Author: ericthepoolboy, published on 2015-01-22
Completely reverse engineered Toyota 22RE 4 cylinder engine. Can completely print a fully rotating model. Working crank, pistons, and valve train. The valves open and close!!!. It may not be the most exciting engine but its the only one I had in my garage. Great if you want to learn about engines and how the moving parts in them work. All parts are printed except for a few bearings and fasteners.
More than 3 days of total print time.
The block alone was 34 hours. So make sure you have a well calibrated and reliable printer.
Some print times calculated in Cura at .2mm layer height
Engine Block – 40 hours
Head – 23 hours
Valve Cover – 10 hours
Oil pan – 14 hours
Update 02/01/2015: Updated the oil pan, timing cover, and rear main cover to use 4mm x 2mm disc magnets so that the oil pan will stay on better. Glue magnets in and allow each magnet to be exposed roughly 1mm above surface to allow a gap between the block and the oil pan.
Note!!! Connecting rod caps and spacer .125 were not scaled properly. Way too big/small. Updated 01/27/2015
Update 01/27/2015: Added ported version of head. Has 3mm holes for spark plugs or LEDs for future upgrades. Print with support touching build plate. printed nicely, just a good amount of support material to remove and clean up. But you can see the valve moving if you look through the ports.
Update 01/27/2015: Made intake manifold. Lower can be printed without any support. Upper as been split into two halfs to print and then glue together later. I also uploaded the whole upper intake if you want to print it with all support. Manifold attaches with 4mmx2mm magnets just like the header. I used 14 magnets total(7 on each side. 5 on top, 2 on bottom) due to the weight of the intake. I assembled the lower, upper, and throttle bossy with m3 SHCS but you can glue it if you want. Will upload a new version of the head that is ported with spark plug holes tomorrow. Just test printing it now.
Update 01/25/2015: I made a header for the engine and uploaded it. It printed wonderfully in Cura with support. Make sure to select “touching buildplate” for you support option as the header is hollow just like a real one and if you don’t, it will fill the inside with support. It’s held on with 8 4mm x 2mm disk earth magnets epoxied in.
This model was reverse engineered from a 22RE Toyota engine, All modeling was done in SolidWorks and the STL files were scaled to 35% for printing since that the biggest my printer could print. All parts were printed in PLA on my RepRap original Prusa. There are 80 printed parts in this assembly, not including any fasteners or bearings. Probably a whole 1kg roll of plastic.
The model can be built in different stages, if you only want the short block then only print those parts. The head is completely removable so you can see the pistons moving and also the valves opening and closing. The oil pan is attached with magnets so you can take it off and see the crankshaft moving.
It’s a complex print and model. Total print time of the block at 35% scale of the original was just over 34 hours. Just the head print time was 20 hours. Make sure you have a well calibrated and robust machine if you want to print this. It’s definitely is a challenge for you and your printer. You can scale the model even further but sourcing bearings and fasteners will be an issue.
See the hardware list for all none printed parts, bearings are all common bearings used on 3D printers so they should be easy to source. Hardware is best sourced from bolt depot since you can purchase individual quantities. For the valve springs, I formed them using my drill and a 1/4″ ratchet extension as a mandrel. I used 0.023″ steel mig welding wire but you can use anything similar. The outer diameter of the spring should roughly be 0.470″. Each spring has 10 loops and just stretch it long enough to keep the valve closed. I wasn’t able to find a pre-made springs with the right size and spring constant. If somebody does know of a spring that will work with this please let me know.
For Drive belts to connect the fan pulley and the electric motor, I used rubber bands. The crank pulley and electric motor pulley are setup to use a timing belt but I never got around to sourcing one. The teeth spacing is for a gates extra light timing belt. 1/8″ wide, and .080″ pitch.
If you do decide to print and build this model you will probably run into some fitment issues due to different printers, plastics, etc. If you have any questions let me know. All STL files are good, they have been repaired with NetFabb so there shouldn’t be any problems there.
I’ll upload assembly drawings in the future when I get a chance.
Tags: 22re, 22_re, 4runner, Auto, Automobile, Automotive, awesome, cool, crankshaft, cylinder, cylinders, educational, Engine, fan, gear, gears, model, Motor, Pickup, piston, pistons, rotating, rotational, scale, scaled, Toyota, valve, valves