Not with such efficient chamber designs :)

how about provision for direct injection? since you can custom almost anything, the limit is your imagination.

Awesome work Bede, can't wait to see this progress (I for certain will be wanting one...)

My 2cents:

Ports: Change the short turn shape. You want an elliptical short turn on the intake (ever increasing radius until it reaches the seat) and a rounder short turn on the exhaust. Short turn is where you will get the flow from the head - you want that flow sticking to it as it flows down and over the valve. As soon as the flow separates from the short turn it skips over the inside of the valve and you'll loose potential flow. The other way you can stop this separation from happening is to widen the short turn - D shaped with the floor more flat.
You want the smallest cross sectional area of the port to be back up off the valve in a N/A motor. This choke is spec'd to the engine (revs & capacity) so make sure you have plenty of meat there to be able to port to whats necessary.

Let me know when you want some more in depth specs regarding choke/throat sizing.

I reckon ditch the GA16de stuff - run billet cams (easy to make, and we can grind them for you), and use the largest buckets you can - motorbike maybe? 32mm would suffice. 27mm GA buckets are just too small to make some nice low duration cams with high lift for road motors. Other good thing about running large buckets is it opens up spring options.

Definitely do not run a slave gear like the Toyota 1uz / 4afe stuff. These things suck to time in and means you need to make an adjustable gear setup if you want to change your lobe separation. I'd also run a modern fine pitch chain rather than a belt - look at motorbikes for nice compact sprockets.

Chamber: Do a closed chamber with some mean squish. Like this

Apart from the combustion chamber been closer to the pic above or a clover design the rest is not an efficient solution for using bike parts as it gets out of control for price and far from being able to be finished due to complexity.

The 4afe in question is in a buggy and if 1600cc makes 248hp and Billzilla agrees there is more to come of it then the slave cam is not to be overlooked for the A series as it simplifies the process, works well used by vw, benz and others with great durability while the chain is way too complex, expensive due to the complexity of changing the whole font section where a belt is heaps times easier and more affordable as done to Mini A series engines using the BMW bike head way easier to implement eg. cheaper.

Its about under complicating rather than complicating and never finishing it like many have stumbled on doing the twin cam head as the cost escalate quickly.

With intelligent thinking instead of adding all the bells and whistles like an overgrown operating system you need to make it simpler, affordable using the least of aftermarket or custom parts as possible. The belt drive can still be positioned over the original waterpump with some careful design, retaining oil pump with front pulley to power water,
alternator moved forward to allow for the belt cog.

Bakat, direct injection is not affordable either unless we can find the stuff littered at the wreckers and from what Ive been told the ecu capable of doing DI as its way more complex and expensive to implement.

A 16v head with thats easy to adapt to an A series is a winner but anything that needs a complicated chain, motorbike parts, elec water pump and expert assembly with extra machining and mods will fall flat on a pushrod bottom end. Ideally Neil put a link to pushrod 4v heads that could be easier to implement but in the end is would be easier to make a 2-3 piece bottom end that fits a bike head and common rwd 5 speed.

D, you don't know what you are talking about. That 4a-fe doesn't make 248hp because it has a slave gear setup. It makes it because it has arguably better ports than the g heads, but more importantly larger buckets.

The slave gear complicates things more than using a conventional twin sprocket/gear setup. How do you easily manufacture the gears for the cams? How do you change your lobe separation easily? Most of those slave gears have a 'split' gear setup with a small spring loaded section to help with backlash issues too. Like this




Using off the shelf motorbike buckets (cheap) and modified sprockets (cheap) is a better solution.

Remember, the whole idea behind this is to create a AZ12 replica in spirit. If its going to look like some Frankenstein thing with a single belt drive it kind of defeats the purpose of the project.

You misinterpreted what I wrote and forgot I mentioned the 20v 4age has wide valve angles and yet does have high port design but the valve angles on the late "fe" engines is superior. You jumped to your own conclusion as its obvious a slave cam is not related to making that power in any way - just that a slave cam setup does not restrict a head in making big numbers! providing all else is right of course.

It does simplify the front timing case setup by avoiding to design a complicated chain timing front casing that requires to be properly sealed for lubrication, needing specialist care to implement correctly with custom made right chain guides oiling drainage etc without leaking after 10kms.

If the lifted toyota gear from an A or E cylinder head can possibly be implemented and made to work then theres no need to manufacture any gears from scratch and since you need custom camshafts from the start so the timing & lobe sep can be designed for the performance required. Another option as mentioned is to use a chain setup contained only within the head area and then an external belt to the bottom pulley like on the Mini engines. Its just clean and much easier to implement to retain current water and oil pumps without all the front having to be changed.

quote from you
((Remember, the whole idea behind this is to create a AZ12 replica in spirit. If its going to look like some Frankenstein thing with a single belt drive it kind of defeats the purpose of the project.))

The front timing case area is the key to see if it fails or not and using wreckers parts is more "datsun" in spirit than making everything from scratch and been out of reach to normal datsun enthusiasts. How is a belt setup going to look more Frankenstein than a chain setup that is so complicated and full of custom parts to implement? thats a subjective opinion as they both will look nothing like an A series.

Its easy to say do this do that from scratch but it could be more rewarding and a different kind of challenge to use whats already available from cheap wrecker parts if possible, Im sure the cams are just for starters to make sure it all works then can be changed. If not then its just a head for the user to enjoy then be it and he can go full tilt with the latest and more complicated approach that requires the bottom end to be completely modified beyond the scope of your average datsun joe blo.

The rocker cover is very minor in the scale of things. I drew it up copying the LZ14 rocker cover so it will say nissan for sure.

D i dont see what is complicated with having chain driven camshafts so it will be chain driven unless I'm convinced otherwise or there is a better more justified reason.

For the moment I'm going to stick with the GA16DE cams valves and buckets.
Later on its going to take minimal effort to change things when I start looking at the final details.

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That mock-up in the ute is awesome! Too bad it's not a real engine ... yet. I can't wait!

Been mucking around with modeling up a AZ12 head lately (since I'm living in an apartment at the moment with no garage)

I have sorted the oil return and most of the water gallery. Need to decide if the oil supply will be machined or included in the casting.

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Is there a way to reduce images to below 200k without cropping them down?

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