A12S Head Swap to H89 Head

[Velict]

Is it confirmed that the H89 head will fit the late mode ('80 - '89) A12S engine? 

Also, what is the price point for one, or should I just get my original head worked? 

[Morrisun]

I have not hear of a A12s, an A12A was available in North America from 80-82 in Datsun 210's, mostly the engines were in cars imported to Canada.

 

H89 is a very good flowing head for low and mid range rpms, GX heads flow better at high rpm- 8,000 and higher.

 

H89 came on A15 engines not imported in cars to usa but some have found their way to A series engine freaks. (Lots of JDM imported A15 engines were available)

 

A15's had 76mm pistons, so you will have to check your bore size and camshaft/valve lift as H89 have 37/30 valves where A12 had 35/29 vales as they had to clear 73mm bore in the A12's.

 

For what it's worth, if you do have an A12a, they have a stock bore of 75mm and can be bore to 77mm, sometimes with sonic testing of cylinder liners perhaps 78mm.

 

H89 heads come-up for sale on ebay from time to time, you may list in the Ratsun want ads.

[Velict]

The A12s is just the mid-mounted A12 (stock) late model. I will bore the A12 to 76mm, work the H89 head, and mount it.