If we can help each other like the Ozdat guys input on the L series Ka24de head we would all be not far from buzzing around with Mx5/Miata/323 GTX/Ford Tx3 power in much lighter bodies than the original bodies these heads came in.

So far I can see the timing case area has a cover which must lead to a shortened sump, the cover must have a thin seal to avoid leads from the crank snout which also takes the belt cog to suit the head cambelt cogs, some tensioner pulleys to hold the belt in place, a 3rd camshaft pulley to run the oil pump and dizzie if we like.

The water inlet could be at the front off the head where the provision is easier than straight to the front of the block and side outlet could be used on the block using one of the welsh plugs so water goes into the head first from the front, holes on the gasket towards the rear so water flows across the head then onto the rear of the block and to the front again out the side of the exhaust side front welsh plug. This would make easier setup using a Johnson style mechanical external water pump or custom made external water pump using a common off the shelve waterpump that is relatively square like a suzuki M13a or M series water pump housed in a dome alloy case with in and out pipes.

Carbs could be run using a shorter version distributor with side exit spark plug dissie cap like last pic on my last post.
Bore would need to be like original B or Z series at 78mm or over, belt would have to be custom as it seems longer so will need to be sorted from gates or other belt manufacturer unless the ingenious pioneer of this conversion lets us in a bit more.

Would be nice to invest in some ARP head studs for this conversion and start recasting some of the twin weber manifolds which where avail from japan, south africa and USA.

Also eventually once quite a few are committed to the build we can get a custom made alloy, steel or hybrid alloy/clear plastic belt cover to suit our tastes.

Headers are one of the things which are easily avail for this head amongst a zillion of miata aftermarket goodies.

Some of the Miata forums are taking their BP engines to 173bhp at the wheels normally aspirated so we would need to rev our engines a bit higher for the lack of 200cc or sleeve our A14/15 blocks to 83mm for 1775cc or get someone to prep a handful of E16 cranks along with 83mm bores for 1905cc :))

The other thing is the oil feed, drain and brazing/brass pluging up the pushrod cavities and maybe some of the water galleries need modifying.
Custom head gaskets are avaialable for 100 one off using very good materials and cheaper in quantity once the pattern is sorted but I can see the mazda head has equal bore spacing meaning offset boring is possible or offset sleeving for that extra capacity we hunger for.
Pics below illustrate the areas of interest, look at the oil feed areas!
disregard the head gasket on the head its a b6 hg on the Z head to show
how compatible the Z heads are the B series block.

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Cool stuff but I still would love to know more about the nuts and bolts of the conversion. If we could buy some of the fabricated components that would be really cool.

Tom

funny enough had to check my dungeon for some parts and ironically I had a Z5 head a while back when test fitting a possible twin cam for the A series as the heads where $20 at pick a part one week and also bought a Daihatsu 16v head but never got around to playing with them.

The Mazda Z head has the same bolt up pattern totally compatible with the B series and here are some happy snaps of the Z5 front camshaft lobe cap that separates the oil from the belt drive area at the front. Just a comparison on how narrow and compact these heads are.

Anyone know if they ever made a side style dizzie cap for the A series? the last pics shows a Morris Lucas one with Pertronix kit

Here is a build thread of the Z head on a B series block
http://www.miataturbo.net/build-threa ... zm-de-engine-build-62722/

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You wanna go quads I hear and for the price of a weber manifold for the A series you can go billet manifold for this head! to take 4age 20v quad itbs

https://technotoytuning.com/mazda/na18 ... 4ag-throttles-18l-na-head

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The Z series head which is a modern narrow valve, high port design also available with VVT for the b series. The VE version is for a 1500cc model that produces 96 kws thats 100cc less than the 85 and 100kw 4age.

The Z head is compatible is everyway to the B series block.
There is also the last of the wide angle B series donks with
VVT, solid lifters like the Z head and 1800cc making 163hp.
Same head used for the Australian Bathurst MX5 SP Turbo.

That been said it seems to be also possible to use the smaller diameter Z series pulleys and crank cog which will reduce/improve front cover sizing on the B series.

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The first pic in black is using the 323 rocker cover as they interchange and RWD with front of the head water inlet while the last 1 in white is a FWD BP in a RWD chassis (notice the water outlet on the opposite side as the one in the datsun on this thread and front of head sealed up like on all fwd applications) also notice it doesnt look too bad with quads and white rocker cover:))

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Ive mainly seen the F series mazda engine in Kias but maybe overlooked the B series as they look almost the same on the rocker cover. Wikipedia should have the info on which models to look out for here.

At the bottom front of the block where the crank pulley meets the sump there is some finicky stuff that needs to happen and water outlet could be piped from the head instead as in this pic shows how the rwd miata/mx5 use the provision which is already there for the rwd or fwd layouts to reduce tooling and casting new heads.

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yep, engine is based on the block.

sooooo would it still be classified as a a-series engine for rego purpose's??