Ha! A little bit of an ambiguous title but I thought some people might be interested in this.

Huge weight difference (along with the obvious gigantism of the sr head )

A12GX Head weight (without rockers) 6.0kg approx.
Sr20 Head weight (without cams + gear) 17.5kg approx.

Edit: Just edited the weights, scales weren't calibrated!

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  A12GX vs SR20 1.jpg (187.48 KB)


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Ummm yes.....

not being stupid here but everyone knows an SR it much larger and heavier then an A series.

more information please Chris.

Gary has taken the A series to 1905cc with an E16 crank and 82mm slugs
so with a full works a15 h89 head it will be a gem compared to the bigger
and heavy looking Sr20de. If the A19 could then get the best gear with
titanium valves, retainers, roller rockers and Roller camshaft theres no
way in the world Id go complicated twin cam 16v for a turbo setup.
Im still in love with pushrods and would love to get something like this one day.

Nah that's cool zig-zag. There isn't much more to it really, I'm looking at a handful of Nissan heads to begin working on a cross flow A-series head. This week the SR20 head was on the bench so I decided to snap a few pictures while I was measuring and cc'ing.

Nothing will happen for many, many moons yet as I don't have the cash. But when things get better financially I'll have a twin cam A-series.

I have access to a 3d printer now and have been developing a few smaller things ready for later. I can basically print a plastic version of the trusty A12 head, amazing stuff. You use these models as samples for when you actually consult an engineer so they have something to look at but the general idea is that I get it done bit by bit and then start throwing money at it once uni is over.

ahhh im understanding now, A19 would be sweet and lightwieght but i think the SR would still be the better choice for reliability, factory turbo and has a huge aftermarket parts selection.

twin cam crossflow A series heads would sell like hot cakes

it's goin to be a tight fit, your going straight for dohc not gonna bother sohc?

Whilst a twin cam head idea from scratch is a fantastic idea, people have been trying for years to come up with a cost effective alternative. And that is the whole point. It has to be cost effective. Because while the real serious boys might consider spending $10K on a head, the rest of the Datsun community will not. The best way to make something that is cost effective is to use parts that are easily sourced so the only thing that is really custom is the head itself, not all the gear that goes on it. Then you might be pleasantly suprised. The biggest thing is the pattern work, which I have stated before, because machining a head from billet would cost a crapload and would most likely be done in 2 pieces. I for one would love to see one, but I am yet to see one running, and some seriously smart blokes have tried and failed, because it cannot be done cheap, or without consuming huge amounts of time along with the huge influx of cash. Why would you? When so many aftermarket alternatives are at your feet anyway.

Morning,

In this instance I guess I have a bit of a head start, as I'm using the twin-cam Datsun AZ12 as a reference.

With regard to the WOFTAM factor (I really didn't intend to mention the twin cam head but instead just show the A12GX vs SR20 images) I'm prepared to spend a fortune, even if it isn't a screaming success.

And as for sales, well I hadn't even considered that yet, could you imagine a Datsun fan getting sold a head that costs a few thousand dollars and then forking out a further fortune to have it machined and prepped....I can hear the whinging from here. I guess if any leave the production line they will do so in very small numbers.

With regard to the pattern work I intended to model the water jacket galleries or the void spaces of the head and have that component CNC machined (out of what material I'm yet to find out) for the casting. I guess all the CNC work would be done to make the mold ready for the cast rather than CNC machining the whole lot, when I last looked into it the biggest hurdle was the design and the costs of consulting an expert to have his opinion on the format.

Chris on the grape vine Ive head of twim cam heads for the A series from Factory.
Only 2 or 3 where made from sand casts and some people have a hold of it.
If that can be somehow lent to you or bought then you can either use it for your
mock up or just use it for yourself :) Im not sure where they are and if anyone
would let go of such rare items though.

The honda blackhawk cbr1000xx head Simon used is not far off as most of the studs fit
however needs custom timing mech/case and electric water pump at minimum unless you
can modify a vw 4 golf one or use a custom billet one. The original oiling could be
used keeping the original cam machined down to work for the oil and dizzie if budgetting
or use a megajolt or megasquirt setup for ignition.

When I went to Vic Motorcycle wreckers the bloke there had vividly in his scone how Simon
came in with a A Hgasket, tried several heads when bang the CBR one was so close.

Its alot of work but who knows you might be able to use a cbr head as a reference?
The only thing I would change about the bike heads is how the exhaust curves down
to far to suit the bikes where they could also be angle up for better auto headers
resembling the formula 1 spaghetti style setups.

If I could go back in time (just ten years) I would have used RMITs equipment to
make a ga16de alloy block that suited a hayabusa head and directly to a t5 box.