http://web.ncf.ca/ez273/toyota_links.htm1981-82
The 22R was introduced in 1981 on the Corona, Celica and pick-ups replacing the smaller bore 20R. The crankshaft and connecting rods were carry-over parts from the 20R. The cylinder head was a hemispherical chamber with canted valves.
The rocker arm assembly was held on by the head bolts (see Photo 1). The overhead camshaft was driven by a double roller chain. For 1982 the motor stayed the same, with no changes.
1983-84
In 1983 several changes were made.
Main bearing alignment tangs were changed, requiring the use of different main bearings (see Photo 2).
Timing components were changed from the double roller to a single roller chain and sprockets, different guides, tensioner, and a splined drive for the oil pump (see Photo 3).
Some models had fuel injection, but the only difference was the addition of some extra bolt holes to the intake manifold side for the EFI intake. This head will retro-fit back to the 1981-82 head, but you cant use the earlier head on an EFI 83-84 model.
1985-94
