 and its measly 625kg standard no radio no heater no passenger sunvisor!! poor mans ice cream box. I love dattos for handling, power, quirky funk styling on a budget.
However I also love new technology for the masses and the K-series was designed as the replacement for the a-series BMC version and if you look at whats available like KAD twin cam head for that old a-series donk youll see what I mean. The K-series is the next design the japs copied in the s2000 honda (honda used to work in conjuction with rover till 93)
Open your mind and check out:
http://www.btinternet.com/~v11ufo/kseries.htm and
http://members.tripod.com/~RoverSD_1/k-series.html
and www.caterham.co.uk
(original still produced pommie not malaysian lotus 7 r500 - r500 stands for 500hp per tonne!!! and world record 0-100mph-0 11.44 seconds from a 1950's design!!!)

Funny thing is the 2001 160hp r1 motorbike uses downdraught mikunis!! not sidedraughs
and the semi sidedraughs downdraugh mikuni set available through pitroad in japan and nismo in the states are stated to produce 20% more than webers.
There is a chart showing two identical 1400 a14s worked by www.Matsuoka-ts.com that when tuned with either miks and webs the miks setup produced around 174hp and the web only 150 odd! But dam those miks are pricey lol ;0

Steve Newing as most should know from speed technology missed out by 1 point from the sport sedan championship in Vic cause he was sorting out his new car and new engine with no aftermarket off the shelf stuff as youll see read on.
He has a coupe stanza with the ca18 producing in excess of 230 hp NA and everyone else uses 1600s with sr20.
However this was the first year in his new car with new engine as he held the 2litre and under championship for years with his a14/a15 engined 1200 before. 400cc less than the others!!!
Hes a man after a challenge and on the last race missed out by 1 point however won the last 3 races of the last meet by a huge margin.The guy who won never came first but consistant 3rds, a handful of 5th and 4ths in a well sorted 1600 with sr20.
The CA is lighter and more compact and therefore more suited to the 1200, 1000.
however the best production engine in the world before the s2000 honda (which is limited in numbers anyway and weighs more) and with the same and better technology is on the following link and is used in the worlds fastest car 0-100mph-0 in 11.44 seconds and many kit cars. It weighs 96kg!!!!!!! like the a15 but at 1.8ltr and easy 180hp.
http://members.tripod.com/~RoverSD_1/k-series.html
and
http://www.btinternet.com/~v11ufo/kseries.htm
If only Nissan woke up now under 51% ownership by renault.
Remember fellow datoo freaks we love the 1200/1000 for being one of the best for power to weight and handling on a budget so theres no use in falling into the v8 mentality by having another person sitting on the bonnet and destroying handling with is by the means of putting a heavy donk in your lightweight baby.
Less is more not more is more (lotus motto)
unless you want to go in a straight line only.

Tell me about it however out of all the things available at pitroad, nismo and other jp places they dont use roller rockers!!! just those triple bloody valve springs. Apparantely they keep the valve to stable in such small geometry valve gear compared to v8 ones they dont need roller rockers.

When I rang YT and another engine builder they told me that there needs to be machine work to get them in right, so i dont know who else to believe. If yours fit straight in and is running well everyday then thats promising considering YT sales said it wouldnt.
Im chasing 78mm high comp pistons with valve resets like in the pitroad website to avoid valve to piston contact at high rpm. Well thats what it says in Jp as it reads in many japanese mags. However if the mazda ones work what do I have to do to the main end?
They also have if you find them, triple valve springs of the iskenderian brand which are used in 10,000rpm drag engines aparantely they work better at high rpm.

I just saw a datsun 1200 with l16 twin dellortos and all round disks for $800 but you should see how bad the crossmember was moded to fit the tall bastard and yet if he lowered it the sump would be a rock collector.
So Dimlight's must have a crazy split vcrossmember to sit that low with such a tall engine as the z20 is, then again it would have been worse with a z24! :))

Its a shame no one knows at least what pistons we can use in Australia for an oberbored a15 without going to custom made stuff or expensive pitroad or Nismo.

Does anyone know who makes roller rockers for the a15 that dont need modifications like the yella terra ones? (YT rollers for a15 are from v8 parts bin)
The funny thing is too that japs dont use them and rev their drag 1200 utes to 10000 rpm. The other thing is does anyone know which 78mm pistons I could use for an a15 overbore?

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. ;))

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/