Heel2toe's I wanna go fast build
Jun 19, 2018, 08:04 AM
#61
EvoM Guru
iTrader: (1)
Engine bearings are hydrodynamic journal bearings, so the pressure may not be what lubricates (the hydraulic wedge created by the spinning shaft/journal is what it rides on), but without pressure the oil won't go into the bearing. So, its 6 of one, and one half dozen of the other. If pressure wasn't needed, engines would use high volume, low pressure oil pumps to limit parasitic losses.
Jun 19, 2018, 08:40 AM
#62
Fluids travel the path of least resistance. Even if the pressure coming from the pump is minimal wouldn't the oil from the accusump prefer to travel away from the pump?
Also, as Im thinking about this it makes me wonder if having my oil pressure sending unit tapped into the OFH might possibly give me a false sense of security? Would I be better suited attempting to move my dummy light to the OFH instead of back of the block and moving my sending unit for my gauge to the back of the block instead?
Also, as Im thinking about this it makes me wonder if having my oil pressure sending unit tapped into the OFH might possibly give me a false sense of security? Would I be better suited attempting to move my dummy light to the OFH instead of back of the block and moving my sending unit for my gauge to the back of the block instead?
The OFH is different between the 8 and 9 with the (only) difference I'm aware of is that the 9 has the sending unit for the dummy light on the OFH from the factory. Going straight off the main galley would be best but I'm not sure it'd read all that differently. Post filter is only like 6" before the main galley so the pressure differential between those two points won't be much. But then there is pressure across the main galley and IIRC the stock sending unit is most of the way down the galley which is where you want to read since 4 is the rod that gets oil last.
Jun 19, 2018, 10:14 AM
#63
EvoM Guru
iTrader: (1)
The accusump will fill the galley to the pump, but since the pump is still spinning, oil isn't going to back feed through the pump. My is it would be about a pint of oil lost to filling the galley that goes back to the pump.
Jun 19, 2018, 02:28 PM
#65
The pump is one way though, if its spinning forward your arent going to push fluid back through it. It may be possible oil could go back through the bypass valve though?
The accusump is just a big damper though. It doesnt work once you get to a certain low pressure unless you have the electric valve the doesnt flow well. Its just going to delay response of oil pressure change. And it will do it in both directions.
The accusump is just a big damper though. It doesnt work once you get to a certain low pressure unless you have the electric valve the doesnt flow well. Its just going to delay response of oil pressure change. And it will do it in both directions.
Jun 19, 2018, 06:21 PM
#66
My concern with no check valve isn't pushing oil back through the pump (even if it were possible), it's having it waste oil capacity having to push oil back through the cooler and cooler lines.
From what Canton says, their EPC valve flows pretty on par with a manual valve. IMO, if you're gonna go drop $500 on an accusump setup, another $30 for a check valve wouldn't even be a question.
From what Canton says, their EPC valve flows pretty on par with a manual valve. IMO, if you're gonna go drop $500 on an accusump setup, another $30 for a check valve wouldn't even be a question.
Jun 20, 2018, 12:27 PM
#67
You guys have officially confused me. I thought an accusump is a pressurized oil chamber call it a bladder like an expansion tank almost. However in this case instead of dampening the spikes in pressure instead it helps to regulate and keep oil pressure consistent. The oil pressure from the oil pump is what keeps the ooil in the chamber however when pressure falls off the oil is then forces out into the rest of the engine. In theory in a long enough corner all the oil from the accusump can be depleted and then you can still drop oil pressure hence why its a band aide fix. However, once oil is in the pan or should I say once the pickup tube is submersed in oil again the accusump will then pressurize again.
So I guess what I dont understand is what benefit, if any does an electronic valve provide aside from convenience of not having to open up the manual ball valve? Unless Im missing something it seems like if youre dinking the car around keep the valve closed, but if youre racing start the car open the valve and leave it be until you go to shut back off the car in which I believe youre supposed to build up some revs to increase pressure in the tank then close the valve so it doesnt dump all the oil to the sump. What else is there to it? When I previously did research on this it seemed the racers preferred the manual ball valve over electronic since flow wasnt reduced. Maybe that is no longer the case? Even still Im not seeing the benifits to an electronic valve as long as you can access the ball valve painlessly.
