cam oiling investigation

[madkaw]

After reading through the archives on cam oiling I thought i would do my own research on this subject. I wanted to prime my engine with oil before starting so I thought it would be cool if i could see this in action plus verify my spray bar is working correctly. When i rebuilt my engine I had the spray bar cleaned with everything else, but I have been skeptical of those little hole getting clean. The cam is an internally oiled, but I was going to use the spray bar also.This was another reason to look at things a little closer.

So I found an old oil pump shaft from another car that would work and used a variable drill that had a 2800 max rpm to rime the motor . I used aluminum tape to make a barrier around the head.This actually worked very well to keep the oil in, just make sure you get the head perfectly clean so the tape sticks well to prevent leaks. (pic#1)

What I found was that i am glad I did this test. With the plug in the end of the cam the oil shot out of the lobes more then i thought it would.(pic #2) I kept the drill speed low probably 1000rpm and the pressure was always good coming out of the lobes.And with the plug in there was still decent oil coming out of the spray bar. With the plug out, the oil pressure from the spray bar increased but not as much as you would think, and the oil was still coming out of the lobes but not with any pressure.(pic#3) I think a compromise could be made by drilling the plug to lower internal pressure and maintain spray bar pressure

The biggest find was that my "cleaned spray bar" was not putting oil out on some of the lobes.(pic#4) So I did what many have recommended and ordered a new one. The oil pump I am using is supposed to be a high volume pump I bought off of e-bay but there is no way of proving this. When I get my new spray bar I will continue this with some more pics . Hopefully this will fix the lack of oil from the spray bar.

[240ZMan]

Why are you using the spray bar with an internally oiled cam?

[madkaw]

If there was anywhere that i would want redundancy it would be there. There is quite a few guys running both set-ups, but I wanted to see first hand how both systems would work together. From what I have seen thus far they would compliment each other well plus giving the added protection of two oil supplies. Like I said though this started out as a way to verify my spray bar was doing it's job, and it wasn't.

[240ZMan]

I've read in several places that the stock oiling system does not have enough volume to properly supply both the internally oiled cam AND the external sprary bar. This has lead to cam lobe failure. You don't sound convinced that the ebay pump you ordered is really a high volume one, so I can't help but wonder if you're actually increasing the risk of cam failure with this approach.

Just because your bar was plugged doesn't mean that the spray bar, OR the internally oiled cam, is inadequate in any way when properly cleaned and installed.

Just my $.02.

[240ZX]

I lean toward what 240ZMan has mentioned. Generally speaking on any pressurized oiling system the less the resistance to flow is, the lower the pressure will be. Simply said, if you had no resistance you could not obtain any pressure.

[madkaw]

That is exactly why I am checking this out. I am not saying I am right or wrong but there a quite a few guys who have done this with success.I wanted to see with my own eyes what kind of pressure loss there is with using both.Also Daniel, I will be be buying a stock oil pump to try this with too. Like you said, I am not sure what pump I have ,so I want to start with a stock pump and see how the pressure looks. And I don't think either system is inadequate, obviously the spray bar was used for years with success.This is just my way of verifying some of the stuff that's posted on these sites and I appreciate the feedback

[beandip]

I have been running this same set up on my engine and now it has just over 40K on it with no problem so far. I am running a TURBO PUMP though. I have about 20 psi oil pressure on a warmed up engine at idle and right about 50 or so at 2500 RPM . This is with 10w30 . This was measured with a manual oil pressure gage . Gary

[madkaw]

Gary,

Is that the turbo automatic or manual oil pump, I guess there was a difference. I believe the manual was a "higher volume" pump but not like the automatic.

[Arne]

I have been running this same set up on my engine and now it has just over 40K on it with no problem so far. I am running a TURBO PUMP though. I have about 20 psi oil pressure on a warmed up engine at idle and right about 50 or so at 2500 RPM . This is with 10w30 . This was measured with a manual oil pressure gage . Gary

You know, Gary, those numbers would bother me a bit, they seem low when compared to either of my cars. With 10W-30 I get about 40 psi at warm idle, and around 70 psi at 2000-2500 rpm. Of course, that's just on my dash gauge, so who knows how accurate that is.

[jmortensen]

You know, Gary, those numbers would bother me a bit, they seem low when compared to either of my cars. With 10W-30 I get about 40 psi at warm idle, and around 70 psi at 2000-2500 rpm. Of course, that's just on my dash gauge, so who knows how accurate that is.

Arne, that is your inaccurate stock gauge talking. Hot oil pressure on an L is usually somewhere around 15-20 at idle.

My question in regards to this whole setup is why would you possibly want to unplug the cam? Are you worried about too much pressure, or is it that the spraybar seemed to work better with the cam unplugged? Regardless of the reason why you're trying it both ways, when the engine is actually running you want the pressure, so you'll want to have the cam plug in. Right now you're testing FLOW, not pressure. When the engine is running, you need pressure as much as flow, especially for the bottom end.

[mlc240z]

i've seen the replacement springs for the oil pumps being sold.

not sure if there is much of a difference between the replacement NA/turbo springs.

is this the way to 'convert' a stock NA oil pump into a turbo pump?

or are there other internal differences between the NA and turbo pumps.

[kinfish]

My stock '71Z was victim of that cantilevered spray bar feeding #6 cylinder when it broke at braze joint. Bigger orifiice translated to lower pressure and essentially zip for oil to #6. Wiped out cam lobes before I caught the problem. If you upgraded to internally oiled cam, shitcan the spraybar and cap the feed port (MSA says kit to do so). Spray bar is bad design and has durability issues.