I've never heard that....

 

The R Family Motors started out with Toyota in 1953, here are a list of all of the R series motors. As far as swapping those heads around, I just dont know. . . .
1953 - R - OHV/SOHC/DOHC
1953-1964 - 1.5 L (1453 cc) R
1964-1969 - 1.5 L (1490 cc) 2R
1959-1968 - 1.9 L (1897 cc) 3R
1965-1968 - 1.6 L (1587 cc) 4R
1968-1986 - 2.0 L (1994 cc) 5R
1969-1974 - 1.7 L (1707 cc) 6R
1968-1970 - 1.6 L (1591 cc) 7R
1968-1972 - 1.9 L (1858 cc) 8R
1967-1968 - 1.6 L (1587 cc) 9R
1969-1988 - 1.6 L (1587 cc) 12R
1974-1980 - 1.8 L (1808 cc) 16R
1971-1982 - 2.0 L (1968 cc) 18R
1975-1977 - 2.0 L (1968 cc) 19R
1974-1980 - 2.2 L (2189 cc) 20R
1978-1987 - 2.0 L (1972 cc) 21R
1980-1995 - 2.4 L (2366 cc) 22R

Taken from http://en.wikipedia.org/wiki/List_of_Toyota_engines

 

Very interesting...

 

21r engines are rare and suck. Chances are, he's got a 20r head. Couldn't tell you what the differences are between 21 and 22, but my 20/22r engine will flat out haul.

And 22re fuel injection on a 20r head isn't easy.

 

The plot thickens. I bet they are all the same block & bore. The 21r head has less ccs in it's combustion chamber which would = higher compression. He said he only had to drill & tap 4 bolts to make the EFI work?

 

Sounds kinda sketchy to me. Not sure what the 21r intake ports were like. the 20r and 22r had different intake port shapes.

 

Care to make a bet ... say a 12pk at our next mutual event? I trust my 'guy'. Somebody clear this up ... are the intake ports on a 21r head shaped to match EFI?

 

Sounds sketchy to me.. 21s are rare breed and not much work with them. Time to do some searching.

 

21R engines were never imported to the US, they were only used in Japan, the engine is slightly smaller in displacement than the 22R, if I remember correctly the block is the same externally but the cylinder head is different, the 21R used two carburetors, this did not meet emission control requirements in the US and that's why they were not allowed here, the manifolds were also different and did not match up to the cylinder heads of the 22R

Also found this on another forum : "21r motor it has 84mm pistons dual timing chain 35mm round ex ports 37mmx42mm in ports combustion chamber is round with 26mm dome deapth"

 

21R engines were never imported to the US

Yes they were

They had 21R-C that was California emissions ones in 1982-1985 .. The Jap versions were 21R-U.

Also the intake design is different than the 22r series as well as the bore is smaller than a 20r.

 

Also they were a 2.0l

http://en.wikipedia.org/wiki/Toyota_R_engine

"21R

The 2-valve SOHC 2.0 L (1972 cc) 21R was produced from 1978 through 1987.
Cylinder bore was 84 mm (3.31 in) and stroke was 89 mm (3.5 in).

Output in 1978, constrained by emissions, was 105 hp (78 kW) at 5200 rpm and 116 ft·lbf (157 N·m) at 3600 rpm. Air injection and California emissions equipment for the 21R-C (1982-1985) dropped power down to 90 hp (67 kW) at 5000 rpm. The air-injected Japanese version, the 21R-U, produced 105 hp (78 kW) at 5200 rpm and 120 ft·lbf (162 N·m) at 3600 rpm but dropped to 101 hp (75 kW) at 5400 rpm and 114 ft·lbf (154 N·m) at 4000 rpm in 1986."

 

Cool, twin carb....durn emmissions.

 

I've heard of a couple of 21Rs in the states. Coulda be possible to get a JDM used 21R back in the day.

 

I've seen a couple of these in New England. I was wondering as well, if the early 21R's head could be installed on a tall 20R/22R block? I don't see anything on the net about the 21R being fuel injected but I do see an 85 4runner in sacramento on craigslist and it says it has a 21RE

Interested because if the combustion chamber is designed for a 2.0, then it should result in more compression ratio when installed on a 22R block than a 20R head.