Oil Jet Installation Jigs for Toyota 1G-GTEU / 1G-FE (BEAMS) Engine Blocks

This project provides two precision drilling jigs designed for installing aftermarket oil jets into the cylinder block of Toyota 1G-GTEU (last generation) and 1G-FE (BEAMS) engines.

🔧 Included Jigs:

Main Oil Jet Hole Jig – ensures accurate drilling of the oil jet orifice in the engine block.
Bolt Mounting Hole Jig – guides drilling for the threaded bolt that secures the oil jet in place.
🛠️ Required Tools:

Lathe (for custom oil jet machining)
Milling machine or rotary tool (e.g., Dremel) for precise fitting
Drill press or hand drill (used through the jig for alignment)

Drilling Instructions:

First, drill an 8 mm hole through the jig all the way into the engine block. This hole connects directly to the oil gallery — the nozzle tip of the oil jet will extend into this passage to deliver oil.
Next, drill a 10 mm counterbore (or stepped hole) from the same side using the second jig or the same jig with a larger drill. This 10 mm bore is the mounting seat for the oil jet body. Do not drill through — stop 2 mm short of the oil gallery to maintain gallery wall integrity and prevent oil leakage.
⚠️ Always use the jig to ensure perfect alignment. Measure depth carefully with a depth gauge or marked drill bit.

🔧 Compatible Oil Jets (custom solution):

Hyundai/Kia G4KD / G4KE oil jet assembly
Hyundai Sonata (2014+) oil jet – OEM part #21150-2E720
🔩 Assembly Tip:
Use medium-strength threadlocker (e.g., Loctite 243) on the mounting bolt to prevent loosening under engine vibration.

⚠️ Note: These jigs assume proper engine block preparation and alignment. Always verify fitment before final drilling. Machining experience is recommended.

Designed for performance builds and oiling system upgrades. Print in durable filament (e.g., PETG or ABS) and consider adding metal inserts for extended tool life.

✅ Bonus Use:
In addition to guiding drills, these jigs can also serve as alignment and measurement templates to verify the correct position of oil jet mounting points before any permanent modification. This is especially helpful when adapting non-OEM oil jets or designing custom brackets.1