At idle ?(warm)...........20-ish maybe...sorta...enough to keep the oil light OFF ! (that always bugged me)

6sally6

I had put high volume oil pump in my 5.0 build  not sure what it is soon as I get the 3;55 gears in it is going to another buddys house to check the roller rockers and push rod length along with cam stuff.

TKOPerformance wrote:

I would swap it for a standard volume pump.  All a high volume pump does is suck all the oil out of the pan and pump it into the top end,  

 
Since the top end gets its oil thru the push rods, I find it hard to believe it's possible  to drain the oil pan. The drain holes in the head are mucho bigger than the supply holes in the pushrods.

TKOPerformance wrote:

RPM, aka Bearing Bob wrote:

TKOPerformance wrote:

I would swap it for a standard volume pump.  All a high volume pump does is suck all the oil out of the pan and pump it into the top end,  

 
Since the top end gets its oil thru the push rods, I find it hard to believe it's possible to drain the oil pan. The drain holes in the head are mucho bigger than the supply holes in the pushrods.

Pressure vs. gravity.  Yes, the passages are smaller than the drainback holes, but the oil coming through them is under pump pressure.  On race engines with wide clearances where a HV pump is recommended it is also recommended to enlarge the drainback holes, go to edge orifice lifters, or install restrictors in the oil galleries.  There are quite a few threads about people who failed to do this and ended up with smoking caused by too much oil in the top end. 

Also when draining back the oil hits the cam, crank, rods, etc.  This tends to rope and aerate the oil, neither of which is good.  Then the pump sucks up that aerated oil at a faster rate than a standard volume pump would exacerbating the problem due to wash, rinse, repeat occurring more rapidly. 

In the end my thoughts are simply why take the chance?  Run the pump you need. 

TKO – good explanation, one comment I’ll offer is that oil pumps are a “positive displacement” type pump.  Each rotation of the pump discharges a specific volume of fluid, pressure is regulated by a pressure relief spring mounted in the pump. 
 

BobE wrote:

TKOPerformance wrote:

RPM, aka Bearing Bob wrote:

 
Since the top end gets its oil thru the push rods, I find it hard to believe it's possible to drain the oil pan. The drain holes in the head are mucho bigger than the supply holes in the pushrods.

Pressure vs. gravity.  Yes, the passages are smaller than the drainback holes, but the oil coming through them is under pump pressure.  On race engines with wide clearances where a HV pump is recommended it is also recommended to enlarge the drainback holes, go to edge orifice lifters, or install restrictors in the oil galleries.  There are quite a few threads about people who failed to do this and ended up with smoking caused by too much oil in the top end. 

Also when draining back the oil hits the cam, crank, rods, etc.  This tends to rope and aerate the oil, neither of which is good.  Then the pump sucks up that aerated oil at a faster rate than a standard volume pump would exacerbating the problem due to wash, rinse, repeat occurring more rapidly. 

In the end my thoughts are simply why take the chance?  Run the pump you need. 

TKO – good explanation, one comment I’ll offer is that oil pumps are a “positive displacement” type pump.  Each rotation of the pump discharges a specific volume of fluid, pressure is regulated by a pressure relief spring mounted in the pump. 
 

Correct, and so long as you don't get a pump which is billed as being "high pressure".  You could always shim the pressure relief spring if you wanted more pressure, but I'm not sure why you would. 
 

What are the main and rod bearing clearances in the 427 vs. the 331?  I would posit that the 427, being a very high performance engine has wide clearances.  I also seem to remember the 427 is an aluminum block engine, and from what I've read the clearances in an aluminum block tend to open up as the engine comes up to operating temperature due to aluminum's higher coefficient of thermal expansion compared to cast iron.

No one ever said the gauge would go to zero because there was NO oil in the pan.  That scenario is indeed laughable.  However, you can absolutely over oil the top end leading to smoking, AND what's the quality of the oil in the pan?  Highly aerated oil will still show pressure, but isn't doing your engine any favors over oil that is less aerated. 

Again, neither I, nor anyone else ever said NO engine needs a HV pump, in fact exactly the opposite.  What I'm saying is that based on my experience, my discussions with engine builders and machinists, and the dozen or so books I've read on engine building is that a TYPICAL street engine doesn't need one.  An oil pump is like any other part.  It needs to be matched to the combination.
 

DC…do you have a picture of this?

Just curious…perhaps I can help someone in future…or myself.

One of my favorites at the South Eastern Gasser races is a 63 Fairlane  with a SBF engine....351 base. (IT'S A BAD 'UN !!!)
He leaves the line at 12,000RPM and shifts at 10,000 !!  YIKES!!      (thx RPM)
Wonder what kinda oil press he runs ?!
6sal6

I'm guessing that engine is destroked.  I used to see some guys run SBCs like that.  Big bore, short stroke, long rod. 

6sally6 wrote:

One of my favorites at the South Eastern Gasser races is a 63 Fairlane with a SBF engine....351 base. (IT'S A BAD 'UN !!!)
He leaves the line at 12,000RPM and shifts at 10,000 !! YIKES!! (thx RPM)
Wonder what kinda oil press he runs ?!
6sal6

At that RPM, I wonder how often he needs to replace valve springs!
 

Nos681 wrote:

DC…do you have a picture of this?

Just curious…perhaps I can help someone in future…or myself.

I do not have a pic, but it was an extension on the end of the spool that created a slower pressure drop as you opened the valve more. it had an angle on it which took some playing to get correct.