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oil pump

I've run Melling for 30 yrs. and have never had an issue with one.
 
Gentlemen,
For my 2 cents worth....
When i built my 440, it's 0.030" over bore, and while apart, i had the oil pump pick up tube connection drilled and tapped for 1/2" NPT. My oil pump is the Mopar HP HIGH VOLUME pump (thicker body, rotor and ring). I have full groove main bearings installed at 0.002" clearance. Bearings are Clevite 77 tri-metal (steel shell, babbitt with copper-tin over lay). Main cap torque increased 10 ft/lb additional to guard against turning. Rod bearing are the same Clevite 77 at 0.002" standard torque setting. ARP bolts & nuts holding everything together.
I use Mobil 1 10W-30 synthetic oi, Fram HP-1 filter. I get 80 psi oil pressure cold and 70 psi hot at 3000 RPM and 60 psi hot at 1200 RPM (idle).
Running oil pressure is determined by bearing clearance, oil viscosity, and pump capacity. If using a standard pump, and standard bearing clearance, with 10W-40 oil, hot running oil pressure will likely be in 60-65 psi range, lower at idle. The high pressure relief valve spring in the pump determines the max pressure. Volume is determined by the pump body, rotor and ring dimensions.
Which is more important: volume or pressure? For my money I'll go with the high volume pump every time. Remember that the crankshaft is "floating" on an oil film...a hydro-dynamic wedge, between the two surfaces. Thus endith the lesson...
Bob Renton
 
RJRENTON,keep in mind that the Fram filter will flow about 12 to 14 GPM.If any oil pump is flowing more than that,the bypass stays open and you are NOT filtering all you oil.Take a look at Jomar oil filters with NO bypass.
 
I dug up this thread as i am looking into a new oil pump for my '69 440 HP engine.
My question is, what is the height dimension of a stock rotor compared to a high volume one?
I did not find any numbers on my old pump to identify it.
On the old pump the rotor and ring are about 1.190" high, is this an original pump or a high volume?
 
when racing we put HV with HP spring in the pump but mounted adjustable remote relief at the back of the block
HV pump mostly recirculates back into pan , so does std vol pump
.002 is new wave we ran .003 with thicker oil
today
0W-40 Dexos 2 (not Dexos 1 ver 2) like new Corvette Example is Mobil 1 (or 5W) with today's synthetics (especially with tight clearances)
 
Wietse said:
I dug up this thread as i am looking into a new oil pump for my '69 440 HP engine.
My question is, what is the height dimension of a stock rotor compared to a high volume one?
I did not find any numbers on my old pump to identify it.
On the old pump the rotor and ring are about 1.190" high, is this an original pump or a high volume?
Click to expand...

I think that's high volume.

Std is 0.9435" - ish, IIRC.
 
Ok, thx.
I am planning on buying a Melling M63HV pump to replace this one.
Old one still gives good pressure, but looking at the internals there is quite some wear in it.
 
Currently no pressure as the engine is out of the car, but before i was seeing 60 psi most of the time.
And using Kendall Racing Green GT 20W50 oil.
But if this is a HV pump i will replace it with same, never had any pressure issues but since it is out for a refresh i will stick a new oil pump on it as well.

Edit: I will have to double check i guess on the old pump relief valve spring if there were any modifications done.
Not sure what the standard setting is for the relief valve.
 
That does sound like it's the high volume. Being scared up a new one will probably get you higher readings. If they end up being too high a quick fix is to lower the viscosity.

I started out with a 30 wt break in oil, then went to a 20w 50w and that was too much so I went to a 10w 30w and it's much better.
 
Last edited:
HEMI-ITIS said:
RJRENTON,keep in mind that the Fram filter will flow about 12 to 14 GPM.If any oil pump is flowing more than that,the bypass stays open and you are NOT filtering all you oil.Take a look at Jomar oil filters with NO bypass.
Click to expand...

Without a bypass valve, you run the risk of oil starvation or destruction of the filter media at high flow rates. I went looking for the flow specs for both Fram HP1 and WIX 51515R filters. Could not find any correlation between your stated 12-14 GPM and the filters bypass valve's pressure setting. The bypass valve setting is a function of the pressure drop across the filter media not the total applied pressure or the filter's GPM rating. IF the flowing pressure and GPM are less than bypass valve setting, the oil will go thru the media. With clean hot oil of a sensible flowing viscosity, the pressure drop across the media will be 1-2 PSI. Perhaps, with cold oil of a heavy viscosity, at high inlet pressures, the delta P across the media MAY BE high enough to open the bypass valve, then what you state will likely occur. The governing factor is the pressure deferential ACROSS the media not the inlet pressure.
The Wix 51515R filter has a 28 GPM max flow with an bypass valve setting of 8-11 PSI @ 50 micron filtering rate. The HP1 filter bypass valve setting is 22 PSI, with a slightly less max flow rate, at 20 micron filtering rate. Both filters are rated at 250# PSI max pressure. Which is better ??? Its a trade-off between filtering rate and bypass valve setting.....i'll take the filtering rate.....for bearing protection. Just my opinion of course.
BOB RENTON
 
I am using the Mopar Performance filters, not sure if they have a by-pass.
As you said Bob, the by-pass reacts on differential pressure, if the feed is 10PSI or 100PSI, they will open with the same differential pressure across the filter.
 
newer full synthetics Redline, Mobil 1 ESP, DEXOS2 Corvette oil are better than old racing dyno oils
 
wyrmrider said:
newer full synthetics Redline, Mobil 1 ESP, DEXOS2 Corvette oil are better than old racing dyno oils
Click to expand...

Specifically, which "old racing dyno oils" that you are referring to? Any specific characteristics or brand names ....viscosity stabilizers, base stock origins, ashless detergent-dispersants (the old Valvoline Racing single viscosity blends oil), ZDDP additives, or what??
Synthetics like Mobil 1 etal are great lubricants IF your engine's bearing clearances and oil pump's performance can take advantage of their capabilities. But be aware that these lubricants have limited (or none) ZDDP additions which guard against cam/lifter scuffing.
BOB RENTON
 
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