So I guess what I dont understand is what benefit, if any does an electronic valve provide aside from convenience of not having to open up the manual ball valve? Unless Im missing something it seems like if youre dinking the car around keep the valve closed, but if youre racing start the car open the valve and leave it be until you go to shut back off the car in which I believe youre supposed to build up some revs to increase pressure in the tank then close the valve so it doesnt dump all the oil to the sump. What else is there to it? When I previously did research on this it seemed the racers preferred the manual ball valve over electronic since flow wasnt reduced. Maybe that is no longer the case? Even still Im not seeing the benifits to an electronic valve as long as you can access the ball valve painlessly.
Jun 20, 2018, 12:59 PM
#68
If you have a manual valve it will be open at all times so when pressure drops in between the pump and the galley the accusump's pressure will drop as well because the valve is always open and pressure drops would be more delayed rather than prevented. With an electronic valve (like Canton's EPC) it only opens if oil pressure drops below a certain pressure but it also has a check valve so when above that set pressure the accusump can still be filled.
I feel like that was a poor explanation but hopefully it makes sense. I wouldn't waste my time with a manual valve, kind of defeats the purpose of the accusump IMO.
With the manual valve you'll pretty much always have the same pressure in the accusump as you do post oil pump because it's all part of the same system essentially with nothing to dictate when oil should be released from the accusump.
I feel like that was a poor explanation but hopefully it makes sense. I wouldn't waste my time with a manual valve, kind of defeats the purpose of the accusump IMO.
With the manual valve you'll pretty much always have the same pressure in the accusump as you do post oil pump because it's all part of the same system essentially with nothing to dictate when oil should be released from the accusump.
Last edited by Ayoustin; Jun 20, 2018 at 01:04 PM.
Jun 20, 2018, 01:19 PM
#69
Not to be argumentative but what youre saying contradicts a lot of what I read about these things while I was trying to research them and figure out what route I was going.
As the accusump is releasing oil into the engine, yes the pressure is dropping in the accusump however its sending a volume of oil into the engine.
I saw this video and thought it was a pretty good explanation of how the systems operates. What am I missing here?
As the accusump is releasing oil into the engine, yes the pressure is dropping in the accusump however its sending a volume of oil into the engine.
I saw this video and thought it was a pretty good explanation of how the systems operates. What am I missing here?
Jun 20, 2018, 02:38 PM
#70
That's a decent video and I like how they demonstrate the difference in precharge amounts but it's not the greatest representation of actual use. Oil pressure will never be perfectly consistent (which is what they show in the video). When you downshift you'll get a spike in oil pressure because engine speed goes up very suddenly. When you up shift oil pressure will drop accordingly with engine speed. It's never going to be perfectly constant. As this normal pressure rises and drops occur, if the accusump is always open like with a manual valve, you'll constantly be filling and releasing oil to/from it because the pressure in the accusump will always be roughly what you've got for pressure between the oil pump and the bearings.
Essentially it's acting as a temporary storage bladder. It's not necessarily a bad thing but if you go into a corner with low oil pressure, you're going into that corner with lower pressure in the accusump as well. Whereas if you have a pressure switch to control when the accusump can let oil out, you can go into a corner with low oil pressure but higher oil pressure in the accusump.
For example, you've got a manual valve setup, you into a sweeper with pump pressure (post pump, pre bearing) at 80psi. Since the system is always open your accumulator pressure is also going to be 80psi. As you're going through the corner oil pressure begins to drop, but the accumulator pressure will also drop at the same rate (yes it still releases oil which is good) and when the oil pump gets to low pressure (30 or below) the accumulator will also be at low pressure and you've just got to hope that you can get through the sweeper before your time runs out.
