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Old 04-23-2020, 06:51 AM   #201
pcampbell
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Any thoughts on oil pump sizing for
1) stock ej257 with 251 heads revving to 7500
2) forged 257 (let’s just say iag) with 251 heads revving to 7500

Stock 251 for the same heads is 7mm. I haven’t tested “high” (above 6400) rpms with the stock block and head yet but I will.
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Old 04-23-2020, 10:55 AM   #202
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Quote:
Originally Posted by stu View Post
What sensor are you using? try a 50wt.
Im using the sensor that came with the Prosport oil pressure sensor kit along with a remote sensor relocation kit.
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Old 04-23-2020, 11:12 AM   #203
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Originally Posted by AnthonyF24 View Post
gravel and snow don't count.
Dry blacktop 50° hazes tires @60mph

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Old 04-23-2020, 11:15 AM   #204
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Quote:
Originally Posted by GK1707 View Post
In for some feedback, I currently idle at 12-17~ psi hot idle (oil dependent) and 60-70~ psi at 3k rpm highway cruise. On a built motor with 11mm pump running your oil pickup. Do you think that hot idle is a bit low?

I noticed with Motul Xcess 5w40 I hot idle from 12-14psi
with Rotella T6 5w40 hot idle is about 15-17psi
In general with Motul, the oil pressure has been lower overall.
Sure sensor and gauge are reading correctly?

If so and oil pressure was higher before I'd change oil filter and maybe pump could have relief valves stuck open. Fsm says about over 14psi at 750rpm
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Old 04-23-2020, 11:24 AM   #205
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Quote:
Originally Posted by stu View Post
What sensor are you using? try a 50wt.
This can mask a bigger issue. If it's an issue that can cause damage, reducing flow to boost oil pressure at the gauge can be a dangerous step to go in.

Quote:
Originally Posted by GK1707 View Post
I have a sensor in the oil pressure switch location below the alternator that sends it to a pro sport oil pressure gauge.
Quote:
Originally Posted by GK1707 View Post
Im using the sensor that came with the Prosport oil pressure sensor kit along with a remote sensor relocation kit.
Remote relocation kits have a pressure drop to them. I'm personally not a fan because it adds more potential leak points and stuff.

Whenever there's an oil pressure concern, a good first move is to get a $15 mechanical gauge and verify. Way more accurate than an electronic gauge and will immediately let you know if it's a gage/sensor issue, or something bigger and/or more critical.

Quote:
Originally Posted by pcampbell View Post
Any thoughts on oil pump sizing for
1) stock ej257 with 251 heads revving to 7500
2) forged 257 (let’s just say iag) with 251 heads revving to 7500

Stock 251 for the same heads is 7mm. I haven’t tested “high” (above 6400) rpms with the stock block and head yet but I will.
What is a 251 head?

That block, like all EJs, still uses a positive displacement pump, so flow scales up with RPM. What pressure did you see at 6,400 RPMs?
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Old 04-23-2020, 11:53 AM   #206
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Quote:
Originally Posted by GK1707 View Post
In for some feedback, I currently idle at 12-17~ psi hot idle (oil dependent) and 60-70~ psi at 3k rpm highway cruise. On a built motor with 11mm pump running your oil pickup. Do you think that hot idle is a bit low?

I noticed with Motul Xcess 5w40 I hot idle from 12-14psi
with Rotella T6 5w40 hot idle is about 15-17psi
In general with Motul, the oil pressure has been lower overall.
I had the same issue.

Get yourself a mechanical gauge from Harbor freight to verify, but my car would idle at 12-15 psi warm running 15w-50 mobil 1.

my electrical gauge is not accurate at all, as when i hooked up my mechanical gauge it was 30 psi warm idle and 70+ above 2500 RPMs.
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Old 04-23-2020, 12:11 PM   #207
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Quote:
Originally Posted by KillerBMotorsport View Post
This can mask a bigger issue. If it's an issue that can cause damage, reducing flow to boost oil pressure at the gauge can be a dangerous step to go in.





Remote relocation kits have a pressure drop to them. I'm personally not a fan because it adds more potential leak points and stuff.

Whenever there's an oil pressure concern, a good first move is to get a $15 mechanical gauge and verify. Way more accurate than an electronic gauge and will immediately let you know if it's a gage/sensor issue, or something bigger and/or more critical.



What is a 251 head?

