Degreeing a cam

[james duncan]

How do you degree a cog belt camshaft engine? Specifically a 2.3L OHC engine.

 

[Dave R]

It's not difficult. But in order to take full advantage of the degreeing process you'll need an adjustable sprocket, about $90-150, depending on the year of the truck and how "nice" of a sprocket you want to purchase.

To degree the cam you'll need access to the front belt area, to install the adjustable sprocket, and the camshaft. So remove everything in your way including the rocker cover. To do a top notch job you'll have to find TDC on the crank but generally the factory's notch can be taken as good enough. Leave the belt off of the cam sprocket, after changing it, turn the cam until both of #1 cylinder's lobes are pointed 'up' (one will be aimed at 10 O'clock and the other at 2) and then take a 6-8" long plate (steel, wood, dosen't matter as long as it's flat) about 4" wide and place it across both lobes. Now you'll need to measure, carefully and accurately, the distance between the bottom of the plate and the head's cover cover surface on both sides. Then shift the cam until there is equal distance on both sides. That is now 0* on the cam. Now look at the sprocket and note the indicated position. You can adjust it from there, (i.e. if at actual 0* the sprocket says 2*A then shifting it to 4A would actually be 2*A) most people don't find much benefit to going beyond 6-8* from 'stock', retard the timing to shift the power band towards the upper RPMs, advance it for the opposite. If you truck sits perfectly level on a level surface this can also be done with a spirit level on top of the plate but the measuring method is more accurate.

Hopefully that is reasonably clear. Try it, if you have any suggestions for clarifying the destructions given here, please let me know as I'd like to write that up as a 'stickied' subject, as the question has been asked before. I'm thinking timing belt change would be a good subject for one as well.

 

[james duncan]

Thanks for the responce! jd