20R or 22R — and What Interchanges

The 20R ran from 1975 to 1980 and the 22R replaced it for 1981. They are close relatives, and a great deal crosses over: clutch and flywheel, exhaust and headers, distributor, many valve cover and block-off parts. Where they differ is the bore and stroke, so anything internal is engine-specific.

One combination people ask about constantly is running a 20R head on a later 22R block. It is a real and popular build, and we wrote it up properly rather than leaving it to forum folklore — see using a 20R head on an 85-95 22RE block. If you are not certain what you have in front of you, block and head identification will tell you.

People write it 20R, 20-R or "toyota 20 r", and some call it the 2.2. Same engine.

Fuel It — Carburetion

The 20R is carbureted, and the factory Aisan was built to pass emissions rather than to make power. Replacing it is the single biggest change available to this engine, and it is the most common reason people come to this page.

The Weber 32/36 carb and intake package with electric choke is the sensible street answer. It is progressive, so it keeps cold-start manners and reasonable economy while giving you the top end the factory carb never had. For a more serious build, the Cannon Performance downdraft intake manifold in a 2-barrel Weber flange opens up the induction side properly.

There is also a 20R/22R propane injection kit for anyone going that route.

Advice we give often: size down rather than up. A large carburettor on an otherwise stock 20R makes the truck worse to drive, not better.

Boost It

Turbocharging a 20R is less common than turbocharging a 22R, but it is well-trodden ground and we stock for it. The 1978-1983 Pickup turbo kits cover the 20R era.

Rebuild It

Most 20R work is a rebuild rather than a modification, because the engines that are left have earned it. The Premium Master Rebuild Kit for 1975-1980 covers the job in one part number.

If you are weighing rebuild against replacement, our engine replacement article walks through how we would think about it — including the case for stepping up to a 22R block rather than rebuilding a 20R, which is often the better answer and not the one that sells us the most parts.

Breathe — Headers and Exhaust

The LCE 20R/22R/RE shorty header kit fits where space is tight, and the Trail-Gear Rock Ripper 4WD header kit for 1979-1984 is the non-smog option for a 4WD truck. Both cover the 20R and the early 22R.

Spark, Clutch and Detail Parts

The 20R/22R dual row timing chain kit for 1975-84 is the one upgrade we would put ahead of everything else on this list. The factory single-row chain and its plastic guides are the known weak point on this family, and a failed guide can put the chain through the timing cover. If the engine is apart for any reason, do this.

The 20R/22R street distributor replaces a part that is now fifty years old on most of these engines and rarely still in specification.

For the clutch, the 8 7/8 inch Pro Clutch and flywheel bundle covers the 20R and 22R, and a 12 lb lightweight steel flywheel is available — quick to rev, though harder to pull away smoothly on a street truck, so think about how you actually drive it. Hydraulics by application: clutch master cylinder for the 1976-78 Pickup, clutch slave cylinder for the 1977-78 Celica, and the 1978-81 Celica master cylinder.

Also here: the red race valve cover for 1975-84, the fuel pump block-off plate kit for engines converted to an electric pump, and the Pro water block plate kit.

Which Vehicle Is It In?

If you would rather shop by vehicle: 2nd gen Pickup (1972-1978), 3rd gen Pickup (1978-1983), 1st gen Celica, 2nd gen Celica (1978-1981).

The 22R and 22R-E page covers the engine that followed, and is where most of the shared parts live.

These engines are old enough that the right answer is often not the obvious one. Tell us what you have and what you want from it — we would rather sell you the right part once than the wrong part twice. If the engine is beyond a rebuild, let us do your build.

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