Now if you have a 40psi pressure switch on an electric valve if you go into the sweeper with pump pressure at 80psi you'll still have accumulator pressure at 80psi (or higher if oil pressure had gone above that). As you go through the corner pump pressure will begin to drop from 80 but the accumulator will remain at 80 since it is still shut. Once pump pressure drops below 40psi the accumulator will open and temporarily bring the pump pressure up again as the accumulator had twice the amount of pressure stored in it. Another advantage of a pressure switch is that since it's holding peak pressure in you can go into a corner at 60psi but have 80psi in the accumulator, they don't have to start at the same pressure, but if you have a manual valve you would be going into that corner with 60psi in both. So by using a pressure switch it not only gives you more time since it's not draining the accumulator until pump pressure hits a certain point, but it can also raise pump pressure when it opens. In this setup it's acting as more of a pressurize triggered failsafe than a storage bladder.
Sorry for the wordy explanation, but I don't think I really got my point across well in the last post.
Essentially it's acting as a temporary storage bladder. It's not necessarily a bad thing but if you go into a corner with low oil pressure, you're going into that corner with lower pressure in the accusump as well. Whereas if you have a pressure switch to control when the accusump can let oil out, you can go into a corner with low oil pressure but higher oil pressure in the accusump.
For example, you've got a manual valve setup, you into a sweeper with pump pressure (post pump, pre bearing) at 80psi. Since the system is always open your accumulator pressure is also going to be 80psi. As you're going through the corner oil pressure begins to drop, but the accumulator pressure will also drop at the same rate (yes it still releases oil which is good) and when the oil pump gets to low pressure (30 or below) the accumulator will also be at low pressure and you've just got to hope that you can get through the sweeper before your time runs out.
Now if you have a 40psi pressure switch on an electric valve if you go into the sweeper with pump pressure at 80psi you'll still have accumulator pressure at 80psi (or higher if oil pressure had gone above that). As you go through the corner pump pressure will begin to drop from 80 but the accumulator will remain at 80 since it is still shut. Once pump pressure drops below 40psi the accumulator will open and temporarily bring the pump pressure up again as the accumulator had twice the amount of pressure stored in it. Another advantage of a pressure switch is that since it's holding peak pressure in you can go into a corner at 60psi but have 80psi in the accumulator, they don't have to start at the same pressure, but if you have a manual valve you would be going into that corner with 60psi in both. So by using a pressure switch it not only gives you more time since it's not draining the accumulator until pump pressure hits a certain point, but it can also raise pump pressure when it opens. In this setup it's acting as more of a pressurize triggered failsafe than a storage bladder.
Sorry for the wordy explanation, but I don't think I really got my point across well in the last post.
Jun 21, 2018, 02:43 PM
#71
Thanks for expanding on that and no worries for the wordy explanation. Im happy to be talking about this but sad we're discussing it now after having thought I was past this and moving forward with my current strategy. For now I think Im going to stick with the manual valve and if it needs to be revisited so be it not the end of the word just add in the valve and switch and wire it up.
But what you just wrote makes way more sense and I think Im now picking up what youre putting down. I do have a few followup questions. For starters are these pressure valves a fairly new product? Reason I ask is that the consensus in the past was that the electric valves do not react quickly enough. So while, it sounds great in theory when it comes down to it, switch sees low pressure opens solenoid and now oil is injected into the engine. So it has more pressure behind it but how long does it actually take for that oil to make it into the engine?
Also it sounds like the pressure switch is exactly that just a switch so its either open or closed. Where do you set the threshold for where it closes the circuit? It would be nice if it followed a similar trend where say every 1000RPM pressure should rise 10PSI. As you can tell Im not too well versed on this stuff, sure know more than the average Joe but by no means an expert. But Id think as the RPMs rise Id want more oil pressure too within reason of course. At 4grand sure 40# is fine but at 8grand 40# isnt enough. If the pressure switch is set to 40# it isnt even opening until it gets to that. Now it seems 40# probably drops even lower before accusump starts dumping oil in. Is it too late already at that point? At least with the manual valve ideally its never getting to 40# at 8grand unless youve depleted all of the oil through a really long sweeper.
Once again really not trying to be argumentative. I love these back and forths, it helps me learn and grow and hopefully this info will be helpful for others down the road. Thats the point of these forums after all! It jsut seems like at the end of the day they both have strengths and weaknesses and neither is a perfect solution. But which is best? That I still do not know!
