The 20R 2200cc. / 22R 2400cc. engines were the
most popular US Toyota engines. For 20 years, 1975 to 1995, these motors
served as U.S. Toyota's dependable workhorse engine. These engines
powered the popular Celicas until 1985, and the unbreakable Pick-up
models used these engines until 1995 (in commercial models). Turbo
models appeared briefly as the 22RTE in 1985-1988 on Pick-up and
4Runners. The 22RE Fuel injection models appeared in 1983, on some
Celica and Pick-up models. In 1985- the 22RE had a major change. The
block was taller and the head shorter, compared to the earlier models.
The engines' blocks and heads are not interchangeable (for practical and
The engines are OHC design, with hemispherical combustion chambers. The cross-flow head was very efficient, short of a 2 or 4 valve (per cylinder) Twin Cam. The long stroke provided a lot of torque at a reasonable RPM range. The engine responded well to all the tuning tricks. The 20R head is different from the 22R heads. The 20R had open combustion chambers and the 22R had a swirl-inducing chamber (for cleaner emissions). The intake ports on the 20R were round, and rectangular on the 22R. Exhaust ports were identical round design. The later 22RE (with the shorter deck height) had keyhole shaped exhaust ports. There were available 22RE models that used the earlier 22R head, in the 1982 to 1984 Celica GTS. All 22RE from 1985 used the later blocks and heads.
The 22RTE Turbo engine was based on the later model 22RE (short block /tall head). This is a similar but entirely different block and head. The block was drilled with different oil passages to accommodate the Turbo oil requirements. The cylinder head's combustion chamber had a different shape. The piston was dished. Advertised horsepower was 145. The factory set the boost at 5.5-6 pounds, but completely stock internals survived boosts of up to 17-22 pounds, with proper fuel injection modifications. This is a testimony to the bulletproof bottom end design. Nitro / Methanol fueled dragsters, producing in excess of 1100 HP- used the original (modified) crankshafts and TOYSPORT pistons!
Toysport built the first 2400 cc. 20R, these evolved in the 20/22R hybrid engines, in the later years when the 22R engine was introduced in 1981. The 20R head holds a distinct advantage over the 22R / RE heads, it flowed better. The availability of big valves extended the tuning potential for the 20R (and all the other engines).
There was a Japanese version 21R 2000cc, which had both an early and late model cylinder head similar to the 20R and 22R. These were imported due to the big demand for used engines. There is nothing of interest from these engines.
In 1985 Toysport raced a 22RE Toyota Celica GTS in the Macao Grand Prix. The original plan was to use an 18RG, but since the vehicle had US serial #'s (from Toyota Motorsport) they were forced to use the U.S. engine the 22RE! To the entertainment of the other Toyota Teams from Japan, they qualified at the last minute, in the last half of the grid. The other Celicas (with their Twin Cams) were all in the top 6 positions. At the finish the Toysport Celica placed 3rd- behind 2 BMW Motorsport prepared 6 cylinder BMWs! This is the highest finish achieved by the 22RE in international racing competition.
From 1984 to 1989 Toysport prepared a Spec-Engine for SCORE / HDRA Toyota private entrants. The winnings from the Toyota Contingency Program testify to the racing capability of the set-up. The engine package kit is still available, as complete engines. This set-up won National Championships for Toyota in Class 7 and Class 7 4WD. The carbureted engines developed 185-195 HP, but consistently out ran the 239-240 HP Ford engines in the same class. The secret is in the torquey characteristics of the power band. The limiting factor of this engine is also its strongest point. The long stroke limits RPM capability to about 6200 maximum, but the bottom end will take a lot of abuse. The crankshaft is forged.
MODIFYING THE 20R / 22R / 22RE / 22RTE ENGINES
BLOCK: The best set-up is achieved by starting with a 20R head and a 22R early block. This allows the use of the twin-row timing chains- over the late model single-chain type. Boring the 20R to 92mm is possible but some castings will develop bubbles in the bores that eventually clean up at 92mm. The high compression pistons for the 20R / 22R are forged. The stock early 22RE piston (full crown type) can also be used under the 20R head but the block and deck must not have more than .5mm cut, if used with big valves.
The 20R / 22R early and 22RE late model, responds well to high compression pistons. The rods can be prepped by stress relieving and shot-peening. The crankshaft oil galleys may be chamfered. High Tensile bolts can be upgraded to ARP- main, rods, and head bolts or stud kits.
The early and late style blocks have different engine mounting bosses, so interchangeability of late block to early chassis and vice versa may come up. Some early and late blocks have provisions for both. Really early and really late blocks do not have these provisions. When preparing an engine, make sure that the block has the correct mounting boss- or else you will have to deal with modifying them mounts.
