C2 oil loss

[Joe C.]

Re: C2 oil loss

John,

A high pressure pump is not a high volume pump, and vice versa.
The Melling 55 HV should NOT BE USED in any stock application.
The Melling 55 A should be used with the SHP engines
The Melling 55 should be used with low horse engines.

This, from the Melling website:

"Pressure is created by the resistance to flow. For example, the water flowing out of a garden hose has relative low pressure, but when you put your finger over the end of the hose, restricting that flow, the pressure within the hose increases and you see the result by increasing the distance the water travels as it leaves the hose. The resistance to oil flow Inside an engine is from the clearances of the bearing and lifter bore. Engines with increased clearances will require greater flow to maintain the same pressure. As the RPM of the engine increases more oil is required. The oil pump selected should be able to flow the volume of oil required to maintain the pressure desired. A relief spring within the pump relieves the pressure when it reaches the desired level. High pressure pumps have a higher pressure relief spring as also do most high volume pumps. The main disadvantage of using a pump with the ability to flow more than required by the engine resulting in this bypass opening is a very small loss of horsepower."

Joe

[Joe C.]

Re: C2 oil loss

John,

A high pressure pump is not a high volume pump, and vice versa.
The Melling 55 HV should NOT BE USED in any stock application.
The Melling 55 A should be used with the SHP engines
The Melling 55 should be used with low horse engines.

This, from the Melling website:

"Pressure is created by the resistance to flow. For example, the water flowing out of a garden hose has relative low pressure, but when you put your finger over the end of the hose, restricting that flow, the pressure within the hose increases and you see the result by increasing the distance the water travels as it leaves the hose. The resistance to oil flow Inside an engine is from the clearances of the bearing and lifter bore. Engines with increased clearances will require greater flow to maintain the same pressure. As the RPM of the engine increases more oil is required. The oil pump selected should be able to flow the volume of oil required to maintain the pressure desired. A relief spring within the pump relieves the pressure when it reaches the desired level. High pressure pumps have a higher pressure relief spring as also do most high volume pumps. The main disadvantage of using a pump with the ability to flow more than required by the engine resulting in this bypass opening is a very small loss of horsepower."

Joe

[Duke W.]

Re: C2 oil loss

Rod side clearance is one of the many "restrictions" in the oil flow path.

A "loose" engine will allow more oil flow, which means a higher volume pump may be needed to maintain acceptable pressure. This is often the case with racing engines, but rarely with road engines built to sensible road engine clearances.

The rod side clearance listed in service manuals is typically in the range of .008-.014". Yours are a little "loose" but not enough to drop pressure below acceptable values with a standard volume oil pump.

Duke

[Duke W.]

Re: C2 oil loss

Rod side clearance is one of the many "restrictions" in the oil flow path.

A "loose" engine will allow more oil flow, which means a higher volume pump may be needed to maintain acceptable pressure. This is often the case with racing engines, but rarely with road engines built to sensible road engine clearances.

The rod side clearance listed in service manuals is typically in the range of .008-.014". Yours are a little "loose" but not enough to drop pressure below acceptable values with a standard volume oil pump.

Duke

[John D.]

Re: C2 oil loss

Hi Joe,Thanks for the good info. My 63 FI car then has the wrong oil pump. Just plain old Melling 55. But the oil pressure is fine and it passed ops. I just printed your info. Thanks again, John D.
P.S. you are one of the few that spell Melling correctly. Most put an S on the name.

[John D.]

Re: C2 oil loss

Hi Joe,Thanks for the good info. My 63 FI car then has the wrong oil pump. Just plain old Melling 55. But the oil pressure is fine and it passed ops. I just printed your info. Thanks again, John D.
P.S. you are one of the few that spell Melling correctly. Most put an S on the name.

[Joe C.]

Re: C2 oil loss

John,

The "little white car" should be just fine with the std (lo press/lo vol) pump, so long as you keep the R's down, south of about 6 grand.
If yer nutz like me, then you need the hi press pump.

So, yer car passed PV with a std pump, eh?
Did the feller who did yer PV check have too much coffee that day? Maybe had the jitters & couldn't see the gauge? Was it Carlton? Did somebody re-silkscreen your 80 pound gauge as a 60 pounder, just fer the PV test??

Happy cooking,
Joe

[Joe C.]

Re: C2 oil loss

John,

The "little white car" should be just fine with the std (lo press/lo vol) pump, so long as you keep the R's down, south of about 6 grand.
If yer nutz like me, then you need the hi press pump.

So, yer car passed PV with a std pump, eh?
Did the feller who did yer PV check have too much coffee that day? Maybe had the jitters & couldn't see the gauge? Was it Carlton? Did somebody re-silkscreen your 80 pound gauge as a 60 pounder, just fer the PV test??

Happy cooking,
Joe

[Michael H.]

Re: C2 oil loss

Joe,

The oil pump in ALL early 63's was the low pressure version. From start of production to somewhere around the middle of production, the standard 283/327 oil pump was used. Eventually, this was changed and the mech lifter 63 engines used the high pressure pump from the Sp/H/Perf 409.

Somewhere around that same time, the oil pressure guage was also changed to an 80#, replacing the 60# unit.

[Michael H.]

Re: C2 oil loss

Joe,

The oil pump in ALL early 63's was the low pressure version. From start of production to somewhere around the middle of production, the standard 283/327 oil pump was used. Eventually, this was changed and the mech lifter 63 engines used the high pressure pump from the Sp/H/Perf 409.

Somewhere around that same time, the oil pressure guage was also changed to an 80#, replacing the 60# unit.

[Joe C.]

Re: C2 oil loss

Thanks Mike. I'm happy that you reminded of that, but it's more information than Patrick Boursier 39712 asked for.
Are you listening, John?

Joe

[Joe C.]

Re: C2 oil loss

Thanks Mike. I'm happy that you reminded of that, but it's more information than Patrick Boursier 39712 asked for.
Are you listening, John?

Joe

[J M.]

Am I correct in assuming ...

that if you have a standard volume, standard pressure pump and your pressure is 20 - 30 lb, that by adding a high pressure spring, it will do you no good because you are not high enough to reach the overflow pressure of the standard spring to begin with. IE: if your pressure is not high enough to trip the overflow spring, adding a high pressure spring won't make any difference. Do you follow what I am trying to say?

[J M.]

Am I correct in assuming ...

that if you have a standard volume, standard pressure pump and your pressure is 20 - 30 lb, that by adding a high pressure spring, it will do you no good because you are not high enough to reach the overflow pressure of the standard spring to begin with. IE: if your pressure is not high enough to trip the overflow spring, adding a high pressure spring won't make any difference. Do you follow what I am trying to say?

[Duke W.]

Hydraulics 101

The oil pump is a CONSTANT VOLUME design. It delivers volume approximately proportional to the speed it is driven. Double the speed and the pump delivers double the volume.

Because the pump is pumping into a hydraulic resistance, pressure increases as pump speed/delivery increases. Once pressure reaches the point where the bypass valve opens, excessw volume is shorted back into the pump inlet. The "normal" pressure relief spring on hydraulic lifter SBs and mechanical lifter SBs up to late '63 should yield 40-45 psi at 2000 engine RPM with fully warmed up oil.

If the pressure doesn't exceed 30 psi at high speed then then there is either a problem with the spring, the pump, or a major internal oil leak.

The standard pump has PLENTY of capacity to deliver the 55-60 psi with the stiffer spring that was used on late '63 to '65 mechanical lifter small blocks.

Duke