But what you just wrote makes way more sense and I think Im now picking up what youre putting down. I do have a few followup questions. For starters are these pressure valves a fairly new product? Reason I ask is that the consensus in the past was that the electric valves do not react quickly enough. So while, it sounds great in theory when it comes down to it, switch sees low pressure opens solenoid and now oil is injected into the engine. So it has more pressure behind it but how long does it actually take for that oil to make it into the engine?
Also it sounds like the pressure switch is exactly that just a switch so its either open or closed. Where do you set the threshold for where it closes the circuit? It would be nice if it followed a similar trend where say every 1000RPM pressure should rise 10PSI. As you can tell Im not too well versed on this stuff, sure know more than the average Joe but by no means an expert. But Id think as the RPMs rise Id want more oil pressure too within reason of course. At 4grand sure 40# is fine but at 8grand 40# isnt enough. If the pressure switch is set to 40# it isnt even opening until it gets to that. Now it seems 40# probably drops even lower before accusump starts dumping oil in. Is it too late already at that point? At least with the manual valve ideally its never getting to 40# at 8grand unless youve depleted all of the oil through a really long sweeper.
Once again really not trying to be argumentative. I love these back and forths, it helps me learn and grow and hopefully this info will be helpful for others down the road. Thats the point of these forums after all! It jsut seems like at the end of the day they both have strengths and weaknesses and neither is a perfect solution. But which is best? That I still do not know!
Jun 21, 2018, 04:19 PM
#72
No worries, i don't really see it as an argument, really just a discussion. I always enjoy seeing other peoples' explanations/experience/point of view.
I'm not sure how long Canton's EPC product line has been out for so can't say for sure but I haven't read of people saying that they lack performance. As to how long it takes for the oil to make it into the engine it would vary on a few things but mostly rides on how much volume of oil is already post pump. This is where I think things get a bit tricky and people may disagree but I would think that the post pump volume isn't much less than max pressure as pressure isn't the sole dictating factor to flow (think of it like a fuel pump). So with that mindset I would think that the oil released from the accusump would arrive almost instantaneously, er at least the pressure would rise instantaneously, granted there may be small trace amounts of air and oil does compress a little bit.
As for the pressure switch, yes it is just that, an on off switch. As far as I know they're not adjustable and you have to order the pressure you want. Canton offers a 25-30, 35-40, and 55-60 IIRC as to why there's a pressure range on them I'm not sure. If you wanted a more advanced system I'm sure it'd be pretty easy to control the valve with a computer or arduino to provide more intelligent times to open the valve but in order to have it provide a form of controllable pressure release/staggered release by engine speed you would need a style valve other than a ball valve to gain that kind of granularity. Realistically I don't think the effort and expense for setting something like that up would really pay off.
I'm not sure how long Canton's EPC product line has been out for so can't say for sure but I haven't read of people saying that they lack performance. As to how long it takes for the oil to make it into the engine it would vary on a few things but mostly rides on how much volume of oil is already post pump. This is where I think things get a bit tricky and people may disagree but I would think that the post pump volume isn't much less than max pressure as pressure isn't the sole dictating factor to flow (think of it like a fuel pump). So with that mindset I would think that the oil released from the accusump would arrive almost instantaneously, er at least the pressure would rise instantaneously, granted there may be small trace amounts of air and oil does compress a little bit.
As for the pressure switch, yes it is just that, an on off switch. As far as I know they're not adjustable and you have to order the pressure you want. Canton offers a 25-30, 35-40, and 55-60 IIRC as to why there's a pressure range on them I'm not sure. If you wanted a more advanced system I'm sure it'd be pretty easy to control the valve with a computer or arduino to provide more intelligent times to open the valve but in order to have it provide a form of controllable pressure release/staggered release by engine speed you would need a style valve other than a ball valve to gain that kind of granularity. Realistically I don't think the effort and expense for setting something like that up would really pay off.
Jun 27, 2018, 09:18 AM
#73
All interesting stuff thanks for sharing. To your point if we get deep into the weeds its probably not worth the effort or expense or added complexity for that matter. Im sticking with the plan for now and testing the manual valve and hoping that between that and my new pan I should have sufficient pressure. If its still not where it needs to be then maybe Ill consider the electronic valve but honestly at that point Ill probably start savings for dry sump.
