New Cam, Old Engine
Captain
Joined: Jul 2008
Posts: 678
Likes: 1
From: Houston, TX
If you are going with a stock type roller cam (same as factory), then technically, there should be no issues with making the swap unless it's ultra high lift/long duration. However, I did run into some unforseen issues with my cam swap:
1. Be very careful when removing your original cam. The cam bearings are very easily damaged if a cam lobe is allowed to fall on or nick a bearing. Don't kid yourself, it is very easy to do. Even if you get the cam out cleanly, you still might have some bearing errosion/damage. In my case, I either damaged the #4 bearing while removing the cam or it erroded over time. I don't know for sure. In any case, I had to replace the bearing and polish it down to get my replacement cam to fit. Total PITA.
2. You need to take the time to degree-in your new cam. I used the 3-key timing chain set Hughes sells and wound up using the advanced keyway to get the valve timing right.
3. If your lifters need to be replaced, buy a good quality set and be sure to soak them in a quart of engine oil for several hours before you install them. Don't pump them up first like old school. I wound up just rebuilding my factory lifters because there was no play in the rollers and they were not gummed or varnished up. Plus, by comparison with a new set I had, they looked more HD than the replacements.
4. Make sure your pushrods are straight before reusing.
5. If your factory rockers are in good condition, they can be reused. Just my opinion here, but I believe the stockers are much stronger in the fulcrum area than the rollers are. Not dissing the rollers mind you, but in a street level engine (under 6,000 rpm), I don't think they give you any advantage over stock other than looks. Please note all you 1.7 owners with original factory cams, this does not include you.
1. Be very careful when removing your original cam. The cam bearings are very easily damaged if a cam lobe is allowed to fall on or nick a bearing. Don't kid yourself, it is very easy to do. Even if you get the cam out cleanly, you still might have some bearing errosion/damage. In my case, I either damaged the #4 bearing while removing the cam or it erroded over time. I don't know for sure. In any case, I had to replace the bearing and polish it down to get my replacement cam to fit. Total PITA.
2. You need to take the time to degree-in your new cam. I used the 3-key timing chain set Hughes sells and wound up using the advanced keyway to get the valve timing right.
3. If your lifters need to be replaced, buy a good quality set and be sure to soak them in a quart of engine oil for several hours before you install them. Don't pump them up first like old school. I wound up just rebuilding my factory lifters because there was no play in the rollers and they were not gummed or varnished up. Plus, by comparison with a new set I had, they looked more HD than the replacements.
4. Make sure your pushrods are straight before reusing.
5. If your factory rockers are in good condition, they can be reused. Just my opinion here, but I believe the stockers are much stronger in the fulcrum area than the rollers are. Not dissing the rollers mind you, but in a street level engine (under 6,000 rpm), I don't think they give you any advantage over stock other than looks. Please note all you 1.7 owners with original factory cams, this does not include you.
Captain
Joined: Jul 2008
Posts: 678
Likes: 1
From: Houston, TX
