this instructable will show you how to make a car with a crankshaft and two pistons. if you do not have pieces that I do improvise and if you see a better way to do things, feel free to make adjustments.

Step 1: Materials

1x flat 6x16 piece,

1x flat 6x10 piece,

1x flat 6x2 piece,

1x tall 6 piece,

2x tall 4 pieces,

2x tall 8 pieces with holes,

2x tall 10 pieces with holes,

2x tall 12 pieces with hole,

2x tall 2 pieces with crossbar hole,

3x tall 4 pieces with holes,

3x tall 2 pieces with hole,

8x tall 6 pieces with holes,

12x tall 2 pieces (regular)

1x driveshaft u joint,

1x propeller/fan (optional)

4x T crossbar pieces,

6x long crossbar wheel stopper,

2x short crossbar wheel stopper,

2x long crossbar,

4x kinda short cross bar,

2x shorter crossbar,

3x shortest crossbar,

4x 2 level crossbar stopper,

2x low friction pin,

4x low friction pin cutoff

1x medium gear,

1x medium gear w/ bent teeth,

2x wheel with holes and no tire,

2x front wheel,

2x rear wheel,

2x tall 1 space wide slanted piece (needed in making track for other piston (continued))

Step 2: Make Crankshaft

use 2 level crossbar stoppers and shortest crossbar and T crossbar pieces to make the crank. on the rod use shorter crossbars to connect the 2 T pieces and I think you can see the rest.

Step 3: Make Crankcase.

use tall 6 pieces to set the crank in. for base use the flat 6x16 piece. leave 2 places in front for "radiator" thing

Step 4: Put in Cooling Fan

put cooling fan on front of "engine"

Step 5: Making Fan Cover

build up 3 tall 2 pieces on each side of the cooling fan and put the flat 2x6 on top

Step 6: Making Track for "piston"

stack 1 of the tall 2 pieces with the hole in it on each side of the "piston" (make sure you put these on the back of your engine)

Step 7: Making Track for Other Piston

on top of the "radiator" box put 2 tall 2 pieces 2 spaces apart

Step 8: Making Track for Other Piston (continued

put the slanted pieces on the tall 12 pieces and then put then slanted piece toward the front onto the top. put two tall 2 pieces on to of that one space from the end so when you turn the crossbar from the crank the "pistons" will smoothly go up and down along their track.

Step 9: Putting on U Joint Driveshaft

that seems pretty self explanatory put it on the opposite end that the fan is

Step 10: Put Wheel Base On

use the tall 8 piece to put the other flat base on the back

Step 11: Adding to Rear Wheel Base

add 1 tall 6 piece with holes on either side of base and then a tall 4 piece with hole on the end.

Step 12: Making Rear Whells Work for Me (depends on Wheels)

put 3 cut off low friction pins on opposite sides of wheels with hole and insert the onto the other wheels. I did this because my crossbar for rear wheels was not long enough.