Loss of oil pressure on braking

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Re: Loss of oil pressure on braking

Post by BOOT » Tue Oct 24, 2017 12:39 pm

As mentioned I don't think baffles will help much, sump covers mostly help with windage from blowing oil out/away from the pick-up

1g acceleration https://youtu.be/jL8-amRzsv4?t=3m29s

If it were actual oil pan shaped about all the oil would be out of the sump or at least not covering the pick-up on hard braking. Been thinking bout this myself lately since I changed oil pump & pick-up to one that is rear sump located, from a central sump location. Launch I'll be good but braking has me strongly considering an accumulator. Same pan as oldhead.
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Re: Loss of oil pressure on braking

Post by Coloradoracer » Wed Oct 25, 2017 1:46 pm

pamotorman wrote:
Mon Oct 23, 2017 9:41 pm
when chevy came out with the BBC they switched to piddle valve lifters. at the drag strip you needed to run a quart over full to prevent a oil pressure drop because the piddle valve lifers allowed more oil to be trapped upstairs. we just changed the lifters to edge orifice type to stop the problem.
NEVER overfill on oil to cure an oil pressure problem. This creates more windage issues and can result in foaming of the oil and potential engine damage due to loss of oil pressure. Also extra windage is a horsepower loss. FIX THE PROBLEM, overfilling is not a wise thing.
Mark Goulette
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http://www.livinthedreamracing.com
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Re: Loss of oil pressure on braking

Post by redliner » Wed Oct 25, 2017 1:59 pm

BOOT wrote:
Tue Oct 24, 2017 12:39 pm
As mentioned I don't think baffles will help much, sump covers mostly help with windage from blowing oil out/away from the pick-up

1g acceleration https://youtu.be/jL8-amRzsv4?t=3m29s

If it were actual oil pan shaped about all the oil would be out of the sump or at least not covering the pick-up on hard braking. Been thinking bout this myself lately since I changed oil pump & pick-up to one that is rear sump located, from a central sump location. Launch I'll be good but braking has me strongly considering an accumulator. Same pan as oldhead.
I don't think the video applies to an engine very well as there is no crank etc. slinging around in there. A windage tray extended into the sump might cure yer problem. An oil accumulator is just a band-aid. Fix the problem and cover the sump, then have your pickup directly under the middle of the pump. I had the same problem you are speaking of and I was using a STEFFS high dollar oilpan with a screen baffle.... It lost oil pressure in the traps when I slammed on the brakes. I went to a MOROSO pan with a built in windage tray that extends over the sump and fixed the problem.... I also run a small baffle between the oilpump/maincap which theoretically keeps the oil from climbing the back of the sump on blast off.... JMHO....

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Re: Loss of oil pressure on braking

Post by statsystems » Wed Oct 25, 2017 2:15 pm

Coloradoracer wrote:
Wed Oct 25, 2017 1:46 pm
pamotorman wrote:
Mon Oct 23, 2017 9:41 pm
when chevy came out with the BBC they switched to piddle valve lifters. at the drag strip you needed to run a quart over full to prevent a oil pressure drop because the piddle valve lifers allowed more oil to be trapped upstairs. we just changed the lifters to edge orifice type to stop the problem.
NEVER overfill on oil to cure an oil pressure problem. This creates more windage issues and can result in foaming of the oil and potential engine damage due to loss of oil pressure. Also extra windage is a horsepower loss. FIX THE PROBLEM, overfilling is not a wise thing.
Unless the pan isn't filled correctly to begin with. Or, the engine retains oil. It can be expensive to fix the oil retention issues and adding a quart is easier than an accusump.

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Re: Loss of oil pressure on braking

Post by allencr267 » Wed Oct 25, 2017 2:42 pm

+2 :wink: for the above
Does the lube climb the front of the pan & get windaged to hell, or is the pickup's funnel too high and/or too large and/or too misplaced to escape being exposed?
Anecdotal stuff is really great, thank you! \:D/

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Re: Loss of oil pressure on braking

Post by pamotorman » Wed Oct 25, 2017 3:22 pm

Coloradoracer wrote:
Wed Oct 25, 2017 1:46 pm
pamotorman wrote:
Mon Oct 23, 2017 9:41 pm
when chevy came out with the BBC they switched to piddle valve lifters. at the drag strip you needed to run a quart over full to prevent a oil pressure drop because the piddle valve lifers allowed more oil to be trapped upstairs. we just changed the lifters to edge orifice type to stop the problem.
NEVER overfill on oil to cure an oil pressure problem. This creates more windage issues and can result in foaming of the oil and potential engine damage due to loss of oil pressure. Also extra windage is a horsepower loss. FIX THE PROBLEM, overfilling is not a wise thing.
chevy says in the corvette owner manual to run a quart over full when doing track days because of the oil trapped upstairs due to G forces in the turns.

