oil pressure, VVT head with non-VVT (thin) oil pump - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 01-24-2011, 03:31 PM   #1
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default oil pressure, VVT head with non-VVT (thin) oil pump

Anyone noticed a drop in oil pressure?

With 82*C oil (180*F), I only get
16-17 psi at idle,
28 psi at 3000 RPM, and
38 psi at 6000 RPM.

With stone cold morning oil (50 *F) it's 65 psi at idle and tops out at 75 psi, so I know my oil relief valve is working.
JasonC SBB is offline   Reply With Quote
Old 01-24-2011, 04:28 PM   #2
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

Maybe it needs to be shimmed.
neogenesis2004 is offline   Reply With Quote
Old 01-27-2011, 03:36 PM   #3
Elite Member
iTrader: (9)
 
Join Date: Jun 2008
Location: Houston, TX
Posts: 1,583
Total Cats: 8
Default

There is a reason they increased the size, the oil pumps are designed at exactly what they need to be to create the proper flow in the engine. 38 PSI sounds very low to me, I'd be worried about your bearings. There is a reason why I recommend 70-90 PSI for my customers! All that extra flow affords a lot of protection.
TravisR is offline   Reply With Quote
Old 01-27-2011, 03:48 PM   #4
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Neo shimming won't help because 38 psi is below the bypass opening pressure.

Would thicker oil for higher pressure help? This won't improve flow though.
JasonC SBB is offline   Reply With Quote
Old 01-27-2011, 03:58 PM   #5
Elite Member
iTrader: (9)
 
Join Date: Jun 2008
Location: Houston, TX
Posts: 1,583
Total Cats: 8
Default

No, the thicker oil won't do anything for you. What you need is flow!

Flow is what actually keeps the surfaces apart. You can drop a fork into a 5000psi body of water and it'll sink at the same rate as one at atmosphere. The high speed movement of the fluid pushes the metal parts apart doing the bulk of the work.

Ideal would be dynamic viscosity being low, and pressure is high! 0w-20 @ 90 PSI!
TravisR is offline   Reply With Quote
Old 02-07-2011, 06:36 PM   #6
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Argh PSI is dictated by other things as well including various restrictions etc. I thought what you wanted with the oiling system was massive flow, not pressure.

BTW FWIW Y8S and I, with VVT heads never see more than 45psi or so at 5000RPM. VVT will **** with the oil pressure too.
Faeflora is offline   Reply With Quote
Old 02-07-2011, 06:59 PM   #7
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Fae,

Which oil pump do you have?
JasonC SBB is offline   Reply With Quote
Old 02-07-2011, 07:00 PM   #8
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

BTW Travis,

If 100% true, why not use 5w-20 oil and get more flow despite less pressure? (for those with lots of pressure)...
JasonC SBB is offline   Reply With Quote
Old 02-07-2011, 07:03 PM   #9
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

Oh I definitely have more than 50psi at or above 5000rpm, albeit this is a stock VVT engine, not a built one.
Reverant is offline   Reply With Quote
Old 02-07-2011, 07:10 PM   #10
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Quote:
Originally Posted by JasonC SBB View Post
Fae,

Which oil pump do you have?
mz-bp4w-14-100A

I have no clue what year that pump is from. It is an old miataroadster billet OPG assembly. It would be nice if I could find out :{


Quote:
Originally Posted by Reverant View Post
Oh I definitely have more than 50psi at or above 5000rpm, albeit this is a stock VVT engine, not a built one.
How much more? 50psi @ 5000RPM is about where mine tops out at.
Faeflora is offline   Reply With Quote
Old 02-07-2011, 07:11 PM   #11
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

60 to 65.
Reverant is offline   Reply With Quote
Old 02-07-2011, 07:18 PM   #12
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,896
Total Cats: 109
Default

Quote:
Originally Posted by TravisR View Post
There is a reason why I recommend 70-90 PSI for my customers! All that extra flow affords a lot of protection.
Does that not rob horsepower to have oil pressure at a high PSI?
miata2fast is offline   Reply With Quote
Old 02-07-2011, 07:20 PM   #13
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

OK NM

The MZ-bp4w-14-100A is the oil pump that was standard through '99. A "non VVT oil pump".
Faeflora is offline   Reply With Quote
Old 02-07-2011, 07:22 PM   #14
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Quote:
Originally Posted by TravisR View Post
There is a reason they increased the size, the oil pumps are designed at exactly what they need to be to create the proper flow in the engine. 38 PSI sounds very low to me, I'd be worried about your bearings. There is a reason why I recommend 70-90 PSI for my customers! All that extra flow affords a lot of protection.
Why is all the PSI necessary? If there's a film of oil, there's a film of oil right? Doesn't matter what the PSI through the system is does it?
Faeflora is offline   Reply With Quote
Old 02-07-2011, 07:49 PM   #15
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

All else being equal more oil pressure means there's more flow too.

Now if you're in the middle of the acceptable ranges, is thinner oil for more flow better, or thicker oil for more pressure?
JasonC SBB is offline   Reply With Quote
Old 05-16-2011, 05:40 PM   #16
Elite Member
Thread Starter
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Arrrgghhh!!! I'm not getting significantly higher oil pressure with 5w50 oil

How do I change the oil pump without pulling the motor?

Anyone want to buy billet OPGs blueprinted in its housing, for a non VVT application?
JasonC SBB is offline   Reply With Quote
Old 05-16-2011, 05:48 PM   #17
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

Quote:
Originally Posted by JasonC SBB View Post
Arrrgghhh!!! I'm not getting significantly higher oil pressure with 5w50 oil

How do I change the oil pump without pulling the motor?
Can be done but you will need to raise the car up enough to work under and then prepare to break your back several times. I would rather pull the engine out.
Reverant is offline   Reply With Quote
Old 05-16-2011, 06:08 PM   #18
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,776
Total Cats: 1,106
Default

Quote:
Originally Posted by JasonC SBB View Post
Arrrgghhh!!! I'm not getting significantly higher oil pressure with 5w50 oil

How do I change the oil pump without pulling the motor?

Anyone want to buy billet OPGs blueprinted in its housing, for a non VVT application?
Pulling the motor is the easiest way to swap oil pumps. So what gears are you using? I am using a 94 OP with the BE billet gears on my 94 block with the VVT head and oil pressure has been fine so far. I will look tonight to see what my oil pressure is at idle, but I do not think it is anywhere near as low as yours?
shuiend is offline   Reply With Quote
Old 05-16-2011, 06:10 PM   #19
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default



Jason, before pulling the motor do an oil analysis. That's what I'm doing at the next oil change.
Faeflora is offline   Reply With Quote
Old 05-16-2011, 10:21 PM   #20
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,776
Total Cats: 1,106
Default

Warmed up I sit right above 30psi and cruising at 45mph in 5th I am a little below 60psi. When VVT kicks in oil pressure does drop a little. I am still using the stock oil pressure sender from my 94 with the stock gauge.
shuiend is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 12-13-2017 10:04 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 04:20 PM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:38 AM.