I Am Running A High Volume Oil Pump 80 Lb Hot On A 302 Drag Car But It Is A Lot Of Pull On The Dist Gear (bronze On A Roller Cam) I Replace It Once A Year From Wear. What Do You Think Of A Standard Volume Pump And What Pump & Gear Are You Running ? I Use A Deep Oil Pan
I run a mechanical flat tappet cam so no bronze gear. Been running a blueprinted Melling high volume pump (85psi cold, 30-40psi hot at idle with 10w30 full synthetic oil) for about two years now. No problems yet.
Sounds like way to much pressure in your descrirtion. Hope you have screw in plugs in the oil galleys, that is how I grenaded my 331 last spring, popped a press in plug out and took out a rod bearing and everything else along the way. Lesson learned the hard way with 3000 denero's, down the crapper. Have always run Mellings HV pumps until I installed a different brand in the 331, never had trouble with them even in the 302's. I assume you check the gear placement measurements each time you change it, so will rule that out. Did have a wear problem on a flat tappet cam, in the stang drag car, found out it was a worn groove in the cam retainer plate, allowing the cam to walk a bit and wear out the dizzy gear quickly. As Ray has said, I have always run a 10w40 Valvoline oil in my race cars, summer and winter, if using heavier such as 20w50, a std. volume pump should be a better choice along with an ARP pump shaft. Just a few idea's on the subject.
A Melling standard-volume oil pump with a stock pan, ARP rod, and a windage tray. You better be running a deep sump pan if you have a high-volume pump...
Oh no, the old HV vs Std vol pump debate again!!! Personally, i'd run an HV pump...oil pressure is a good thing. I did run a std one on a 393 once, and it ran well, but I never got to inspect the bearings as it self-destructed before it's first freshen-up. I have an HV pump on everything but my truck...which is bone-stock, and will stay that way. The street Mustang has a HV pump and bronze gear on a roller cam. Been that was for 33,000 street miles, and I inspect the gear often. Both race cars have HV pumps, and the Drag Mav 414w also gets one. Keep in mind that heavy oil will kill a dizzy gear in short order if you've got a HV pump and good clearances. I ran 5w30 last season mostly because it was quicker in the 1/8. You wouldn't believe how much power it takes to turn the oil pump with 20w50 or other "heavy" "racing" oils. Try turning the oil pump shaft with the dizzy removed with a cordless drill....we've smoked more than one like that. as far as HV vs Std vol, if the clearances are LOOSE inside (cam bearings especially) yeah, it's very possible to suck the pan dry. Had a 460 do that several times. Seemed to be worse with heavier oil, I guess it didn't drain back as fast. For a while I'd use 5w30 and it worked great, but it developed a mysterious knock that I never did figure out and I built another one to replace it....this time with better internals and excellent heads. Another tip...on 302 and 351w engines (especially 302's) there is a galley plug directly behind the dizzy gear. 302's use expansion plugs, 351w's use a 1/4 NPT screw-in plug. Drill a small hole in the plug to where it sprays oil on the gear. It'll help it live longer. In agreement with old guy, I suggest tapping all of the galley holes to accept 1/4" npt plugs. Just don't tap any further than needed, and watch the lower one on the driver's side....the main oil feed galley intersects directly behind the front of the block and it's easy to tap too far, then the plug has to be threaded in too far and will block the intersecting hole. 460's have a special shorty plug that goes in there...I just happened to have one when I tapped the 414w holes and it worked PERFECT. No chance of the threaded plugs coming out! If they do, uh...you got bigger problems
Let me show my ignorance here (again). I'm pretty sure my engine builder put a high PRESSURE oil pump in my 347 - NOT a high volume (purposely). I remember the deal about too much oil going to the top of the heads/emptying sump, etc with high volume pumps - unless precautions were taken. Yes, a high pressure oil pump is what I have - and that's my final ansa.
Mellings HV and yes with a stock type pan it can wipe bearings did my 393w 2 times before we fig it out stock type front sump pan --90-10 shocks on the front ..made it worse im sure
I'm running a Melling HV as well. I was not planning on using a HV pump but that's what my engine builder put in it, and I trust him.
I'm running a stock oil pump with a heavy duty oil pump shaft in my 302. The stock shaft twisted like a candy cane & broke on my maiden run after the rebuild. A piece of silicone got sucked up the pump. So, I also put a finer mesh screen on the pump. Don't want that to happen again.....LOL Very scary, but was only a block from the house. Didn't hurt the motor.
I've seen those candy canes before. There's an argument on whether or not to run a hardened shaft. Some say the mild steel shaft acts as a fuse link. :confused:
Mine is a melling hv in a deep sump pan..pressures run the same as Rays...no problems yet...knock on wood
I have a melling HV and the ARP hardened shaft. When some debris got in the pump, it locked up, and instead of my pump shaft breaking, I lost the cam and dizzy gear. A high volume pump can't pump anymore than the passages will flow. This from the Melling website: Let us consider what a high volume pump will not do. 1. It will not replace a rebuild in a worn-out engine. It may increase pressure but the engine is still worn-out. 2. 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. 3. 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. 4. 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. 5. 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. High volume pumps can be a big advantage if used where needed. If installed in an engine that does not need the additional volume, they will not create a problem. The additional flow will be recirculated within the pump.
It was a new billet steel roller cam with a new bronze gear ran it this year and it had wear on the bronze gear cam looked good. Got to be the drag on the HV pump thats why i was thinking of running a STD pump but i went back with the HV pump with a new gear.I had a block cracked in the number two main that may had something to do with it could have been running a little out of line ??
