Have not tested the STP filter. I don't think there will be any measurable differences in pressure readings from 1 filter to the next. The thing that matters on filters is the anti drainback valve. And that only matters on cars that sit long enough for the oil to drain back to the pan. Maybe a week or 2. It just takes time to fill the filter and that runs the bearings dry causing wear. The hi volume oil pump setup is really not helpful if your engine is within spec. On an old wornout engine it can provide more oil to the bearings but it's only a crutch to a engine about to expire. On a tight engine the high drag of the high volume pump causes accelerated wear on the timing chain, front cam bearing, and distributor/cam gears.
https://www.speed-talk.com/forum/viewtopic.php?t=27041 Chevy-based tech, but interesting observations about oil/air solubility (inherent cavitation based on pressure) and the potential benefits of a high-volume pump coupled to thin synthetic oil.
Interesting, I've pondered that theory, thinner oil with a high volume/pressure pump I have to finish reading that, but for now, its time to leave for work
Schurkey, Thanks for the post. Good info there. Pretty much what I've been trying to let people know about the need for volume over pressure. That post also explained why I was pumping foam with the 0w20.
When running my 406 smallblock super stock I was having a problem with rod bearing eroding a groove where the oil holes are. Changed out high volume to stock volume and the problem was resolved with no more issues. The real issue was that the crank was cross drilled providing too much oil volume with high flow pump.
Just some thinking out loud here, been pondering this a few days. Were all after adequate pressure BUT not using thicker oil to do it, like 20-50. 10-30, 10-40 is more than enough viscosity for most applications, but as it gets hot and thins out, pressure lowers. Longer gears increase volume, and a stiffer spring will increase maximum pressure with either standard volume or longer (Hi volume) gears. Why don't we just increase oil pump rpm, instead of camshaft speed (half crank rpm) run it twice as fast, or crankshaft speed like Buick did with the later 3800's and how GM does the LS engines. At an 800 rpm hot idle in gear, the pump is only turning 400 rpm. If only there was a way to multiply the shaft speed by 100% Im wondering if that's how the OEM's get away using 0/20 5/30 oil, the pump runs at crankshaft speed, lotta volume, and pressure.
Mark, or are you Gary Farmer? Kidding. Interesting thought. I think they are running a totally different style pump (gerator?) than we have. Similar to what in a auto trans. I think ours would have worse cavitation concerns if they were turning faster.
Jim Blackwood says there is a factory Rover timing cover that has the distributor hole and has a crank driven oil pump but is a one year only part. Maybe TA can make that for the sbb engines? That would also be a VERY cool option for a BBB as well!
Some info..... https://landroverforums.com/forum/discovery-i-39/front-timing-cover-distributor-49033/
I believe it is a gerotor pump driven off the crank. IIRC, Mopar big blocks use a gerotor pump instead of spur gears driven off the distributor. Doesn't the big block Chevy use a spur gear type pump BUT more teeth? I know this isn't going to change anything as far as the style of the Buick pump, just pondering
Have any of you guys used an oil accumulator on your cars? The way I understand is it has a diaphragm in a tank. When the oil is pumped in one side, it pushes against the diaphragm on the sealed side of the tank and raises pressure. Once you equal that pressure to your oil pumps pressure, it just hangs there. But when you turn off the car, a solenoid closes and the pressure is held in the tank. Then you come back 2 weeks later, turn the key on and the solenoid opens and you wait till you have oil pressure BEFORE turning it over.
That would be interesting for testing purposes for sure. I imagine the electric motor would have to be around 5 h.p. tho since its dealing with hydraulics.
I have a belt driven oil pump driven off the crank, it sucks right from the side of my custom alum oil pan using a special pickup. It is adjustable for pressure, pretty slick setup. I haven't used it yet but it should do the job.