That block, like all EJs, still uses a positive displacement pump, so flow scales up with RPM. What pressure did you see at 6,400 RPMs?
I definitely had suspicions about the remote kit dropping pressure, but its my only choice at the moment as the sender prosport has sent with the kit does not clear underneath the alternator.

Quote:
Originally Posted by Waddlz View Post
I had the same issue.

Get yourself a mechanical gauge from Harbor freight to verify, but my car would idle at 12-15 psi warm running 15w-50 mobil 1.

my electrical gauge is not accurate at all, as when i hooked up my mechanical gauge it was 30 psi warm idle and 70+ above 2500 RPMs.
Thanks for the feedback I will definitely grab a mechanical gauge.
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Old 04-24-2020, 10:05 AM   #208
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Default Why you don't need GR (11mm) Oil Pump in GD (10mm) Engine

Quote:
Originally Posted by KillerBMotorsport View Post
This can mask a bigger issue. If it's an issue that can cause damage, reducing flow to boost oil pressure at the gauge can be a dangerous step to go in.











Remote relocation kits have a pressure drop to them. I'm personally not a fan because it adds more potential leak points and stuff.



Whenever there's an oil pressure concern, a good first move is to get a $15 mechanical gauge and verify. Way more accurate than an electronic gauge and will immediately let you know if it's a gage/sensor issue, or something bigger and/or more critical.







What is a 251 head?



That block, like all EJs, still uses a positive displacement pump, so flow scales up with RPM. What pressure did you see at 6,400 RPMs?

Ej251 is sohc with no avls/avcs.

I’d say I’m around 70 psi hot at 6400rpm with an aem electric oil sender in the pressure location.
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Old 04-24-2020, 01:23 PM   #209
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Quote:
Originally Posted by Waddlz View Post
I had the same issue.

Get yourself a mechanical gauge from Harbor freight to verify, but my car would idle at 12-15 psi warm running 15w-50 mobil 1.

my electrical gauge is not accurate at all, as when i hooked up my mechanical gauge it was 30 psi warm idle and 70+ above 2500 RPMs.
Before everyone goes flippin crazy about gauges I have something to say.
Do not run to Harbour Freight expecting quality or accuracy, just because it's a mechanical gauge.
I was an aircraft instrument technician for four years and I've worked on all kinds of mechanical gauges. Cheap gauges are just that. There's little emphasis on accuracy or reliability. You are lucky if you get +/- 5% accuracy. They are often out of balance, meaning they read differently depending on how you have them oriented. They are sometimes not linear in accuracy. They can be thrown out of calibration by dropping them or hitting them. On the other hand electronically controlled gauges have few of these issues and digital readouts have no balance issues and are not susceptible to vibration. Stepper motor gauges can be +/- .5% accuracy or better!
The pressure transducers (usually called the sensor or sender) are often solid state and are typically quite accurate and reliable. Again, quality counts. Sensors are available separately. Autometer is made in the US. So are Omega's sensors.
There are other places to tap into the oil system. When I first start a new engine I have a gauge in the top of the left AVCS banjo bolt. Tapped banjo bolts are readily available. Autometer sells one.
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Old 04-24-2020, 03:51 PM   #210
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From what I've learned the biggest thing with any gauge on an internal combustion engine is dampening. You need to dampen the gauge or the pressure wave differential will be hard to gather information from. The abrupt changes in pressure can cause needle fluctuation.

You can dampen a gauge with a filter or coiled rubber hose.

Same applies to the map sensor. Lgt and many other cars use a filter pre map sensor readings and this makes the reading more linear and smooth. Otherwise you see a large Spike and pressure drop to it's actual flow pressure.
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Old 04-24-2020, 03:55 PM   #211
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Also mechanical gauges can go bad and be bad out of the box like any other item. Make sure you look for the QC sticker indicating it was a quality checked item. You can reach out to a manufacturer to ensure this is a tested product. Quality checked items are usually more expensive as it takes time to test each item companies need to pay people for there time to do this.
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Old 04-24-2020, 04:50 PM   #212
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Originally Posted by spoolinsti05 View Post

You can dampen a gauge with a filter or coiled rubber hose.
.
^WTF?
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Old 04-24-2020, 10:45 PM   #213
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Quote:
Originally Posted by GK1707 View Post
In for some feedback, I currently idle at 12-17~ psi hot idle (oil dependent) and 60-70~ psi at 3k rpm highway cruise. On a built motor with 11mm pump running your oil pickup. Do you think that hot idle is a bit low?

