What oil pump?

07-08-2001, 12:35 AM

I would say go with the High Volume Oil Pump. I say this with a few suggestions and personal experience.

First, if your using a High Volume Oil Pump, I would recommend an Oil Pan that can hold a couple of extra quarts of oil. Since you mentioned you are building a 347 I would urge you to work closely with a qualified engine builder and follow his recommendations. A High Volume Oil pump will normally use 20-30% more oil during circulation, which takes allot more oil out of the pan, thus the benefit of the extra quarts of a bigger pan. Also the added benefit of cooling since their is more oil for circulation( or something like that). I am by far no expert, just a few tips that have served me well over the past ten years with my two 347 Stroker Kits.

Here are some tips from Melling on what a High Volume Pump will NOT do:It will not replace a rebuild in a worn-out engine. It may increase pressure but the engine is still worn-out.

1.) It will not pump the oil pan dry. Both solid and hydraulic lifters have metering valves to limit flow of the oil to the top of the engine. If a pan is pumped dry, it is because the holes that drain oil back to the pan are plugged. If the high volume pump is also higher pressure, there will be a slight increase in flow to the top.

2.) It will not wear out distributor gears. The load on the gear is directly related to the resistance to flow. Oil pressure is the measure of resistance to flow. The Ford 427 FE "side oiler" used a pump with relief valve set at 125 psi and it used a standard distributor gear. Distributor gear failures are usually caused by a worn gear on a new cam gear and/or worn bearings allowing misalignment.

3.) It will not cause foaming of the oil. With any oil pump, the excess oil not needed by the engine is recirculated within the pump. Any additional foaming is usually created by revving the engine higher. The oil thrown from the rod bearings is going faster and causes the foaming. This is why high performance engines use a windage tray.

4.) It will not cause spark scatter. Because of the pump pressure there is a load on the distributor gear. The number of teeth on the oil pump gears determine the number of impulses per revolution of the pump. In a SB Chevy there are seven teeth on each gear giving 14 impulses per revolution. At 6000 RPM the oil pump is turning 3000 RPM or 50 revolutions per second. To have an effect on the distributor, these impulses would have to vibrate the distributor gear through an intermediate shaft that has loose connections at both ends. Spark scatter is usually caused by weak springs in the points or dust inside the distributor cap.

Hope this helps.

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07-08-2001, 12:35 AM	#7
stanglx347 Guest Posts: n/a	I would say go with the High Volume Oil Pump. I say this with a few suggestions and personal experience. First, if your using a High Volume Oil Pump, I would recommend an Oil Pan that can hold a couple of extra quarts of oil. Since you mentioned you are building a 347 I would urge you to work closely with a qualified engine builder and follow his recommendations. A High Volume Oil pump will normally use 20-30% more oil during circulation, which takes allot more oil out of the pan, thus the benefit of the extra quarts of a bigger pan. Also the added benefit of cooling since their is more oil for circulation( or something like that). I am by far no expert, just a few tips that have served me well over the past ten years with my two 347 Stroker Kits. Here are some tips from Melling on what a High Volume Pump will NOT do:It will not replace a rebuild in a worn-out engine. It may increase pressure but the engine is still worn-out. 1.) It will not pump the oil pan dry. Both solid and hydraulic lifters have metering valves to limit flow of the oil to the top of the engine. If a pan is pumped dry, it is because the holes that drain oil back to the pan are plugged. If the high volume pump is also higher pressure, there will be a slight increase in flow to the top. 2.) It will not wear out distributor gears. The load on the gear is directly related to the resistance to flow. Oil pressure is the measure of resistance to flow. The Ford 427 FE "side oiler" used a pump with relief valve set at 125 psi and it used a standard distributor gear. Distributor gear failures are usually caused by a worn gear on a new cam gear and/or worn bearings allowing misalignment. 3.) It will not cause foaming of the oil. With any oil pump, the excess oil not needed by the engine is recirculated within the pump. Any additional foaming is usually created by revving the engine higher. The oil thrown from the rod bearings is going faster and causes the foaming. This is why high performance engines use a windage tray. 4.) It will not cause spark scatter. Because of the pump pressure there is a load on the distributor gear. The number of teeth on the oil pump gears determine the number of impulses per revolution of the pump. In a SB Chevy there are seven teeth on each gear giving 14 impulses per revolution. At 6000 RPM the oil pump is turning 3000 RPM or 50 revolutions per second. To have an effect on the distributor, these impulses would have to vibrate the distributor gear through an intermediate shaft that has loose connections at both ends. Spark scatter is usually caused by weak springs in the points or dust inside the distributor cap. Hope this helps.