So I dont have that many exciting updates for the time being. Still slowly crossing things off the list but looks like this weekend Ill get to dedicate my entire time to car stuff so Im hoping to get the cams degreed and get the longblock ready to be dropped in. Im still waiting on my turbo kit so that'll be here hopefully in the next couple weeks.
Im hoping to have the car running by end of July; I think that is a reasonable goal. It would be great to have dedicated time to get it all done but seems time just keeps passing and here I am doing everything but working on the car.
So I dont have that many exciting updates for the time being. Still slowly crossing things off the list but looks like this weekend Ill get to dedicate my entire time to car stuff so Im hoping to get the cams degreed and get the longblock ready to be dropped in. Im still waiting on my turbo kit so that'll be here hopefully in the next couple weeks.
Im hoping to have the car running by end of July; I think that is a reasonable goal. It would be great to have dedicated time to get it all done but seems time just keeps passing and here I am doing everything but working on the car.
Jun 27, 2018, 03:08 PM
#75
Yeah so I would have never guessed the car would still be apart; I killed the motor in the end of Oct and had it apart like maybe a week later. I didn't even take it off the road bc after talking to my insurance agent I was informed that I would need to cancel the reg and then renew it again after and then get the car reinspected which is a giant PITA and I had just got a sticker so I said screw it hopefully it'll be together in 3 months or so.
Then I completely underestimated the cost of a build of this nature. One thing led to the next and I did go overboard but if I knew then what this was going to cost I would have thought I was insane. But the numbers don't lie and my spreadsheet kept growing and the build was on hold since I wanted to make sure I had the money before I started sending things out. Then of course the typical delays customs parts take time to make out of stock BS with vendors promising a set lead time and it being 2x that etc.
And of course it didn't help with the tire iron to the head right after I got the block back which has set me back about a month and other life struggles like house projects and finding time for the GF and friends. So here I am its almost July race season is like half over and I'm nowhere to be seen
Regarding oil pressure, we're on the same boat. I sure as hell hope this works bc it it doesnt it either means that I killed my new motor which is even worse than killing my old motor or after monitoring oil pressures its still dropping too much and either I go back to street tires for a bit or start saving for dry sump. Sadly I don't have data logs of actual oil pressure so the best I can do for before is what we saw above eyeballing my oil pressure gauge from the videos. I purchased new AEM x series gauges where I can set warnings and I believe there is a way to export the data but I didn't set any of that up nor have I looked into it. My intent was just to find a gauge that will yell at me if pressure drops below a certain threshold so I know to let off.
What would be really interesting is to record a run with my accusump ball valve closed to see what my pressures drop down to relative to with the accusump operating. However, as interesting as that sounds I don't want to test it for obvious reasons, lol!
Then I completely underestimated the cost of a build of this nature. One thing led to the next and I did go overboard but if I knew then what this was going to cost I would have thought I was insane. But the numbers don't lie and my spreadsheet kept growing and the build was on hold since I wanted to make sure I had the money before I started sending things out. Then of course the typical delays customs parts take time to make out of stock BS with vendors promising a set lead time and it being 2x that etc.
And of course it didn't help with the tire iron to the head right after I got the block back which has set me back about a month and other life struggles like house projects and finding time for the GF and friends. So here I am its almost July race season is like half over and I'm nowhere to be seen
Regarding oil pressure, we're on the same boat. I sure as hell hope this works bc it it doesnt it either means that I killed my new motor which is even worse than killing my old motor or after monitoring oil pressures its still dropping too much and either I go back to street tires for a bit or start saving for dry sump. Sadly I don't have data logs of actual oil pressure so the best I can do for before is what we saw above eyeballing my oil pressure gauge from the videos. I purchased new AEM x series gauges where I can set warnings and I believe there is a way to export the data but I didn't set any of that up nor have I looked into it. My intent was just to find a gauge that will yell at me if pressure drops below a certain threshold so I know to let off.
What would be really interesting is to record a run with my accusump ball valve closed to see what my pressures drop down to relative to with the accusump operating. However, as interesting as that sounds I don't want to test it for obvious reasons, lol!