cam oiling investigation

[madkaw]

Good point john about the maintaining pressure for the bottom end. I was planning on putting a direct oil pressure guage on there also. Like I said before , this is just playing around , I'm not trying to re- engineer the oil system. I'm just glad i didn't just go with the spray bar without checking it out first. I don't know if I would say it is a bad design, but it's an item that should be replaced periodically, especially during a rebuild.I wonder how many cases of badly worn lobes on new cams are caused by using the old spray bar?

[beandip]

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.

I measured the pressure over a 3 week period while driving the car . I used a mechanical gage connected directly to the block with the gage on the console. I didnt calibrate the cage separately however . I was showing low pressure with this engine so I wanted to see what was going on. I have a new sens er now and it seems to be showing comparable readings. As much as the stock set up will allow. Gary

[beandip]

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.

I HAVE NO IDEA . I HAVE NEVER HEARD THERE WAS ANY DIFFERENCE. One thing I have heard though , is many times when you buy a ''turbo'' pump at a parts house . A rebuilt unit, they are not turbo pumps , but standard parts. FOR WHAT IT IS WOURTH.

[jmortensen]

You can buy a "real" turbo pump from the dealer. I have never heard that there is a difference between the standard and auto either, so you'll have to figure that out for yourself. The turbo pumps have larger gears, and that's what distinguishes them from the stock one. They have a higher flow output because they had to push oil out to the cooler and back. Add Nissan comp springs and now you have the comp pump with higher pressure and volume.

I've never heard of issues from running both oiling systems. The solder joints are the weak point in the spray bar, but if you're concerned, resolder the joints. The spray bar should be the more effective method for oiling the cam, and lots of 510 racers add the spraybar to the stock internal oiling (although they run a separate oil line from the block).

If it were me I'd run one comp pump spring and one standard pump spring on the turbo pump.

[madkaw]

I called MSA today and asked about there "high volume" pump for 69$. Garrett ,I believe was his name, said that was merely the turbo pump for the manual trans. He said it would be cheaper(49$) to by the stock repalcement and put the higher pressure springs(14$) in because that is exactly what the turbo pump is(excluding the auto trans version). Not a whole lot of savings, but there price is pretty good actually .

[Go240Zags]

I called MSA today and asked about there "high volume" pump for 69$. Garrett ,I believe was his name, said that was merely the turbo pump for the manual trans. He said it would be cheaper(49$) to by the stock repalcement and put the higher pressure springs(14$) in because that is exactly what the turbo pump is(excluding the auto trans version). Not a whole lot of savings, but there price is pretty good actually .

madkaw, so if we buy the higher pressure springs for $14 and just change them with the ones in our current pump it will work same as the manual turbo pump? If you have a stock pump that should be even cheaper. I've been thinking of this upgrade, but if my stock pumps work just fine maybe I'll just change the springs.

[mlc240z]

jmortensen:"The turbo pumps have larger gears, and that's what distinguishes them from the stock one. They have a higher flow output because they had to push oil out to the cooler and back. Add Nissan comp springs and now you have the comp pump with higher pressure and volume."

that makes sense, Jon.

so changing the springs on a stock pump should, at the very least, give a boost in pressure without adding the extra volume of the larger gears.

[jmortensen]

The turbo pumps have larger gears, and that's what distinguishes them from the stock one. They have a higher flow output because they had to push oil out to the cooler and back. Add Nissan comp springs and now you have the comp pump with higher pressure and volume.

This is correct.

so changing the springs on a stock pump should, at the very least, give a boost in pressure without adding the extra volume of the larger gears.

Yes. Rule of thumb is you want 10 psi oil pressure for every 1000 rpm. When I installed both comp springs, it was way too much pressure. 1 comp spring and one stock spring is about right with no external cooler IME

[mlc240z]

i'm probably staying with the spray bar, so this sounds like $14 well spent.

thanks, Jon

[bjhines]

The pump housing and gears are LONGER in the Turbo pump... It may contact your sway bar if your engine mounts are shot... be careful checking clearance onder load... bore diameter and all other housing dimensions are the same...

[madkaw]

Still waiting on my new spray bar from MSA. They sent me one ,but my luck it didn't line up with the towers . I guess I got a defective one . Sal was very helpful and has sent me another to try . I have a oil presssure guage mounted to the motor(mechanical type), and I will checking pressures with the new spray bar mounted.

[madkaw]

I left off waiting on an oil pump and a new spraybar from MSA.I failed to fix my original spray bar and actually melted it trying to resolder it. I had another one but couldn't find anyone who wanted to mess with it. I will assume for the sake of this experiment that the Nissan replacement that MSA sells performs the same.

I ordered the high volume pump plus some HP springs so I knew what I had doing this experiment. I also mounted a pressure guage on the block to keep an eye on things.

Bottom line is that I could NOT get satifactory results using both oiling systems. I never could get the spray bar to spray with enough pressure to actually reach the lash pad even with the HP springs installed and showing 75psi. So IMHO there is no reason to run a spray bar and the internally oiled cam both.

My disclaimer is that i am a novice mechanic and your results may vary. Hope you guys get something out of this:)