I noticed with Motul Xcess 5w40 I hot idle from 12-14psi
with Rotella T6 5w40 hot idle is about 15-17psi
In general with Motul, the oil pressure has been lower overall.
Quote:
Originally Posted by Scargod View Post
Do not run to Harbour Freight expecting quality or accuracy, just because it's a mechanical gauge.

Autometer sells one.
Good point. I was careless with my words. I believe the last mechanical gauge I bought was an Autometer at AutoZone and it cost $15. That might have been some years ago. It is liquid filled and +.-1psi to a calibrated air regulator/gauge setup I have.

Aviation gauges, lol. How is a fuel gauge considered accurate if it only has to show accurately when the tank is empty? I never understood how gauge accuracy is so important, except for fuel Gotta stay on your toes as a pilot I suppose

Quote:
Originally Posted by GK1707 View Post
I definitely had suspicions about the remote kit dropping pressure, but its my only choice at the moment as the sender prosport has sent with the kit does not clear underneath the alternator.
Couple tricks you can try to get that sender in place... Get a +1/2 or +1 size belt. It will raise the alternator, and the tensions still has enough travel to keep the belt to the proper tension. Or, grind the alternator housing a bit. Sounds drastic, but it's very common. You'll likely find some decent DIYs on it too.
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Old 04-25-2020, 11:42 AM   #214
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Quote:
Originally Posted by KillerBMotorsport View Post
Good point. I was careless with my words. I believe the last mechanical gauge I bought was an Autometer at AutoZone and it cost $15. That might have been some years ago. It is liquid filled and +.-1psi to a calibrated air regulator/gauge setup I have.

Aviation gauges, lol. How is a fuel gauge considered accurate if it only has to show accurately when the tank is empty? I never understood how gauge accuracy is so important, except for fuel Gotta stay on your toes as a pilot I suppose



Couple tricks you can try to get that sender in place... Get a +1/2 or +1 size belt. It will raise the alternator, and the tensions still has enough travel to keep the belt to the proper tension. Or, grind the alternator housing a bit. Sounds drastic, but it's very common. You'll likely find some decent DIYs on it too.
It's been a while since I used the spot where the oil pressure sensor goes for anything else, but I know I once used a SS Tee off it so that my Spa gauge sensor was horizontal.
Any mechanical gauge on a race car ought to be liquid filled. That damps it and keeps it from vibrating to death. We used to put very thick silicone oil on all the pivots of mechanical gauges. Gauges are often damped by having a very small orifice in the fitting end.
It's nice to know your true airspeed and altitude. Small engine plane pilots lean their engines based on EGT's.
Like for my torque wrenches, I have a 4" "standard gauge" that I check other gauges with. Tire gauges can be way off. I hate borrowing them at the track.
Lastly, I always recommend a liquid-filled gauge for the fuel pressure regulator. Not that expensive. Tuners (and me too) like to see the fuel pressure and know that it's keeping up.
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Old 04-25-2020, 12:26 PM   #215
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You can get a Quantum mechanical fuel gauge for $15 shipped and they are pretty accurate, and liquid filled. Yeah, I wouldn't get one at Harbor Freight but you don't need to spend bling money to get a decent mechanical gauge.

I trained to be an A and P mechanic and yeah accuracy was paramount when dealing with things like turbine blade measurements etc, but I think a $15 pressure gauge will be fine for the OP's temporary needs. Now if he plans on using it constantly, as in as a dash gauge, I'd invest in a quality gauge with a quality 5v sender like autometer.

Also consider if you're only using a gauge for lower pressure range diagnosis, a lower range gauge will help get a closer idea of actual pressure. This gauge http://www.marshallinstruments.com/p...s/MNB00060.cfm for example, has a max reading of 60, so at the lower pressures it will have a little better resolution.

Last edited by 2slofouru; 04-25-2020 at 12:35 PM.
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Old 07-26-2020, 09:52 PM   #216
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Since my old vid seems to be no more, I took a new one showing why the 11mm pump is really necessary on the DAVCS engines. While amplified at this load RPM, you can see it elsewhere as well. What you are seeing is the exhaust cam moving from mid-20s to ~0° and a 20-30psi pressure drop. This particular engine is one of our higher end specs (in a 2019 STi), but the pump is a standard new OEM 11mm. We didn't even give it a massage, because there were no rough areas worth touching up. The worst I've ever seen was ~40psi on a low mileage untouched GR.

