head markings resolved - which to use?

[fillpoke]

I asked earlier about difference between 12g202 and 12a1456 heads. I now find that the 12a1456 is a small valve from a 998cc engine. Since I have one of these heads all in good condition can I successfully fit it to my 1098cc bottom end? What difference, if any, could I expect in performance and fuel consumption?

[bmcecosse]

You will lose performance because of the smaller inlet valves - and poorer porting. Partially offset by slightly raised compression ratio - which may of course cause pinking......forcing you to retard the Ignition. I suppose there is a chance of slight fuel consumption improvement - mainly because you will be forced to drive more slowly because of the reduced power - but I doubt it will be significant. I would stick with the 202.

[fillpoke]

Thanks for the advice BMC. I'll stick with the 202. Will the rocker assby from the 1456 be ok on the 202? The shaft is in much better condition than which is on the 202.

[bmcecosse]

Oh yes -it's fine.