TexasMidget asked:
Quote:
is there much difference between early and late A12 engine ... Advantages of one over the other? Any limitations with cylinder heads?
There are quite a few changes, none related to performance or durability. The same strong crank, overly strong rods and robust cylinders are used
The changes are mostly related to getting more room for engine accessories, namely better AC compressor placement and smog pump
* Distributor moved from front of block to middle, allowing to move alternator to right side
* Engine mount brackets moved back to make more about 1" room (and so fuwl pump moved forward, which in turn bumped to dipstick to a new location)
* Due to dipstick location change, slight change to oil pan. New A12 and old A12
use nearly the same pan but with room for the (moved) oil dipstick. The new A12 oil pan is same as A12A/A14 pan, which is commonly found in Americas, so no worries find a replacement oil pan
* New crank uses all-metric bolts. This is a standards change, not a performance factor
* No limitations with cylinder heads, any of which
can be used with old engine or redesigned engine
* Advantage of old A12 for Americans is that it was the only A12 sold in USA/Canada, so is more readily available. Advantage of new A12 is more room for engine accessories like AC (old A12 used complicated bracket to do this) and turbo fitting
For more details see our tech article
A Engine Redesign
Early A12 pan VS New A12 pan .jpg (62.24 KB)
Transfer
