I would Like to know if does the A10 Engine head fits on
the A12 engine Block.

Regards

Never tryed it. Theres probably smaller valves and smaller chamber with more compression. Why not just
use A12 head?

I want to use the A10 head because i want to shave it for increased compression, and i dont want to do anything to my stock
A12 engine head

Hi Group,
I started to post yesterday on this subject but had a momentary power outage right in the middle of doing it and lost all I had entered ! So I'll try agian.
There are Pro's and Con's about what you want to
do with the A 10 head jm as I have had some experience in that area. The A 10 head will most likely have a smaller volumn combustion chamber and shaving it will boost it even more (Pro).
On the other hand as Davo said it will also have
smaller valves and ports(Con) so it may counter the effect of the higher compression.
To take best advantage of this set up it would be advisable to port as much as you can and polish
the ports to get some of the flow back or even do
the above and install some larger valves too.
The real key to getting the most from a large compression ratio is a good cam grind. There are however some limitations to what you can install in the A series blocks that will hinder
getting the best cam to punch up this combination.
Small bore and shorter stroke engines like an
A Symetrical cam grind and don't require a lot of
lift ( around 450)or duration( around 288) But the
lobes are ground to open the valves real fast and slam them closed just as fast and this unfortunetly requires a roller lifter and
I've not seen that for the A series ( though I've thought about trying to figure out how to do it !!)
Anyway I would think about putting an A14 or A15
head on it and changing to a more aggressive cam
and you should be able to shave about .0085 off
of it and see some improvement ,more reliability
and see more torque at lower RPM which is more practical if you drive your car regularly on the street!! The best way to boost compression on these engines is to go to a domed piston but
I realize money is always a consideration too
Let me know what you think.
Good Luck
Steve

I have already taken the A10 head apart, and the ports seem to bo the same size as the A12 head, however since i have never seen a A12 head unmounted, i cannot compare, i have
also measured the diameter of the valves, the intake valve is 35mm wide and the exaust is 30mm wide, if anyone knows the size of the A12 valves and ports please let-me know so
that i can compare.

Regards

a12 valve size are intake 35mm and exhaust 29mm unsure of port size difference
or chamber size.