Pulling down the engine today - haddn't paid to much attention to the head until i saw the inlet ports - my A14 came with a free A12 head.

Has anyone seen this before? I was thinking of opening the ports out to match the intake manifold better sort of ramping the inlet port a bit - is this possible??

note below: as far as I understand standard A12's came with 35mm inlet valve and 29mm exhaust and A14's had 37mm inlet and 30mm exhaust

this head has 35mm inlet and 30mm exhaust!

you wont be able to open the round ports up because you will break through to the water galleries. im pretty sure people do this to get a higher compression especially with it being the kidney shaped head

you would have the "economy" a14 they came with round port heads but with the later bolt pattern

There's every chance that it's the original head on that engine as has been noted already, there was a 'thrift' version of the A14 whose sole purpose in life was to get as much mileage from a gallon of fuel as possible.

As usual, those clever Datsun engineers did a great job of achieving that goal & this is one of the things that they did to do it.

A guy that i met years ago told me that he would prefer to run his A14 with an A12 head, he found that whilst getting the economy of the A12(as Dodgeman mentioned) but you get the grunt of a A14. He mentioned something about the Compression Ratio being raised but i can't confirm that, he swears by it! He recommends it still to this day every time i see him, even when i showed him my A14 turbo set-up,
"did you use a 1200 head????"
"it'll run better with a 1200 head" he says
"yeah righto dave!!!!!"

my a15 runs like ####e with an a12 head,

Kidney shaped head?

I didn't know there was a difference - I really should pay more attention to this stuff.

thanks for the help guys, It is going to be the workshop runarround so economy with some grunt is a bonus. i was only going to open the ports a little to match the intake manifold which is an A14 setup - but since this is not advised I might whack on an A12 manifold to match the ports up as I felt that having a big piece of alloy blocking the airflow from the A14 intake to the A12 type head wasn't good for power or enconomy.

I have just purchased some nice light tomei pushrods A14 spec - are these the same length as the A12 ones?

cheers

the a12 manifold will not bolt onto thathead it has different bolt pattern

Quote:The 1200 & A12 inlet manifold will not fit as it uses a different stud pattern. I think I have a round port manifold to match this head, so if you become desperate, let me know & i will go have a look.

There are essentially three different pushrods.
A10.
This engine had the shortest stroke [59mm] & the shortest deck height block, so it used the shortest pushrods.

1200, A12, A12A, & A13 [short stroke]
These all used the 70mm stroke & were the next tallest block, so they all used the next longest pushrod.

A13[long stroke] A14 & A15.
These used the tallest block to handle their 77 & 82mm strokes & these used the longest of the A series pushrods

D-man, you wouldn't perchance know the length of A13(short) standard pushrods?