The Rover gearotor pump uses a longer crankshaft snout so I'm not sure what you would have to do to drive it with a SBB but I expect it could be done, there is also the Buick V6 gearotor setup. So if someone was that curious there's enough to experiment with. It's not that the stock system is deficient, but more that serious attention has to be paid to oil control when building the engine. Any system with excessive leakage is going to perform poorly. The key is to control the leaks, the worst of which are always the main and rod bearings, usually followed by cam bearings and pump clearances. A bearing with less than 1.5 thou of clearance is not going to leak much oil out. If you can hold it to a thou the leakage will be very little and you will have no trouble maintaining oil pressure. Factory specs allow clearances down to as little as .00075" IIRC. If you let it get up to .002' or more the oil is going to just gush out of there and here's where we run into trouble. It's like trying to hose down the car in the driveway with the washing machine, the dishwasher, the shower, and the toilet all sucking water at the same time. OK, maybe not the best example but I hope you get the point. Yeah, if you supply the house with a 4" water main it'll never be an issue but is that really the solution? Same here. Buick chose to hold bearing clearances tighter than was common across the industry and we all know that. Part of their engineering plans included reducing parasitic losses in the oiling system. But if you do what has the same effect as opening a big valve in the line by allowing large clearances the pump is never going to keep up. Modern engines all run tighter clearances so it isn't such a battle anymore to get machine shops to hold clearances properly, meaning we no longer have any real excuses. Personally I think it's better to stop looking for bandaids and just do what works. If the goal is to modernize the engine there are better ways to go about it. For instance, I am about to finish retrofitting a GM '0411 controller to my 340 SBB. There are a lot of details but nothing about it is particularly hard to do given the right equipment to work with. Because the 411 was used with both the LS and the preceeding early SBC that has the same firing order as the SBB it can be made to work and best of all they are cheap. About $40 at the local pick-n-pull. I think that's time better spent than trying to re-engineer the oil pump. Jim
Many people think and have stated they believe the sides of the gear pockets wear out increasing tip clearance and reducing oil pressure. This may be true if it was pumping mud for a long time. I was curious to see how an NOS GM cover would do in testing so I dug one out of my stash and built it up. This cover came bare and never had an oil pump installed. It came out to .002" end clearance. On the fixture it produced 53psi at top drill speed with the same orifice I've used for all testing. This is right in line with 4 used covers I rebuilt in the last month. All ranged from 52 to 54. From this test I don't believe that pump cavity sides wear enough in normal use to be concerned about. Probably be safe to say if the gears protrude from the cover at around .004" the cavity is good as the ends wear more due to contact. I present this data for informational purposes only. Not intending anyone to change their long held beliefs.
So I replaced this cover since I was worried about the scoring reducing the oil pressure. Bad? Average?
From the looks of that I would reuse that cover. Those look like the machining marks on the NOS cover I just built. If you put the gears in it and measure how far they stick out above the surface is a good gauge. About .004" would show the bottom is not worn away enough to worry about. Any dirt in the oil is going to grind away at the bottom of the cavity and the bolt on cover. In other words at both ends of the gears. The clearance is only .002" There is way more clearance between the gear tips and the walls of the cavity. Chunks would need to be quite a bit larger to get wedged between them to score the cavity.
I have used an accumulator for years. Flick a switch, wait to see 20 psi and then start the motor. Can also help if pickup is uncovered for a few seconds. Also works great no new engines or if you are working on the oil pump. Do not have to fill pump with vasoline, just let the accumulator fill the pump.
Bearings are cooled by the oil that flows through them. The oil carries the heat away from the bearing as the oil passes through the bearing clearance. More flow equals a cooler bearing, and cooler oil. The oil flow through the bearing is a result of the bearing clearance, the oil viscosity, and the oil pressure. Of those three, oil pressure has by far the least effect. Proper clearance and oil viscosity is the first step, and having an oil pump that is able to keep up with it is the second step. Buick designed their entire engine around using tight bearing clearances and relatively low viscosity oil (10w30). 0.0010"-0.0020" bearing clearance is vital. Getting that clearance is hard because the machine shops and bearing manufacturers fight you the whole way on it. You have to sometimes tell the machine shop to grind your crank 0.019" undersize rather than 0.020" undersize because the 0.020" undersize bearings you bought were manufactured to produce 0.002" clearance on the nominal journal diameter and you want 0.001" clearance instead. Then you run into the problem of most machine shops are not used to or equipped for the level of precision required when building to clearances that tight. There can be no taper or oval in the journal when an engine is that tight. Buicks are precise. It's what makes them good, but also what makes them unforgiving. A tight engine with precise tolerances and low viscosity oil is actually how engines are made today. It's a superior method. It's only a problem because the machine shops and bearing manufacturers are used to engines with a lower standard of tolerance.
