1UZ Non VVTI timing correction kit for 3UZ Oil Pump

1UZ Non VVTI timing correction kit (for use with 3UZ oil pump).

We would like to give a special thanks to JP Street Performance and Pop
Shop (Silvia Vert) for being a part of the journey to finding the solution to this issue. True
1UZ enthusiasts putting forth their best foot in pushing this engine platform forward.***

With the 1UZ Non VVTI oil pumps no longer being available from Toyota, many have switched to using the late model 3UZ oil pumps since they are abundant and easily available. However, this has caused many issues leading to engine failure. Not because of oiling issues but due to lack of tension on the timing belt.

When Toyota redesigned the UZ family of engines they redesigned the heads to now feature VVTI. A few things were adjusted but the manufacturer claimed some of the new components were backwards compatible. But that was not completely true. One of the components was the 3UZ oil pump. While the oil pump gear widened to 13mm to give you more oil flow, the position of the idler pulley boss for the timing belt (found on the 3UZ oil pump) was moved almost 7mm farther away which transferred into less tension on the timing belt between the crankshaft and the bank 1 cylinder head when putting this oil pump on a 1UZ Non VVTI engine.

The result was not only less tension between the crank and bank one, the bank one and bank two set of cams became retarded in their position respective to the crankshaft. Following that, all the belt slack would migrate to the tensioner side of the engine, and the tensioner arm and tensioner were on overtime attempting to maintain things in order. If the tensioner maxed out, then the timing belt would jump timing leading to engine failure from bending the intake valves. Given that the manufacturer also made the false statement that the VVTI tensioner arm is backwards compatible, while having 5mm less travel, this added to the issue and caused the tensioner to max out sooner when using a VVTI tensioner arm. Many timing kits claim Non VVTI but end up mixing in a VVTI tensioner arm, so please double check your timing kits.

Early warning signs that you have a problem could be any of the following: engine set on time but excessive slack on timing belt between crankshaft and bank 1, you can visibly see completely through the machined hole where the pin goes on the hydraulic tensioner (meaning the tensioner is already very high on its travel), while engine is running the timing belt looks like it is slapping.

The proper way to fix this solution is already available with what we are providing for the market: a larger proper sized pulley (to make up for the idler boss being moved), a stainless steel adapter (shouldered and tight fitting for the idler pulley bearing), a longer bolt (that ensures full engagement of the threads through all of the new components), proper washer (to hold on the inner race of the bearing to not obstruct the seal of the bearing). This robust solution kept in mind that stronger valve springs and bigger cams will most likely be used. While others have brought to the table a 6061 aluminum offering, we feel it is inappropriate to use that soft of a material when aggressive valve train components will be used.

While this solution will bolt on to the oil pump, you will be required to make clearance for the now bigger pulley behind the fan clutch bracket. Please refer to the photos above.

• Increased pulley size brings back proper tension on the timing belt between bank 1 and crankshaft.
•  Stainless Steel Machined adaptor ensures a rigid mounting platform for the bigger idler pulley, and it is a tight tolerance fit to make sure the pulley is true with the belt.
• Bolt on solution. The fan clutch bracket must be clearanced to not hit the now bigger pulley. A plastic cover for the timing belt (on the same side as the pulley) also needs to be clearanced.
• To guarantee proper tension on the timing belt YOU MUST USE THE PROPER TENSIONER ARM in conjunction with this product when using a 3uz oil pump. VVTI tensioner arms have 5mm less travel than the Non VVTI tensioner arms. If you feel your timing marks are not lining up even after installing this kit verify that you have the right tensioner arm and the correct idler on the tensioner arm.
• Keep in mind that any water pump not made exactly to the manufacturer’s specs can cause correlation issues between bank 1 and bank 2. Example: bank 1 will be on time but only bank two is in a more retarded timing position. Incorrect tensioner arm can cause this as well but usually if the issue is the arm the bank two cams are slightly advanced.
• If this is going on an engine where the block and head have been machined combined with a non-standard head gasket thickness, please be aware that this kit will get you very very close to the OEM timing marks but you may be slightly off due to variables beyond this kits control.