Bought the entire front cover from TA Performance, because we didn't want to dick around with setting the clearances on a worn out pump, cover, etc. Called them, and they said, we could take it out of the box, and bolt it on...so other than making sure there was no crap on any of the surfaces, we bolted it on.
This thread is an interesting read, http://www.v8buick.com/index.php?threads/oil-pressure-equalization-line.293955/
I don't remember the clearances. I'm not sure he listed them. I'd search for it but unfortunately the search function with the board's new software really stinks on my phone. It falls right in with Boyle's laws though. It is a semi closed system-there can't be much of a difference. A 15 psi drop isn't realistic. 60 at the front couldn't be 45 at the back. That's 25%..
Look at my previous post, first few posts on that thread. If you build a Buick BB with Chevy clearances it could very easily be that bad. Read Jim's post about #4 main and #7 rod bearing failures. The back rods are the ones to go first. It's from the drop off. It depends on clearances.
Awhile back when I changed the cam in my GS and I was priming the pump, I was generating over 100 psi, and I saw the oil filter actually expand Had my wife look at the gauge as I ran the air drill, the gauge was showing over 100 psi.
That negates the laws of physics. A loosely built engine will experience the same pressure fluctuation from front to rear. Google Boyle's laws..
Boyle's law is a gas law. It applies to a gas in a confined space. The oil system isn't a closed system. A certain amount of oil hemorrhages from around the bearings. It is worse with larger clearances. Think of it as a closed pipe into which you introduce a constant oil pressure. Then drill holes along the length of the pipe. You lose pressure through the holes. Bigger holes, more pressure loss.
That's incorrect and not a valid example. First Boyle's pressure laws apply to liquids and gas. Pressure in a system is the same through out the entire systm. Period. That's a law. While the oil system is not closed it still generates pressure. The oil will escape the path of least resistance and the pressure within the system will follow suit. Hence why when the number 6 spins there is no oil pressure anywhere. All the front mounted pressure gauges proved that 100 times over. Obviously you are correct the bigger the holes the larger the psi loss. Again the pressure would be the same at both ends of the system. Regarding your pipe example you are simply drilling enough holes so that the surface area of the holes is the same as the inlet and there is no pressure. A more valid example would be a lawn sprinkler. They all shoot out the same distance.. The pressure is the same at the front and the rear of the sprinkler.
That's incorrect and not a valid example. First Boyle's pressure laws apply to liquids and gas. Pressure in a system is the same through out the entire systm. Period. That's a law. While the oil system is not closed it still generates pressure. The oil will escape the path of least resistance and the pressure within the system will follow suit. Hence why when the number 6 spins there is no oil pressure anywhere. All the front mounted pressure gauges proved that 100 times over. Obviously you are correct the bigger the holes the larger the psi loss. Again the pressure would be the same at both ends of the system. Regarding your pipe example you are simply drilling enough holes so that the surface area of the holes is the same as the inlet and there is no pressure. A more valid example would be a lawn sprinkler. They all shoot out the same distance.. The pressure is the same at the front and the rear of the sprinkler.
Joe, we could keep going back and forth here. Boyle’s law is a gas law. Gas is compressible, fluid is not. It deals with a gas in a combined space and the inverse relationship between pressure and volume. Not really applicable here. https://en.m.wikipedia.org/wiki/Boyle's_law Pascals law applies to hydraulics but doesn’t really apply here as well. We could argue back and forth about chemistry and physics, the oil pressure at the back of a Buick block is less than at the front of the block. You saw that in JW’s thread about the balance line. It was roughly 8 psi, and that was in a correctly built engine. If you build a BBB with big clearances and don’t up the oil pressure, you will hurt the back bearings of the motor where there is less oil. Maybe we should be talking about volume instead of pressure, but they are related. There is a reason why bearing clearances are so important for the motor to live at higher RPM HP use. The HV/HP oil pump, the TA cover, the balance line are all fixes for the stock Buick oiling. Back in the day, burned 7 and 8 rod bearings were a common problem for lack of oiling at the rear of the block. That is the real world, maybe I am not explaining it right, but it exists. The spinning crank, especially the BBB with it’s huge mains, forces oil out of the bearings at high RPM. Why read oil pressure off the back of the block at all? Even the article on George N’s site relates the reason is because it is lower. We can disagree about why that is, but it can be and has been a problem for some. http://www.buickperformanceclub.com/Oilmods.htm
Spoke with Haydn this morning, and asked him what his oil pressure was. (Since he pulled his GS out the other day) He said cold, it's at 80psi. Let's it warm up, and starts to drive when it's around 60psi. When warm, at an idle, it's at 35-40psi, and goes up from there when accelerating. When we got the 100psi, it was a brand new engine, new oil, packed pump, etc. To me, having 10+psi of oil pressure for every 1000rpm is a good thing. (6500=65psi, 7000=70psi) ...and I know it revs easily to 6500.
Yeah that’s fine, just don’t blast on it until the oil warms up. That’s for any engine. If you are going to rev it to 6500, sure, you need the extra pressure. As long as you aren’t seeing 100 Psi when fully warm, I wouldn’t be worried. Oil pressure in excess of what you need is taking extra power, further heating the oil, and back loads the pump drive.
This guy over here talkin about havin 100psi, here I am thinkin I'm hot **** with my 50 cold and 20 hot at idle with 10w30.
Yeah and he's talking about 7,000 RPM with a sbb! I guess you can do that when the engine has good rods in it even if they were used before he got them.(nascar take out rods)
