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EVO: Engine Mechanicals - Sub-02A

Installing Evo Cams

¹⁾

The pinion gear has a notch on one of the teeth. Rotate the notch to point towards the center of the #2 cam hole. ²⁾	It may not be easy to get it to settle straight on. At this location, the piston is rising to about 3 teeth before TDC (exhaust stroke). It's too far right in the this pic. ³⁾	And too far left in this one. While rolling the engine backward to align the mark, the weight of the rod / piston adds a small amount of motion force to a small turn of the wrench or rear tire. ⁴⁾

Read the Service Manual prior to performing any work! ⁵⁾
Make sure the cams are clean and free of debris prior to installation (brake cleaner works well for this).
Lube the cam journals and bores before installing them.
You can wait until the cams are in place to lube the gears but this needs to be done as well to help lube them until oil pressure can get to them.
Install each cam in it's respective bushing (1-4 from back to front).
There is only a very small clearance between the camshaft and the bushing.
If there is any binding, do not force the cam in. The steel shaft can damage the brass bushing. Pull it back out and try again.

⁶⁾

Obviously, it's easier to have the lifters removed and out of the way when installing cams.
However, it's not a real issue with the lifters installed. They will probably have to be raised up slightly so the cam lobes clear them on installation.
Just make sure the lifters have been primed and pumped up with oil before buttoning up the cam chest.

It is common practice to leave them soaking in clean oil (same as you'll be using) while removed.

Bring each cam up to it's bushing and align it straight before attempting to slide it in.	The lifter hangs down below the cam lobe camshaft lobe ⁷⁾	A telescoping magnet can be useful to hold them out of the way ⁸⁾

Or, the lifter can be bumped a little while the cam is on it's base circle as in below.

Roll the cam around to it's base (small) circle end, slip the shaft under the lifter and turn the dot where it needs to be ⁹⁾

The engine will not be at top dead center on either cylinder when you time the cams.
All you have to do is line up the dots on the cams. ¹⁰⁾

Caution:
The dots on the cams correspond to the cam lobe positioning in relation to the crankshaft, pistons and valves.
Cam lobes open / close the valves at the proper 'time' and in relation to the rise and fall of the pistons.
All dots must line up properly.
Incorrect cam timing can result in engine damage from the valves opening / closing out of sync.
Some damage pics from this can be seen below.

Double Check the numbers on #1 and #4 cams before installing them.
These two look alike from the front and are the only ones that have 1 dot each.
The notch on the pinion gear tooth can be difficult to make out. It's just a small slot cut long-ways on one tooth face.
Clean the pinion gear enough to be able to tell the difference.

#1 and #3 cams should go in first. The order of these two are unimportant as long as the dots are aligned properly.

#1 cam dot faces the center of the #2 cam bore	#3 has two dots. Each dot faces toward the center of the two adjacent cam bores (#2 and #4 respectively). The dots won't line up correctly installed upside down.

#4 cam can be installed at any time after #3 is in place and it's the least of the worries of installing incorrectly (outside of checking that the cam number is correct).
#2 cam has two separate gears on the same shaft and three alignment dots.
The smaller gear behind meshes with both #1 and #3 while the bigger outside gear meshes with the pinion gear.
(The outside gear drives all of the cams with help from the pinion gear).
- It is also the most difficult one to install.
  With all three dots seemingly aligned properly, you'll probably still have to massage any one of the adjacent gears to get #2 to slide in.
  Be patient and don't force it or scarring of the bushing can occur.
- Match up the pinion gear mark and the middle cam dot first. Then massage or move cams 1 or 3 to mash up in alignment.
  You'll have to pull #2 out (just out of mesh in order to move the others.

#4 cam dot faces the dot on #3	#2 cam dots line up with 1,3 and the pinion gear mark. This is how it should look when done

Lube the cover bushings and the cam gears and shafts. ¹¹⁾

All dots on the cams are correct but the pinion gear and #2 cam marks were out of alignment. ¹²⁾		Resulting in bent intake pushrods and valves ¹³⁾