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Re: Loss of oil pressure on braking

Post by BOOT » Wed Oct 25, 2017 7:49 pm

redliner wrote:
Wed Oct 25, 2017 1:59 pm
I don't think the video applies to an engine very well as there is no crank etc. slinging around in there. A windage tray extended into the sump might cure yer problem. An oil accumulator is just a band-aid. Fix the problem and cover the sump, then have your pickup directly under the middle of the pump. I had the same problem you are speaking of and I was using a STEFFS high dollar oilpan with a screen baffle.... It lost oil pressure in the traps when I slammed on the brakes. I went to a MOROSO pan with a built in windage tray that extends over the sump and fixed the problem.... I also run a small baffle between the oilpump/maincap which theoretically keeps the oil from climbing the back of the sump on blast off.... JMHO....
It applies well enough for any oil in the sump that is not circulating thru-out the engine and even more so if you have a sump cover/tray, if your crank is submerged then you found your problem. Oil will slosh too easy when hot and hard braking will force it right out of the sump or at least away from the pick-up, the video clearly shows how it would slosh right on out if one end extended like a typical oil pan. Do not get my 1st post or this one confused with windage or oil wrapping around the crank issues. An accumulator is a great safety measure for multiple possible issues. How do you propose I move the pick-up on a Melling billet oil pump? The rear pump baffle is more of a crank scraper in my opinion.
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Re: Loss of oil pressure on braking

Post by redliner » Fri Oct 27, 2017 11:40 am

BOOT wrote:
Wed Oct 25, 2017 7:49 pm
redliner wrote:
Wed Oct 25, 2017 1:59 pm
I don't think the video applies to an engine very well as there is no crank etc. slinging around in there. A windage tray extended into the sump might cure yer problem. An oil accumulator is just a band-aid. Fix the problem and cover the sump, then have your pickup directly under the middle of the pump. I had the same problem you are speaking of and I was using a STEFFS high dollar oilpan with a screen baffle.... It lost oil pressure in the traps when I slammed on the brakes. I went to a MOROSO pan with a built in windage tray that extends over the sump and fixed the problem.... I also run a small baffle between the oilpump/maincap which theoretically keeps the oil from climbing the back of the sump on blast off.... JMHO....
It applies well enough for any oil in the sump that is not circulating thru-out the engine and even more so if you have a sump cover/tray, if your crank is submerged then you found your problem. Oil will slosh too easy when hot and hard braking will force it right out of the sump or at least away from the pick-up, the video clearly shows how it would slosh right on out if one end extended like a typical oil pan. Do not get my 1st post or this one confused with windage or oil wrapping around the crank issues. An accumulator is a great safety measure for multiple possible issues. How do you propose I move the pick-up on a Melling billet oil pump? The rear pump baffle is more of a crank scraper in my opinion.
I agree an acc. is great for multiple issues. I would not use it as a band aid tho, I would cure the problem. Isn't the pickup close to being centered under the pump with your billet pump? My billet Mellings pump has the inlet centered pretty much.... If you run a windage tray like I described earlier with the tray extending into the sump, I bet it will keep the oil in the sump enough to prevent uncovering the pickup. I cannot say what will work for you as there are so many variables. I DO know that I solved MY deceleration oil pressure problem by shit canning that junk Steffs pan/ windage screen set up and installing a good Moroso pan with a well engineered tray etc.....

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Re: Loss of oil pressure on braking

Post by BOOT » Sun Oct 29, 2017 1:43 pm

I have a tray and modded it some, also have modded the pan but for others reason than uncovering the pick-up. Even if baffles kept the oil from completely sloshing away what little remains will be sucked up quickly.
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Re: Loss of oil pressure on braking

Post by Coloradoracer » Sun Oct 29, 2017 3:26 pm

pamotorman wrote:
Wed Oct 25, 2017 3:22 pm
chevy says in the corvette owner manual to run a quart over full when doing track days because of the oil trapped upstairs due to G forces in the turns.
Not anymore they don't. That was a bandaid to fix an issue that could have cost millions of dollars to reengineer.... If you're losing oil pressure on braking, decel, or cornering, you have to address the problem, not bandaid it. Oil return is everything, as well as oil control. Same goes for high g-force cornering. Wet sump systems can be worked to prevent most of this but not all. Only actual cure is a dry sump system.
Mark Goulette
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Speed kills but it's better than going slow!
http://www.livinthedreamracing.com
Authorized Amsoil Retailer

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Re: Loss of oil pressure on braking

Post by pamotorman » Sun Oct 29, 2017 4:06 pm

Coloradoracer wrote:
Sun Oct 29, 2017 3:26 pm
pamotorman wrote:
Wed Oct 25, 2017 3:22 pm
chevy says in the corvette owner manual to run a quart over full when doing track days because of the oil trapped upstairs due to G forces in the turns.
Not anymore they don't. That was a bandaid to fix an issue that could have cost millions of dollars to reengineer.... If you're losing oil pressure on braking, decel, or cornering, you have to address the problem, not bandaid it. Oil return is everything, as well as oil control. Same goes for high g-force cornering. Wet sump systems can be worked to prevent most of this but not all. Only actual cure is a dry sump system.
not all corvette engines have the dry sump system so if you want to do track days you better run a quart over to be safe. I built all my oval track engines with a road race wet sump pans and raced at poconos and trenton with no oil problems.

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