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F/S Worked a12 engine (ex minisprint )
Posted: Tue Sep 03, 2013 8:36 pm
by 1171dato
As above its a oval port head with only Nissan japan stamped on it
Re: Help with ID-ing this A12/14/15 head
Posted: Tue Sep 03, 2013 9:21 pm
by Bartman
You're GT escortina on OS, aint ya?
Great news!!!!!
Your head is the greatly sought after, and much reveered A12 GX head.
They have the largest intake ports of all the A series heads.
But they have the smaller A12 sized valves. 35mm, and 30mm, as oppoised to the A15 37mm, and 32mm.
The good news is the hardened seat inserts are large enough to take a recut to accept a set of A14/15 valves if you lay your hands on some.
If you remove the manifold, I'd wager you'll see four 4-5mm water ports beneath the intake ports. Whereas the H89 A15 heads only have three 3mm (Approx) water ports.
I also saw at OS that your motor has had the rocker post hold down bolts replaced with studs. This is a great mod, as those bolts are VERY easy to strip. 14mm headed bolts, on a 6mm thread are very easy to overtorque.
Another great trick is to replace the springs on the rocker shaft between the rocker arms with bushes. This prevents the rocker arms from migrating at monster revs, and compressing the springs leading to bent push rods.
Re: Help with ID-ing this A12/14/15 head
Posted: Tue Sep 03, 2013 9:24 pm
by Bartman
Also,
holy fuck, how much has been skimmed off that head?
I've never seen so much thread poking out of the tappet adjuster screws.
Especially when a reground camshaft usually means that the screws need winding down further to compensate for the reduced base circle diameter.
Re: Help with ID-ing this A12/14/15 head
Posted: Tue Sep 03, 2013 9:56 pm
by 1171dato
yeah im gt_escortina on OS
the engine is out of a mini sprint race car the cam is big at 298" duration
heres an idea how much has come of the head
in the weekend ill get it running post vid
Re: Help with ID-ing this A12/14/15 head
Posted: Wed Sep 04, 2013 8:49 am
by 1171dato
I kinda got excited after you said it was a a12gx head im not so sure now no holes at all tho the port size are big 40mm x 31mm
Re: Help with ID-ing this A12/14/15 head
Posted: Wed Sep 04, 2013 5:02 pm
by 1171dato
Re: Help with ID-ing this A12/14/15 head
Posted: Wed Sep 04, 2013 7:50 pm
by Bartman
Definitely a GX head.
The water holes must have been filled.
If you need any parts or advise, perhaps talk to brnwgn. He's down your ways, and an A series fiend to boot.
Re: Worked a12 engine (ex minisprint )
Posted: Mon Sep 16, 2013 5:29 pm
by 1171dato
After having a good think I really don't have time for a project at the moment.
So its now for sale open to offers
Re: F/S Worked a12 engine (ex minisprint )
Posted: Mon Sep 16, 2013 9:39 pm
by beaver
ballpark? PM me if you like, would go nice in the 120y....haha
Re: F/S Worked a12 engine (ex minisprint )
Posted: Wed Sep 18, 2013 5:06 pm
by 1171dato
http://www.trademe.co.nz/Browse/Listing ... 70&ed=true" onclick="window.open(this.href);return false;
now on trademe