This pressure drop does not exist on a SAVCS engine (pre-08).


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Old 07-26-2020, 11:43 PM   #217
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Yep, 10mm for none or 1 avcs, 11mm for dual. I thought this was settled like 5+ years ago?
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Old 07-26-2020, 11:54 PM   #218
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Thought the DAVCS requires the 12mm, especially since the 11mm shows a pressure drop with DAVCS in the video.

10mm - no avcs and standard oil clearances

11mm - single avcs or no avcs with larger oil clearances

12mm - dual avcs


?
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Old 07-27-2020, 07:59 AM   #219
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Originally Posted by 2slofouru View Post
Thought the DAVCS requires the 12mm, especially since the 11mm shows a pressure drop with DAVCS in the video.

10mm - no avcs and standard oil clearances

11mm - single avcs or no avcs with larger oil clearances

12mm - dual avcs


?
No.

SAVCS = 10mm

DAVCS = 11mm

12mm = JDM/EU EJ20 limited production cars only
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Old 07-27-2020, 11:57 AM   #220
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Quote:
Originally Posted by KillerBMotorsport View Post
No.

SAVCS = 10mm

DAVCS = 11mm

12mm = JDM/EU EJ20 limited production cars only
So the video you posted shows the pressure drop for a 2019 which came with a 11mm and you are saying to use a 11mm? sorry kinda confusesed
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Old 07-27-2020, 05:26 PM   #221
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So the video you posted shows the pressure drop for a 2019 which came with a 11mm and you are saying to use a 11mm? sorry kinda confusesed
Yes, on a DAVCS engine use the 11mm.

With a GD (as stated in the OP) SAVCS there is no reason to use an 11mm because this drop does not exist since there is no exhaust cam actuation, and the 10mm already has excessive flow capacity.
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Old 07-27-2020, 05:54 PM   #222
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Quote:
Originally Posted by KillerBMotorsport View Post
Yes, on a DAVCS engine use the 11mm.

With a GD (as stated in the OP) SAVCS there is no reason to use an 11mm because this drop does not exist since there is no exhaust cam actuation, and the 10mm already has excessive flow capacity.
right i got it, but the video you posted is from a 2019 sti which is davcs right? SO even with the 11mm there is a drop in oil pressure? or am i looking at the video incorrectly?
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Old 07-27-2020, 06:34 PM   #223
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right i got it, but the video you posted is from a 2019 sti which is davcs right? SO even with the 11mm there is a drop in oil pressure? or am i looking at the video incorrectly?
You are not. The pressure drop is normal.

The DAVCs will drop pressure like that, and is why Subaru started using the 11mm in the cars with DAVCs

My 2012 will do exactly the same thing as killer-b is showing, but my buddies GD with SAVCs does not.
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Old 07-27-2020, 08:50 PM   #224
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What is the magical JDM and Euro reason for using the 12mm oil pump? It's obviously beneficial in an oem setup with oem oil clearances and you can't have any more than dual AVCS. Were those models running massive external oil coolers?

Frankly seeing a pressure drop of 30psi would make me nervous, depending on engine rpm and load, especially if under boost.

More info plz
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Old 07-28-2020, 12:02 AM   #225
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Quote:
Originally Posted by 2slofouru View Post
What is the magical JDM and Euro reason for using the 12mm oil pump? It's obviously beneficial in an oem setup with oem oil clearances and you can't have any more than dual AVCS. Were those models running massive external oil coolers?

Frankly seeing a pressure drop of 30psi would make me nervous, depending on engine rpm and load, especially if under boost.

More info plz
You wont see that pressure drop under load. The reason for the pressure drop that KB is illustrating is under throttle the ECU is calling for "X" Advance/Retard on the respective cams. Pressure goes up during this. Pressure drops on throttle lift because ECU under typical conditions/tuning commands 0 Advance/Retard which allows free flow of oil, essentially adding 0 restrictions in the oil flow, dropping pressure. When stroking the valve spool for the Advance/Retard commands it adds a restriction in the oiling system allowing for pressure to build.

SAVCS will also show a pressure drop on throttle lift, I have see 15psi drop on throttle lift. Typically it is 9-12psi pressure drop between off and on throttle with SAVCS. KB saying this pressure drop doesnt exist with pre 08 cars is correct when compared to a DAVCS motor as it will never see even a 20psi drop, but it still has a measurable drop.
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