The 22RTE with forged pistons will survive 25 lbs! A metal head gasket is required.
CYLINDER HEAD: It is mandatory to port all the heads. Big valves are also necessary to achieve and maximize the flow. Avoid cutting more than .50mm since valve clearance may be a problem with some piston combinations. Tri-Y headers work the best because they complement the wide torque band of these engines. If you are converting into the 20R head make sure that the 20R head has provisions for power steering (if you have power steering).
The choice in camshafts from many sources, must be carefully considered. High lift and long duration cams may affect the rocker arm geometry (and oil spraying function of the oil feed). Unless you take the time to ensure that the rocker arms are repositioned correctly (modifying the rocker assembly) do not even attempt. The long stroke / low RPM design of the engine dictates very mild cam lift and duration. You cannot redesign an engine with camshafts! Mild cams up to about 280 duration will work with the EFI with some adjustments to the AFM (air flow meter).
Stiffer valve springs are a safeguard from valve-float, but will not enhance performance since the best cam profiles will run fine with stock valve springs. An adjustable camshaft gear will allow the most accurate setting (remember that a Celica is totally different from a 4WD Pick-up).
There are no TwinCam heads available for these engines.
The 22RTE head chambers can be opened to lower compression and increase the flow. Big valves should also be considered, but not obligatory since this is forced induction.
FUEL SYSTEM: Twin side draft carburetors are a natural choice, but the EFI system will work excellent if the vehicle is originally equipped with one. (Some manifolds for the dual carbs have poorly designed water outlets that may cause overheating.) Long duration cams will seriously affect EFI engines, since combustion pressure drop dramatically even with high compression pistons. A fuel pressure adjuster may be needed. The Weber 32/36 or 38DPS are good upgrades for single carb set-ups. For carburetors, use a low pressure, high volume fuel pumps. Do not try to regulate lower fuel pressure with an adjuster because volume will also decrease. A fuel return line is mandatory to allow the fuel pump and carburetor to function properly. For any kind of performance do not rely on Toyota's mechanical or electric pump, they do not have enough volume. The 22RTE with any upgrade will need a higher output pump. The fuel pressure regulator should also be upgraded.
TURBO UPGRADE: The 22RTE needs forged pistons for any serious performance upgrade. The CT26 Supra Turbo (not the MR2/AllTrac) can be installed with minor fabrication. With boost controller, upgraded fuel delivery, 3" exhaust system, and intercooler- the 22RTE will put out in excess of 350HP, at about 25 psi!
Normally aspirated 20R / 22R engines can be turbocharged without too much problems. The stock pistons have to be replaced with low compression forged units.
IGNITION SYSTEM: The basic ignition unit was designed for low revving conditions. The electronics must be updated to the performance level intended for the engines. EFI engines converted to carburetors must use carburetor style distributors. Ignition amplifiers and knock sensors must be used to avoid high RPM misfires and detonation.
SOME RECOMMENDED SET-UPS:
For stock configuration- the 20R / 22R / 22RE engines are very easy to work on. Due to different emission requirements for the different model years, try to work on the original engine. Porting the head will increase breathing and will not hurt emissions- so basically to stay legal and improve performance- the cylinder head must be ported. The early 22RE pistons can be used to upgrade the 20R to 2400cc.
For modified configuration- the 20R head on top of early 22Rs will instantly give higher compression. All heads must be ported with big valves installed. Be careful of camshaft choice, just remember that all slow modified 20 / 22R / 22RE engines have been over-cammed. Do not try to install cams with duration over 280 on single carb or fuel injection models. Twin side carburetors are the best way to go. For limited budget use the Weber 38 DPS. Headers installed with 2 3/4" exhaust will be optimal. A heavier flywheel will help 4WD models, that should also have the gear ratios changed to compensate for tire sizes.
For racing configuration- basically these engines are truck engines. For off-road truck racing and high performance street use (both pick-ups and Celicas) the Toysport Spec SCORE / HDRA set-up is reliable and impressive.
Although some have successfully used the 22RE in circuit racing and rallying, and truck off-road racing- the only reason these engines were used was because of the race regulations. The handicap is the block configuration- which was built for torque and longevity- meaning slow and heavy. The cylinder head modifications, if properly done increases head flow by up to 200%.
For turbo set-up- forged pistons, ported head with open chambers, big valves, TO4 or CT26 turbo, 3" exhaust, mild cam, Carillo Rods, boost controller, blow-off valve and keep the boost under 25 psi!!
|*******On this website I am sharing the things I find out along the way. I do not guarantee that these modifications will work on your specific vehicle, any damages caused as part of the installation or use of these modifications are the the responsibility of the person who performed the installation.|