If you change cams and the internals , do you have to change the oil pump?

I don't see why you would have to unless you plan to run the **** out of it and was wondering about getting a larger amount of flow. I'm not too familiar with the lubrication system for the Series 2 engine, however, if it has oil passages in the rockers and connecting rods, you should have to make sure you're new set has the same.

Or maybe you can run a secondary pump with a hose carrying oil to the top of the engine. You might have to expand your current oil pan though.

It is always wise insurance to replace the oil pump during a major over haul because it'* inexpensive and easy to do while everything is apart.

But no, it is not necessary when doing a cam change.

You may want to increase the oil pressure a bit, like I did with a simple spring change. This will increase flowrate slightly and help if revving higher than stock.
10 psi per 1000 rpm is the general rule for high load applications.

Lol... I wasn't aware it was common practice to change oil pumps when doing major internal work. I guess Doug and I didn't get that memo!

When we did my cam, we reinstalled the old pump. I'm also embarrassed to admit that we forgot to pack it with Vaseline, and started the car on a dry pump. Needless to say, it took the lifters a little while to stop ticking. I would imagine you would be fine reusing the old pump, though if your budget allows, you might as well pick up a replacement.

As long as the engine never over heated 99.9% of the time the oil pumps are fine. Out of all the motor I've seen, I've only ever seen 1 bad pump. Funny thing is the motor also had spun every bearing .

The way it looked is it spun a bearing, metal went thru the pump, and then lost ALL the bearing. Needless to say they called Ed, and had a new setup in 2 days.

If you have the pan off anyways, then at least check it for clearance inside. On engines with conventional distributors I usually replace the pump anyways or at the very least the collar on the drive shaft. (only because the distributor is driving the oil pump and a worn oil pump effects the timing.)

Like the fellow mentioned, if you blew a bearing in the motor, replace the oil pump. In fact, tear down the engine completely and clean out all the passeges in the block, crank, etc. Those metal chips get everywhere...no sense replacing the blown bearing if you are going to leave the metal floating around in the oil system to wipe them out again.

On a distributor-less motor that had no other wear issues, just inspect the oil pump and put it back in if good.

One other item is the oil pump drive gear. If you change the cam, replace the gear that mates to it with one of suitable material. As a general rule: steel cams get bronze gears, cast iron cams use ductile iron gears. (Check with the manufacturer of the cam as to which gear to use.) This is a long-term wear issue...most cast iron cams are like a tootsie-pop...crunchy on the outside, chewy on the inside. The soft iron gear is a nice, long wearing material. A steel cam is so friggin hard that it would break the teeth out of a ductile iron gear, so a bronze gear is used...it absorbs the impact of the steel teeth. Yeah, it wears out quicker but at least it doesn't break.

That was a very good explanation clm2112. I particularly liked your reference to a tootsie pop.

When I had my pump out and all, I didn't do the Vasaline thing, but I forgot to remount my coil pack, so I did A LOT of turning. I didn't get any noise after it started (after I figured out that I neglected to ground the coil)