Theory:Standard JDM CA18DET Cam specs: In lift - 7.8mmEx lift - 8.5mmIn duration - 240Ex duration - 248In opens - 0 BTDCIn closes - 60 ABDCIn center lobe angle - 120degEx opens - 64 BBDCEx closes - 4 ATDCEx center lobe angle - 120deg(Courtesy of Niscort)
I had read a lot about doing this, so I bit the bullet and picked up an exhaust cam. Following is a simple how to. All of this is covered in the FSM from EM-12 to EM-18, except for the setting for the new cam. Much of the theory on this is covered in detail here:http://www.sxoc.com/vbb/showthread.php?t=281511
A simple visual comparison of the two cams (crappy pics, but you can see the difference in lobe angle and duration).
Tools:-Metric socket set-2 medium crescent wrenches-Hex set-Socket for crank (I use a 1 1/16")-Small screwdriver-Something to tap in cam seals (I used a 1 3/4" exhaust adapter pipe from the parts store)
Supplies:-CA18DET exhaust cam-224052 Federal Mougl (or comparable) seals-Oil-Towels
Procedure:Step 1Remove the water pump pulley. Loosen the 4 10mm nuts on the fan/water pump. Loosen the 14mm lower alternator mount, 12mm alternator tension bracket bolts (1 on alternator, 1 on tensioner). Slide alternator to the right and slip off belt. Remove the 4 10mm nuts on water pump pulley and remove.
Step 2Remove upper timing cover. Remove the 5 6mm hex bolts and 4 10mm bolts that hold the upper timing cover on. Locations can be found in FSM. Remove 3 10mm bolts holding on CAS. Remove CAS, then timing cover.
Step 3Remove coil pack cover, valve covers, cam gears, and timing belt tensioner. I have hex hardware on my valve covers, but you need a phillips head screw driver for the 16 valve cover screws (8 each) and a 10mm socket for the 8 10mm bolts for the timing cover. Leave covers in place to avoid debris entering valvetrain as you continue to work.
Now, set the motor to TDC.
Loosen 13mm nut on tensioner. Loosen the tensioner by inserting 5mm hex into the hole provided on tensioner and swing counterclockwise to remove tension. Slip Timing belt out of the way. Remove the 13mm but on the tensioner and make sure and keep track of the Marcel spring underneath (looks like a wavey washer). Now, take a few towels and stuff them in the gaping maw to catch any debris or falling screws.
Now, remove the valve cover for the cam you are working with. Use a crescent wrench on the place provided on the cam to hold it in place as you remove the 4 12mm bolts holding the cam gear on. Repeat for other cam. Replace cover when done. Remove the cam gear backing plate via the 4 10mm screws. Pull off.
Step 4Removing the cam. Inspect the key for the CAS on each cam and use the one with a cleaner key on the exhaust side. The one in place on the exhaust side of my motor was fine, so I only removed the intake cam for the swap. Follow the diagram below for removing the cam.
Here is the cam removed. This would be a great time to change out lifters if your are making noises.
Keep caps in order. They are numbered to assist in reinstall. Here they are arranged, right to left for front to back.
Now, place the new cam in its new home, and replace cam caps in reverse of install.
Step 5Cam seals. Even though I only swapped one cam, I went ahead and replaced both seals.
Since I am not swapping exhaust side cam, I just removed the front cap entirely. You may need to use a small screwdriver to lightly pry the cap off. Remove the cam seal, and lightly coat the new one in some motor oil. Slip it on, making sure the inner ring seats. Tap into place with suitable diameter pipe or tool.Once seated, seal will be flush with the head.
Step 6Setting cams. As outlined in the article linked above, we need to advance the new intake cam 1 tooth if you do not have adjustible cam gears. If you do, reset the cam to 8* advanced.
Replace cam gear backing plate.
Double check that the crank is set to TDC (second mark from left). Use 2 crescent wrences on the cams to position them. Havng a friend helps. I painted the cam gear backing plate white at the timing marks, as well as the small divets in the cam gear where TDC should line up to assisit in visual. Replace cam gears and tensioner. Now, line up the cam gears. Here is the position of the intake cam. It sould be 1 tooth advanced (clockwise) from stock.
Rotate the enigne over with a wrench two full revolutions, making sure that the marks still line up. Button everything back up, reset CAS timing, and go.
Final ThoughtsI have not had a chance to go on a real test drive, so impressions will follow. I noticed that when resetting the CAS, the motor likes to idle be at ~17TDC now. Dunno. I'll play with it later. Any questions, comments or concerns ... I know you will just post.